Proteinuria Dr. Sachin Verma MD, FICM, FCCS, ICFC Fellowship in Intensive Care Medicine Infection Control Fellows Course Consultant Internal Medicine and Critical Care Ivy Hospital Sector 71 MohaliWeb:- http://www.medicinedoctorinchandigarh.com Mob:- +91-7508677495
Proteinuria – early indicator of renal disease Increases the risk of renal impairment, hypertension & cardiovascular disease. Proteinuria of 1+ or more persisting on 2 subsequent dipstick tests at weekly intervals – requires further investigations. Causes of transient proteinuria to be excluded.
CAUSES Transient proteinuria UTI Fever Heavy exercise Pregnency Orthostatic proteinuria - not found in early morning sample, uncommon over age of 30 yrs Vaginal mucus
Evaluation History Symptoms of renal failure CTD – arthralgia, mouth ulcers, rashes. Past h/o DM, HTN, CCF, CTD H/O drugs ass. with proteinuria – NSAIDs, captopril, penicillamine Family h/o PCKD, reflux nephropathy, CTD.
Examination Look for signs of Nephrotic syndrome Signs of multisystem dis – rashes, splinter haemorrhage, bruits. B.P Urine dipstick test to check for microscopic haematuria – if + go for urine microscopy. Rule out Diabetes and UTI
Quantification of proteinuria 24 hr urinary collection Spot morning protein/creatinine ratio – simpler & as accurate. 24 hr urinary protein excretion (mg/24hrs) can be approximated as (mg/l protein) / ( mmol/l creatinine) × 10 or (mg/l creatinine ) × 100. More than 150 mg in 24 hr or protein to creatinine ratio of 15 mg/mmol or 150 mg/mg is abnormal Nephrotic range - >3.5 g/24 hr or a ratio > 3500 - check for serum albumin and cholesterol.
Assessment of renal function Check serum creatinine, urea, electrolytes. Creatinine clearance gives more accurate picture of renal function than creatinine alone, can be calculated by Cockcroft- Gault formula. Best to estimate GFR by MDRD formula GFR or creatinine clearance > 90ml/min can be considered normal. Lower values may be normal in old age and in people with low muscle mass.
Significant proteinuria > 100 mg/mmol although values > 50 may be significant if other features of renal disease are present like Impaired renal function Coexistant microscopic haematuria Hypertension Features underlying systemic disease.
Further investigations Renal tract USG Immunology Serum and urine protein electrophoresis ANA ANCA Complements Hepatitis B & C serology
Follow-up Review after six months and then annualy to reassess quantity of proteinuria, renal function and blood pressure. Any hypertension if present – to be treated aggressively with an ACE inhibitor or ARB.