Background: Immunological investigation is a part of the complex view on a child with juvenile chronic arthritis (JCA). We analyzed the data of a cohort of children with JCA in order to determine the real contribution of this investigation to their diagnosis and therapy.
Material and methods: We included the investigation of humoral immunity and autoantibodies of 78 children with JCA. 18 children completed investigation of both humoral and cellular immunity of paired peripheral blood (PB) and synovial fluid (SF). Humoral immunity consisted from immunoglobulins, complement, circulating immune complexes, rheumatoid factors, soluble HLA I. molecules and antinuclear and antineutrophil cytoplasmic antibodies. Cellular immunity included cytometric studies of CD3, CD4, CD8, CD16/CD56, CD19, CD20, 23, CD3 HLA DR+, CD45 RA, CD45 RO, alpha/beta and gamma/delta T cells. To observe the status of Th1/Th2 balance in children with JCA, the cytokines IL-4, IFN gamma, TNF alpha and IL-6 were measured in the tissue culture of the synovial cells.
Results: The parameters of humoral immunity in serum showed wide variability. We could not confirm particular changes specific for the forms or stage of the disease. ANCA were positive in 21 out of 78 children with JCA, 3 times both in PB and SF. More typical pattern could be followed in the comparison of PB and SF, with immunoglobulins and complement always found lower in SF than in PB. The cellular immunity was represented by the activation of lymphocytes mainly in SF, reverse ratio of CD45 RA and RO cells in PB and SF with marked predominance of memory T cells in the joint. High levels of sHLA in SF are the nonspecific marker of activation, the same is true for high levels of TNF alpha and IL 6 in SF cell culture supernatant.
Conclusion: The described changes in immunological parameters of humoral and cellular immunity are not specific for JCA. In the individual cases they can contribute to the diagnosis and monitoring of the disease. The investigation of sHLA molecules and cytokine profile should be restricted only for research.