Simon M. Helfgott

Pharmacokinetics, safety, and efficacy of combination treatment with methotrexate and leflunomide in patients with active rheumatoid arthritis.

OBJECTIVE To examine the safety and pharmacokinetics of and clinical response to leflunomide, a de novo pyrimidine synthesis inhibitor, when administered to patients with active rheumatoid arthritis (RA) who have been receiving long-term methotrexate therapy. METHODS This was an open-label, 52-week study in which 30 patients with RA that remained active despite therapy with methotrexate at 17+/-4 mg/week (mean +/- SD) for > or =6 months were given leflunomide, 10-20 mg/day. Patients were assessed for adverse effects, pharmacokinetic measurements of leflunomide and methotrexate, and clinical response by American College of Rheumatology (ACR) 20% response criteria. RESULTS Twenty-three patients completed 1 year of treatment. No significant pharmacokinetic interactions between leflunomide and methotrexate were noted. This combination therapy was generally well tolerated clinically, with the exception of elevations of liver enzyme levels. Seven patients withdrew from the treatment regimen: 2 withdrawals were voluntary, 3 were due to persistent elevation of plasma transaminase levels, and 2 were due to lack of efficacy. Of the patients, 16 (53%) met ACR 20% response criteria. Two met ACR criteria for remission after 1 year. CONCLUSION The combination of methotrexate and leflunomide has therapeutic potential in RA.

Pathologically expanded peripheral T helper cell subset drives B cells in rheumatoid arthritis

CD4+ T cells are central mediators of autoimmune pathology; however, defining their key effector functions in specific autoimmune diseases remains challenging. Pathogenic CD4+ T cells within affected tissues may be identified by expression of markers of recent activation. Here we use mass cytometry to analyse activated T cells in joint tissue from patients with rheumatoid arthritis, a chronic immune-mediated arthritis that affects up to 1% of the population. This approach revealed a markedly expanded population of PD-1hiCXCR5−CD4+ T cells in synovium of patients with rheumatoid arthritis. However, these cells are not exhausted, despite high PD-1 expression. Rather, using multidimensional cytometry, transcriptomics, and functional assays, we define a population of PD-1hiCXCR5− ‘peripheral helper’ T (TPH) cells that express factors enabling B-cell help, including IL-21, CXCL13, ICOS, and MAF. Like PD-1hiCXCR5+ T follicular helper cells, TPH cells induce plasma cell differentiation in vitro through IL-21 secretion and SLAMF5 interaction (refs 3, 4). However, global transcriptomics highlight differences between TPH cells and T follicular helper cells, including altered expression of BCL6 and BLIMP1 and unique expression of chemokine receptors that direct migration to inflamed sites, such as CCR2, CX3CR1, and CCR5, in TPH cells. TPH cells appear to be uniquely poised to promote B-cell responses and antibody production within pathologically inflamed non-lymphoid tissues.

The relationship between disease activity, sleep, psychiatric distress and pain sensitivity in rheumatoid arthritis: a cross-sectional study.

IntroductionDespite recent advances in anti-inflammatory therapy, rheumatoid arthritis (RA) patients continue to rate pain as a priority. The etiology of RA pain is likely multifactorial, including both inflammatory and non-inflammatory components. In this study, we examine the association between disease activity, sleep, psychiatric distress and pain sensitivity in RA.MethodsFifty-nine female RA patients completed questionnaires and underwent pressure pain threshold testing to assess hyperalgesia/allodynia at joint and non-joint sites. Blood samples were taken to measure C-reactive protein (CRP). The association between disease activity, sleep problems, psychiatric distress and pain threshold was assessed using Pearson/Spearman correlations and multivariable linear regression. Disease activity levels, sleep problems and psychiatric distress were compared between RA patients with fibromyalgia and RA patients without fibromyalgia.ResultsIn unadjusted analyses, CRP was not correlated with pain threshold, but tender joint count was inversely correlated with pain threshold at all sites (P ≤ 0.004). Sleep problems were associated with low pain threshold at all sites (P ≤ 0.0008). Psychiatric distress was associated with low pain threshold at the wrist and thumbnail (P ≤ 0.006). In multivariable linear regression models, CRP was inversely associated with wrist pain threshold (P = 0.003). Sleep problems were inversely associated with pain threshold at all sites (P ≤ 0.01), but psychiatric distress was not. Despite differences in pain threshold, CRP levels and sleep problems between RA patients with fibromyalgia and those without fibromyalgia, associations between these variables did not change when patients with fibromyalgia were excluded.ConclusionsMultivariable models are essential in analyses of pain. Among RA patients, inflammation is associated with heightened pain sensitivity at joints. In contrast, poor sleep is associated with diffuse pain sensitivity, as noted in central pain conditions such as fibromyalgia. Future studies examining pain sensitivity at joint and non-joint sites may identify patients with different underlying pain mechanisms and suggest alternative approaches to treating RA pain.

