A 44 year old man with previous interstitial nephritis (22)

This man was diagnosed with interstitial nephritis secondary to mesalazine (prescribed for ulcerative colitis) in 2009.  His eGFR has remained stable since and is curently 42.  Last year he was started on lisinopril for hypertension but this was stopped some months later as his BP was too low.  The plan then was to reintroduce if BP over 130/80 or if proteinuria worsened.  Urinary PCR was 15 mg/mmol.

His PCR has increased a bit to 20; blood pressure on his last two visits 123/83, 124/96.  I just wanted to check that we should add in lisinopril 2.5mg in vew of this.

I also note that his cholesterol was recently 6.1, LDL 4.2, chol/HDL ratio 4.2.  I wonder if we should be starting a statin also?  He has no significant family history of heart disease and is an ex-smoker.  Other therapy is azathioprine (only) for ulcerative colitis.

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That level of proteinuria, just outside the normal range, wouldn’t trigger me in his case.  Any threshold is going to be arbitrary, but 50 is sometimes uesd.  Consistently over 50 maybe.  His BP is well within limits. His CV risk is low (see Further Info)

Proteinuria is in general a strong marker for progression of renal disease, with higher levels indicating much higher risk.  Mostly we are talking about glomerular leaking of protein.  He actually had tubulointerstitial disease rather than glomerular, which is associated iwth lower levels of proteinuria in general, and lower risk of progression if the cause is removed (as it is in him).

If he showed any signs of long term deterioration I’d be stricter but he seems to have experience a small fall in creatinine over the last couple of years.

Further info

  • CV risk calculator gives him a 10y risk of CV events of 3.6% – this does not include proteinuria however, which would ‘usually’ probably at least double risk, though this is contentious in this patient’s unusual circumstances.
  • Interstitial nephritis (Edren Textbook)
  • The Edrep Glomerulonephritis page has a link to a 10 min lecture on Interstitial nephritis (requires Flash).  The Resources page there has more links

An oedematous 15 year old

A 15 year girl presents to Queen Elizabeth Hospital Blantyre with a one-month history of facial oedema.  It is worse in the morning, slightly better at night and not associated with shortness of breath or cough.  She has been well recently, with no intercurrent illnesses.  She has never had any body swelling until noticing swelling of her feet in the last week or two. On further questioning, 6 months ago she probably had an episode of macroscopic haematuria.  She has not reached menarche.  She lives in Nkhotakota.

On examination she is slim but has marked bilateral pitting pedal oedema and facial puffiness; she probably also has ascites.  She is apyrexial.  General examination is unremarkable.  Her BP is 110/60, pulse 72.  She has reduced breath sounds and dullness to percussion at both lung bases.  Heart sounds and abdomen are normal and she has no neurological deficit.

A urine dipstick shows 4+ protein, 3+ blood.  She has a serum creatinine of 60 micromol/l (0.7 mg/dl) and a normal blood count.  Tests of liver function, serum proteins are not available.

  1. What is the differential diagnosis at this stage?
  2. Further immunological tests are not possible, nor is a renal biopsy, but what simple tests are essential to your management?

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The urine dipstick findings are strongly suggestive of ‘nephritic’ type glomerulonephritis.  In this region, post-infectious glomerulonephritis is the most likely cause, though the history here is long, and she is not hypertensive.  Other causes are certainly possible.  However …

Urine microscopy is a key test in a patient with suspected glomerulonephritis.  In her case it showed red cells, but these were of normal shape, and no casts were seen.  However Schistosoma haematobium ova were seen.

Schistosomiasis is endemic around Lake Malawi.  A positive dipstick test for blood would usually be taken to indicate current infection.  Serology for Schistosoma antibodies is of no value as previous exposure is usual.

This complicates interpretation and management significantly.  Given that her creatinine and blood pressure were normal, she was treated for Schistosomiasis and reviewed one month later.  At that review she is still oedematous and urine dipstick shows 4+ protein.  Now what do you think?

