Expression of 5-lipoxygenase and 5-lipoxygenase activation protein in glomerulonephritis.

The gene transcription of 5-lipoxygenase (5-LO) and 5-lipoxygenase-activating protein (FLAP) in renal tissue of patients with IgA nephropathy and mesangial proliferative glomerulonephritis were analyzed by amplification of reverse transcribed mRNA with polymerase chain reaction (PCR). The level of expression was determined by analysis of the PCR products of 5-LO, FLAP, and beta-actin. Forty percent of the patients expressed both 5-LO and FLAP. Relative to beta-actin, FLAP expression (0.42 +/- 0.21) was higher than 5-LO (0.14 +/- 0.10). Comparison of clinical data showed that patients who expressed 5-LO and FLAP had a lower glomerular filtration rate and an increased level of blood urea nitrogen, serum creatinine, and proteinuria. The results suggest arachidonic acid metabolism by inflammatory cells in renal tissue may play an important role in human glomerulonephritis.