Which nonimmune complex-mediated mechanisms have been proposed to explain the pathogenesis of acute poststreptococcal glomerulonephritis (APSGN)?

Updated: Dec 05, 2018
  • Author: Rajendra Bhimma, MBChB, MD, PhD, DCH (SA), FCP(Paeds)(SA), MMed(Natal); Chief Editor: Craig B Langman, MD  more...
  • Print
Answer

Other nonimmune complex mediated mechanisms have been proposed for the development of APSGN, such as delayed-type hypersensitivity, superantigens, and autoimmune phenomena.

A role for delayed-type hypersensitivity has been implicated in the pathogenesis of this disease. Early in the course of APSGN, resident endothelial and mesangial cells are predominantly proliferated, and this is accompanied by infiltration with polymorphonuclear leukocytes and monocytes. Macrophages are effector cells that cause resident cellular proliferation. The infiltration of macrophages in the glomeruli is mediated by complement-induced chemotaxis and, most likely, by an antigen-specific event related to delayed-type hypersensitivity mediated by helper/inducer T cells.

Streptococcal M proteins and pyrogenic exotoxins can act as superantigens. These cause a marked expansion of T cells expressing specific T-cell receptor B-chain variable gene segments. Massive T-cell activation occurs, with release of T-cell–derived lymphokines such as IL-1 and IL-6.

Autologous IgG in APSGN becomes antigenic and elicits an anti-IgG rheumatoid factor response, leading to formation of cryoglobulins. Cryoglobulins, rheumatoid factors, and other autoimmune phenomena occur in APSGN and are thought to play a role in the pathogenesis of the disease together with streptococcal superantigens.


Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!