Influence of Polymorphisms of Pro-Inflammatory (IL-12, TNFa and LTa) and Anti-Inflammatory Factors (IL-10 and CTLA4) in Autoimmune Hemolytic Anemia.

The Autoimmune Hemolytic Anemia (AIHA) is caused by the destruction of antibody-coated red blood cells, but mechanisms that initiate the production of autoantibodies remains unclear. It had been suggest that decreased production of Th1-type cytokines and production of autoantibodies in AIHA can be secondary to the imbalance between anti- and pro-inflammatory factors. Moreover, the presence of single nucleotide polymorphisms (SNPs) showed association with different production of immunoregulatory factors which may modulate the disease expression in AIHA.

OBJECTIVES: To determine the importance of SNPs of pro- and anti-inflammatory factors in the development of AIHA.

PATIENTS: We studied 17 patients with AIHA who has been followed in the Hematology and Blood Transfusion Unit at the Federal University of Sao Paulo (UNIFESP/EPM), Brazil. The control group was composed by 40 healthy volunteer blood donors.

METHODS: After DNA extraction from peripheral blood samples, the frequency of the SNPs was determinate by PCR-RFLP in patients and healthy individuals. The following SNPs were analyzed: Interleukin 12: IL-12 1188 (A/C), Tumor Necrosis Factor alpha: TNFa-308 (G/A), and Lymphotoxin alpha: Lta +252 (A/G); Interleukin 10: IL-10-592 (C/A), and Cytotoxic T-lymphocyte associated protein 4: CTLA4 exon 1 49 (A/G).

RESULTS: The patient group was composed predominantly by female individuals (14 or 82%) and the median of age was 56 years old (18 to 76 years). The frequency observed for each allele studied in the patient group was: allele A of IL-12 = 0.82; allele G of FNTa = 0.85; allele A of Lta = 0.68; allele C of IL-10 = 0.82; allele G of CTLA4 = 0.59. No differences in allele frequency were found between patient and control groups.

CONCLUSIONS: Our results suggest that these polymorphisms appear not to contribute for the development of the AIHA.