Anaemia of inflammation in sickle cell disease: A review of aetiopathogenesis, management, and prevention of sterile and septic inflammation in patients with sickle cell disease

Ahmed SG; Ibrahim UA

doi:10.61386/imj.v18i1.584

Authors

Ahmed SG Consultant, Department of Haematology, Aminu Kano Teaching Hospital, Kano, Nigeria
Ibrahim UA Consultant, Department of Paediatrics, Aminu Kano Teaching Hospital, Kano, Nigeria

DOI:

https://doi.org/10.61386/imj.v18i1.584

Keywords:

Sickle Cell Disease, Anaemia of Inflammation, Sterile Inflammation, Septic Inflammation, Aetiopathogenesis, Management, Prevention

Abstract

Background: SCD is strongly associated with sterile inflammation (STERIN) and septic inflammation (SEPTIN). Thus, in addition to haemolysis, anaemia in SCD has dual ‘inflammatory’ components; (1)-anaemia of sterile inflammation (ASTERIN) and (2)-anaemia of septic inflammation (ASEPTIN). Hence, the need to explore the relatively understated but important concept of ‘anaemia of inflammation in SCD’.

Objectives: The objectives of this review are tri-fold; (1)-To reappraise the aetiopathogenesis of STERIN and SEPTIN in SCD; (2)-To highlight the roles of STERIN and SEPTIN in causation of ASTERIN and ASEPTIN in SCD; and (3)-To underscore the roles of mitigators of STERIN and SEPTIN in managing/preventing ASTERIN and ASEPTIN in SCD.

Methodology: Literature search was done using terms relevant to ‘SCD/inflammation/anaemia’. Only articles on aetiopathogenesis, management, and/or prevention of STERIN/ASTERIN and/or SEPTIN/ASEPTIN were selected.

Results: Hyper-inflammation in SCD has dual components; STERIN (caused by tissue injury/haemolysis) and SEPTIN (caused by infections). Accordingly, ‘anaemia of inflammation in SCD’ has dual components; ASTERIN and ASEPTIN. ASTERIN is driven by STERIN, which is relentless and occurs even in steady-state, and is often aggravated by crisis and/or autoimmune diseases. ASEPTIN is driven by SEPTIN, which occurs only during infections. Hence, during infection, ASTERIN and ASEPTIN act synergistically to worsen anaemia and increase transfusion risk in SCD. Mitigators of STERIN (e.g., hydroxyurea, immune-modulators) and SEPTIN (e.g., anti-microbials, vaccines) have beneficial roles in managing and preventing ASTERIN and ASEPTIN in SCD.

Conclusion: Anaemia in SCD has significant inflammatory components. Hence, managing/preventing STERIN and SEPTIN are important strategies for down-regulating ASTERIN and ASEPTIN, improving Hb-concentration, and reducing transfusion risk in SCD.