In minimal-change glomerulonephritis (MCGN) (synonyms: Minimal-change glomerulonephritis; minimal glomerulonephritis; minimal change glomerulopathy (disease) = MCD; ICD-10-GM N05.0: Unspecified nephritic syndrome: minimal glomerular lesion), glomerular minimal lesions occur that can only be visualized under the electron microscope.
The glomeruli (glomeruli corpusculi renalis) are an important morphological component of the renal corpuscles and are responsible for the ultrafiltration of the primary urine.
The following main forms of glomerulonephritis are distinguished:
- Minimal change glomerulonephritis (MCGN) (glomerular minimal lesion) – the most common cause of nephrotic syndrome in childhood.
- Focal segmental sclerosing glomerulonephritis (FSSGN) – associated with nephrotic syndrome in approximately 15% of cases.
- Membranous glomerulonephritis (MGN) – the most common cause of nephrotic syndrome in adults; accounts for 20-30% of all glomerulonephritides; may be primary or secondary (resulting from other diseases)
- Membranoproliferative glomerulonephritis (MPGN) – associated with nephrotic syndrome in 50%.
- Mesangial IgA glomerulonephritis – most common form with up to 35% of cases.
- Rapid progressive glomerulonephritis (RPGN) – occurs in 2-7% of patients; the disease is classified into several causative groups
An idiopathic (with no apparent cause) form is distinguished from a secondary form (in the context of hematologic neoplasms (these include leukemias and lymphomas), the use of drugs/active substances such as NSAIDs, gold, penicillamine, lithium, mercury, and others).
Minimal-change glomerulonephritis is the most common cause of nephrotic syndrome in childhood (usually with acute onset). Nephrotic syndrome is characterized by proteinuria (increased excretion of protein in the urine), resulting hypoproteinemia (too little protein in the blood), and hyperlipoproteinemia (lipid metabolism disorder) and edema (water retention). In adults, minimal change glomerulonephritis is the cause of nephrotic syndrome in approximately 10% of cases.
Frequency peak: The disease predominantly occurs at an age below 10 years, mostly between 2 and 6 years.
Course and prognosis: Minimal change glomerulonephritis (MCGN) may heal spontaneously (on its own). In children, full remission (complete resolution of symptoms) is observed in about one-third with adequate therapy. Within 25 years, about 5% of those affected develop terminal renal failure (kidney failure).
MCGN is often relapsing (recurrent). The recurrence rate is 30%.
Note: MCGN is also thought to progress to “focal segmental glomerulosclerosis” (FSGS).
