Association of GSTT1, GSTM1, and NQO1 Gene Polymorphisms With Susceptibility, Clinical Severity, and Treatment Response in Aplastic Anemia

Introduction Aplastic anemia (AA) is an uncommon hematologic condition in which markedly reduced bone marrow cellularity results in decreased production of red blood cells, white blood cells, and platelets. Its etiology is complex and multifactorial, with evidence suggesting an interplay of immune-mediated destruction of hematopoietic progenitor cells, environmental exposures, and genetic predisposition. In this study, we focused on genetic polymorphisms in detoxification enzymes, which may influence individual susceptibility to AA by altering the ability to manage oxidative stress and metabolize xenobiotics. Methods We enrolled patients with AA (n = 200) and age-matched healthy controls (n = 200). Genotyping of GSTM1 and GSTT1 (null/present polymorphisms) was performed using multiplex PCR, while the NQO1 C609T polymorphism (rs1800566) was determined by PCR-restriction fragment length polymorphism. Genotype distributions were compared using chi-square tests, and ORs with 95% CIs were calculated. Results The GSTT1 null genotype and NQO1 CT genotype were significantly associated with increased susceptibility to AA (p < 0.05). The GSTT1 null polymorphism was also correlated with both severe and non-severe disease according to the Camitta criteria. GSTM1 showed a trend toward association but was not statistically significant with respect to treatment response (p > 0.05). Conclusions The GSTT1 null and NQO1 CT genotypes are associated with increased susceptibility to AA. In addition, the GSTT1 null genotype predicts poor response to immunosuppressive therapy, indicating its potential as a prognostic biomarker.