Association of calcium urolithiasis with urokinase P141L and 3′-UTR C>T polymorphisms in a Japanese population

This was a case–control study to analyze the associations between calcium urolithiasis and the urokinase polymorphisms, P141L (rs2227564) and 3′-UTR C>T (rs4065), in a Japanese population. Cases consisted of 232 patients with urinary calcium stones (174 men and 58 women) who presented to a general hospital between April 2009 and June 2011. Among these cases, 115 (49.6 %) patients had calcium oxalate stones alone, and 113 (48.7 %) patients had calcium oxalate stones mixed with calcium phosphate stones. Controls consisted of 454 subjects who had a routine health check-up in the same prefecture. The two polymorphisms were genotyped via polymerase chain reaction with confronting two-pair primers. In the control group, the genotype frequencies of P141L were 0.573 for PP, 0.375 for PL, and 0.052 for LL, and those of 3′-UTR C>T were 0.835 for CC, 0.165 for CT, and TT was not identified. Neither of the polymorphisms was significantly associated with urolithiasis. The age- and sex-adjusted odds ratios of urolithiasis were 0.96 [95 % confidence interval (CI), 0.66–1.41] for PL and 1.22 (0.58–2.57) for LL as compared with PP genotype of P141L, and 1.01 (0.62–1.64) for CT as compared with CC genotype of 3′-UTR C>T. When compared with the PP genotype of P141L, the frequency of PL was significantly lower in female cases with a family history of urolithiasis than in females without such family history (p = 0.028). P141L and 3′-UTR polymorphisms of the urokinase gene are not associated with urolithiasis in a Japanese population.