Arthritis Research & Therapy - Latest Comments

Resolved hepatitis B and immunosuppressive and biological therapies.

Rene Gerolami — 2010-03-26T10:38:40Z

Title: Resolved hepatitis B and immunosuppressive and biological therapies.
Philippe Colson 1, Sandrine Guis 2, Patrick Borentain3, Caroline Charpin2, Jean Pierre Mattei2, Rene Gerolami3
1. Laboratoire de Virologie, Fédération Hospitalière de Microbiologie Clinique, Centre Hospitalo-Universitaire Timone, Marseille, France
2. Service de Rhumatologie, Centre Hospitalier Universitaire Conception, Marseille, France.
3. Service d'Hépato-gastroentérologie, Centre Hospitalier Universitaire Conception, Marseille, France

To the Editor:
We would like to thank Dr Jansen for his interesting editorial on our article recently published in this journal (1). This author points out the evolution of therapies in rheumatology and the concerns related to their administration to patients with on-going and resolved hepatitis B virus (HBV) infection (2). Nevertheless, we would like to clearly distinguish between patients with resolved HBV infection, who were those targeted in our work, and HBV carriers, to avoid bringing misunderstanding to the aim and interpretation of our study.
Chronic HBV carriers are HBV-infected individuals positive for hepatitis B surface antigen (HBsAg) for more than six months. Their serological pattern associates positive testing for HBsAg and anti-HB core (HBc) antibodies. Among them, inactive HBsAg carriers are defined by very low or undetectable serum HBV DNA levels (<2,000 IU/ml), persistently normal ALT/AST levels, and absence of significant hepatitis (3). By contrast to HBV carriers, people in whom hepatitis B resolved spontaneously are HBsAg-negative but still harbor anti-HBc antibodies, which are promoted by a very robust and persistent immune response against HBc antigen (4); concurrently, anti-HBs antibodies can be present or absent. HBV DNA in serum, when tested, is classically negative. Nevertheless, to add pitfalls to define clearly the status of HBV infection, recent dramatic decrease of the detection threshold of PCR assays (from 20,000 to about 10 IU/ml) revealed that a very low HBV DNA level (< 200 IU/ml) might be present occasionally in the absence of detectable HBsAg, defining one of the two categories of so-called occult hepatitis B (5). As stated by Jansen, HBV infection, regardless its outcome, results in the production of covalently-closed circular HBV DNA (HBV cccDNA), an episomal resistant HBV genomic form that serves as template for transcription of viral messenger RNA and pre-genomic RNA, and which might persist beyond hepatitis B resolution (6). Thus, HBV cccDNA could be found in the nucleus of hepatocytes from individuals with resolved HBV infection (7).
As a matter of fact, HBV reactivation depicts two different events. It can correspond to the re-occurence of active necroinflammatory disease of the liver, concurrently to re-appearance or increase of HBV DNA in serum, in patients known to have the inactive HBsAg carrier state (3). In these HBsAg positive patients, HBV reactivation has been documented following immunosuppressive or immunomodulatory treatments including anti-TNF, and the prophylactic use of antiviral agents has been proposed (8,9). Alternatively, HBV reactivation can consist in reappearance of HBV DNA and HBsAg seroreversion in individuals previously negative for HBsAg, i.e. with a serology indicating resolved HBV infection. In such a setting, HBV reactivation has been observed following immunosuppressive or biological therapies, although much less frequently than in HBsAg-positive patients. Nonetheless, rates of 9-25% HBV reactivation have been recently described in patients with a serology indicating resolved HBV infection and who received polychemotherapy for lymphoma, especially in case of rituximab use (10,11). The risk of anti TNF-alpha -induced HBV reactivation is therefore a concern not only in chronic HBsAg carriers but also in HBsAg-negative patients presenting with resolved HBV infection. In our work, we focused on 21 rheumatic patients presenting with such a serological pattern indicating resolved HBV infection and undergoing anti-TNF-alpha therapy. Thus, none of them was HBsAg-positive at the time of treatment initiation. All patients remained HBsAg-negative and were HBV DNA negative after a mean duration of 27 months of therapy. Further studies including a larger number of patients and a longer follow-up are however necessary.
Finally, it should be pointed out, from an epidemiological perspective, that a serological pattern indicating resolved HBV infection is harbored by a non negligible proportion of people, including those who have to face cancer and auto-immune diseases and will receive immunosuppressive therapies. In France, in line with reports in other developed countries, an estimated 7.3% of adults have serological markers indicating resolved HBV infection, and this proportion increases with age (12). As an illustration, in our study, resolved HBV infection had been diagnosed in 58 (13%) of 504 rheumatic patients. Taken together, these data prompt to be cautious about the HBV status of any patient who will undergo an immunosuppressive therapy and to perform surveys on large cohorts to determine the appropriate monitoring in case of resolved HBV infection. Concomitantly, the propensity of each immunosuppressive treatment to promote HBV reactivation in patients presenting HBsAg-positivity as well as serology indicating resolved hepatitis B should be studied.

