T cell subsets: an integral component in pathogenesis of rheumatic heart disease

Abstract

Acute rheumatic fever (ARF) is a consequence of pharyngeal infection of group A streptococcal (GAS) infection. Carditis is the most common manifestation of ARF which occurs in 30-45% of the susceptible individuals. Overlooked ARF cases might further progress towards rheumatic heart disease (RHD) in susceptible individuals, which ultimately leads to permanent heart valve damage. Molecular mimicry between streptococcal antigens and human proteins is the most widely accepted theory to describe the pathogenesis of RHD. In the recent past, various subsets of T cells have been reported to play an imperative role in the pathogenesis of RHD. Alterations in various T cell subsets, viz. Th1, Th2, Th17, and Treg cells, and their signature cytokines influence the immune responses and are associated with pathogenesis of RHD. Association of other T cell subsets (Th3, Th9, Th22, and T) is not defined in context of RHD. Several investigations have confirmed the up-regulation of adhesion molecules and thus infiltration of T cells into the heart tissues. T cells secrete both Th type 1 and type 2 cytokines and these auto-reactive T cells play a key role in progression of heart valve damage. In this review, we are going to discuss about the role of T cell subsets and their corresponding cytokines in the pathogenesis of RHD.

CP‐25 Alleviates Experimental Sjögren's Syndrome Features in NOD/Ltj Mice and Modulates T Lymphocyte Subsets

“…Th3 cells are regulatory cells and cause immunosuppression through TGF‐β production . There are three closely related members in the TGF‐β family: TGF‐β1, TGF‐β2 and TGF‐β3.…”

“…However, there are no significant differences between the model group and drug‐treated groups in the level of TGF‐β1. Furthermore, there are other T helper subsets such as Th9, Th22 and TFH which play important roles in some autoimmune diseases . Further studies are required to explore that these subsets could be implicated in pSS and also may be the target of the immunomodulatory action of CP‐25.…”

Trends in Deaths from Rheumatic Heart Disease in the Eastern Mediterranean Region: Burden and Challenges

“…Our study shows that the total deaths from RHD are not declining possibly related to improved detection and reporting. The pattern of the burden of death from RHD in the EMR countries is moving to a higher age group compared to the patterns reported in the past century [ 4 , 5 , 6 ]. Late adolescence and early adulthood are mostly at risk of death from RHD, possibly due to the drop-out from health care, and gaps in adolescent health care services in these age groups, particularly in middle- and low-income countries.…”

“…The World Health Organization [ 1 ] was the first to release guidelines for the prevention and control of streptococcal disease and Rheumatic fever (RF) that have since been updated and adapted by many countries and regions around the world [ 2 , 3 ]. In Egypt in the 1960s, the Abdin and Eissa working group [ 4 , 5 ] established a link between streptococcal disease and RHD, and attributed it to poor living conditions, overcrowding, poor hygiene, and a lack of exposure to health education. They were among the first workers in the Egypt to report its high incidence in the tropics and its occurrence in children under-five years of age [ 5 ].…”

“…In Egypt in the 1960s, the Abdin and Eissa working group [ 4 , 5 ] established a link between streptococcal disease and RHD, and attributed it to poor living conditions, overcrowding, poor hygiene, and a lack of exposure to health education. They were among the first workers in the Egypt to report its high incidence in the tropics and its occurrence in children under-five years of age [ 5 ]. They identified 68 cases among children below 5 years of age, of whom 28 were below the age of 4, out of the one thousand children with RHD who attended their clinic for treatment.…”