BOARD REVIEW

NEPHROLOGY 2

Renal imaging

• X Ray- all renal stones show up except uric acid• Renal US- size, obstruction, masses, screening for Polycystic dz,

stones> 5 mm• IVP- non glomerular hematuria, renal stones, voiding disease,

unexplained flank/ abdominal pain• Spiral CT without contrast- stones, perirenal hrg• CT with contrast- staging of renal masses• Radionuclide scan- to assess renal perfusion• Renal arteriography- renal artery disease• MRI- renal vein thrombosis• Renal bx- glomerular disease

GlomerulopathyPearl to remember-when glomerulus affected- urine should have 3 things!Dysmorphic RBC, RBC casts, proteinuria

• 1. subepithelial- small deposits of membranous GN,

• 2. subendothelial-lupus• 3. mesangial-Ig A

nephropathy• 4. basement membrane

deposits: Good Pasture, hump appearance of deposits in poststreptococcal GN on the epitelial side of GBM

Presentation of glomerular disease

Nephrotic syndrome

Nephritic syndrome

Urinary findings Fatty casts, oval fat bodies

RBC casts, cola, smoky urine

proteinuria > 3 g/day <2.5 g/day

hematuria +/- +

Clinical features Generalized edema, periorbital edema, HTN

HTN

Histopath presentation

Minimal change

……

Post strep GN

….

Glomerular disease with nephrotic sdr

Primary Secondary

Minimal change disease

Focal segmental glomerulosclerosis

Membranous glomerulopathy

DMSLE

Amyloidosis

Vasculitis

Glomerular disease with nephritic sdr

Low serum C Normal serum C

Post streptococcal

SLE

Cryoglobulinemia

Idiopathic membranoprolipherative

IgA nephropathy( Berger’s disease)

Goodpasture’s srd

Systemic vasculitis( Wegener, PAN, Henoch Schonlein Purpura)

TTP/HUS

Minimal change disease

• Etio: mostly idiopathic• sec: Hodgkins/ Leukemia/NSAIDs/ Lithium• Bx: normal• IM: normal• EM: diffuse effacement of the epit foot processes• Complement: normal• Tx: steroids• Best prognosis of nephrotic syndromes

Focal segmental glomerulosclerosis

• Etio: Most common cause of idiopathic nephrotic syndrome in African Americans

• Sec causes: heroin use, HIV, sickle cell disease, obesity, urinary reflux

• Heroin has been associated with this condition but this association has waned in the past decade(MKSAP 13)

• Bx: sclerosis of part of glomerulus in few glomeruli• IM: IgM + C3• C: normal• Tx: steroids /cyclophos

Question

• 1. 31 year old AA male comes with BP of 150/90. His father has HTN. Patient has history of drug abuse in the past. Urine check up reveals hematuria + proteinuria> 3g/day. What is the most likely renal lesion:

• A) Focal segmental glomerulosclerosis• B) minimal change disease• C) HTN nephropathy• D) Membranous glomerulopathy• 2. A 33 year old male with Hodgkin’s disease has 2 months h/o

edema of the feet. He now comes to you with acute SOB. O/E lungs are clear, CXR is normal. ABG: ph 7.56, pCO2 20, pO2 62, urine 4+ prot, 24 h urine prot 5g. What is the possible diagnosis?

Membranous glomerulopathy

• Etio hep B, C, syphilis, tumors( solid), NSAIDs, SLE, captopril

• Gold, penicillamine• Bx: thickened capillary loops• IM: granular IgG+ C3• EM: subepitelial deposits( wire loop changes)• C: normal• Tx: steroids, cyclophosphamide

Membranoproliferative GN

• Etio: hep B, C, malaria, SLE, cryoglobulinemia, subacute bacterial endocarditis

• Bx: tramtrack appearance• IM: mesangial deposits• EM: ribbon, sausaging of membrane• C: low• Tx: steroids, Cyclophosp

Complications of nephrotic sdr

• Prot> 3g/day hypoalbuminemia edema• hypogammaglobulinemia infections• loss of antithrombin III thrombosis, PE• loss of transferrin iron def anemia• fat bodies, fatty casts in

urine, hyperlipidemia • Tx: ACE inhibitors• Low salt • Loop diuretics• HMG CoA reductase inh

Diabetic glomerulopathy

• DM is the commonest secondary cause of nephrotic sdr in adults

• Sequence of events are microalbuminuria( not detected by urine dipstick) decline in renal function diabetic microvascular retinopathy gross proteinuria( detected by dipstick)

• Nephropathy that is diffuse and nodular, develops slowly and dialysis or transplant is required

Diabetic glomerulopathy- questions

• 1. a patient with DM has proliferative changes in the fundus. He also has prot-uria. Would you expect him to have DM nephropathy?

