Association of renal function with haematological indices in patients with sickle cell anaemia in Mulago Hospital sickle cell clinic.
Background: Patients with sickle cell anemia may present with several types of renal abnormalities, however the type and prevalence of these abnormalities and the association with hematological indices have not been investigated in Ugandan patients attending Mulago Hospital. Main objective: To determine the association of hematological indices with renal function in patients with sickle cell anemia attending sickle cell clinic at Mulago Hospital. Methods: A cross sectional study was conducted on 236 patients with sickle cell anemia. Random urine samples were collected and dipsticks were used to detect hyposthenuria and proteinuria. Blood samples were taken for hematological indices and plasma creatinine. They were analyzed automatically by Coulter counter and Kone lab TM machine respectively. Plasma creatinine was used to estimate glomerular filtration rate using Schwartz formula for individuals less than 20 years, and Cockroft and Gaut formula for individuals above 20 years. Results: Of the 236 patients studied, 20(8.5%) had proteinuria, 96(40.7%) had hyposthenuria, 8(3.5%) had subnormal glomerular filtration rate, 171(74.0%) had glomerular hyperfiltration. Proteinuria was noted to increase with age. Impairment of urine concentration was observed to increase with age; glomerular hyperfiltration was noted in individuals below 20 years. The study subjects had low hemoglobin and hematocrit values, normal mean corpuscular volume and mean corpuscular hemoglobin concentration, and elevated white cell counts. In individuals between 10 and 19 years hemoglobin concentration correlated negatively with glomerular filtration rate (r = - 0.219, P= 0.033) and hernatocrit also correlated negatively with glomerular filtration rate (r = -0.283, P =0.006). High mean corpuscular volume was positively correlated with glomerular filtration rare in individuals between the age of 0 and 9 years(r = 0.303, P = 0.004) and in individuals between the age of 10 and 19 years (r = 0.207, P = 0.044). Higher mean corpuscular hemoglobin concentration was associated with proteinuria in individual between 20 and 29 years of age (PC0.05). Conclusion: Patients with sickle cell anemia attending Mulago Hospital have sickle cell nephropathy presenting with hyposthenuria, proteinuria and impaired glomerular filtration which start early in life and increase with age. The association between abnormal hemoglobin concentration, hematocrit, mean corpuscular volume with glomerular filtration rate and proteinuria is age related. Recommendation: Further elaborate studies of the association between hematological indices and renal function in larger series than the present one are recommended to determine the association and the significance of the findings in the present study.