Today we discussed an interesting patient with acute kidney injury in the setting of HIV, HCV, and DM II.
Acute kidney injury occurs more frequently in HIV+ patients than in HIV- individuals. This is distinct from the increased frequency of chronic kidney disease we sometimes see as the result of the HIV-associated glomerulonephropathies (ie HIV-associated nephropathy, IgA nephropathy).
The approach to renal failure remains the same: prerenal, renal, and postrenal. However, there are some specific causes that must be weighted more heavily or added to this list as a function of the patient being HIV+. For example:
Aside from the usual, prerenal causes must also include:
Pancreatitis (leading to 3rd spacing)
Cirrhosis/hepatorenal syndrome
Diarrheal illnesses
Renal causes must also include:
ATN
prolonged prerenal failure (not specific to HIV, but still the most common cause for ATN)
amphotericin B
aminoglycosides
pentamidine
ritonavir
cocaine
Acute tubulointerstitial nephritis
Several Abx, H2RB (ie ranitidine), NSAIDs
glomerular
HIVAN
IgA nephropathy
Immune-complex GN (ie cryoglobulinemia in the setting of HCV coinfection)
vascular
TTP, HUS
drug-induced
infection
crystal-associated nephropathy
sulfadiazine
indinivir
acyclovir
Aside from the usual, post-renal should also include:
nephrolithiasis (increased suspicion)
urethritis
retroperitoneal disease (ie lymphadenopathy)
infections (including fungal, TB-suspect in aseptic pyuria)
See here for a review that outlines the broad ddx.
Lastly, this study here looked at ARF in hospitalized HIV+ patients before and after the advent of HAART and found that HIV+ patients were more likely to have CKD, but also more likely to have ARF before and after HAART (adjusted OR 4.62 (4.3-4.95), and 2.82 (2.66-2.99), respectively. Age >65, DM, CKD, acute/chronic liver disease, and hepatitis co-infection were all statistically significant risk factors for development of ARF - interesting given that our patient had many of these. Interestingly, the incidence of acute renal failure was higher in the post-HAART era. Not surprisingly, in-hospital mortality was higher in HIV+ patients with ARF than in those without (OR 5.83 (5.11-6.65). Of course, it is difficult to say whether ARF is an independent predictor or more a marker of more severe illness.
Also important to remember a couple of very common drugs that are used in the current management of HIV. Trimethoprim/Sulfamethoxazole (Septra (R) and others) can cause ATIN although it more commonly causes hyperkalemia. Tenofovir is a very commonly prescribed antiretroviral (one component of Atripla (R)) that has been associated with proximal tubular dysfunction and renal failure although the exact risk is not yet quantified. It might be more concerning when used with other nephrotoxic drugs. An earlier related drug, adefovir, is no longer used for HIV because of safety concerns (it is used in much lower doses to treat Hepatitis B).
ReplyDeleteDr. Bayoumi definitely beat me to this, but indeed, I have seen a few patients with an increased Cr who were on tenofovir (TDF); once removed, the Cr normalized once again! In terms of reversibility, it appears to be fairly reversible, but I guess this is a multivariable function and would need to take into consideration underlying possible HIV-nephropathy or other renal issues present. I thought I would bring it up as Atripla (efavirenz, tenofovir, and FTC), one pill once a day, is gaining popularity and may become much more prominent in your patient population. If you ever encounter a patient with proximal renal tubular dysfunction +/- hypocalcemia or present similarly to a Fanconi Syndrome and on TDF, think TDF as part of your differential diagnosis!!!
ReplyDeleteOther bits of information not specifically dealing with AKI but with antiretrovirals is that atazanavir (ATV) may increase bilirubin levels; furthermore, ATV needs an acidic milieu to be absorbed properly, so if you are prescribing a PPI, it is unadvisable to take the two concurrently.
Some may say I am in the wrong programme with my passion in HIV :-)
I hope that helps,
Gianni Lorello