Chronic Haemolytic–inflammatory Activation Persists beyond Clinical Crisis in Adults with Sickle Cell Anaemia: A Comparative Cross-sectional Study

Abstract

Background: Sickle cell anaemia is characterised by chronic haemolysis and inflammation. Whether these processes persist during clinically stable periods or are mainly associated with painful crises remains unclear in the local literature. Objective: To compare lactate dehydrogenase (LDH) and C-reactive protein (CRP), markers of haemolysis and inflammation, among adults with sickle cell anaemia in steady state, those admitted with a painful crisis, and healthy controls. Methods: This comparative cross-sectional study was conducted at the Haematology Day-care Unit, University College Hospital, Ibadan. The final analysed cohort comprised adults aged 18–67 years: 60 patients in steady state (ASS), 41 admitted with painful crisis (Bed), and 60 healthy haemoglobin AA controls (AHI), recruited by convenience sampling. Steady state was defined as at least three weeks without a painful crisis and three months without transfusion. Serum LDH was measured by a kinetic IFCC liquid, version 2 method on a Cobas c 111 clinical chemistry analyser (Roche Diagnostics), while CRP was measured by particle-enhanced immunoturbidimetry. Group comparisons used one-way ANOVA with Bonferroni post hoc testing and chi-square analysis; p<0.05 was considered significant. Results: Mean LDH was 831.2±313.8 U/L in ASS, 811.4±246.2 U/L in Bed, and 165.7±36.6 U/L in AHI (F=154.645, p=0.0001). CRP was elevated in 86.7% of ASS and 97.6% of Bed participants, compared with none of the AHI group (χ²=128.705, p<0.001). LDH and CRP did not differ significantly between ASS and Bed groups (p=1.000 and p=0.090, respectively), but were significantly higher in both sickle cell groups than in AHI (p<0.001). Conclusion: LDH and CRP were markedly elevated in adults with sickle cell anaemia during both steady state and painful crisis compared with healthy controls. The absence of a statistically significant difference between steady state and crisis does not establish equivalence, but indicates that substantial haemolytic and inflammatory activity was detectable during clinically stable periods. The findings require confirmation in longitudinal studies before routine biomarker monitoring is recommended.