Endothelial nitric oxide synthase polymorphisms in biopsy-proven erythema nodosum from a defined population

Objective. To assess the potential influence of endothelial nitric oxide synthase (eNOS) polymorphisms in the susceptibility to and clinical expression of a series of patients diagnosed with biopsy-proven erythema nodosum (EN). Methods. Ninety-seven unselected patients from Northwest Spain with biopsy-proven EN were studied. Patients and ethnically matched controls were genotyped by PCR based techniques for a variable number tandem repeat polymorphism in intron 4, a T/C polymorphism at position - 786 in the promoter region and a polymorphism in exon 7 (298Glu/Asp or 5557G/T) of the eNOS gene. Results. No differences in allele or genotype ftequencies for any of the individual eNOS polymorphisms were observed between biopsy-proven patients with EN and controls. It was also the case when patients with EN secondary to sarcoidosis were compared with the remaining patients or controls. In the group of patients with EN, no linkage disequilibrium between these polymorphisms was found. Also, no significant differences in haplotype frequencies were observed between patients and controls. Conclusions. Our present results do not support a role for eNOS polymorphisms in the susceptibility to and clinical expression of EN. © Copyright Clinical and Experimental Rheumatology 2007.