Evaluation of hematological parameters in patients with leprosy in Southern Nigeria.

Introduction: Leprosy is a chronic granulomatous infectious disease caused by Mycobacterium leprae that mostly result in immunological reactions that affect the skin, peripheral nervous system and mucosa of the upper respiratory tract. This study aimed to evaluate hematological parameters among subjects with leprosy and deduce biomarkers for onset of leprosy reaction.

Methods: This was a cross-sectional study performed from September 1, 2018 to August 1, 2019. Sixty patients with leprosy (30 on multidrug therapy (MDT) and 30 that had completed MDT) and 30 apparently healthy controls were enrolled. Hematology auto-analyzer (Sysmex KX-21N by Sysmex Corporation Kobe, Japan) was used in sample analysis. ANOVA and Kruskal Wallis were used for mean comparison. Eta squared was used to assess effect size. Sensitivity and specificity were assessed using receiver operator characteristic (ROC) curve. Association was checked using bivariate logistics regression.

Results: The majority (68.3%) of the patients with leprosy were males and a larger proportion were either farmers or unemployed. The prevalence of leprosy reaction in the studied population was 40%. The following parameters were significantly (p<0.05) reduced: red cell count, hemoglobin and hematocrit in patients with leprosy compared to controls. Total white cell count, absolute lymphocyte, neutrophil, monocyte and eosinophil counts were significantly elevated in patients with leprosy compared to controls. The hemoglobin and mean corpuscular volume of patients with leprosy on treatment were significantly higher compared to those who had completed treatment, while the mean corpuscular hemoglobin concentration was significantly reduced. Overall, 65% of patients with leprosy were anemic. Eosinophil count showed good biomarker potential for leprosy reaction onset with AUC 0.709. Sex and absolute eosinophil count were associated with leprosy reaction (OR=11.194; 95%CI: 1.775-70.586).

Conclusions: This study has shown a high frequency of anemia in patients with leprosy, both those on treatment and those that had completed MDT, necessitating incorporation of post treatment plan in the management of leprosy. This study has reported absolute eosinophil as potential biomarker of leprosy reaction.