8^th Molecular Immunology & Immunogenetics Congress

Alkaptonuria (AKU; MIM no. 203500) is a recessive inborn error disorder in the phenylalanine and tyrosine metabolism pathway, arising due to the defi cient activity of the enzyme homogentisate 1,2-dioxygenase (HGD). Consequently, the homogentisic acid (HGA; 2,5-dihydroxyphenylacetic acid) will deposit in the connective tissue of various organs, causing a pigmentation known as ochronosis, leading to dramatic tissue degeneration, infl ammation and arthritis. Th e disease prevalence worldwide is estimated as an ultra-rare, although higher incidence rates are recorded in Jordan. Data regarding the levels of infl ammatory mediators in patients suff ering of the rare disease Alkaptonuria are limited. C-reactive protein (CRP), Interleukin-1 Beta (IL-1β) and Interleukin-6 (IL-6) are acute-phase markers associated with joint infl ammation. The aim of the present study is to compare the serum levels of the pro-infl ammatory mediators, CRP, IL-1β and IL-6 in alkaptonuria patients (n = 17) with those measured for age-matched healthy controls (n = 17). Moreover, we attempt to determine the association between cytokine levels with the disease severity score and age using the Spearman correlation and multiple linear regression. The results show that the serum concentrations of the IL-1 β, IL-6 and CRP are higher in AKU patients compared with healthy controls, with a signifi cant diff erence in IL-6 (p = 0.02). Moreover, a positive correlation is found between the patients' serum IL-6 and patients' age and the AKU Severity Score (ro = 0.73 and 0.7, respectively; p < 0.05). Th us, the patients' IL-6 serum levels can predict the disease severity score in alkaptonuria patients (p < 0.05). These findings suggest that the IL-6 might play a role in the pathogenesis of infl ammation in AKU patients and thus targeting it may be one mode of treatment in future. However, these fi ndings need to be supported by further studies, conducted on a larger sample of patients.