References

1. Charpin C, Guis S, Colson P, Borentain P, Mattéi JP, Alcaraz P, Balandraud N, Thomachot B, Roudier J, Gérolami R: Safety of TNF-blocking agents in rheumatic patients with serology suggesting past hepatitis B state: results from a cohort of 21 patients. Arthritis Res Ther 2009, 11(6):R179.
2. Jansen TL: When rheumatology meets hepatology: are anti-TNFs safe in hepatitis B virus carriers? Arthritis Res Ther 2010, 12(1):103.
3. Lok AS, McMahon BJ: Chronic hepatitis B. Hepatology 2007, 45(2):507-39.
4. Liaw YF, Chu CM: Hepatitis B virus infection. Lancet 2009, 373(9663):582-92.
5. Raimondo G, Allain JP, Brunetto MR, Buendia MA, Chen DS, Colombo M, Craxì A, Donato F, Ferrari C, Gaeta GB, Gerlich WH, Levrero M, Locarnini S, Michalak T, Mondelli MU, Pawlotsky JM, Pollicino T, Prati D, Puoti M, Samuel D, Shouval D, Smedile A, Squadrito G, Trépo C, Villa E, Will H, Zanetti AR, Zoulim F: Statements from the Taormina expert meeting on occult hepatitis B virus infection. J Hepatol 2008, 49(4):652-7.
6. Zoulim F: New insight on hepatitis B virus persistence from the study of intrahepatic viral cccDNA. J Hepatol 2005, 42(3):302-8.
7. Nassal M: Hepatitis B viruses: reverse transcription a different way. Virus Res 2008, 134(1-2):235-49.
8. Chung SJ, Kim JK, Park MC, Park YB, Lee SK: Reactivation of hepatitis B viral infection in inactive HBsAg carriers following anti-tumor necrosis factor-alpha therapy. J Rheumatol 2009, 36(11):2416-20.
9. Esteve M, Saro C, González-Huix F, Suarez F, Forné M, Viver JM: Chronic hepatitis B reactivation following infliximab therapy in Crohn's disease patients: need for primary prophylaxis. Gut 2004, 53(9):1363-5.
10. Borentain P, Colson P, Coso D, Bories E, Charbonnier A, Stoppa AM, Auran T, Loundou A, Motte A, Ressiot E, Norguet E, Chabannon C, Bouabdallah R, Tamalet C, Gérolami R: Clinical and virological factors associated with hepatitis B virus reactivation in HBsAg-negative and anti-HBc antibodies-positive patients undergoing chemotherapy and/or autologous stem cell transplantation for cancer. J Viral Hepat. [Epub ahead of print]
11. Yeo W, Chan TC, Leung NW, Lam WY, Mo FK, Chu MT, Chan HL, Hui EP, Lei KI, Mok TS, Chan PK: Hepatitis B virus reactivation in lymphoma patients with prior resolved hepatitis B undergoing anticancer therapy with or without rituximab. J Clin Oncol 2009, 27(4):605-11.
12. Meffre C, Le Strat Y, Delarocque-Astagneau E, Dubois F, Antona D, Lemasson JM, Warszawski J, Steinmetz J, Coste D, Meyer JF, Leiser S, Giordanella JP, Gueguen R, Desenclos JC : Prevalence of hepatitis B and hepatitis C virus infections in France in 2004: Social factors are important predictors after adjusting for known risk factors. J Med Virol 2010, 82(4):546-55.

