Handbook of Genetic Counseling/HIgA Nephropathy

IgA Nephropathy

What is IgA Nephropathy?

 * the most common non-diabetic kidney disease
 * IgA, a normal component of the blood, collects in the kidney as damaging deposits
 * due to either increased production or reduced clearance of the immune protein IgA and associated antigen complexes
 * deposits collect in small blood vessels in the glomeruli (the filtering structure of the kidney)
 * 20%- 30% of patients will suffer eventual kidney failure within 10-20 years
 * more likely if they have high levels of creatinine in blood at time of diagnosis
 * will require life saving dialysis and/or a kidney transplant
 * a large proportion of patients who present with symptoms have a mild form of the disease
 * most people probably never know they have the disease or discover it at a late stage

Warning Signs of Kidney Disease

 * tea colored urine (hematuria - blood in the urine)
 * very foamy urine (proteinuria - protein in the urine)
 * puffiness around the eyes, hands, or feet (edema - fluid retention)
 * high blood pressure
 * pain in the small of the back just below the ribs not aggravated by motion.
 * frequent urge to urinate especially at night, and/or reduced amount of urine produced

Treatment

 * no medical treatments except in the latest stages of the disease
 * transplant success rate is good (symptoms mild, though deposits will appear in the transplanted kidney after one year)
 * some therapies can delay the deterioration of kidney function for many years
 * ACE inhibitors, fish oil, steroid treatment, tonsillectomy
 * control of associated hypertension is important

Diagnosis

 * the presence of blood and/or protein in the urine
 * some nephrologists may microscopically examination urine and red blood cell casts
 * to confirm a diagnosis, it is necessary to perform a renal biopsy and examine kidney tissue microscopically for the presence of the characteristic IgA deposits in the glomeruli
 * no genetic testing available

Causes

 * unknown (recurrence risk also unknown)
 * genetic influences may play a role in the development of the disease
 * seems to cluster in certain families and in certain areas of the world
 * associated with major histocompatibility HLA and certain other genetic markers
 * HLA-DR4 is detectable in about 50% of patients