BG 0 patients (pts) have lower risk for cardiovascular-thromboembolic disease than A-AB-B pts, particularly males. This might be related to blood hypocoagulability (lower Factor VIII). We report BG frequencies in our Caucasian renal transplant population divided in two groups, ES reflux nephropathy (RN) and ESRD of other etiologies excluding diabetes mellitus.BG 0 male pts are protected, especially for ESRN. To determine whether this sex dependency could be related to different VIII: RWF levels or PS, VIII:RWF levels (n=82) and 51Cr-labelled PS (n=74) were analyzed in controls according to sex and BG.VIII: RWF is sex independent and lower in BG 0. PS is BG independent and shortened in males. A hypercoagulable State reflected by high VIII: RWF and short PS might explain the increased risk of non-BG 0 males to develop ESRD. Non-BG 0 male pts with RN may be more susceptible to develop progressive RD.