Non usage of hydroxyurea is associated with high oxidative stress index at steady-state and predicts occurrence of Vaso-occlusive Crisis in Nigerian adults with sickle cell anaemia

Abstract

Context
Background Vaso-occlusive crisis (VOC) is the primary complication driving hospitalisation in Sickle Cell Anaemia (SCA) and is linked to chronic inflammation and high oxidative stress. While Hydroxyurea (HU) is effective in reducing VOC and modulating oxidative pathways, the integrated predictive value of HU usage, steady-state oxidative stress index (OSI), and white blood cell count (WBC) is unestablished in Nigerian SCA adults.


Aims
We developed a predictive model to evaluate the combined and independent roles of HU usage, OSI, and WBC on short-term VOC occurrence.


Settings and design
This prospective observational study consecutively enrolled 120 SCA adults recruited at steady-state and followed them for 1-month for VOC development.


Patients and methods
Socio-demographics and clinical parameters were collected at baseline. The OSI was computed as a ratio of total oxidant status to total antioxidant status.


Statistical analysis used

Data was analysed using Mann–Whitney
U
test and a multivariate logistic regression model to identify independent predictors.



Results

Age and socio-demographics were statistically similar between the VOC and non-VOC groups (
P
>0.05). However, participants who developed VOC had significantly higher steady-state WBC and OSI (
P
<0.05). In the final logistic regression model [
χ
2
(3,
N
=120)=48.06,
P
<0.001], only HU usage was a significant predictor. Non-usage of HU increased the likelihood of developing VOC 10-fold within one month [Odds ratio (95% confidence interval)=0.10 (0.04–0.26),
P
<0.001].



Conclusion
The non-usage of HU is the most powerful and significant independent predictor of short-term VOC occurrence in Nigerian SCA adults. These findings strongly underscore the critical protective role of HU against VOC and mandate its prioritization in clinical management, especially in resource-constrained settings.