Serum very long-chain fatty acids (VLCFA) levels as predictive biomarkers of diseases severity and probability of survival in peroxisomal disorders

Peroxisomal disorders (PD) are a heterogeneous group of rare diseases caused by a defect in peroxisome biogenesis or a disruption of a peroxisomal function at a single enzyme or at transporter level. The main biochemical markers for PD are very long-chain fatty acids (VLCFA). The aim of the study was to investigate the correlation of basic diagnostic parameter, i.e. VLCFA, with disease severity, determined through the survival time. We performed a retrospective study in patients with PD (n = 31; aged 1 week—21 years). Evaluation of VLCFA results from patients were as follows: 15 patients with classical Zellweger syndrome (ZS), 3 patients with mild outcome of ZS, 9 individuals with D-Bifunctional Protein Deficiency (DBP), and no specified results in the case of 4 patients. Patients with classical ZS had higher VLCFA levels, compared to individuals with mild form of ZS and also to patients with DBP; for C26:0/C22:0: 0.65±0.18; 0.11±0.09; 0.30±0.13 (P < 0.001) and for C26:0: 5.20±1.78; 0.76±0.46; 2.61±0.97[mg/mL] (P < 0.001) respectively. The only variable parameter, i.e. the one that determines the survival time of patients, was C26:0 (Chi(2) = 19,311, P < 0.0001). Correlation coefficient between survival time and C26:0 level was statistically significant (r = -0.762), and the results showed that high levels of C26:0 were associated with short survival time. CONCLUSION: VLCFA levels correlate with the severity of the clinical course of ZS, DBP and mild ZSD. The best predictive value for estimating the projected disease severity and survival time is a concentration of C26:0.