Definition of Acute nephritic syndrome:

Acute nephritic syndrome is a group of disorders that cause inflammation of the internal kidney structures (specifically, the glomeruli).

Causes, incidence, and risk factors:

Acute nephritic syndrome is often caused by an immune response triggered by an infection or other disease.

Causes seen more frequently in children and adolescents include the following:

• IgA nephropathy
• Henoch-Schonlein purpura
• Hemolytic uremic syndrome
• Post-streptococcal glomerulonephritis

Associated diseases seen more frequently in adults include:

• Abdominal abscesses
• Infective endocarditis
• Klebsiella pneumonia
• Goodpasture syndrome
• Hepatitis
• Membranoproliferative GN I
• Membranoproliferative GN II
• Rapidly progressive (crescentic) glomerulonephritis
• SLE or lupus nephritis
• Syphilis and other sexually transmitted diseases
• Typhoid fever
• Vasculitis
• Viral diseases such as mononucleosis, measles, mumps

The inflammation disrupts the functioning of the glomerulus, which is the part of the kidney that controls filtering and excretion. This disruption results in blood and protein appearing in the urine, and the build up of excess fluid in the body. Swelling results when protein is lost from the blood stream. (Protein maintains fluid within the blood vessels, and when it is lost the fluid collects in the tissues of the body). Blood loss from the damaged kidney structures leads to blood in the urine.

Acute nephritic syndrome may be associated with the development of high blood pressure, inflammation of the spaces between the cells of the kidney tissue, and acute kidney failure.