Pathogenesis of Post-Streptococcal Glomerulonephritis PDF

PATHOGENESIS OF POST-STREPTOCOCCAL GLOMERULONEPHRITIS Hager&Martina Group: 8 Dr.Mohammed Adel Pbl: 30 DEFINITION Streptococcal glomerulonephritis (GN) is a type of kidney disease caused by an immune response to infection with certain strains of group A strept...

PATHOGENESIS OF POST-STREPTOCOCCAL GLOMERULONEPHRITIS Hager&Martina Group: 8 Dr.Mohammed Adel Pbl: 30 DEFINITION Streptococcal glomerulonephritis (GN) is a type of kidney disease caused by an immune response to infection with certain strains of group A streptococcus bacteria. It typically occurs after a throat or skin infection with these bacteria, such as strep throat or impetigo. The pathogenesis of streptococcal glomerulonephritis involves several key steps:  1: INFECTION The process begins with a primary infection of the skin or throat by group A streptococcus bacteria. These bacteria possess certain virulence factors, such as M protein and other surface antigens, which allow them to evade the host immune system and establish an infection  The immune system recognizes the presence of 2: Immune response the and mounts an immune response to eliminate the infection. Antibodies, specifically immunoglobulin G (IgG) and immunoglobulin M (IgM), are produced against the streptococcal antigens. 3: immune complex formation During the immune response, antigen-antibody complexes, also known as immune complexes, are formed. These complexes are composed of streptococcal antigens and antibodies, primarily IgG but also IgM, and complement proteins. 4: Deposition in glomeruli The immune complexes circulate in the bloodstream and can deposit within the glomeruli of the kidneys. The glomeruli are the filtering units of the kidneys responsible for removing waste products and excess fluid from the blood  5: COMPLEMENT ACTIVATION AND INFLAMMATION Once the immune complexes are deposited in the glomeruli, they activate the complement system, a cascade of proteins involved in the immune response. Complement activation leads to the recruitment of inflammatory cells, such as neutrophils, and the release of inflammatory mediators. 6: Glomerular damage The influx of inflammatory cells and the release of inflammatory mediators in the glomeruli lead to damage of the glomerular basement membrane and the surrounding structures. This disruption impairs the filtration function of the glomeruli, resulting in proteinuria (presence of protein in the urine) and hematuria (presence of blood in the urine)..  7: activation of immune system The glomerular injury triggers a sustained immune response, causing further damage to the glomeruli. The immune system continues to produce antibodies and immune complexes, perpetuating the inflammatory process.  conclusion Overall, streptococcal GN is an immune-mediated disease involving the deposition of immune complexes in the glomeruli, complement activation, and subsequent inflammation. The exact mechanisms underlying the pathogenesis are not fully understood, and individual factors, including host immune response and bacterial virulence, can contribute to the severity and outcome of the disease.