PEDBASE.org - The Pediatric Database - Detailed information of IgA NEPHROPATHY (BERGER NEPHROPATHY)

IgA NEPHROPATHY (BERGER NEPHROPATHY)

DEFINITION:

An immune-complex mediated secondary glomerulopathy caused by glomerular deposits of IgA characterized by recurrent episodes of gross hematuria.

EPIDEMIOLOGY:

incidence: most common cause of gross hematuria
age of onset:
- commonly affects young adults (uncommon before 6 years of age)
risk factors:
- M > F (2:1)
- associated with HLA BW35 and DR4
- may be familial (inheritence pattern not established)

PATHOGENESIS:

1. Background

disorder thought to cause a secondary glomerulopathy
unknown etiology, but the systemic character of the IgA deposits (skin and glomerular) and the presence of circulating IgA and IgG complexes suggest that it is an immune-complex mediated disease
may represent only the renal manifestations of Henoch-Schoenlein Purpura in a mature host (i.e., circulating immune complexes do not generate a systemic response but only a local [renal] response) as the renal lesions are indistinguishable histopathologically from that of HSP
immune response to Hemophillus parainfluenzae may be an important triggering agent

CLINICAL FEATURES:

1. Renal Manifestations

1. Hematuria

1. Minor form

intermittent gross hematuria +/- persistent micro-scopic hematuria

2. Major form

persistent gross hematuria with + proteinuria

2. Proteinuria

can progress to the nephrotic level

3. Complications

Nephritic Syndrome (edema, hypertension, azotemia, oliguria)
Nephrotic Syndrome (edema, hypoalbuminemia, hyperlipidemia)
Chronic Renal Failure

Note: usually history of abrupt onset of gross hematuria in association with an IgA-triggering illness (respiratory or intestinal-inflammatory bowel disease or celiac) or vigorous exercise

2. Extrarenal Manifestations

30% have extrarenal manifestations of rash and arthralgia

INVESTIGATIONS:

1. Urinalysis

hematuria, proteinuria (zero to nephrotic)
microscope - glomerular pattern - damaged RBC's & RBC casts

2. Serum

elevated IgA and circulating immune complex of IgA
normal urea, creatinine, and C3

3. Renal Biopsy

focal and segmental mesangial proliferation
diffuse mesangial deposition of IgA with lesser amounts of
IgG, IgM, C3, and properdin
renal lesion indistinguishable histopathologically from that of Henoch-Schoenlein Purpura

MANAGEMENT:

1. Supportive

no treatment for underlying disorder
multidisciplinary approach
- Paediatrics, Nephrology

2. Medical

1. For Active Disease

1. Acute Phase

1. Methylprednisolone (Solu-Medrol)

pulse steroids
10 mg/kg IV every 2nd day x 6 doses

2. Chronic Phase

1. Prednisone

2 mg/kg/day po od (to max. of 60 mg/day) x 4 weeks
2 mg/kg/day po alt. day (to max. of 60 mg/day) x 6-12 months

2. Medical Management of Complications

1. Nephritic Syndrome

fluid restriction, control hypertension, manage hyperkalemia, manage pulmonary edema

2. Nephrotic Syndrome

fluid restriction, salt-free diet, diuretics, albumin transfusions, prednisone, alkylating agents

3. Chronic Renal Failure

dialysis, transplant

3. Prognosis

many have persistent benign mild disease
10-50% of cases progress to renal failure
poor prognostic signs
- hypertension
- decreased renal function
- proteinuria (>1g/day)
- diffuse glomerulonephritis

Pediatric Database - IgA NEPHROPATHY (BERGER NEPHROPATHY)

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