A patient's response

Kelly Young — 2010-02-24T14:25:16Z

I disagree with the premises and conclusions of this article. My full reply is here. In addition to living with Rheumatoid Arthritis personally, I have compared the responses of thousands of RA patients' statements about pain.

Your theory does not offer explanation for this key fact: Onset of RA pain tends to be sudden in nature and extremely severe. If maladaptation to chronic pain were the reason for perception of its severity, then what explains sudden extreme pain during disease onset?

Have you considered the possibiity that rather than "amplified responses to pain," RA actually causes severe pain? You would have no way to objectively measure this, but RA patients are able describe it.

What of RA patients who have decades of living with various pains in life such as broken bones and childbirth prior to diagnosis? They indicate that, objectively compared, RA pain is worse than any other pain ever experienced.

Is it so difficult to believe that a disease that is as destructive as RA is to human tissue can cause extreme pain in that destructive process? We are obviously in our infancy of the understanding of this disease. Hearing the patient's viewpoint of what the disease actually entails would be the best way to progress.

Note:. Regarding the conclusion that RA patients would benefit from more studies of this kind: Rheumatoid arthritis patients would benefit more from having their disease treated than from having their claims of pain diminished. We ought to put our resources toward curing RA and reducing its mortality gap.

Thank you for reading.
Kelly Young
Rheumatoid Arthritis Warrior

Phytalgic: goldfish or flash in the pan? response to editorial

Nicholas Moore — 2010-02-16T10:34:39Z

I fully agree with all of this editorial's comments, and would like to answer what I may:
- The registration with clinicaltrials.gov was indeed done after the end of the study, because of a confusion between the study sponsor, Phythea, and our department, each thinking the other had done it. When discussing at the end of the study, I asked the sponsor, which is a small non-pharma company, whether they had registered with clintrials as I had asked them to before the study. I realized they had not. This was its first randomized double-blind trial, and they were somewhat at a loss on a number of these things. We had taken care of ethics and regulatory stuff, but forgot about clintrials. I therefore registered the study at that time, and just put in the numbers as they were, including dates. In the same way, when I wrote that the secondary evaluation criterion was the WOMAC functional score, it was not to the function subset of the WOMAC score I was alluding, but to the whole score and all three subsets. I had not thought the data in the clinicatrials.gov database would be subject to such semantic scrutiny or interpretation. The protocol (in french) clearly specified WOMAC, which for me is a functional score, in that it has no Xray or physical measure, or biology. Maybe some translation issues here for which I apologize.
In any event the WOMAC was only a secondary item: the main item was the use of analgesia and NSAIDs, as a relatively solid measure of OA activity and impact: this was also because initially the company came to us saying: "we have patient testimonies stating they could stop their NSAIDs after a few months of treatment. How can we verify this?"

We just wanted to test this, and make sure that any decrease in analgesic use was not at the expense of pain or function. We also wanted to stay as close as possible to the real-life circumstances, and decided not to change the patients' usual care, which was reasonably effective, but to study phytalgic as an add-on therapy, which is how it would normally be used.

The study happened exactly as described in the publication. There were no other excluded patients. We had aimed for 80 patients, and stopped the preinclusion and patient selection process when the number was reached, with a little overshoot (81 in fact by the time we got there).
Patient attrition during the study, as reported was related to adverse events (1 per group), pregnancy (1 with placebo) and lack of efficacy (2 with placebo). Lack of effect being more common with placebo could be bias, or placebo-resistance; pregnancy seems to be a coincidence (or an effect of placebo on compliance?): all women were on contraceptives and this one accidentally forgot to take it. We did not consider terminating the pregnancy... All happened very early in the study. We had initially excluded them from the analyses since we had no data beyond inclusion, then reinstated them at the request of the referees (quite rightly) using inclusion data carried forward. Whether these are included in the study or not did not change the overall results. No other patient was lost to follow-up or to attrition. Since the effect was much greater than expected, sample size was not really relevant. In fact, since we had no idea of what the effect might be, we chose 30% difference in use of analgesics as something that would be clinically relevant, which gave a sample size around 30 patients per group, then factored in a 25% dropout rate to come up with the number of 40 per group.

