Autoimmune manifestations of visceral leishmaniasis in Chinese patients

Visceral leishmaniasis (VL) is a rare, parasitic infection with distinctive features that may mimic autoimmune diseases. In this study, we report on the laboratory autoimmune manifestations of VL in Chinese patients.

Twenty-seven patients who were hospitalized with VL were included in this retrospective study. Routine blood and biochemical tests were conducted, and a variety of autoimmune antibodies and complement fractions were detected. Continuous variables are expressed as means ± standard deviations, and categorical data are expressed as a number (percentage). Missing data were not included for statistical analysis. Data were analyzed with SPSS v. 13.0 statistical software.

All patients had cytopenia (82% with pancytopenia) and hepatosplenomegaly, and 25 (93%) patients also suffered from fever. The prevalence of autoantibodies (number of patients with antibody detected/total number of patients tested for the antibody) for each antibody tested was as follows: antinuclear antibodies (ANA; 18/22, 82%), anti-neutrophil cytoplasmic antibodies (ANCA; 4/5, 80%), anti-mitochondrial M2 antibodies (AMA-M2; 1/6, 17%), anti-liver cytosol specific type 1 antibodies (anti-LC1; 1/6, 17%), anti-liver/kidney microsomal type 1 antibodies (anti-LKM1; 1/6, 17%), anti-centromere protein-B antibodies (anti-CENP-B; 4/21, 19%), anti-Sjögren's syndrome type A antibodies (anti-SSA; 2/21, 10%), anti-Sjögren's syndrome type B antibodies (anti-SSB; 1/21, 5%), anti-Jo-1 antibodies (1/21, 5%), anti-double-stranded DNA antibodies (anti-dsDNA; 1/25, 4%), direct antiglobulin test (direct Coombs; 6/6, 100%), and rheumatoid factor (RF; 3/11, 27%). Increased serum C-reactive protein (CRP) was found in 14 (100%) patients. Of the 19 patients tested for serum IgG, 17 patients (89%) were found with increased IgG levels, while complement 3 protein (C3) and complement 4 protein (C4) levels were not decreased in any of the 19 patients. Of note, in one patient followed up 1 month after therapy, only ANA was still present, and all the other laboratory autoimmune manifestations had disappeared.

VL infection associated with laboratory autoimmune manifestations is common. This may lead to patients with VL being misdiagnosed as having an autoimmune disorder. An obligatory differential diagnosis that considers VL should be undertaken for patients diagnosed with systemic lupus erythematosus (SLE), especially in endemic areas, is necessary.