Lack of association between single-nucleotide polymorphisms of pro- and anti-inflammatory cytokines and HTLV-1-associated myelopathy / tropical spastic paraparesis development in patients from Rio de Janeiro, Brazil

Background

HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a progressive neurological and inflammatory disease, associated with HTLV-1 infection. HAM/TSP neurological disease is a consequence of an inflammatory reaction, and adaptive immune responses, through the secretion of anti-inflammatory and pro-inflammatory cytokines, play an important role in the outcome of infection and disease progression. Studies addressing the association between cytokines functional single nucleotide polymorphisms and HAM/TSP development are scarce.

Methods

The genetic polymorphisms of cytokine genes were evaluated in HAM/TSP patients (n = 68) and in asymptomatic HTLV-1 positive carriers (n = 83) from Rio de Janeiro, Brazil, in a case-control study. HTLV-1 infected patients were genotyped for SNPs in five cytokine genes: TNFA-308G/A, IL6-174G/C, IFNG + 874 T/A, TGFB at the codons + 10 T/C and + 25G/C, IL10-592C/A and -819C/T, and -1082A/G and proviral load (PVL) was quantified. Associations between genotypes, haplotypes, clinical outcome and pro viral load were evaluated.

Results

Lack of association between the cytokine polymorphisms and disease outcome was observed. The genotypes TNFA-308GG, IL6-174GG/GC, IL10-592AA and -819CC and TGFb1 high producers phenotypes were correlated with higher PVL in HAM/TSP patients versus asymptomatic carriers.

Conclusions

We did not observe association between cytokine polymorphisms and risk for HAM/TSP development in Brazilian HTLV-1 infected individuals, regardless of differences in PVL between HAM/TSP versus asymptomatic carriers in specific cytokine polymorphisms.

HLA in a cohort of Brazilian patients with sarcoidosis

Sarcoidosis is a multisystem granulomatous disorder of unknown etiology. Hereditary etiology has been proposed as a cause of the sarcoidosis, and some Human Leucocyte Antigen (HLA) alleles have been related to the diagnosis or severity of the disease. Löfgren's syndrome has been linked to patients with the DRB1*03 allele, and non-resolving disease has been associated with the DRB1*07, DRB1*14 and DRB1*15 alleles. However, the results observed in Caucasian patients are not reproducible in other populations, such as in Japanese individuals. The aim of this study is to examine the HLA alleles in Brazilian patients with sarcoidosis confirmed by biopsy. Sixty-three patients were included in the study, and the HLA alleles were compared with 126 control individuals. HLA-A, -B, -C, -DRB1 and -DQB1 genes were typed using a Luminex Multi-analyte profiling system (One Lambda, Inc. Canoga Park, CA). Among sarcoidosis patients, the HLA A*23, A*80, B*08, B*41, DQB1*05 and DRB1*14 antigens tended to be more common than in the controls, whereas the B*44, B*45, B*51, B*58, DRB1*15 and DRB1*16 alleles were more frequently found in control subjects than in the sarcoidosis patients. However, after Bonferroni correction, only the HLA-DRB1*14 allele was found to be significantly different between sarcoidosis patients and controls (pC=0.0047, OR=11.69, CI=2.47-55.22). This allele was more frequent in mestizos and black patients. The presence of an HLA-DRB1*14 allele might determine the risk of sarcoidosis in Brazilian individuals, especially in mestizos and black patients.