[A paired case-control study for assessing the relationship between the incidence of malignant lymphomas and the...

To evaluate the relationships between the viruses infections and the incidence of malignant lymphomas (ML) in Sichuan province.

A hospital-based paired case-control study was designed with two controls per case. The case group comprised 97 cases diagnosed as ML by pathological examination; the control group A consisted of 194 subjects randomly selected from those with non-malignancies by matching on both gender and age in the corresponding period. Additionally, a control group B for Epstein-Barr virus(EBV), including 80 subjects, were chosen from other non-malignant diseases at the same time. Enzyme-linked immunosorbent assay(ELISA) was employed to test the serum antibodies and antigens of hepatitis C virus (HCV), human immunodeficiency virus (HIV), cytomegalovirus (CMV), and hepatitis B virus (HBV). The EBV was confirmed by the EBER in situ-hybridization (EBER-ISH) of pathological tissue.

The positive rate of EBV in ML group was 70.1%(68/97) and that of control group was 7.5%(6/80). The difference between these two groups showed a statistical significance by conditional logistic regression analysis (OR = 6.58, 95% CI: 16.164-82.846, P = 0.0001). The differences in HCV, CMV and HBV infections between case group and control group demonstrated no statistical significance with P-values of 0.260, 0.258 and 0.399 respectively. We found no positive results of HIV antibody in case group and control group.

The incidence of ML in Sichuan displayed a significant association with EBV infection. However, there were no relationships between the incidence of ML and the HCV, HBV, HIV, CMV infections in the area.