Persistent Albuminuria and Chronic Kidney Disease in Adults with Sickle Cell Disease: Results from a Multicenter Natural History Study

• Published in: Blood 2023-11, Vol.142 (Supplement 1), p.1124-1124
• Main Authors: Derebail, Vimal K., Zhou, Laura Y., Tang, Yihan, Elsherif, Laila, Patillo, Kammie L., Wichlan, David, Landes, Kristina, McCune, Paula, Loehr, Laura R., Desai, Payal, Cronin, Robert, Cai, Jianwen, Ataga, Kenneth I.
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2023-179675

Background: Patients with sickle cell disease (SCD) are at high risk for developing kidney disease. Albuminuria, an early marker of kidney injury, may be initially transient in patients with SCD. Existing guidelines propose confirming albuminuria at multiple timepoints before intervention. A recent study suggests a urinary albumin-creatinine ratio (UACR) ≥ 100 mg/g correlates highly with persistent albuminuria and subsequent decline in estimated glomerular filtration rate (eGFR). We examined a cohort of patients with SCD to assess those characteristics associated with persistent albuminuria and chronic kidney disease (CKD). Methods During routine clinical visits, we enrolled patients with HbSS or HbSß 0 thalassemia between 18 and 65 years at 4 centers into a prospective study to assess the natural history of kidney disease in SCD. We excluded patients if they had bone marrow transplantation, cancer, connective tissue disease, diabetic nephropathy, other glomerular diseases, hepatitis (B or C), HIV, or were on dialysis. Blood and urine were collected for routine clinical laboratory assessments. Serum cystatin C was measured by commercially available ELISA, and eGFR was calculated using the CKD-EPI-2012 cystatin C equation. We defined CKD as an eGFR < 60 mL/min/1.73m 2 or presence of albuminuria. Glomerular hyperfiltration was defined as an eGFR>130 in females and >140mL/min/1.73m 2 in males, respectively. Persistent albuminuria was considered present if 2 or 3 UACR values were ≥30 mg/g or if initial baseline value was ≥100 mg/g (PMID: 32289161). We utilized generalized linear models adjusting for age and sex to identify characteristics associated with persistent albuminuria and CKD. For multivariable selection, we fit binomial or multinomial LASSO regression models adjusted for age, sex, hemoglobin, %Hemoglobin F, hemoglobinuria, and hydroxyurea to identify those variables associated with outcomes of interest. Results Of 284 enrolled patients, 268 had complete data for UACR, cystatin C and serum creatinine at baseline; 104 (38.8%) of these had persistent albuminuria (Table 1). CKD was present in 40.7% of patients and 26.5% exhibited hyperfiltration. In analyses adjusted for age and sex, several factors were associated with the likelihood of persistent albuminuria. Higher hemoglobin, higher %Hemoglobin F, higher serum bicarbonate and use of NSAIDs were associated with decreased likelihood of persistent albuminuria. Higher systolic and diastolic blood pressur