The exact pathogenesis of undifferentiated connective tissue disorder (UCTD) is not fully understood. It is understood that UCTD is the result of an autoimmune process and occurs in phases: Initial phase: which is asymptomatic and is characterized by absence of auto-antibodies and second phase which is characterized by the presence of auto-antibodies. The second phase is usually triggered by the environmental factors, such as infection. Auto-antibodies appear before the symptoms of the disease.The time between the two is variable. Autoantibodies usually seen in UCTD with positive correlation are antibodies against C1q ,Anti heat shock protein (hsp)-65, Anti hsp 60. The clinical picture involves the overlap of symptoms of other rheumatological disease but not completing the criteria of their diagnosis. More studies are needed to find the pathogenesis of UCTD.
An increase in CD4+ memory and a decrease of naive CD4+ T cells were detected in patients with UCTD in a study that points to an ongoing active immune reaction.[7]
One study has shown the basis of impaired endothelial function in UCTD is due to inflammation.[8]
The clinical picture involves the overlap of symptoms of other rheumatological disease but not completing the criteria for their diagnosis.
Some studies show that about one-third of patients with UCTD can develop other connective tissue diseases.[6][9]
More studies are needed to find the pathogenesis of UCTD.
↑Mosca M, Neri R, Bombardieri S (1999). "Undifferentiated connective tissue diseases (UCTD): a review of the literature and a proposal for preliminary classification criteria". Clin. Exp. Rheumatol. 17 (5): 615–20. PMID10544849.
↑Bizzaro N, Tozzoli R, Shoenfeld Y (June 2007). "Are we at a stage to predict autoimmune rheumatic diseases?". Arthritis Rheum. 56 (6): 1736–44. doi:10.1002/art.22708. PMID17530702.
↑Horváth L, Czirják L, Fekete B, Jakab L, Prohászka Z, Cervenak L, Romics L, Singh M, Daha MR, Füst G (January 2001). "Levels of antibodies against C1q and 60 kDa family of heat shock proteins in the sera of patients with various autoimmune diseases". Immunol. Lett. 75 (2): 103–9. PMID11137133.
↑ 6.06.1Cavazzana I, Franceschini F, Belfiore N, Quinzanini M, Caporali R, Calzavara-Pinton P, Bettoni L, Brucato A, Cattaneo R, Montecucco C (2001). "Undifferentiated connective tissue disease with antibodies to Ro/SSa: clinical features and follow-up of 148 patients". Clin. Exp. Rheumatol. 19 (4): 403–9. PMID11491495.
↑Szodoray P, Nakken B, Barath S, Gaal J, Aleksza M, Zeher M, Sipka S, Szilagyi A, Zold E, Szegedi G, Bodolay E (August 2008). "Progressive divergent shifts in natural and induced T-regulatory cells signify the transition from undifferentiated to definitive connective tissue disease". Int. Immunol. 20 (8): 971–9. doi:10.1093/intimm/dxn056. PMID18550583.
↑Laczik, R.; Soltesz, P.; Szodoray, P.; Szekanecz, Z.; Kerekes, G.; Paragh, G.; Rajnavolgyi, E.; Abel, G.; Szegedi, G.; Bodolay, E. (2014). "Impaired endothelial function in patients with undifferentiated connective tissue disease: a follow-up study". Rheumatology. 53 (11): 2035–2043. doi:10.1093/rheumatology/keu236. ISSN1462-0324.
↑Bodolay E, Csiki Z, Szekanecz Z, Ben T, Kiss E, Zeher M, Szücs G, Dankó K, Szegedi G (2003). "Five-year follow-up of 665 Hungarian patients with undifferentiated connective tissue disease (UCTD)". Clin. Exp. Rheumatol. 21 (3): 313–20. PMID12846049.