• 2. When would you do kidney bx in a patient with DM and nephropathy?

• 3. Under a light microscope, a kidney bx shows large appearing nodular masses in the glomerulus. What is the differential diagnosis?

• Next- do congo red and examine under the polaring microscope

Amyloidosis

• 1. AL type is the primary disease( macroglossia) and is also associated with MM. It is due to the overproduction of light chains- mostly lambda chains. Dg can be made from gingival, rectal, fat pad, renal bx

• Al type is congo red positive Renal failure occurs in 1-2 years. Treatment with melphalan and prednisone.

• 2. AA type is the secondary form-due to chronic inflammation and it occurs in chronic drug abusers where amyloid nephropathy follows the chronic skin infection resulting from skin popping. It is treated by correcting the underlying inflammatory condition- some patients respond to colchicine

Skin popping

Glomerulopathy following URI

• An 18 year old male Asian male has gross hematuria developing over few days after URI. BUN and creatinine are normal. Serum C is normal. Urine is conc with specific gravity of 1030. There is 2+ prot-uria and 4+ blood. Urine sediment shows dysmorphic RBC and RBC casts. What is the possible diagnosis?

• Post strep GN or IgA nephropathy?

Post streptococcal( post inf nephritis)

IgA nephropathy

(Berger’s disease)

Latent period Occurs within 3 weeks after URI or impetigo with nephritogenic strains

It occurs within 3 days after URI and is the commonest cause of acute GN

pathogenesis Entire glomerulus with many glomeruli are involved causing oliguria, azotemia, HTN

Subepitelial humps( IgG, C3)

It is the mesangial hypercellularity( mesagial proliferative GN) in few glomeruli and causing hematuria- which commonly occurs either during a viral illness or after execise

Lab findings CH50 and C3 level are low, ASLO positive

Serum C is normal

Serum IgA elevated

treatment antibiotics None. ACE inhib slow the progression of disease

Question

• 1. A 24 year old female presents with arthralgias, low grade fevers, Raynaud’s phenomenon. Malar rash+, bilateral pedal edema+. BUN/ creatinine 35/2.2. Serum complement decreased. ANA anti dsDNA increased.

• UA 15-20 RBC, RBC casts+, prot 4+• 24 h urine prot- 4 g/day• Renal bx will most likely show:• A) mesangial lupus nephritis• B) membranous nephritis• C) focal proliferative GN• D) membranoproliferative( diffuse proliferative)

Question

• All of the following will have low complement except?• A) post streptococcal GN• B) SLE• C) SBE• D) cryoglobulinemia• E) MPGN• F) minimal change disease

Question

• 1. All of the following have normal complement except?• A) minimal change disease• B) focal segmental glomerulosclerosis• C) membranous nephropathy• D) IgA nephropathy• E) Henoch Schonlein nephropathy• F) Cryoglobulinemia

Question

• A patient is admitted with massive hemoptisis. Workup reveals severe renal failure. There is no past history of renal disease. A renal bs shows diffuse glomerulonephritis with giant cell granuloma. What is the most probable diagnosis?

• You are shown a biopsy of the glomerulus with linear deposits ( IgG in linear fashion along the capillary loop) What Ab would you order in serum?

• Anti glomerular basement membrane

Question

• A 17 year old male homosexual having a single partner, comes with hemoptysis 2 days after an URI. Chest Xray shows bilateral interstitial infiltrates. Urine exam shows gross hematuria, modest proteinuria, and on microscopy, dysmorphic RBCs and red cell casts. A kidney biopsy shows IgG deposits in linear fashion along the capillary loop. What is the possible diagnosis?

• A) Good Pasture• B) Wegener’s• C) Kaposi’s sarcoma• D) HIV nephropathy

Question

• A 65 year old woman is referred to you for evaluation of HTN. Six months ago, initial serial blood pressure readings range from 160/110 to 170/120 mmHg. BP was brought under control with three antihypertensive agents. The patient has been asymptomatic. There is no family history of HTN. On exam BP 170/105 in both arms, and similar readings are recorded in both legs. Fundoscopy reveals hemorrhages and exudates. A systolic and diastolic bruit is heard in the left mid abdomen and through the back. Serum creatinine is 2.3 mg/dl, K is 3.9. UA shows 1+ prot-uria. An EKG shows LVH. What is the most appropriate noninvasive screening test for possible renal artery stenosis in this patient?

• A) pre and post captopril peripheral plasma renin activity?• B) CT angiography with contrast• C) rapid sequence iv urography• D) magnetic resonance angiography