Patients may have an overlap of categories or express different MSK disorders over time. Several studies10, 12 and 16 from rheumatology clinics have unequivocally demonstrated that a significant proportion of leprosy patients

may present for click here the first time with acute severe inflammatory arthritis, often a component of lepra reaction, and are mistakenly treated for prolonged periods with anti-rheumatic drugs (with potentially disastrous consequences). Articular involvement is generally ignored in children and adolescents with leprosy, and differential diagnosis of chronic polyarthritis includes juvenile idiopathic arthritis, acute leukemia, and childhood-systemic lupus erythematosus.14 To summarize, leprosy is the great mimic of the MSK-articular system and can present with protean manifestations requiring a high index of clinical suspicion to make a correct and timely diagnosis.10 and 12

It is well known Selleckchem BLU9931 that leprosy patients can be flooded with antibodies. From a rheumatological perspective, it is important to recognize false positive AAb; these include RF, ANA, antibody to anti-citrullinated cyclic peptides (a-CCP), antibody to anti-neutrophilic cytoplasmic antigens (ANCA), and antiphospholipid antibodies (APL)/anti-cardiolipin antibodies (ACL). The frequency of seropositive RF (Table 2) has varied considerably, which is due to assay methods, patient selection, and other reasons. In a controlled leprosy study,17 35% and 55.8% of patients tested seropositive for RF and ANA, respectively; 15.8%

patients were seropositive for both AAb. There was no correlation between RF/ANA and arthritis (68% prevalence) in the latter study.17 The frequency of Fossariinae seropositive RF was reported11 to vary considerably in different leprosy types (lepromatous > borderline > tuberculoid > Indeterminate). Ribeiro et al.13 (Table 2) demonstrated a lower prevalence of a-CCP (2.6%) and IgM RF (1.3%). A Mexican adult leprosy study18 reported significant a-CCP in 5.9% patients and RF in 16.8% patients; polar lepromatous (LL) patients had higher a-CCP and RF levels than polar tuberculoid (TT) patients. The low seropositivity of a-CCP can usefully differentiate between RA and leprosy associated inflammatory arthritis. ANCA, a marker of vasculitis, was reported in leprosy19 and p-ANCA (31% lepromatous, 16% borderline, nil tuberculoid) had a higher frequency than c-ANCA (5% lepromatous only).