Hematological and Biochemical Alterations in Leukemia Patients Compared with Healthy Controls: Diagnostic Value of G6PD, Ferritin, and Zinc by ROC Curve Analysis

Background: Leukemia is a diverse group of hematological malignancies, the diagnosis and monitoring of which are now supplemented by ancillary hematological and biochemical biomarkers in addition to traditional morphological and molecular tests. Aim: This case–control study compared hematological parameters (WBC and RBC counts, hemoglobin), glucose-6-phosphate dehydrogenase (G6PD), iron-status markers (ferritin, iron), electrolytes (sodium, potassium), and zinc in leukemia patients with healthy controls and examined the diagnostic potential of G6PD, ferritin, and zinc; using receiver operating characteristic (ROC) curve analysis. Methods: Between 12 April and 23 August 2025, 65 leukemia patients and an equal number of age comparative healthy volunteers were recruited from Baghdad Governorate/Iraq. Serum G6PD levels were measured by enzyme-linked immunosorbent assay (ELISA), complete blood count (CBC) parameters were characterized on an automated hematology analyzer, ferritin, iron, sodium, potassium and zinc tested on automated biochemistry/electrolyte analyzers. Independent-samples t-test was used to compare group means, Pearson correlation for associations and ROC/area-under-the-curve (AUC) analysis for diagnostic accuracy. Results: The leukemia patients had significantly higher WBC, ferritin, iron and sodium but lower RBC, hemoglobin, G6PD, potassium and zinc than controls (all p <0.05). Ferritin was positively correlated with WBC (r = 0.500, p= 0.0001) and iron (r =0.402, p =0.001); Iron inversely correlated with zinc (r = −0.241, p =0.045); G6PD was positively correlated with age (r =0.307, p = 0.013). There was very good discriminative accuracy for zinc (ROC AUC = 0.876, SE = 0.033), acceptable discriminative accuracy for G6PD (ROC AUC = 0.798, SE = 0.039) and ferritin (ROC AUC = 0.723, SE = 0.044) based on ROC analysis (all p <. 0.001). Conclusions: Leukemia has a signature hematological and biochemical profile and serum zinc, G6PD, and ferritin display acceptable to excellent diagnostic accuracy; therefore, they are useful low-cost adjunct markers in the laboratory diagnosis of leukemia.