Chapter 29: Membranoproliferative Glomerulonephritis
MPGN is associated with abnormal activation of in which of the following systems?
C. Alternate pathway of complement
D. Vasopressin-V2 receptor
The answer is C. Abnormal activation of the alternate pathway of complement has been documented in patients with MPGN. It can be due to genetic mutations that alter the activity of complement regulatory proteins. The kallikrein system is involved in blood pressure control but is not specific for MPGN. The pituitary-adrenal axis is normal in patients with MPGN, interaction between AVP and the V2 receptor contribute to autosomal dominant polycystic kidney disease but not MPGN. There is no evidence of a specific disturbance in the Th1 or any other lymphocyte subset in patients with MPGN.
A 62-year-old man is noted to have fatigue and impaired renal function. eGFR 46 mL/min/1.73 m2. He has not traveled recently, He has nephrotic range proteinuria. He has no fever and his BP is 148/86. He has no jaundice and is breathing comfortably. The cardiac examination is normal. The ANA and ANCA titers are negative. A renal biopsy reveals type 1 MPGN. The most likely cause is
The answer is B. This older man has no pulmonary or hepatic complaints making sarcoidosis and hepatitis unlikely. The absence of travel makes malaria an unlikely diagnosis. He has no fever or murmur which would exclude endocarditis. The presence of MPGN with nephrotic range proteinuria is most consistent with the presence of a monoclonal gammopathy.
A 14-year-ol adolescent girl is noted to nephrotic syndrome. The eGFR is 101 ml/min/1.73 m2 but the C3 is 36 mg/dl and the ANA titer is normal. Which of the following laboratory tests is most likely to establish the diagnosis?
B. Anti-neutrophil cytoplasmic antibody titer
E. Neutrophil gelatinase associated lipocalin
The answer is D. Serum amyloid protein is a nonspecific acute phase reactant. ANCA associated vasculitis is not associated with hypocomplementemia. IgA nephropathy rarely presents with nephrotic syndrome ...