We had computed for a 30% decrease in the use of analgesia and NSAIDs, and no change in WOMAC. The results surprised us as much as it did the editorialists, and we consider them with as much circumspection, for exactly the same reasons. There may have been an identification by all patients in the treated group of the fish oil (but only a few complained of fish-smelling burping), but even so, and even if we were comparing in effect two placebos, one with a much stronger effect provided by fishoil smell, this would give a very large placebo effect. Even this may be possible, and maybe we should add some fish scent to a double-placebo study (the same vegetable oil in both capsules, but one with just some fishoil for the smell) to see the effect of the fishoil smelling placebo. I believe there have been tests of cod-liver oil, which does stink if I remeber my youth, and that it was not really effective.
Because of the risk of patients and investigator discovering the treatment allocation through the fishoil burps, we minimize the importance of the WOMAC, which might be more sensitive to bias. Our main objective was the use of analgesia and NSAIDs, which was reported on a diary, filled daily by the patients. Would patients have omitted the noting of drugs because they were on active treatment? Over three months, it takes a lot of perseverance.

In any event, I believe one should not really consider the magnitude of the effect, but only its existence: in a small single centre study (pilot?) that was done as best we could, we found that the regular use of Phytalgic was associated with a clear reduction in the use (need?) of analgesia and NSAIDs, the latter being quite desirable for someone as involved as I am in drug safety issues, and this reduction was not accompanied by a worsening of symptoms, but in fact may have been the consequence of an improvement in the symptoms. It might be due to the effect of the product on OA, it might be an interaction with the pharmacokinetics or dynamics of the NSAIDs or analgesics (so that the same NSAIDs might be more effective longer) or to an analgesic effect of the product per se (are there natural opiates in fishoil or nettles?) or any other number of reasons.

But as the editorialists state, certainly this effect, whatever its magnitude, needs further exporation:
- other clinical trials, larger and multicentre
- and maybe more fundamental studies to understand this effect if confirmed.

In conclusion we in no way wish to affirm that Phytalgic is the new panacea for OA, just that maybe there is something that should be further explored here, maybe a hope for the painful.
Like many others it will probably be dashed, but then who knows?
Just decreasing the need for and use for NSAIDs is enough for me, and that too warrants further testing of this compound.

The intriguing CD4+CD25-/lowFoxp3+ cells in SLE

Xuan Zhang — 2010-02-09T11:17:07Z

The Fluorescence intensity of CD25 is apparently influenced by the staining intensity of the conjugated antibody and the setup of flow cytometer parameters, therefore definition of CD25 expression as high or low, bright or dim, is relatively arbitrary and should be taken into consideration when comparing the results from different research groups.

Nevertheless, the expression of Foxp3 could not simply be substituted for by CD127-/low, but rather correlates with CD25 expression in CD4+CD127-/low subgroups[1]. The expression rate of Foxp3 is the highest (greater than 90%) in CD4+CD127-/lowCD25high subgroup, which is, without controversy, the classical regulatory T cell (Treg) that possessing immuno-regulatory capacity, and it is possible to use CD4+CD127-/lowCD25high as surrogate to sort out these classical Tregs, whereas this is not the case in CD4+CD127-/low subgroups that are CD25low or CD25-. For those CD25low, Foxp3 expression is not so high as in CD25 high subgroup (72%), and for those CD25- cells, Foxp3 expression dramatically drops to 10%. Similar finding was also reported by Miyara and colleagues[2]. They observed that when CD45RA was not taken into account, the expression of Foxp3 was downregulated when CD25 expression was low. Therefore it is not possible to sort out CD4+CD25-Foxp3+ subgroup using CD4+CD127-/lowCD25- as the surface surrogate markers. It is not surprising to see that CD4+CD127-CD25- cells sorted out by Bonelli M and colleagues[3] expressed Foxp3 at a rate of 53% and suppressed T-cell proliferation but not production of interferon-gamma, as these cells might be ‘contaminated’ by some CD4+CD127-CD25low cells. Indeed CD4+CD127-/lowCD25low cells can express considerable amount of Foxp3 and to some extent, also have anergic and suppressive capacity though not as potent as classical Tregs. Therefore it may not be feasible to pick out a homogeneous subgroup of cells that could represent CD4+CD25-Foxp3+ with combination surface markers of CD4,CD127 and CD25. Those abnormally increased CD4+CD25-Foxp3+cells in lupus [4] not only phenotypically resemble effector T cells (Teffc) on expressions of CCR4, GITR, CD152, but also can secret cytokines such as IL-2 and interferon-gamma[1]. In terms of CD4+CD127low/- cells, CD25low cells contamination in CD25- subgroup may affect the regulatory capacity detected.

