Pathology-Glomerular Diseases Flashcards
What are the main causes of end-stage kidney disease?
Diabetes (40%), HTN (30%), Glomerulonephritis (20%) and Cystic (10%)
When is a kidney biopsy indicated?
Nephrotic proteinuria, nephritic syndrome and unexplained CKD.
What clinical features are hints at a diagnosis of nephrotic syndrome?
Proteinuria > 3.5 g/day, spot urine protein/creatinine ratio > 2 g/g, hypoalbuminemia, hyperlipidemia and edema.
A mother brings her 5 year old girl to see you. She says that she got a really puffy face overnight (anasarca). Her blood pressure was normal and she had a spot urine protein/creatinine ratio of 10g/g. An image from her kidney biopsy is shown below. What would you expect to see under EM imaging of this patient’s glomerulus? How would this account for the edema observed in this child?
Effacement of the podocyte foot processes. This is typical in minimal change disease and accounts for the proteinuria w/protein leaking through the effaced basement membrane. Loss of protein in the urine would account for the edema seen in this child
A mother brings her 5 year old girl to see you. She says that she got a really puffy face overnight (anasarca). Her blood pressure was normal and she had a spot urine protein/creatinine ratio of 10g/g. Renal biopsy is shown below. Her symptoms resolved with treatment after just a few days. What was the likely treatment?
This child has Minimal Change Disease. Treatment is oral Prednisone for 8 weeks and then they will probably relapse and then you do more rounds of steroids and relapse until the condition resolves.
A 17 year old high school football player goes to his pediatrician for a physical. His UA reveals proteinuria 3g/L and 1st void urine protein/creatinine ratio is 4g/g. His renal biopsy is shown below. What is your diagnosis?
Focal Segmental Glomerular Sclerosis. Note the segment of fibrosis in the urinary pole of the glomerulus. On a more low-power view you would also note that not all of the glomeruli are affected this way.
The famous NBA player Alonzo Mourning has a certain glomerular disease. What lab value is a key indicator about how long his kidneys will survive?
In Focal Segmental Glomerular Sclerosis renal survival is indicated by proteinuria response to therapy. 20% of patients have complete remission, 40% have partial and 40% have no response to therapy.
A 60 year old retired Army sergeant came to see you because he said his pee has been foamy over the last month. He also says that his ankles have gotten swollen over the past month. He has no significant medical history. His labs reveal serum creatinine 1.4 mg/dL compared to 1.1mg/dL one year earlier. His urine protein is 6g/day. Renal biopsy is shown below. What would you expect to see on EM?
This patient has membranous nephropathy. Note that on light microscopy his basement membrane is thickened. On EM you would see immune complex deposits confined to the basement membrane (sub epithelial).
A 60 year old retired Army sergeant came to see you because he said his pee has been foamy over the last month. He also says that his ankles have gotten swollen over the past month. He has no significant medical history. His labs reveal serum creatinine 1.4 mg/dL compared to 1.1mg/dL one year earlier. His urine protein is 6g/day. Immunofluorescence staining is shown below with IgA antibody and C1. What is your diagnosis?
Membranous nephropathy. It is characterized by IgA autoantibody binding to antigen in the glomerular basement membrane. Complement is also involved.
A 70 year old man presents with a pathologic bone fracture in his right femur. Radiographs show a lytic lesion in the other femur. Labs reveal a total serum protein of 8g/dL and serum albumin of 2g/dL. Bone marrow biopsy shows 40% plasma cells. His plasma electrophoresis is shown below. What effect will this condition have on the patient’s kidney?
The patient has multiple myeloma. His history, radiograph, high plasma cell count and dark smears of specific for IgM and lambda confirm this diagnosis. The overproduction of lambda causes amyloid deposition in the glomerulus as shown below in the congo red stain with apple-green birefringence and PAS+ clumps.
What are the diagnostic features of glomerulonephritis?
Proteinuria 1-5g/day, edema, hematuria, cellular casts in urine, HTN and reduced GFR.
A 14 year old boy comes to your office with impetigo. You give him some topical antibiotics and send him home. Two weeks later he comes back complaining of dark urine and peripheral edema. Physical exam reveals an elevated blood pressure, Urinalysis reveals elevated serum creatinine, hematuria and RBC casts in the urine (seen below). What would you expect to see on this patient’s renal biopsy?
This is Post-Streptococcal Glomerulonephritis. This happens when autoantibodies find their way into the basement membrane. You would see PMN infiltrate and mesangial proliferation in the glomerulus. You would also see sub epithelial humps on EM.
An 18 year old man comes to see you complaining of cola-colored urine lasting a few days after he has upper respiratory infections. His blood pressure is 140/90. Labs reveal urine protein of 400mg/day when he is asymptomatic. What would your expect to see on renal biopsy in this patient?
This patient has IgA nephropathy. You would see and increase in mesangial cells and matrix. You would see IgA immune complex deposition in the mesangium.
What racial groups are at greater risk for IgA nephropathy?
African descent> European descent> Asians
A 23 year old woman comes to see you because she is worried that her hands turn blue in the cold. Physical exam reveals a facial rash. Labs reveal a hematocrit of 30%, increased creatinine of 1.8mg/dL and WBC/RBC casts in the urine. Her urine protein/creatinine ratio is 4g/g. She tested positive for ANA and anti-DS DNA antibody. What would you expect to see on renal biopsy?
This patient has Diffuse Proliferative Lupus Nephritis. You would see increased mesangial cellularity and subendothelial and mesangial immune complex deposition.
What are the differences between nephrosis and nephritis in these categories?
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