Chronic Glomerulonephritis are a group of disorders in which the glomeruli are predominantly involved due to an inflammatory process which does not abate; becoming indolent and frequently leading to glomerular destruction and End Stage Renal Disease (ESRD).
In majority of cases the cause or initiating injury is not known, whilst in some an infectious agent such as Streptococcal or Staphylococcal infection (throat, VP shunt, sub-acute bacterial endocarditis, abscesses, etc.), viral infection like Hepatitis B, Hepatitis C, rarely CMV, HIV, EB viruses, parasitic infections like malaria and immunological diseases like SLE, HSP, Wegner's granulomatosis, Polyarteritis nodosa (in whom clinical clues such as joint pains, skin rash nodules, sinusitis, bronchitis are important for correct diagnosis). Hence before labelling a patient as primary or idiopathic CGN, serologic and immunologic tests eg. ASO Titre, ANA, AntidssDNA, ANCA, serum C3 and C4 levels, Anti-phosholipid antibodies (APLA), anticardiolipin, anti-SM, anti-GBM and immune complexes should be examined.
The hallmark of chronic glomerulonephritis is proteinuria with or without hematuria which is persistent and may be accompanied with edema, hypertension, azotemia or renal failure.
Screening of school children for presence of proteinuria +/- hematuria is one of the methods of diagnosis of glomerulonephritis in asymptomatic stage. In advanced countries like Japan, Taiwan, Korea, yearly urinalysis is mandatory and if 3-4 urinalysis are abnormal further investigations are asked to establish the diagnosis of chronic GN. This is not cost-effective in our country.
Typical age group: It is commonly found in school-going children especially above 6 years of age.
Suspect Chronic GN: - Acute glomerulonephritis is not completely resolved by 6-12 months i.e. urine shows proteinuria + hematuria, serum C3 is persistently low, hypertension, azotemia persist.
- Persistant urinary abnormalities - proteinuria, hematuria, isolated micro/macro hematuria
- Hypertension, nephritis syndrome
- Puffiness of eyes & edema, nephrotic syndrome
- Systemic diseases like Henoch's Schonlein Purpura, SLE, Polyarteritis Nodosa, pulmonary-renal syndrome (Good Pasture's Syndrome).
- Nephritic syndrome
When to suspect?
In a patient with edema or hypertension, if urine shows proteinuria / hematuria at least 3-4 times done one week apart in absence of sorethroat / pyoderma or typical features of post streptococcal glomerulonephritis, then CGN may be suspected. In fact, in an asymptomatic child; urine examination may have presence of proteins /RBCs which when repeated monthly may still be abnormal. That may be the 1st indication of CGN. These children usually become symptomatic within 6-12 mths.
Frequently asked questionsWhen do you do the
renal biopsy in CGN?
As early as possible. Even when the child is asymptomatic, if urine shows persistant abnormality then renal biopsy is indicated so that treatment can be started early to halt the progression of the disease. Once every 2-5 years, a biopsy may be required to check for progression of disease.
What is the
treatment of CGN?
Treatment depends on the cause of the CGN. Most of the times steroids are the mainstay of the therapy. In Wegner's and SLE, azathioprine & cyclophosphamide may be used in severe cases. All these are empirical treatments and not curative treatment.
When do these children develop ESRD?
If treated early and effectively, they usually end up in ESRD by the early twenties. However, untreated and undiagnosed patients usually succumb to the disease in the adolescent age almost within 5 years of onset.
Since renal transplant may be eventually required in these children, what are the chances that the disease may recur in the transplanted kidney?
The chances are as high as 50% in case of membranoproliferative GN. But the good news is that, though the patient may have recurrence in form of proteinuria and histological abnormality, they do not go into renal failure again for almost their entire life.
What is the
role of steroids in CGN due to hepatitis B virus?
Hepatitis B usually does not cause end stage renal disease. In fact, these children usually die because of liver failure due to hepatitis B rather than renal failure. Interferon alpha has been tried in these children and has been quite successful but its use in case of CGN is controversial.
Regarding use of steroids in a patient who is HBs Ag +ve, then first rule out whether the child is a carrier. If the child is a carrier, the disease may not be due to Hepatitis B and the child may revert back to HBs Ag negative status within 6 months. To prove that CGN is due to Hepatitis B, then biopsy with viral culture may be required which is not available here. However, if CGN is likely to be due to Hepatitis B, then steroids are contraindicated. In a carrier, you can wait till the serology becomes negative in 3-6 months and then steroids can be started. Till then only symptomatic and supportive treatment can be given in form of antihypertensives and diuretics. Even if child has Nephrotic syndrome with positive Hepatitis B, then treatment is the same.
chances of complete remission?
Complete remission is rare, however there are cases of burnt out disease on record where the disease is just lingering and these children have not gone into renal failure. They need treatment for hypertension/edema but have not required dialysis or renal transplant.