Background. Albuminuria is an early manifestation of sickle cell nephropathy. Prior small case series suggests benefit of hydroxyurea in reducing albuminuria, with a similar trend noted in pediatric studies. We aimed to comprehensively evaluate hydroxyurea use and prevalence of albuminuria in adult sickle cell patients. Methods. We performed a cross-sectional study of 149 adult patients followed between 2000 and 2011 in a comprehensive sickle cell clinic. All patients were assessed for albuminuria either by direct measurement or by urinary chemical strip (dipstick) testing. Urinary albumin-to-creatinine ratios (UACRs) were available for 112 patients. Hydroxyurea exposure was defined as ≥3 months of therapy before the assessment of albuminuria. Albuminuria was defined as either UACR ≥30 mg/g or ≥1+ proteinuria on two separate dipsticks. We constructed a multivariate logistic regression model to assess the association between hydroxyurea and albuminuria. Results. The prevalence of albuminuria was lower among patients on hydroxyurea (34.7 versus 55.4%; P = 0.01) as was median albumin excretion (17.9 versus 40.5 mg/g; P = 0.04). In multivariate analysis, hydroxyurea was associated with a lower likelihood of albuminuria (odds ratio 0.28, 95% CI: 0.11-0.75, P = 0.01), adjusting for age, angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use, tricuspid regurgitant jet velocity, hypertension and acute chest syndrome. Conclusions. In our population of sickle cell patients, those using hydroxyurea were less than one-third as likely to exhibit albuminuria. Hydroxyurea use may prevent development of overt nephropathy or the progression of sickle cell disease nephropathy to end-stage renal disease, and its use for this indication merits further investigation.
Bibliographical noteFunding Information:
The authors thank Susan K. Jones for her help in data management. L.-P.L. received salary support from Hôpital Maisonneuve-Rosemont Scholarship of Improvement Program, Société Qué-bécoise de Néphrologie and Department of Medicine, Univer-sité de Montréal. V.K.D. received support from Duke–UNC Clinical Hematology Research Career Development program (NIH/NHLBI K12HL087097-05, PI: Telen) and NIH/NHLBI 1R01HL111659-01, PI: Ataga.
- chronic kidney disease
- sickle cell