Usefulness of the renal resistive index to predict an increase in urinary albumin excretion in patients with essential hypertension.

Microalbuminuria is a risk factor for cardiovascular events and death in hypertensive patients. Patients who are expected to increase albuminuria need strict blood pressure control. In the present study, we assessed the association between the renal resistive index (RI) and future increases in albuminuria in patients with essential hypertension. Sixty-six patients with essential hypertension were included in the study. Univariate and multivariate logistic regression analyses were used to identify the factors, including renal RI, that were significant independent determinants of increased in urinary albumin excretion (UAE), defined as an increase of >50% in the urinary albumin-to-creatinine ratio over 2 years. Receiver operator characteristics curve analysis was used to select the optimal cut-off point that predicted an increase in UAE. RI was the only significant variable that predicted the increase in UAE, with the optimal cut-off value of renal RI that predicted this increase being 0.71 (sensitivity 52.4% and specificity 84.4%). Renal RI is associated with the future increase in albuminuria in patients with essential hypertension.

Genetic regulation of anti-erythrocyte autoantibodies and splenomegaly in autoimmune hemolytic anemia-prone new zealand black mice.

New Zealand Black (NZB) mice spontaneously produce anti-erythrocyte autoantibodies (AEA) in association with splenomegaly, thus serving as a model for autoimmune hemolytic anemia. Although these autoimmune traits are inherited as a dominant fashion, expression in F(1) hybrids of NZB and most non-New Zealand strains is suppressed due to the contribution of wild-type modifying genes present in the latter strains. Using chromosomal microsatellite markers in the (C57BL/6 x NZB)F(1) x NZB backcross progeny, we mapped C57BL/6 modifying loci for AEA production and splenomegaly. Generation of AEA was found to be down-regulated by a combined effect of two major independently segregating dominant alleles-one linked to D7MIT30 on chromosome 7 and the other linked to D10MIT42 on chromosome 10. Splenomegaly was modified mainly by a single C57BL/6 allele linked to D4MIT58 on chromosome 4. Thus, the autoimmune hemolytic anemia in the NZB strain is under multigenic control and a combined action of not only susceptibility but also modifying alleles with suppressive activities affects the outcome of disease features in the progeny. There are potentially important candidate genes which may be linked to the regulation of AEA and splenomegaly.