Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 22-14: Nephritic Spectrum Glomerular Diseases + Key Features Download Section PDF Listen +++ ++ Primary renal disease with IgA deposition in the glomerular mesangium Inciting cause unknown but is likely due to deficient O-linked glycosylation of IgA subclass 1 molecules Can be a primary (renal-limited) disease Can be secondary to Hepatic cirrhosis Celiac disease HIV infection Cytomegalovirus infection Most common primary glomerular disease worldwide, particularly in Asia Usually occurs in children and young adults Males affected 2–3 times more often than females + Clinical Findings Download Section PDF Listen +++ ++ Gross hematuria, frequently associated with a mucosal viral infection often of the upper respiratory tract infection Urine becomes red or smoky-colored 1–2 days after illness onset Can present anywhere along the nephritic spectrum from asymptomatic microscopic hematuria to rapidly progressive glomerulonephritis Rarely, a nephrotic syndrome can be present as well + Diagnosis Download Section PDF Listen +++ ++ Can present anywhere along the nephritic spectrum from asymptomatic microscopic hematuria with minimal proteinuria and preserved eGFR to RPGN Rarely, nephrotic syndrome can occur, as well Glomerular hematuria: microscopic is common; macroscopic (gross) can occur after infection Positive IgA staining on kidney biopsy Serum complement levels usually normal No serologic tests aid in diagnosis; serum IgA subclass 1 testing may be possible in future Renal biopsy Light microscopy shows focal glomerulonephritis with proliferation of mesangial cells Immunofluorescence shows diffuse mesangial IgA and C3 deposits + Treatment Download Section PDF Listen +++ ++ Patients with low risk for progression (no hypertension, normal glomerular filtration rate [GFR], minimal proteinuria) can be monitored annually Angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) Recommended for patients at higher risk for progression (proteinuria > 1.0 g/day, decreased GFR, and/or hypertension) Therapy should be titrated to reduce proteinuria to < 1 g/day and to reduce blood pressure to between 125/75 mm Hg and 130/80 mm Hg Addition of corticosteroids (eg, methylprednisolone, 1 g/day intravenously for 3 days during months 1, 3, and 5, plus prednisone 0.5 mg/kg orally every other day for 6 months) in those with GFR > 50 mL/min/1.73 m2 and persistent proteinuria > 1 g/day Has been shown to reduce proteinuria However, there seems to be little durable effect Risks of infection and dysglycemia are significant Azathioprine and mycophenolate mofetil Have also been used in patients at high-risk for progression However, studies with these agents are small Therefore, routine use is not recommended Cyclophosphamide and corticosteroid therapy should be considered for the rare patient with a rapidly progressive clinical course with crescent formation on biopsy Kidney transplantation ~33% of patients experience spontaneous remission Chronic microscopic hematuria but stable serum creatinine occur in 50–60%; progression to end-stage renal disease occurs in 20–40% Most unfavorable prognostic indicator: proteinuria > 1 g/day Other unfavorable prognostic indicators Hypertension Tubulointerstitial fibrosis Glomerulosclerosis or glomerular crescents on biopsy Abnormal GFR on presentation