[Current opinions on immunological processes in rheumatoid arthritis during pregnancy]

The essential in pathogenesis of RA is induction of incorrect immunological response against synovial and connective tissue antigens, which depends of CD4+ T-cells activation by specific antigen. This stimulation leads to releasing Th1 lymphokines. The most important cytokine is TNF-alpha. An increased level of TNF-alpha, IL-1, IL-6, GM-CSF, IL-8 was observed in patients with RA. PDGF, FGF, TGF, C-X-C a chemokines (IL-GRO-alpha, ENA78) and CCb chemokines (RANTES, MCP1 MIP1 alpha) are also involved in synovial hyperplasia in RA. During a pregnancy a clinical improvement in women with RA is frequent. The reason of this fact is probably connected with Th2 predominance (IL-4, IL-10) caused by presence of fetal tissues. Specific, cell-mediated immunity is suppressed and changed to Th2 by progesterone and PGE2. During a pregnancy a higher sensitivity of lymphocytes to progesterone was found. Progesterone stimulates T cells to PIBF production, which decreases NK activity. Th2 cytokines (Il-6, IL-10, IL-13, TGF) are expressed on decidua and inhibit secretion of Th1 cytokines (IL-2, INF gamma, TNF-alpha, IL-1 alpha, IL-1 beta). Immunosuppression caused by pregnancy probably decreases inflammatory and destructive reactions in tissues women with RA. The first attack of this disease frequently observed during puerperium is connected with a high level of prolactin and a low of estrogens, which causes a increased release of IL-2 and has a main influence on initiation and increasing of inflammatory process in RA.