Use of the T-SPOT.TB Assay to Detect Latent Tuberculosis Infection Among Rheumatic Disease Patients on Immunosuppressive Therapy

Objective. We evaluated the T-SPOT.TB assay to identify latent tuberculosis infection (LTBI) in patients with rheumatic disease receiving immunosuppressive medication including tumor necrosis factor (TNF) antagonists. Methods. A total of 200 patients seen in the Arthritis Center at Brigham and Women’s Hospital were enrolled for study. Most patients were US-born women with rheumatoid arthritis. A medical history was obtained using a questionnaire, whole blood was drawn for the T-SPOT.TB assay, and tuberculin skin testing (TST) was performed. Results. Both tests were performed on 179 subjects, who had no history of a positive TST. All subjects had a strong response to the T-SPOT.TB test positive control, and there were no indeterminate results. Among these 179 subjects, 2 had a positive TST and 10 had a positive T-SPOT.TB test. No subject was positive for both tests. Patients with a positive T-SPOT.TB test did not have typical risk factors for LTBI based on clinical evaluation. Conclusion. The lack of concordance between the TST and the T-SPOT.TB assay may indicate that the immunoassay is more sensitive, particularly in a patient population taking immunosuppressive medications. It is equally likely that the low prevalence of LTBI in this low-risk population led to an increase in the false-positive rate despite the high sensitivity and specificity of the T-SPOT.TB assay. In the context of our patient population, the T-SPOT.TB assay is likely to be most useful in evaluation of patients with a positive TST, since these patients have a higher pretest probability of having LTBI.

Leflunomide-associated weight loss in rheumatoid arthritis

OBJECTIVE To determine the frequency of weight loss in patients treated with leflunomide for rheumatoid arthritis at an arthritis referral center. METHODS We queried 35 rheumatologists at the Robert Breck Brigham Arthritis Center to determine if weight loss had occurred as an adverse event in patients treated with leflunomide between November 1998 and January 2000. Five such patients were identified and their clinical course was reviewed. RESULTS Five of 70 patients who had begun leflunomide therapy had significant weight loss that could not be linked to other identifiable etiologies. The amount of weight loss was substantial in this group of patients, ranging from 19 pounds to 53 pounds. All patients had normal levels of thyroid-stimulating hormone and no other gastrointestinal complaints; evaluation revealed no other cause for the weight loss. Despite the significant weight loss, 4 of the 5 patients continued to take the drug due to its efficacy. CONCLUSION Significant weight loss is a potential adverse event in patients with rheumatoid arthritis treated with leflunomide. Awareness of this may obviate the need for extensive medical evaluations.

Suppressive Effects of Anti-mu Serum On the Development of Collagen Arthritis in Rats

Sprague-Dawley rats were maintained in environmentally isolated conditions and some of them were injected beginning at birth with rabbit anti-mu serum to suppress B-cell maturation. All rats were subsequently immunized with chick type II collagen. Ten (28%) of 36 rats injected with anti-mu antiserum failed to develop serum hemagglutinating antibodies to collagen, and there was a significant (P less than 0.0003) reduction in the IgG-specific antibody titer to collagen in these 10 rats compared to the other 26 rats in this group. Only 1 (10%) of the antibody-suppressed rats developed arthritis compared to 20 (77%) of the 26 other rats in the anti-mu-treated group (P less than 0.001). Twenty-two (61%) of 36 immunized rats administered rabbit anti-ovalbumin serum and 14 (88%) of 16 immunized rats kept in the axenic conditions developed arthritis. Delayed-type hypersensitivity to collagen did not differ significantly between the groups. These data provide indirect evidence that antibodies play a role in the inception of collagen arthritis.

Stiff-man syndrome: From the bedside to the bench

The study of SMS, a rare disease, has resulted in a better understanding of a more common disorder, IDDM, and has allowed investigators to gain insights into the molecular mechanisms of autoimmunity. Many unanswered questions remain, such as the specific site of disease activity in SMS, both at the bedside (cortex, brain stem, or spinal cord) and at the bench (neuronal cytoplasma or synapse). The association of SMS with neoplastic disease and the development of autonomicdysfunction are not understood. The next decade may provide answers to these puzzling issues.

Herpes zoster radiculopathy

Herpes zoster-related radiculopathy usually can be easily diagnosed in the presence of cutaneous lesions. Before development of the skin rash, the diagnosis may be in doubt, particularly if motor symptoms and signs are a major clinical feature. We report a patient with herpes zoster-related radiculopathy whose clinical features mimicked other spinal disorders.

Neurologic complications of systemic lupus erythematosus, sjögren syndrome, and rheumatoid arthritis.

Neurologic complications are frequent and often morbid in systemic lupus erythematosus, Sjögren syndrome, and rheumatoid arthritis. Although all are systemic inflammatory syndromes, each disease affects the nervous system distinctly, such as peripheral neuropathy in Sjögren syndrome, cerebrovascular disease in lupus, and cervical spine subluxation in rheumatoid arthritis. Some neurologic complications share convergent pathophysiology across diseases, such as neuromyelitis optica spectrum disorders in both Sjögren syndrome and lupus. Ill-defined cognitive complaints are especially common in lupus and Sjögren syndrome. For the majority of the complications, evidence for treatment efficacy is limited and requires further investigation.

Nabumetone: A clinical appraisal

Nonsteroidal antiinflammatory drugs (NSAIDs) have long been used as therapy for arthritis patients. However, in some patients these drugs can cause gastrointestinal hemorrhage, perforation, or ulcer through direct topical effects, enterohepatic recirculation, and systemic effects. In an effort to address this problem, new NSAIDs have been developed. Nabumetone, which belongs to a new class of NSAID, is a nonacidic agent that has been associated with a low incidence of peptic ulcer. This article examines available clinical data on nabumetone, including studies on gastrointestinal safety and effectiveness in osteoarthritis and rheumatoid arthritis patients, and data that may provide an explanation for nabumetones low incidence of ulceration.