It is possible that the intriguing CD4+CD25-/lowFoxp3+ cells is a mixture that contains CD45RA+CD25moderateFoxp3low Treg resting precursor cells as well as CD45RA-CD25-Foxp3low nonTreg cells as reported by Miyara and colleagues[2]. In their study, they divided FoxP3+CD4+ T cells into CD45RA+FoxP3low resting Treg cells, CD45RA-FoxP3high activated Treg cells, and cytokine-secreting CD45RA-FoxP3low nonsuppressive T cells, and found abnormal increase of CD45RA-FoxP3low in active SLE, which could also secrete more cytokines than the other two Foxp3+ cells. Therefore it is not surprising to see different results obtained by different research groups. Besides, Systemic lupus erythematosus (SLE) is a heterogeneous disease, of which ethnics, course of disease and immunotherapy may in some ways, have influence on its immunoregulatory network. We enrolled new-onset SLE patients as study subjects to eliminate the interference of therapy, though still we could not exclude the individual difference amplified by the disease per se.

Despite of the dispute discussed, research in this field have reached some consensus, in that in SLE patients do exist a group of abnormally increased CD4+CD25-Foxp3+ cells that decrease in most patients with active SLE after effective treatment, and may be an unique immunological feature of SLE and it does not occur in other autoimmune diseases such as rheumatoid arthritis or systemic sclerosis, though there is report that in non-obese diabetic (NOD) mice, intra-islet Treg cells express decrease levels of CD25[5]. These newly identified cells are not unanimous in property and function. They are neither traditional Treg with intact regulatory capacity nor pure Teffc. Recent studies have demonstrated that instead of being end-differentiated cells, Treg is plastic, and Foxp3+ cells could become IL-17 producers[6][7], expressing the Th1 transcription factor T-bet or produce interferon-gamma[8-10]. As we know, IL-2-induced STAT5 activation is required for Treg development and survival. The Treg-specific determining region in an intron of Foxp3 contains a STAT5 binding site and Tregs with low IL-2Ralpha (CD25) expression levels are unstable and lose FOXP3 expression when transferred to lymphopenic mice or in an IL-2-deficient autoimmune setting[11-15]. Given the plasticity of Foxp3+ cells, in human disease such as SLE, under the immunopathological condition, the upregulated CD4+CD25-Foxp3+ cells may likely be one of the mechanisms that contribute to the maintenance and expansion of autoimmune reponse. These cells may be abnormally differentiated Treg precursor or represent transitional cells during transformation from Treg to Teffc under pathological circumstances.

Advance research on the origin and development of this group of cells and their role in SLE will help us to better understand the immunopathogenesis of lupus. To do that, a specific surrogate marker for Foxp3 other than CD127low/- is needed.

