Answers for Day 2

1) A    –  ds-DNA in lupus is associated with disease activity (increased in active ongoing lupus nephritis)

2)  C  – HSP is associated with IgA deposition in mesangium. Note the fleeting type of symptoms, which is classic for HSP  a) Intermittent abdominal pain

b) Migratory polyarthritis

c) Waxing and Waning palpable purpuric rash

IgA nephropathy is a primary renal disease secondary to under galactosylated IgA and subsequent IgG orIgA1 antibody against the abnormal IgA with deposition of antigen + antibody complex in the mesangium. HSP is a systemic vasculitis !

3) B – MPO ANCA vasculitis with GPA presentation! Given the RPGN picture, cytoxan and glucocoticoids is the right answer. However, if this question is framed as a very mild case of MPO ANCA associated GPA, rituximab with glucocorticoids is the answer.(RITUXVAS)

4) C – APSGN.  Low C3 and normal C4 indicated alternate complement pathway activation(strep infection classically leads to alternate complement activation). You dont expect C1q, C4 in the biopsy !

5) A – Anti-GBM disease


6) D -C3 glomerulopathy. Uninhibited alternate complement pathway activation by the deficiency of complement regulatory factors! In this case factor H related proteins!



X linked diseases in kidney !

What about these X linked diseases in kidney !

From board stand point, Alport syndrome and  Fabry disease are important AND both these disorders are X linked.

Alport syndrome : Mutation in COL4A5 gene (Thin membrane disease is a structural anomaly secondary to mutation in COL4A3 and COL4A4)

Fabry disease : Mutation in alpha galactosidase A gene.

There are autosomal variants of these diseases and can rarely affect females but not tested in the boards usually!

Dent’s disease – familial nephrolithiasis is also X linked.

ADPKD  is autosomal dominant (as the name implies) – 40% associated with liver cysts, 5% associated with AVM . It is not cost effective to do screening for AVM in all patients with ADPKD. However, if there is a family history of Hemorrhagic stroke (where the risk of AVM goes up to 20%), Screening is recommended !

Medullary sponge kidney is usually a developmental anomaly but can have a hereditary predisposition!


Radiology for boards

1) Should be able to identify stone – hypoechoic shadow is a clue

2) Should be able to identify ADPKD, Aquired cystic disease of dialysis (history will be helpful), Benign cyst and RCC  – Understanding Bosniak classification of cyst is helpful for diagnosis

3) Irregular margin and contrast enhancing cyst is RCC

4) US screening for Renal artery stenosis –  RA/A >3.5/1

RA velocity>2mps

It is also useful to understand the downstream waveform in the lobar and lobular arteries- Tardus parvus waveform and loss of ESP(early systolic peak) notch suggests significant RAS

5) Should be able to identify hydronephrosis

6) RI in normal kidney is<75 and Transplant kidney is<80  . RI is systolic/systolic +diastolic flow. RI of1 indicates no diastolic flow.

7) Granulomatous pyelonephritis – easily identified. Needs nephrectomy!

8) Non contrast CT stone protocol has 98%PPV and 98%NPV

9) Calcification – Medullary calcification and cortical calcification is easily recognized by location. Irregular bilateral asymmetric medullary calcification is usually Medullary sponge kidney

10) In post transplant kidney – elevated RI and Elevated Peak systolic velocity in Renal artery >300 cm/sec doen not indicate stenosis and it should normalize within 72 hours of transplant.


These are some of the high yield points in imaging. Please tag other points you may consider worthwhile revising or for understanding.(tag to this post)


Answers to Day 1 questions (10 questions)

1) C – ANCA vasculitis treatment  – prednisone and Cyclophosphamide. There is plasmapheresis in the choice . If they specifically ask for initial therapy, then prednisone and plasmapheresis could be considered. This patient did not have pulmonary hemorrhage and was not sick !

2) B – Fabry disease. This is an X linked recessive disease which predominantly affects male ! Deficiency of Alpha galactosidase A causes accumulation of sphingolipids(glycolipids and in this disease specifically galactoacylcerebrosidase) in blood vessels , nerves kidney and heart. The manifestations are neurological(pain and tingling in extremities, progressive CKD-especially in 3 decade, Cardiac hypertrophy, abdominal pain(accumulation of sphingolipids in blood vessels supplying intestines) and skin rash(especially around the umbilicus)

3) D – Sickle cell/Tylenol/NSAID combination should raise suspicion about papillary necrosis

4)A – Arterial line is negative pressure and is causes dialysis catheter to flatten out!

5) B – most common cause of intradialytic hypotension is diastolic dysfunction. I was tempted to choose pericardial effusion given the stem of the case .

6) E – Hyperglycemia- very common cause of PD ultrafiltration failure since it decreases the solute gradient dramatically!

7) C – Isolated scrotal swelling should raise concerns about patent processes vaginalis in a new PD patient

8) E  -Gentamycin toxicity- hypomagnesemia

9) C – Cyclosporine toxicity causes hirsutism

10) B – Increased urine oxalate -pathogenesis for calcium oxalate stone in Chron’s disease


Hope the explanation helps!