Background Galactosemia – an inherited disorder of carbohydrate metabolism, which requires a strict lactose-free/galaktose-free diet. However, the blood galactose in treated patients with classic galactosemia is higher than that of healthy children.

Objectives To determine the effect of metabolic disorders in galactosemia to the immune status of patients.

Methods 44 patients with classic galactosemia in age from 6 months to 6 years were examined. 20 (46%) patients were younger than 2 years, 24 (54%) – over 2 years. The obtained data were compared with a healthy children group at the same age (n=34). Immunophenotype of peripheral blood lymphocytes was investigated using flow cytometry (flow laser cytometer CYTOMICS FC 500 (Beckman Coulter, USA). Mitochondrial enzyme succinate dehydrogenase (SDH), nikotinamidadenindinukletoid dehydrogenase (NADH-d) and intracellular lactate dehydrogenase (LDH) were used as an energy metabolism markers. Statistical analysis of the data was performed using Statistica 6.0 package (StatSoft Inc., USA). The significance of differences was determined using the Mann-Whitney test.

Results All patients with classical galactosemia have recieved lactose-free/galaktose-free diet, their clinical condition was stable. The galactose level was within limits, but significantly higher than that of a comparison group (p=0,000). The absolute number of B-lymphocytes was reduced in 45% of galactosemic patients older than 2 years (p=0.036) comparing with patients were younger than 2 years. Other parameters of peripheral blood lymphocytes immunophenotype did not depend on the age and had no significant difference with respect to the comparison group. We have found lower total SDH activity (p=0.003) and reducing the ratio of SDH/NADH-D (p=0,000) in galactosemic patients with compared with the reference group. There were no significant changes in the overall activity of NADH-d and LDH.

Conclusions These data suggest that elevated endogenous synthesis of galactose influences negatively on the activity of the intracellular enzymes and immune cells, contributing to their apoptosis and the immune response change.