Establishing Sickle Cell Diagnostics and Characterizing a Pediatric Sickle Cell Disease Cohort in Malawi

Abstract Sickle cell disease (SCD) is highly prevalent in sub-Saharan Africa; however, there are relatively few studies describing the clinical profile for children with laboratory-confirmed SCD. Prior to December 2014, neither neonatal screening nor standardized methods for SCD diagnosis were routinely available in Malawi, as hemoglobin electrophoresis and alternative diagnostic methods were absent. We describe implementation of hemoglobin electrophoresis for children with clinically suspected SCD at Kamuzu Central Hospital, one of two national teaching hospitals in Malawi. Children with clinically suspected SCD were recruited January - May 2015 and underwent comprehensive clinical and laboratory characterization. 137 total patients were recruited and 117 were confirmed to have HbSS disease. Among children who were being cared for as SCD prior to enrollment, 86% had HbSS suggesting generally accurate clinical diagnosis by local providers. Baseline clinical parameters and self-reported SCD complications for the study population are displayed in Table 1. Of those with confirmed SCD, median age was 7.3 years (IQR 2.7-10.4) with 53% males. Prior malaria was reported by 39% of patients, and was higher in the 0-5 age group compared with the over 5 age group (46% vs. 31%, p=0.03). The most commonly reported SCD complications were anemia (72%), joint pain (56%), jaundice (52%), and acute pain episodes (50%). Children with confirmed SCD had median hemoglobin of 7.3 g/dL (IQR 6.9-7.9), total bilirubin of 1.7 mg/dL (IQR 1.1-2.6) and lactate dehydrogenase of 658 IU/L (IQR 527-773). Urinalysis demonstrated 26% of patients with blood and 7% with proteinuria by dipstick. As of May 2015, more than 250 samples for enrolled children as well as routine clinical care had been batch-processed weekly with an average turn-around time of 36 hours for results. Three Malawian laboratory technicians were trained to perform hemoglobin electrophoresis, all of whom have been performing the test independently since April 2015. Our findings highlight a need for wider implementation of resource-appropriate diagnostics as an essential foundation for care and research. Children had substantial clinical and laboratory evidence of SCD-related morbidity. Earlier diagnosis can improve care for this population by facilitating earlier therapeutic interventions, as well as providing a basis for research to better understand SCD-related morbidity in sub-Saharan Africa. These efforts can ultimately inform management strategies to improve outcomes and increase life expectancy among children with SCD in Malawi. Table 1. All (n=117) Male (n= 62) Female (n=55) p value Age years, median (IQR) 7.3 (2.7-10.4) 5.3 (2.3-9.4) 8.9 (4.2-11.9) 0.004 Height cm, median (IQR, n) 115 (88-131, 60) 111 (89-128, 36) 119.5 (93-140, 24) 0.21 Weight kg, median (IQR, n) 19 (13-27, 108) 16.5 (12-23.6, 58) 21 (14-30, 50) 0.01 Blood Pressure Systolic mmHg, median (IQR, n) 103 (98-110, 83) 101 (94-108, 43) 103 (99-110, 40) 0.37 Blood Pressure Diastolic mmHg, median (IQR, n) 60 (55-65, 83) 58 (53-65, 43) 61 (56-68, 40) 0.13 Heart Rate BPM, median (IQR, n) 104 (91-118, 114) 105 (94-123, 61) 104 (88-112, 53) 0.15 O2 Saturation %, median (IQR, n) 93 (88-97, 108) 91 (85-96, 59) 95 (91-98, 49) 0.004 % Hypoxemic (SPO2 < 90%), n (%) 36 (30.7) 26 (41.9) 10 (18.2) 0.005 Body Temperature Celsius, median (IQR, n) 37 (36.7-37.4, 91) 37 (36.7-37, 46) 37 (36.4-37.2, 45) 0.22 Positive History of: Malaria, n (%) 45 (38.5) 22 23 0.34 0-5 years, n (%) 25 (46.3) - - 0.03 6-18 years, n (%) 20 (31.7) - - Pneumonia, n (%) 29 (24.8) 10 (16.1) 19 (34.5) 0.02 HIV, n (%) 0 0 0 - Anemia, n (%) 84 (71.8) 49 (79.0) 35 (63.6) 0.06 Pallor, n (%) 16 (13.7) 7 (11.3) 9 (16.4) 0.43 Jaundice, n (%) 61 (52.1) 33 (53.2) 28 (50.9) 0.82 Received Blood Transfusion, n (%) 87 (74.4) 47 (75.8) 40 (72.7) 0.47 Days since last transfusion, median (IQR) 316 (133-1144) 240 (111-410) 577 (180-1784) 0.03 Pain episodes, n (%) 58 (49.6) 27 (43.5) 31 (56.4) 0.16 Joint pain, n (%) 66 (56.4) 33 (53.2) 33 (60.0) 0.34 Dactylitis, n (%) 41 (35.0) 19 (30.6) 22 (40.0) 0.29 Leg ulcers, n (%) 5 (4.3) 5 (8.1) 0 0.03 Stroke, n (%) 10 (8.5) 5 (8.1) 5 (9.1) 0.84 Nocturnal Enuresis, n (%) 24 (20.5) 12 (19.4) 12 (21.8) 0.74 Disclosures No relevant conflicts of interest to declare.