Table 2.

Similarities and Differences in the Investigation of CKD in HIV and DKD

	DM and CKD	HIV and CKD
Laboratory Investigations
Microscopy	Bland microscopy	Active urine on microscopy if ICGN
Urea	Urea – get symptomatic at a lower urea than normal population	Due to low muscle mass – Urea and creatinine may underestimate degree of KF. Cystatin C currently best measurement of eGFR.
Anaemia	Anaemia develops earlier in CKD	Anaemia likely multifactorial
Markers of MBD	MBD develops earlier in DKD	Tenofovir associated osteomalacia
UPCR	Absence of albuminuria does not exclude DKD Decreasing trend of albuminuria being associated with lower eGFR. Albuminuria may reflect a dynamic, fluctuating condition rather than a linear progression	Variable- depending on cause: Nephrotic range proteinuria (HIVAN) Nephrotic syndrome (Membranous GN/or other GN) Sub nephrotic + blood (ICGN)
Special Investigations
Ultrasound	Increased kidney size despite reduced eGFR	Increased kidney size despite reduced eGFR in HIVAN
Renal biopsy	Classification of DKD histological features: Mild non-specific light microscopy changes and EM showing thickened basement membrane Mesangial expansion: mild Mesangial expansion: severe Nodular sclerosis (Kimmelstiel-Wilson lesions) Advanced diabetic glomerulosclerosis	Multiple pathologies can be found: Glomerular dominant: podocytopathy: Overt Nephrotic syndrome: membranous GN, HIVAN IC mediated GN disease: example, PIGN Tubulointerstitial disease Vascular dominant Other: in setting of HIV: (HPT nephrosclerosis, DKD)
Indication for biopsy	Proteinuria with no retinopathy Onset of proteinuria rapid or onset of proteinuria <5 years in T1DM Macroscopic haematuria or active urine sediment Unexplained rapid decline in KF	Spectrum of kidney disease is broad - Low threshold for biopsy Significant proteinuria (increasing trend or nephrotic range) Haematuria or active urine sediment Unexplained decline in kidney function

Abbreviations: CKD, chronic kidney disease; DM, diabetes mellitus; MBD, mineral bone disease; HIVAN, human immunodeficiency virus associated nephropathy; KF, kidney failure; IHD, ischaemic heart disease; CVA, cerebrovascular accident; PVD, peripheral vascular disease; GN, glomerulonephritis; ICGN, immune complex mediated GN; Hb, haemoglobin; eGFR, estimated glomerulofiltration rate; DKD, diabetic kidney disease; EM, electron microscopy; PIGN, post infectious glomerulonephritis, ESKF: end stage kidney failure, AIN: acute interstitial nephritis; AKI, acute kidney injury; TB, tuberculosis; IRIS, immune reconstitution syndrome.