Guidelines provide recommendations on how to diagnose kidney disease in people living with HIV (PLWHIV):1
in general, reversible causes are sought first when diagnosing the cause of kidney disease2
for patients with unexplained kidney disease, especially those with heavy proteinuria or reduced GFR, a kidney biopsy should be strongly considered as they are at risk of end-stage renal disease.2
UP/C = urine protein/creatinine ratio
UA/C = urine albumin/creatinine ratio
eGFR = estimated glomerular filtration rate
i. eGFR: use aMDRD based on serum creatinine, gender, age, and ethnicity. If not previously known to have CKD, reassess within 2 weeks.
ii. Urinalysis: use urine dipstick to screen for hematuria. To screen for proteinuria, use urine dipstick and if ≥ 1+ check UP/C, or screen with UP/C. Proteinuria defined as persistent if confirmed on ≥ 2 occasions > 2-3 weeks apart. If UP/C not available, use UA/C (see note iii).
iii. UP/C in spot urine (mg/mmol) is preferred to UA/C as detects total urinary protein secondary to glomerular AND tubular disease. UA/C largely detects glomerular disease and can be used for screening for HIV associated renal disease where UP/C is not available, but is not appropriate for screening for tubular proteinuria secondary to drug nephrotoxicity (e.g. tenofovir). Screening values for UA/C are: < 30, 30-70 and > 70. UA/C should be monitored in patients with diabetes mellitus. UP/C ratio is calculated as urine protein (mg/L) / urine creatinine (mmol/L), may also be expressed as mg/mg. Conversion factor for mg to mmol creatinine is x 0.000884.
iv. Check risk factors for CKD, and repeat eGFR and urinalysis as per screening table.
v. Dose modification of ARVs in case of impaired renal function.
Reproduced with permission from the European AIDS Clinical Society Guidelines Version 6.0.
|Assessment||At HIV diagnosis||Prior to start of ARV||
|+||+||3 – 12 m||More frequent monitoring if CKD risk factors present and/or prior to starting on treatment with nephrotoxic drugs|
|Urine dipstick analysis||+||+||annual||Every 6 m if eGFR <60mL/min; If proteinuria ≥1+ and/or eGFR <60mL/min perform UP/C or UA/C|
aMDRD = abbreviated Modification of Diet in Renal Disease formula
Adapted from the European AIDS Clinical Society Guidelines Version 6.0.
A number of tests are recommended to establish renal impairment or determine renal function; these include: 1,3–5
For further information on tests for renal impairment please see tests to establish renal impairment.
It should be noted that renal excretion is decreased by up to 50% in approximately two thirds of elderly patients, but confounding factors such as hypertension or coronary heart disease also account for a decline in kidney function.6 Hence for patients >70 years, eGFR between 45 and 59 mL/min/1.73m2 should be interpreted with caution, particularly in the absence of other symptoms of kidney damage (e.g. proteinuria), as this may be the normal GFR for this age.7