Workers with chronic benzene poisoning (CBP) sometimes have a white blood cell count (WBC) below 4 x 10(9)/L even after cessation of workplace exposure to benzene for years. In order to explore this phenomenon, 120 workers with CBP were divided into two groups depending on the WBC, the mean diagnostic age of CBP, benzene exposure duration, and body mass index (BMI). The proportion of genotypes of cytochrome P450 2E1 (CYP2E1), glutathione-S-transferase mu-1 (GSTM1), glutathione-S-transferase theta-1 (GSTT1), myeloperoxidase (MPO), and NAD(P)H, quinone oxidoreductase 1 (NQO1) were compared between workers with WBC <4 x 10(9)/L and those with WBC > or =4 x 10(9)/L. With methods of logistic regression, a risk model was set up to predict the prognosis of CBP workers. The results indicated that the BMI of workers with WBC <4 x 10(9)/L was lower than that of workers with WBC of > or =4 x 10(9)/L (21.40 +/- 2.76 versus 23.09 +/- 3.36, P = 0.01), and the logistic regression model suggested there was a 4.5-fold increased risk among workers carrying GSTT1 null genotype (95% CI= 1.13- 17.54) compared with workers with GSTT1 non-null genotype. Our findings suggest that benzene exposure duration, BMI, and GSTT1 genotype may impact prognosis of the CBP workers.

ABSTRACT. The prevalence of microdeletions of azoospermia factor (AZF) among azoospermic Klinefelter's syndrome (KFS) patients shows conflicting data. We aimed to detect this frequency in a Northeast Chinese population, and to investigate the possible association between AZF microdeletions and KFS by comparison with previous conflicting reports. Eighty men affected with KFS and a random healthy control group comprising 60 fertile men and women were recruited. AZF microdeletions were detected by multiplex polymerase chain reaction using 9 specific sequence-tagged sites. Karyotype analyses were performed on peripheral blood lymphocytes using standard G-banding. Finally, azoospermia was confirmed in 77 men affected with KFS and no AZF microdeletions were found. Karyotype analysis revealed 1 patient with karyotype 47,XXY,inv (9) (p11, q13), and 2 with mosaic karyotypes (46,XX/47,XXY and 46,XY/47,XXY). All other patients had karyotype 47,XXY. Review of the literature showed that these results 4973©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 12 (4): 4972-4980 (2013) AZF microdeletions in azoospermic KFS patients were similar to those of other regions of Northeast Asia, but differed from those obtained from Caucasian populations. Our results supported the proposal that AZF microdeletions and KFS result from separate genetic defects. The prevalence of AZF in azoospermic KFS patients varies among populations, and it might result from genetic drift or selective pressure. These results suggest that routine screening for classical AZF microdeletions among infertile azoospermic men with a 47,XXY karyotype might not be necessary in Northeast Chinese individuals. However, it remains imperative for patients considering assisted reproductive treatments, particularly for those with mosaic karyotypes.