The impact of foetal haemoglobin levels on several inflammatory markers in patients with steady state sickle cell anaemia at a Nigerian tertiary health institution

Background : Sickle cell anaemia (SCA) is a multifaceted disease characterized by both acute and chronic inflammation. This study aimed to determine foetal haemoglobin (HbF) levels and plasma levels of several inflammatory markers in adult SCA patients in the steady state and to correlate HbF levels with inflammatory markers. Methods: This was a cross-sectional comparative study involving SCA patients in a steady state and apparently healthy haemoglobin AA individuals. Blood samples were collected and analysed for complete blood count via a haematology autoanalyzer. Interleukin 17 (IL-17), interferon-gamma (IFN-g), monocyte chemoattractant protein-1 (MCP-1) and C-reactive protein (CRP) were analysed via ELISA. The HbF level was quantified via high- performance liquid chromatography. Statistical analysis was performed with SPSS software, version 25. Results: One hundred participants comprising 50 adults with SCA and 50 healthy control (HbAA) adults, aged 18-59 years, were studied. The platelet count (461.6±217.3 x10 ⁹ /L versus 227.7±9.4 x 10 ⁹ /L) and white blood cell count (11.4 ± 4.2 x 10 ⁹ /L versus 1.9 ± 0.9 x 10 ⁹ /L; p =0.001), were significantly greater, whereas the haematocrit count (22.5 ±3.3 versus 38.4 ±4.0; p =0.001) was lower in the SCA than in the control ( p =0.01). The HbF levels in SCA patients ranged from 2% to 21%, with a mean of 9.3± 4.9%. IL-17, IFN-γ, MCP-1 and CRP levels were significantly higher in patients with SCA than in healthy controls (p< 0.05). There was a significant negative correlation between HbF and MCP-1 (r= -0.4, p =0.012) whereas the correlations of HbF with CRP, IL-17 and IFN-γ were not significant. There was a statistically significant negative correlation between the HbF level and the PLT (r= -0.5, p = 0.00). Conclusion: Patients with SCA in the steady state have higher levels of IL-17, IFN-g, MCP-1, and CRP than HbAA individuals do. HbF has a significant negative relationship with MCP-1 and platelet count.