Li-dan Zhao, Yang Li, Xuan Zhang
Department of Rheumatology, Peking Union Medical College Hospital，Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China, 100730
Corresponding author: Xuan Zhang, E-mail: zxpumch2003@yahoo.com.cn

1. Yang HX, Zhang W, Zhao LD, Li Y, Zhang FC, Tang FL, He W, Zhang X: Are CD4+CD25-Foxp3+ cells in untreated new-onset lupus patients regulatory T cells? Arthritis Res Ther 2009, 11(5):R153.
2. Miyara M, Yoshioka Y, Kitoh A, Shima T, Wing K, Niwa A, Parizot C, Taflin C, Heike T, Valeyre D et al: Functional delineation and differentiation dynamics of human CD4+ T cells expressing the FoxP3 transcription factor. Immunity 2009, 30(6):899-911.
3. Bonelli M, Savitskaya A, Steiner CW, Rath E, Smolen JS, Scheinecker C: Phenotypic and functional analysis of CD4+ CD25- Foxp3+ T cells in patients with systemic lupus erythematosus. J Immunol 2009, 182(3):1689-1695.
4. Zhang B, Zhang X, Tang FL, Zhu LP, Liu Y, Lipsky PE: Clinical significance of increased CD4+CD25-Foxp3+ T cells in patients with new-onset systemic lupus erythematosus. Ann Rheum Dis 2008, 67(7):1037-1040.
5. Tang Q, Adams JY, Penaranda C, Melli K, Piaggio E, Sgouroudis E, Piccirillo CA, Salomon BL, Bluestone JA: Central role of defective interleukin-2 production in the triggering of islet autoimmune destruction. Immunity 2008, 28(5):687-697.
6. Voo KS, Wang YH, Santori FR, Boggiano C, Wang YH, Arima K, Bover L, Hanabuchi S, Khalili J, Marinova E et al: Identification of IL-17-producing FOXP3+ regulatory T cells in humans. Proc Natl Acad Sci U S A 2009, 106(12):4793-4798.
7. Koenen HJ, Smeets RL, Vink PM, van Rijssen E, Boots AM, Joosten I: Human CD25highFoxp3pos regulatory T cells differentiate into IL-17-producing cells. Blood 2008, 112(6):2340-2352.
8. Koch MA, Tucker-Heard G, Perdue NR, Killebrew JR, Urdahl KB, Campbell DJ: The transcription factor T-bet controls regulatory T cell homeostasis and function during type 1 inflammation. Nat Immunol 2009, 10(6):595-602.
9. Wei G, Wei L, Zhu J, Zang C, Hu-Li J, Yao Z, Cui K, Kanno Y, Roh TY, Watford WT et al: Global mapping of H3K4me3 and H3K27me3 reveals specificity and plasticity in lineage fate determination of differentiating CD4+ T cells. Immunity 2009, 30(1):155-167.
10. Xu L, Kitani A, Fuss I, Strober W: Cutting edge: regulatory T cells induce CD4+CD25-Foxp3- T cells or are self-induced to become Th17 cells in the absence of exogenous TGF-beta. J Immunol 2007, 178(11):6725-6729.
11. Burchill MA, Yang J, Vogtenhuber C, Blazar BR, Farrar MA: IL-2 receptor beta-dependent STAT5 activation is required for the development of Foxp3+ regulatory T cells. J Immunol 2007, 178(1):280-290.
12. Floess S, Freyer J, Siewert C, Baron U, Olek S, Polansky J, Schlawe K, Chang HD, Bopp T, Schmitt E et al: Epigenetic control of the foxp3 locus in regulatory T cells. PLoS Biol 2007, 5(2):e38.
13. Komatsu N, Mariotti-Ferrandiz ME, Wang Y, Malissen B, Waldmann H, Hori S: Heterogeneity of natural Foxp3+ T cells: a committed regulatory T-cell lineage and an uncommitted minor population retaining plasticity. Proc Natl Acad Sci U S A 2009, 106(6):1903-1908.
14. Wei L, Laurence A, O'Shea JJ: New insights into the roles of Stat5a/b and Stat3 in T cell development and differentiation. Semin Cell Dev Biol 2008, 19(4):394-400.
15. Zhou X, Bailey-Bucktrout SL, Jeker LT, Penaranda C, Martinez-Llordella M, Ashby M, Nakayama M, Rosenthal W, Bluestone JA: Instability of the transcription factor Foxp3 leads to the generation of pathogenic memory T cells in vivo. Nat Immunol 2009, 10(9):1000-1007.

