Sero-Prevalence and Immunological Profile of SARS-CoV-2 Antibodies in Nigerian Sickle Cell Disease Patients During the COVID-19 Pandemic

Introduction: Nigeria has the highest prevalence of sickle cell disease (SCD) globally, making it a major genetic disorder of public health concern in Africa. During the COVID-19 pandemic, SCD patients were particularly vulnerable due to their compromised immune and hematological systems. Aim/Objective: This study aimed to determine the sero-prevalence of SARS-CoV-2 IgG and IgM antibodies and assess the associated hematological and immunological profiles in Nigerian SCD patients during the pandemic. Method: A case-control, cross-sectional study was conducted at the University College Hospital (UCH), Ibadan. The study involved 167 participants—122 confirmed SCD patients and 45 healthy controls. Blood samples were analyzed for hematological parameters (white blood cell count [WBC], platelet count, hemoglobin [Hb], and packed cell volume [PCV]), coagulation indicators (prothrombin time [PT], activated partial thromboplastin time [APTT], and D-dimer), and SARS-CoV-2 antibodies (IgG and IgM). Statistical analysis was performed using SPSS version 23.0. Results: SCD patients showed significantly elevated values for white blood cell count (11.37 vs. 5.64 × 10⁹/L), platelet count (351.62 vs. 233.04 × 10⁹/L), prothrombin time (PT: 15.33 vs. 11.86 seconds), activated partial thromboplastin time (APTT: 32.25 vs. 29.27 seconds), and D-dimer levels (3347.08 vs. 1438.13 ng/mL) compared to healthy controls (p<0.05). In contrast, SCD patients had significantly lower hemoglobin concentrations (7.75 vs. 13.13 g/dL) and packed cell volume (PCV: 22.42% vs. 39.64%) (p<0.05). Although SCD patients exhibited slightly higher average levels of SARS-CoV-2 IgG and IgM antibodies, these differences were not statistically significant compared with the control group. A significant negative correlation was observed between age and IgM antibody levels (r = -0.223, p = 0.014), indicating a possible reduction in recent immune response with increasing age. Conclusion: The study revealed significant hematological and coagulation abnormalities in SCD patients, highlighting their heightened risk for thrombotic complications during infections such as COVID-19. Although no significant difference in SARS-CoV-2 antibody levels was found, the observed trends underline the need for routine serological and coagulation monitoring in SCD patients to support better clinical outcomes.