Faculty Bibliography

OBJECTIVE: To clarify the role of common genetic variation in the Interleukin-1beta (IL1B) and Interleukin-1R antagonist (IL1RN) genes on risk of knee and hip osteoarthritis (OA) and severity of knee OA by means of large-scale meta-analyses. METHODS: We searched PubMed for articles assessing the role of IL1B and IL1RN polymorphisms/haplotypes on the risk of hip and/or knee OA. Novel data were included from eight unpublished studies. Meta-analyses were performed using fixed- and random-effects models with a total of 3595 hip OA and 5013 knee OA cases, and 6559 and 9132 controls respectively. The role of ILRN haplotypes on radiographic severity of knee OA was tested in 1918 cases with Kellgren-Lawrence (K/L) 1 or 2 compared to 199 cases with K/L 3 or 4. RESULTS: The meta-analysis of six published studies retrieved from the literature search and eight unpublished studies showed no evidence of association between common genetic variation in the IL1B or IL1RN genes and risk of hip OA or knee OA (P>0.05 for rs16944, rs1143634, rs419598 and haplotype C-G-C (rs1143634, rs16944 and rs419598) previously implicated in risk of hip OA). The C-T-A haplotype formed by rs419598, rs315952 and rs9005, previously implicated in radiographic severity of knee OA, was associated with reduced severity of knee OA (odds ratio (OR)=0.71 95%CI 0.56-0.91; P=0.006, I(2)=74%), and achieved borderline statistical significance in a random-effects model (OR=0.61 95%CI 0.35-1.06 P=0.08). CONCLUSION: Common genetic variation in the Interleukin-1 region is not associated with prevalence of hip or knee OA but our data suggest that IL1RN might have a role in severity of knee OA

OBJECTIVE: Rheumatoid arthritis (RA) patients who have never received treatment for RA have been found to have defective early B cell tolerance checkpoints, resulting in impaired removal of developing autoreactive B cells. However, it is unclear whether these defects in B cell tolerance checkpoints are a primary aspect of the disease or are the result of ongoing inflammatory processes in these patients. The aim of this study was to assess the impact of standard immunosuppressive treatments, methotrexate and anti-tumor necrosis factor alpha (anti-TNFalpha) agents, on early B cell tolerance checkpoints in RA patients. METHODS: Blood samples were obtained from RA patients before and after treatment with methotrexate and/or anti-TNFalpha agents. B cells were tested pre- and posttherapy for reactivity of recombinant antibodies cloned from single B cells, which allowed us to determine the evolution of the frequency of autoreactive clones in the mature naive B cell compartment in RA patients before and after treatment. B cells from healthy donors were used as controls. RESULTS: Posttreatment frequencies of autoreactive mature naive B cells were elevated in the blood of RA patients. Nevertheless, the frequencies after treatment remained similar to those observed in the same patients before treatment. CONCLUSION: Despite the achievement of clinical improvement in RA patients following treatment with methotrexate and/or anti-TNFalpha agents, these therapies did not correct the accumulation of peripheral autoreactive mature naive B cells in these patients, suggesting that inflammation is not responsible for the defective early B cell tolerance checkpoints in RA

OBJECTIVE: Criteria for sonographic diagnosis of monosodium urate (MSU) crystal deposition have been developed, but the interreader reproducibility of this modality is not well established. We therefore assessed agreement using a systematic approach. METHODS: Fifty male subjects ages 55-85 years were recruited during primary care visits to an urban Veterans Affairs hospital, and were assessed by musculoskeletal ultrasound (US) of the knees and first metatarsophalangeal (MTP) joints to evaluate for the double contour sign and tophi as evidence of MSU crystal deposition. Images were read by 2 blinded rheumatologists trained in musculoskeletal US, and the degree of concordance was determined for individual subjects, total joints, femoral articular cartilage (FAC), and first MTP joints. Subjects were further categorized into 3 diagnostic groups: gout, asymptomatic hyperuricemia (no gout, serum uric acid [UA] >/=6.9 mg/dl), and controls (no gout, serum UA </=6.8 mg/dl), and reader concordance within these 3 groups was assessed. RESULTS: We observed almost perfect agreement between readers for 1) individual subjects (yes/no; n = 50, 100% agreement, kappa = 1.000), 2) total joints (n = 200, 99% agreement, kappa = 0.942), 3) FAC (n = 100, 99% agreement, kappa = 0.942), and 4) first MTP joints (n = 100, 99% agreement, kappa = 0.942). Furthermore, findings by side (right/left) and diagnostic group (gout, asymptomatic hyperuricemia, control) showed substantial to almost perfect concordance for all measures. MSU deposition was seen most commonly in gout patients, and deposition was also seen in some subjects with asymptomatic hyperuricemia, but in only 1 control. CONCLUSION: Musculoskeletal US is reliable for detecting MSU deposition in FAC and first MTP joints in gout and asymptomatic hyperuricemia