Collagen type II (peptide 261-273) TCR specific clonotypes confirmed in a subset of DRB1-04+ early rheumatoid arthritis patients.

Maria De Santis — 2010-01-25T10:10:58Z

Sir,
In 2008 we reported the BV-BJ (immunoscope) of the response to human collagen II 261-273 in peripheral blood of DR4+ subjects affected Rheumatoid Arthritis (1). Two of these rearrangements were frequently used; a BV13b-BJ2.3 of 199b length (BV13b) and a BV11-BJ2.2 of 139b length (BV11). Both rearrangements associated with acute presentation of disease, and we suggested a common CDR3 motif for BV13b and two for BV11. Several papers (2,3) have shown a skewing of the repertoire of T cells infiltrating the synovia. The possibility to monitor T cells associate with disease status in peripheral blood would be valuable for management of patients.
To assess the predictive ability of rearrangements BV13b and BV11, we examined PBMC from 31 consecutive patients attending our outpatient early arthritis clinic. Patients were examined as described, blind with respect to DRB1 haplotype and disease status. Nine patients were DR4+, 8 in disease remission (DAS44 < 1.6) and 1 in an acute disease state (DAS44 >3.7). None of them belonged to the cohort previously reported (1). Of the 22 DR4- subjects, 16 were in disease remission and 6 in active disease. Overall, out of 50 samples, BV13b was detected in 5/8 samples obtained from DR4+ patient in active RA, in 1/14 samples obtained from DR4+ RA patients in remission and in 1/23 samples obtained from DR4- RA patients (p<10-8 in all cases). Samples from 5 DR4+ healthy subjects were negative. Thus, detection of BV13b in PBMC is highly indicative of a DR4+ subject in active disease status.
Also detection of BV11 (tested in 58 samples) is associated with DR4 and active disease, but its potency is lower than that of BV13b (p=0.049 versus healthy DR4+ donors, p=0.001 vs DR4+ patients in remission and p<10-5 vs DR4- patients). Three of the 5 positive samples obtained from DR4+ patients at remission of disease had been obtained in proximity of an acute episode (<3 months after (1 sample) or before (2 samples)).
A total of 114 new sequences for BV11 were obtained, 37 of length 139b. Between the two motives proposed for BV11, the SEPR consistently associated with DR4+ subjects in acute or proximity to disease (p=0.0003 vs DR4- patients and p=0.045 vs DR4+ healthy donors).
In conclusion these data support the possibility to monitor T cells specific for human collagen in peripheral blood of DR4+ RA patients, and should prove useful for the clinical management of patients.

Francesco Ria*, Romina Penitente*, Maria De Santis**, Gianfranco Ferraccioli**
Institute of General Pathology * - Department of Rheumatology** -School of Medicine-Catholic University of the Sacred Heart-Via Moscati 31, 00168 Rome, Italy

References.
1. Ria F, Penitente R , De Santis M, Nicolò C, Di Sante G, Orsini M, Arzani D, Fattorossi A, Battaglia A, Ferraccioli G: Collagen-specific T-cell repertoire in blood and synovial fluid varies with disease activity in early rheumatoid arthritis. Arthritis Research & Therapy 2008, 10:R135
2. Backlund J, Carlsen S, Hoger T, Holm B, Fugger L, Kihlberg J, Burkhardt H, Holmdahl R: Predominant selection of T cells specific for the glycosylated collagen type II epitope (263-270) in humanized transgenic mice and in rheumatoid arthritis. Proc Natl Acad Sci U S A 2002, 99(15):9960-9965
3. Sekine T, Kato T, Masuko-Hongo K, Nakamura H, Yoshino S, Nishioka K, Yamamoto K: Type II collagen is a target antigen of clonally expanded T cells in the synovium of patients with rheumatoid arthritis. Ann Rheum Dis 1999, 58(7):446-450.

Response to Editorial by C Ritchlin...