Read more in A 16 year old girl with oedema

Further info

Case contributed by Fran Th’ng and Gavin Dreyer


 

 

 

Optimising an ACEI (16)

An 83 year old woman attends the GP surgery for a blood pressure review.

Blood pressure has been high for a while (systolic ~160).  She was taking ramipril 1.25mg and diltiazem HCL 360 mg OD.  She had been taking bendrofluazide but this was stopped during a recent hospital admission due to hypokalaemia.   BP a couple of weeks ago is still very high with values of 218/93 and 200/100. Consequently, I initially increased her ramipril 10 days ago to 2.5mg OD.  Her BP this week is 210/78 and repeat U+Es were ok, so I increased the dose again to 5mg.

She is sytemically well other than for a recent altered bowel and mild weight loss for which she has been referred to colorectal.

I was planning to increase ramipril to 10mg as tolerated but I am not sure how quickly I should be increasing the dose.   I am concerned about her high BP and also concerned about increasing the dose too quickly due to her age.  I also wonder if she requires any further investigation in view of her significant proteinuria?

What further information would you seek before giving your opinion?

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Urine  ACR 467 and PCR 259.  No haematuria.  Her eGFR is 50 and stable.

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You’re doing all that I’d do. The proteinuria level is technically above the recommended referral threshold (PCR 100), but at her age I’d be unlikely to go on to do a biopsy unless she was actually nephrotic or had deteriorating function.   In view of the proteinuria, maximising ACEi would be my first step too.   This can be done quickly (days to weeks) provided BP and renal f(x) are monitored.

 If her eGFR drifts down or there is an increase in proteinuria then it would be worth referring her to the renal clinic. That said, you can allow up to around a 20% rise in creatinine around the time of institution of ACE inhibition.


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Proteinuria in Type 2 Diabetic (5)

This 63 year old gentleman is a type II diabetic with treated hypertension.  He attended for review 2 weeks ago and had an ACR sent as part of his diabetes care.  The urinary ACR was high with an albumin of 166, creatinine of 2.91 and ACR of 57.4.  The ACR was repeated with an MSU – the MSU was negative with no evidence of red cells.

When I saw the patient today I changed him on to gliclazide from pioglitazone, along with his metformin, and aim to titrate this up to try and get better diabetic control.  The patient is on an ACEi and his BP today was 132/78.

Looking back in the patient’s record he has had problems with right hydronephrosis, left sided renal calculi and a previous renogram showed some scarring. Since then he has had some episodes of renal colic and received lithotripsy in 20 years ago. He has not been troubled by renal colic recently.

My enquiry really is to get some advice as to whether an ACR at this level in this situation requires any further investigation or input from the renal service? Or should we continue to monitor and control his BP? Also at what level would you want to see someone with a high ACR?

What further information would you seek before giving your opinion?

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Medications;
Zopiclone, Quinine, Metformin, Sildenafil, Glicazide, Amlodipine, Fosinopril, Co-codamol, Bendroflumethiazide, Atorvastatin, Aspirin, Diclofenac

A summary of the results for this patient;

Urine 2 years ago – ACR 12.5 mg/mmol
Urine 2 weeks ago – ACR 57.3
Urine today – ACR 55.2

Blood Today – Urea 5.0 / Creatinine 72 / eGFR> 60 / Sodium 138 / Potassium 4.0 /  HBA1c  8.1

Now consider which one of these three options to go for: 

  1. Give Advice
  2. See in Outpatients non-urgently
  3. Send this patient to us now!

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Assuming there is no microscopic haematuria, then I think it is fair to assume that the raised ACR is due to diabetic nephropathy.  At that level, I would be looking to improve his BP further – ideally a target of 125/75 to be sure we match current recommendations.  The ACEi is indicated as he is a diabetic with proteinuria.  In some patients adding in an ARB may improve BP and reduce proteinuria further. (Controversial whether that improves outcomes though).

I would have some concerns about a diabetic patient (albeit good renal function) on the combination of an ACEi, Metformin and regular NSAIDs. Essentially he must discontinue the ACEi and NSAID in the event of any intercurrent illness such as diarrhoea, vomiting or fever. I would review whether he needs regular NSAID.


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