Serum adenosine deaminase activity is elevated in cutaneous leishmaniasis and decreases following treatment

Introduction: Leishmaniases are infectious diseases caused by Leishmania protozoa, affecting millions worldwide. Diagnosis can be challenging. Accurate, non-invasive, and rapid diagnostic methods are needed. Studies suggest that adenosine deaminase activity may serve as a valuable tool. This study aimed to evaluate serum adenosine deaminase activity in patients with cutaneous leishmaniasis in an endemic area of Brazil. Methods: Fifteen patients with cutaneous leishmaniasis were evaluated before starting treatment and then monthly for up to 90 days. Enzyme activity was quantified using a commercial kit. A control group of 10 healthy participants was also included. Anthropometric, sociodemographic, and clinical data were collected. Statistical analysis included Mann-Whitney's U Test, one-way ANCOVA, Fisher's Exact Test, Fisher-Freeman-Halton's Test, and Mixed-Effects ANOVA. Results: The median serum adenosine deaminase level for the control group was 6.29 U/L (4.42-8.86). For the patient group, median levels were 12.34 U/L (9.06-18.12) at Day 0, decreasing to 8.62 U/L (7.84-11.98) by Day 90. The difference between groups at Day 0 was statistically significant (p=0.001). The difference in enzyme levels in the patient group during follow-up was also statistically significant (p=0.0255). Conclusions: Serum adenosine deaminase activity was significantly elevated in patients with cutaneous leishmaniasis and decreased significantly over time after treatment. These preliminary findings are promising, but should be interpreted with caution given the limitations of our study.