The use of musculoskeletal ultrasound (MSKUS) has increased in a variety of rheumatic conditions, particularly rheumatoid arthritis (RA). MSKUS complements the physical examination by allowing for superior visualization of synovitis and erosive changes compared to conventional radiography and provides detail comparable or supplementary to magnetic resonance imaging (MRI). This modality is also less expensive than MRI and CT scans, without claustrophobia or other contraindications, while uniquely providing dynamic, rather than static imaging. A growing body of literature for MSKUS in RA is contributing significantly to the understanding of diagnostic and prognostic utility, longitudinal assessment, and disease remission. Furthermore, scoring systems focusing on the patient level rather than individual joints have been developed, allowing for simplification of exams while still retaining accuracy and utility. The combination of these advances has led to increased use of MSKUS in RA in the realm of research as well as at the bedside and in the clinic

Complement receptor 2-negative (CR2/CD21(-)) B cells have been found enriched in patients with autoimmune diseases and in common variable immunodeficiency (CVID) patients who are prone to autoimmunity. However, the physiology of CD21(-/lo) B cells remains poorly characterized. We found that some rheumatoid arthritis (RA) patients also display an increased frequency of CD21(-/lo) B cells in their blood. A majority of CD21(-/lo) B cells from RA and CVID patients expressed germline autoreactive antibodies, which recognized nuclear and cytoplasmic structures. In addition, these B cells were unable to induce calcium flux, become activated, or proliferate in response to B-cell receptor and/or CD40 triggering, suggesting that these autoreactive B cells may be anergic. Moreover, gene array analyses of CD21(-/lo) B cells revealed molecules specifically expressed in these B cells and that are likely to induce their unresponsive stage. Thus, CD21(-/lo) B cells contain mostly autoreactive unresponsive clones, which express a specific set of molecules that may represent new biomarkers to identify anergic B cells in humans.

Osteoarthritis (OA) is often a progressive and disabling disease, which occurs in the setting of a variety of risk factors--such as advancing age, obesity and trauma--that collude to incite a cascade of pathophysiological events within joint tissues. An important emerging theme in OA is a broadening of focus from a disease of cartilage to one of the 'whole joint.' The synovium, bone and cartilage are each involved in pathological processes that lead to progressive joint degeneration. Additional themes that have emerged over the past decade are novel mechanisms of cartilage degradation and repair, the relationship between biomechanics and biochemical pathways, the importance of inflammation and the role of genetics. In this article, we review the molecular, clinical and imaging evidence that synovitis is not an 'incidental finding of OA', but plays a significant role in disease pathogenesis, and could therefore represent a target for future treatments

BACKGROUND: A lack of biomarkers that identify patients at risk for severe osteoarthritis (OA) complicates development of disease-modifying OA drugs. OBJECTIVE: To determine whether inflammatory genetic markers could stratify patients with knee OA into high and low risk for destructive disease. METHODS: Genotype associations with knee OA severity were assessed in two Caucasian populations. Fifteen single nucleotide polymorphisms (SNPs) in six inflammatory genes were evaluated for association with radiographic severity and with synovial fluid mediators in a subset of the patients. RESULTS: Interleukin 1 receptor antagonist (IL1RN) SNPs (rs419598, rs315952 and rs9005) predicted Kellgren-Lawrence scores independently in each population. One IL1RN haplotype was associated with lower odds of radiographic severity (OR=0.15; 95% CI 0.065 to 0.349; p<0.0001), greater joint space width and lower synovial fluid cytokine levels. Carriage of the IL1RN haplotype influenced the age relationship with severity. CONCLUSION: IL1RN polymorphisms reproducibly contribute to disease severity in knee OA and may be useful biomarkers for patient selection in disease-modifying OA drug trials

Cerebrovascular disease appears to have implications on rheumatic diseases, including gout. Accumulating evidence suggests that hemiparesis exerts a protective effect against gout via the down-regulation of mechanical and neural modulators of inflammation in neurologically impaired extremities. We present 2 divergent cases of unilateral gout following cerebrovascular events. One patient with a hemorrhagic stroke developed polyarticular gout only on the ipsilateral side to his hemiparesis, while another patient with basilar artery thrombosis and locked-in syndrome suffered a polyarticular gout flare only on the side that had regained limited function. As suggested by these cases, the effect of hemiparesis on gout is complex. Further insight into the interplay between gouty flares and hemiparesis may lead to novel therapeutic strategies for gout