[Hypocomplementaemia in children with chronic viral hepatitis as a risk factor for invasive encapsulated bacteria...

The complement system plays an important role in immunological and inflammatory response. Complement deficiency may increase patient's susceptibility to invasive infections caused by encapsulated bacteria (Neisseria meningitidis, Streptococcus pneumoniae, Haemophilus influenzae). One of the causes of reduced production of complement components may be hepatic function disturbances in patients with chronic viral hepatitis.

of this study was to estimate the incidence of complement components deficiency and the risk of hypocomplementaemia as well as the associated risk of invasive bacterial infections in children with chronic viral hepatitis, type B and C.

the studied group consisted of 58 children (45 boys and 13 girls) aged 4 to 18 years (mean 14 +/- 3 years). 35/58 were chronically infected with HBV, 17/58 with HCV while 6/58 had HBV and HCV co-infection. In every child levels of C3 and C4 complement components in serum were determined. Deficiency of C3 component was diagnosed at the level of below 90 g/dl (laboratory normal values: 90-180 g/dl): deficit of C4 component was at the level below 10 g/dl (laboratory normal range 10-40 g/dl). In 43 patients (74%), nasopharyngeal swabs were taken for encapsulated bacteria carrier state. Statistical analysis was carried out using Statistica version 7.1 programme (p<0.05).

hypocomplementaemia was observed in 14/58 (24%) of patients: decrease in C3 component was found in 12/58 (20.5%) of cases, decrease in C4 in 2/58 (3.5%). Among children with chronic hepatitis B 6/35 (17%) had C3 deficiency and 2/35 (6%) C4 deficiency. In 5/17 (30%) of HCV-infected children, decreased level of C3 complement component was found. In one child with HBV and HCV co-infection, a decrease in C3 level was observed. Nosopharyngeal swab was positive for Neisseria meningitidis in 2/43 (5%) of patients and for Streptococcus pneumoniae in 1/43 (2.5%).

1. Hepatic function disturbances in course of chronic viral hepatitis type B and C in children may lead to deficiency of complement components and further to the risk of invasive bacterial infections. 2. To assess the incidence of hypocomplementaemia and its components in children with chronic viral hepatitis, studies on a larger group of patients are needed. 3. In children with chronic viral hepatitis it is indicated to determine complement components concentration. 4. Vaccination against encapsulated bacteria infections should be recommended for patients with chronic viral hepatitis, in particular in cases with lowered complement components concentration.