Primary glomerulonephritis and hydrocarbon exposure: a case - control study

ABSTRACT

This is a case-control study which examines the hypothesis of whether cumulative exposure of hydrocarbons have a contributory role, or not, in the development of Idiopathic glomerulonephritis [IGN]. The study groups included Gr.I composed adult IGN cases, Gr.II composed of patients with kidney disease of known atiology [international control group], and Gr. III composed of subjects with normal kidney function [external control group]. The catchment areas of the 3 groups are the same. Cumulative exposure to hydrocarbons was estimated using a life time hydrocarbon exposure score [LHES]. Odds ratio of having IGN and being exposed to hydrocarbons was calculated as 3.02 compared to the internal control group [p<0.05], and 8.44 compared to the external control group [p<0.0001]. The 3 groups differed in the mean values of LHES. After examination of confounders, only family history of renal disease, cigarette smoking, and holding of blue-collar jobs were found to be different across the study groups. As for type of biopsy of IGN cases, membranoproliferative glomerulonephritis was the most prevalent type in hydrocarbon exposed IGN cases, followed by focal segmental glomerulonephritis. However, all known pathologies of IGN were represented. Finally, two measures of cumulative hydrocarbon exposure were compared the LHES and the hydrocarbon exposure code [HEC] with the conclusion that HEC which is simpler can be used for easier estimation of exposure, bearing in mind its sensitivity and specificity as a screening tool