ALBUMIN CREATININE RATIO (ACR) VERSUS PROTEIN …：尿白蛋白肌酐比值（ACR）与蛋白…

ALBUMIN CREATININE RATIO (ACR) VERSUS PROTEIN …：尿白蛋白肌酐比值（ACR）与蛋白… P28 ALBUMIN CREATININE RATIO (ACR) VERSUS PROTEIN CREATININE RATIO (PCR) FOR NEPHROLOGY REFERRAL CRITERIA IN PRIMARY CARE Pandya, B?, Hayden, K? ?Nephrology and ?Clinical Biochemistry, University Hospital Aintree,Liverpool INTRODUCTION AND AIMS: Proteinuria is important diagnostic test for chronic renal failure i.e. chronic kidney disease (CKD). It is a bad prognostic marker with or without diabetes mellitus and cardiovascular diseases. Identification of significant proteinuria for nephrology referral (>1gm/day) is important in primary care with prevalence of CKD around 10%. Since 2006 eGFR is reported for each s.creatinine value reported from the lab. 24 hour urine test for estimation of proteinuria is not practical in primary setting to identify CKD. The test should be simple, comparable and reproducible in a similar way as in patients with microalbuminuria like diabetics. Screening for microalbuminuria in form of ACR is normal practice in diabetic clinics for a while. This has become very user friendly for the GPs. Total proteinuria consists of albuminuria from glomeruli as well as tubular proteins like Tamm Harsfall protein. The later is of less significance for CKD progression. It is confirmed that spot urine values for ACR (Albuminura) and PCR (total proteinuria) are comparable for 24 hour urine protein values at lower level of proteinuria but not at higher level. Reporting of significant proteinuria as a single value >45 is practical and has comparable cost effect for diagnosis of significant proteinuria. Aims for this review was to confirm that the use of ACR is comparable to PCR in identification of significant (>1gm/day) proteinuria and to identify the most comparable value of ACR for nephrology referrals. METHODS: We reviewed the results of urine samples requested for proteinuria from Nephrology outpatients and inpatients. The results reviewed were to compare the values of ACR>45mg/mmol, PCR >100 mg/mmol and 24 hour urinary protein >1gm/day. Specificity, sensitivity and predictive p-values were used to analyse the data. RESULTS: We analysed 100 specimens of 24 hour urine for protein samples. 39 had proteinuria of >1gm per day. 4 out of 39(10.2%) had ACR<45 while 10 out of 39(25.6%) had PCR <100mg/mmol. Out of 61 specimens with proteinuria <1gm/day none (0 out of 61) (0%) had ACR >45mg/mmol compared to 4 out of 61 (6.5%) for PCR<100mg/mmol . Only 2 specimens with 24 hour urine protein>1gm/day did not fit referral criteria for both PCR and ACR. Sensitivity, specificity, positive predictive value and negative predictive values: For ACR>45mg/mmol - 95%, 100%, 100%, 96% For PCR>100mg/mmol - 81%, 93%, 83%, 88% respectively. CONCLUSIONS: ACR value>45 appears to be acceptable value for nephrological referral from primary care. Reporting of proteinuria as microalbuminuria and overt proteinuria (albuminuria) as ACR in both diabetics and non diabetics simplifies the concept of proteinuria. This maintains ease and uniformity of test of proteinuria in same patient when proteinuria progresses in primary care setting. Adoption of ACR >45 mg/mmol value for all the values over 45mg/mmol does not increase the cost and at the same time has an edge over PCR to identify significant proteinuria.