Lepromatous leprosy simulating rheumatoid arthritis - Report of a neglected disease

Abstract Brazil has the second largest number of leprosy cases in the world; nevertheless, late diagnosis is common. We report the case of a male patient with pain and numbness in both hands and feet for six years with positive rheumatoid factor and anticardiolipin under rheumatoid arthritis treatment for five years. Examination revealed diffuse cutaneous infiltration and leonine facies, characteristic features of lepromatous leprosy. Autoantibodies such as rheumatoid factor and anticardiolipin are markers of rheumatic autoimmune diseases, but their presence is also described in leprosy. We report the present case in order to alert health professionals to remember leprosy, even in areas where the disease is considered eliminated as a public health problem, avoiding misinterpretations of serologic findings and misdiagnosis.

Evaluation of rheumatoid factor and anti-citrullinated peptide antibodies in relation to rheumatological manifestations in patients with leprosy from Southern Brazil.

BACKGROUND: Leprosy patients may present several osteoarticular complaints, which require further evaluation of inflammatory diseases, such as rheumatoid arthritis (RA). Therefore, an adequate clinical assessment in addition to testing for rheumatoid factors (RF) and anticyclic citrullinated peptide antibodies (anti-CCP), can be useful in order to establish the correct diagnosis. METHOD: In this study, the relation of RF and anti-CCP with rheumatological manifestations was evaluated in 97 leprosy patients from Southern Brazil. The results were compared to RA patients and healthy controls from the same geographical area and ethnic background. RESULTS: Neuropathy was observed in 71.1% and arthritis in 35.1% of the leprosy patients. A high frequency of RF positivity was observed among the leprosy patients (41.2%, 40/97), with RF immunoglobulin A (IgA) significantly associated with arthritis (OR = 7.9, 95% CI = 1.5-40.6 P = 0.008). Anti-CCP was observed in 9.3% (9/97) of the patients, with anti-CCP2 being the most frequent subtype. Only 4.1% (4/97) of the patients were RF and anti-CCP concomitantly positive. RF IgM showed a significant association with leprosy when compared to healthy controls (P < 0.0001) whereas for anti-CCP2 no significant results were observed (P = 0.0585). However, both biomarkers showed a strong association with RA when compared to leprosy in patients from the same geographical area and ethnic background (anti-CCP2 OR = 38.6; 95% CI = 16.49-90.26; P < 0.0001 and RF IgM OR = 4.51; 95% CI = 2.62-7.77; P < 0.0001). CONCLUSION: Due to the similarity of some rheumatological manifestations in leprosy with other inflammatory diseases, such as RA, clinical and laboratorial evaluation of affected patients must be carefully assessed in order to achieve proper diagnosis and treatment.

Anti-cyclic citrullinated peptide antibodies and rheumatoid factor in leprosy patients with articular involvement

The objective of the present research was to evaluate the usefulness of anti-cyclic citrullinated peptide (anti-CCP) antibodies and the IgM rheumatoid factor (IgM RF) test for the differential diagnosis of leprosy with articular involvement and rheumatoid arthritis (RA). Anti-CCP antibodies and IgM RF were measured in the sera of 158 leprosy patients (76 with and 82 without articular involvement), 69 RA patients and 89 healthy controls. Leprosy diagnosis was performed according to Ridley and Jopling classification criteria and clinical and demographic characteristics of leprosy patients were collected by a standard questionnaire. Leprosy patients with any concomitant rheumatic disease were excluded. Serum samples were obtained from all participants and frozen at _20°C. Measurement of anti-CCP antibodies and IgM RF were performed by ELISA, using a commercial second-generation kit, and the latex agglutination test, respectively. Anti-CCP antibodies and IgM RF were detected in low frequencies (2.6 and 1.3 percent, respectively) in leprosy patients and were not associated with articular involvement. Among healthy individuals both anti-CCP antibodies and IgM RF were each detected in 3.4 percent of the subjects. In contrast, in the RA group, anti-CCP antibodies were present in 81.2 percent and IgM RF in 62.3 percent. In the present study, both anti-CCP antibodies and IgM RF showed good positive predictive value for RA, helping to discriminate between RA and leprosy patients with articular involvement. However, anti-CCP antibodies were more specific for RA diagnosis in the population under study.