摘要

Background While the incidence of paroxysmal nocturnal hemoglobinuria (PNH) is relatively high in Northern China, the exact mechanism of the disease remains unknown. Immunoregulatory cytokine polymorphisms can directly regulate the expression levels of cytokines, which play a crucial role in many diseases. The purpose of this study was to study cytokine gene single nucleotide polymorphisms (SNPs) and the correlated cytokine expression levels in relationship to the PNH pathogenesis. @@@ Methods Peripheral blood samples were collected from 30 PNH patients and 40 healthy donors; all of the samples were collected from the Han people of Northern China. Eight SNP loci in five cytokine genes, including tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), transforming growth factor-beta (TGF-beta), interleukin-6 (IL-6), and IL-10, and aplastic anemia (AA) were assessed. TNF-alpha, TGF-beta, IFN-gamma, IL-6, and IL-10 were analyzed by sequence-specific primer polymerase chain reaction (PCR-SSP). The plasma protein levels of TNF-alpha, TGF-beta, and IFN-gamma were assessed by an ELISA. @@@ Results The PNH patients had a lower frequency of the TC/GG genotype of the TGF-beta gene (P<0.01) and a higher frequency of the C allele in the TGF-beta gene (+10) compared to the controls (P<0.05). The predominant genotype of the +874 locus of the IFN-gamma gene was TA in the PNH patients, while that in the predominant genotype was AA in the control group and was statistically significant (P<0.001). The frequency of the T allele in the IFN-gamma gene was dramatically higher in the PNH patients than in the controls (P<0.05). The PNH patients had a reduced frequency of the GC and CC genotypes, as well as the C allele at locus 174 of the IL-6 gene compared to the controls (P<0.01). In addition, the plasma concentrations of TNF-alpha, TGF-beta, and IFN-gamma were significantly higher in the PNH group compared to the control group (P<0.01). @@@ Conclusions Expression levels of the TNF-alpha, TGF-beta, and IFN-gamma cytokines play an important role in PNH. The GC and CC genotypes, as well as the C allele of the IL-6 gene may protect the Han people of Northern China against PNH. Additionally, the TC/GG genotype of the TGF-beta gene may be the protective allele. In contrast, the TA genotype and the T allele for the IFN-gamma gene, as well as the C allele of TGF-beta may be susceptible to PNH. However, SNPs in the TNF-alpha and IL-10 genes did not correlate with PNH development. Alternatively, the increased plasma concentrations of TNF-alpha, TGF-beta, and IFN-gamma in PNH patients may also be related to PNH development. Chin Med J 2012;125(9):1576-1580

全文