Evaluation of serum prolidase level in children with Familial Mediterranean Fever

Abstract
Background
FMF (Familial Mediterranean Fever) is the most prevalent autoinflammatory disease. It arises due to mutations in the pyrin-encoding MEFV gene. Prolidase, an enzyme culpable of splitting the bonds of proline-containing dipeptides, is essential for matrix remodeling, collagen turnover, and cell proliferation. It has a crucial role in inflammation.

Aim
To compare serum levels of prolidase between FMF children during the attack-free periods and healthy children and to correlate it with different FMF disease criteria and inflammatory marker, also to investigate if it can serve as a marker for subclinical inflammation.

Results
Forty-one children diagnosed with FMF and 41 sex and age-matched apparently healthy children as a control group were included in this study, serum prolidase was measured by ELISA. The mean ± SD serum level of prolidase among FMF patients was 0.6 ± 0.2 mU/ml × 104, while among the control group, it was 1.3 ± 1.4 mU/ml × 104, a statistically significant difference existed between both groups, p value = 0.001. The level of serum prolidase was not correlated with FMF severity score, inflammatory markers, and other FMF disease criteria.

Conclusion
Serum prolidase level was lower among FMF patients during the attack-free period than in the healthy control group, it was not correlated with disease severity and was not predictive of the presence of subclinical inflammation. Further studies are needed to highlight the role of serum prolidase in FMF children.