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Overview of Glomerular Disorders
The hallmark of glomerular disorders is proteinuria, which is often in the nephrotic range (≥ 3 g/day).
Glomerular disorders are classified based on urine sediment as those that manifest predominantly with
Nephrotic syndrome (see Overview of Nephrotic Syndrome) is nephrotic urine sediment plus edema and hypoalbuminemia (typically with hyperlipidemia).
Nephritic syndrome (see Overview of Nephritic Syndrome) is nephritic urine sediment with or without hypertension, elevated serum creatinine, and oliguria.
Several glomerular disorders typically manifest with features of both nephritic and nephrotic syndromes. These disorders include but are not limited to, fibrillary and immunotactoid glomerulopathies (see Fibrillary and Immunotactoid Glomerulopathies), membranoproliferative glomerulonephritis (GN—see Membranoproliferative Glomerulonephritis), and lupus nephritis (see Lupus Nephritis).
The pathophysiology of nephritic and nephrotic disorders differs substantially, but their clinical overlap is considerable—eg, several disorders may manifest with the same clinical picture—and the presence of hematuria or proteinuria does not itself predict response to treatment or prognosis.
Disorders tend to manifest at different ages (see Glomerular Disorders by Age and Manifestations) although there is much overlap. The disorders may be primary (idiopathic) or have secondary causes (see Causes of Glomerulonephritis and see Table: Causes of Nephrotic Syndrome).
A glomerular disorder is usually suspected when screening or diagnostic testing reveals an elevated serum creatinine level and abnormal urinalysis (hematuria with or without casts, proteinuria, or both). Approach to the patient involves distinguishing predominant-nephritic from predominant-nephrotic features and identifying likely causes by patient age, accompanying illness (see Glomerular Disorders by Age and Manifestations and see Table: Causes of Nephrotic Syndrome), and other elements of the history (eg, time course, systemic manifestations, family history).
Renal biopsy is indicated when diagnosis is unclear from history or when histology influences choice of treatment and outcomes (eg, lupus nephritis).
Glomerular Disorders by Age and Manifestations
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