OBJECTIVETo investigate the relation between the susceptibility to silicosis and the polymorphism of HLA-DRB1 *, DQB1 * genes in Chinese Hans.

METHODSHLA-DRB1 * and DQB1 * gene polymorphism were tested in 48 silicosis patients and 100 normal controls by using polymerase chain reaction of sequence-specific primers (PCR-SSP).

RESULTSThe allele frequencies of DRB1 * 1401 and DQB1 * 05 in silicosis patients were significantly higher than those in normal controls (chi 2 = 5.61, P = 0.0066, RR = 17.40; chi 2 = 10.70, P = 0.0011, RR = 3.81, respectively), while the allele frequency of DRB1 * 09 was significantly lower in silicosis patients than that in controls (chi 2 = 5.70, P = 0.0187, RR = 0.21). There was a significant difference between the patient group and control group.

CONCLUSIONHLA-DRB1 * 1401 and DQB1 * 05 may be the susceptible genes and HLA-DRB1 * 09 the protection gene of silicosis, both susceptibility and protection may be related to HLA-DR gene locus. The joint action of allele genes may affect the pathogenesis of silicosis.

Gene Frequency ; Genetic Predisposition to Disease ; HLA-DQ Antigens ; genetics ; HLA-DQ beta-Chains ; HLA-DR Antigens ; genetics ; HLA-DRB1 Chains ; Humans ; Polymerase Chain Reaction ; Polymorphism, Genetic ; Silicosis ; genetics

Objective:To observe the effect of selenium supplementation on 10-year survival rate of chronic Keshan disease (KD).Methods:The 10-year follow-up data of 302 patients with chronic KD at the KD surveillance sites in Shaanxi Province were collected from the Shaanxi Institute for Endemic Disease Control and Research and Xi'an Jiaotong University, 170 (56.3%) cases were given selenium supplementation (oral administration of sodium selenite tablet, once a week, 1 mg/time) until the end point of follow-up as selenium supplementation group, and the rest (132 cases) were non-selenium supplementation group. Cox proportional hazards models were used to identify the independent predictors for 10-year survival rate of chronic KD. Kaplan-Meier method was used to analyze the 10-year survival rate of patients with chronic KD during the follow-up period and the Log-rank test was used to compare the 10-year survival rate between groups.Results:The follow-up deadline was October 2019. During the follow-up period, a total of 199 patients (199/302, 65.9%) of chronic KD died, including 101 patients (101/170, 59.4%) in the selenium supplementation group and 98 patients (98/132, 74.2%) in the non-selenium supplementation group. In COX proportional hazards model, after adjustment for other baseline characteristics [age, sex, body mass index (BMI), family history of KD, smoking, blood pressure, heart rate, ECG abnormalities, initial cardiothoracic ratio, left ventricular ejection fraction (LVEF), and blood selenium content], selenium supplementation and combined use of angiotensin-converting enzyme inhibitor + β receptor blocker (ACEI + BBs) were protective factors for 10-year survival in patients with chronic KD (selenium supplementation: HR = 0.39, 95% CI: 0.28 - 0.53; ACEI + BBs: HR = 0.57, 95% CI: 0.39 - 0.84). The 10-year survival rate of chronic KD patients after selenium supplementation was significantly higher than that of non-selenium supplementation group (Log-rank test, P < 0.05). Conclusion:Selenium supplementation and combined use of ACEI + BBs in chronic KD patients, are associated with better survival during the 10-year follow-up.