John Hamilton — 2009-07-22T14:30:34Z

We agree with Dr. Ritchlin that our in vitro demonstration that human osteoclast precursors are within the proliferative monocyte subpopulation must be interpreted with caution; we also support his comments that the importance of the proliferative subset in rheumatoid and psoriatic arthritis should be examined. As a point of clarification, the presence and surface phenotyping of this immature proliferative subset in the blood of many donors, as well as the suggestion of its possible relevance to inflammatory/autoimmune conditions, have been reported in a number of previous publications from our laboratory [1-5]. Also, those interested are referred to a recent publication where human osteoclasts could be generated, and potentially in large numbers, from a precursor population derived in turn from hemopoietic stem cells [6].

Dr Ritchlin also raises important questions as to whether the proliferative monocyte subpopulation expresses higher cell surface levels of c-Fms to account for the increased proliferative capacity and whether it expresses a unique surface marker(s). We have not been able to observe any differential expression of c-Fms and no unique surface marker has yet been found, although there is evidence that the subpopulation has altered expression of certain myeloid markers compared with other monocyte populations [5]. As Dr. Ritchlin states, the quest for such a marker(s) on osteoclast precursors should continue so that they can be better characterized.

1. Cheung DL, Hamilton JA: Regulation of human monocyte DNA synthesis by colony-stimulating factors, cytokines, and cyclic adenosine monophosphate. Blood 1992, 79(8):1972-1981.
2. Finnin M, Hamilton JA, Moss ST: Characterization of a CSF-induced proliferating subpopulation of human peripheral blood monocytes by surface marker expression and cytokine production. J Leukoc Biol 1999, 66(6):953-960.
3. Finnin M, Hamilton JA, Moss ST: Direct comparison of the effects of CSF-1 (M-CSF) and GM-CSF on human monocyte DNA synthesis and CSF receptor expression. J Interferon Cytokine Res 1999, 19(4):417-423.
4. Moss ST, Hamilton JA: Proliferation of a subpopulation of human peripheral blood monocytes in the presence of colony stimulating factors may contribute to the inflammatory process in diseases such as rheumatoid arthritis. Immunobiology 2000, 202(1):18-25.
5. Clanchy FI, Holloway AC, Lari R, Cameron PU, Hamilton JA: Detection and properties of the human proliferative monocyte subpopulation. J Leukoc Biol 2006, 79(4):757-766.
6. Way KJ, Dinh H, Keene MR, White KE, Clanchy FI, Lusby P, Roiniotis J, Cook AD, Cassady AI, Curtis DJ et al: The generation and properties of human macrophage populations from hemopoietic stem cells. J Leukoc Biol 2009, 85(5):766-778.

Correction

Naoyuki Tsuchiya — 2009-03-12T12:39:15Z

After the publication of this paper, the authors became aware that "Juntendo University" has been unintentionally deleted from the affiliation of Dr. Yoshinari Takasaki and Dr. Hiroshi Hashimoto.

Affiliation of Dr. Takasaki and Dr. Hashimoto (6) should read
"Division of Rheumatology, Department of Internal Medicine, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan"

I am sorry about this deletion.

Sincerely,
Naoyuki Tsuchiya, MD, PhD
University of Tsukuba

Cause vs effect...

Gershom Lundberg — 2007-04-11T16:42:51Z

Unless I misunderstand the structure of this research, there is no random assignment of participants to active vs inactive groups.

Therefore, it is unjustified to conclude that exercise is beneficial. It may simply be that women with arthritis pain are less active, BECAUSE they are in pain.

A helpful view

Vinod Nikhra — 2007-01-24T10:12:26Z

Good article. In fact it puts forth certain fresh ideas that can help immensely in disease management.

Arthritis and Running - selection bias?

Susan DeVries — 2005-09-28T22:44:35Z

Although Bruce, Fries and Lubeck's article provides validation of the benefits of exercise in the ageing process, there could be some selection biases in the sampling. Had the authors considered that it could be that persons who join a running club would be less likely to have pain in the first place; be more fit and interested in activity to begin with? Maybe there could be a way to randomise the running as an intervention, instead of using 'self selection'. My clinical education and research experience has prompted me to ask this question.