Plasma Calprotectin Level as a Potential Biomarker in Different Phases of Pediatric Hemato-Oncological Malignancies: A Pilot Study

Background: Calprotectin has been known as a biomarker for systemic inflammation, especially in autoimmune disorders. Inflammation is a process associated with malignant progression, and calprotectin is a potential prognostic biomarker in some hematologic malignancies. Our pilot study aimed to evaluate the plasma calprotectin level as a promising biomarker in the relapsed/refractory phase of pediatric hemato-oncological malignancies.<br /> Materials and Methods: This pilot research is a case-control study. A total of 168 individuals were included in the study. The analyses were conducted on 73 pediatric patients diagnosed with acute leukemia and 60 others with solid tumor cancers who had referred to Ahvaz Shafa Hospital in Iran. The patients were subdivided based on the three phases of the disease, including on-treatment, relapsed/refractory, and remission phases. Also, 35 healthy children were considered as the control group. After consent was received from all the participants, their blood samples were collected in ethylene diamine tetra acetate (EDTA) tubes to measure plasma calprotectin levels by the enzyme-linked immunosorbent assay (ELISA) method. The data were analyzed using the SPSS26 software. Kruskall-Wallis, Bonferroni Post hoc, and bivariate correlation tests were used, and a two-sided pvalue < 0.05 was significant.<br /> Results: There was no statistically significant difference among the plasma calprotectin levels in different phases of acute leukemia (P = 0.099); however, the mean levels of the studied groups were higher than the healthy controls. This increase in the average calprotectin level was also observed in different phases of solid tumor cancers compared to the control group. Besides, a significant difference was seen between the ontreatment and remission groups compared to the control group (p = 0.011 and p = 0.016, respectively).<br /> Conclusion: The mean plasma calprotectin levels increase in different phases of some pediatric hematooncological malignancies, but it cannot be used as a specific biomarker for the relapsed/refractory phase.