SPECTRAL PULSED DOPPLER SONOGRAPHY OF RENAL VASCULAR-RESISTANCE IN SICKLE-CELL DISEASE - CLINICAL IMPLICATIONS

The major complications in sickle cell disease (SCD) are microcirculat ion lesions and impairment of renal function. The aim of this study wa s the evaluation of renal vascular resistance by means of spectral pul sed Doppler sonography and its relationships with haematological and c linical features in patients with SCD. 40 patients with SCD (mean age 22.4+/-7.0) and 14 age and sex matched healthy subjects (mean age 25.7 +/-9.5) were included into the study. Spectral Doppler sonography of m ain renal, segmental and interlobar arteries were performed on both ki dneys in all patients and controls. Peak systolic, end diastolic and m ean velocities through the entire cardiac cycle were obtained, with ca lculation of the resistive (RI) and pulsatility (PI) indices. All the patients were investigated in stable state conditions and had not been transfused within a month before investigation. Patients were followe d for up to 6 months. Patients with SCD had higher values of RIs and P Is than control subjects (p<0.0001, p<0.0001, respectively). Patients with high value of RIs (RI>0.70) had more pronounced disturbances of b lood parameters (all p<0.05), than patients with normal RIs (RI<0.70). Significant positive correlation existed between RIs and ISC number, MCHC level (r=0.52, p<0.001 and r=0.42, p<0.01), while RBC count and H b level correlated inversely with RIs (r=-0.39, p<0.01 and r=-0.42, p< 0.01). During follow-up, nine patients (33.3%) with high RIs and only one patient (5.5%) with normal RI developed painful crises. In conclus ion, renal vascular resistance, assessed by Doppler sonography was rai sed in SCD patients as compared with age matched apparently healthy pe rsons. These changes were more pronounced in those with more severe ma nifestations of disease and correlated with haematological and clinica l features of sickle cell disease.