UPDATE IN URINALYSIS

1. UPDATE IN URINALYSIS Diane Gaspari, SH(ASCP) Division Manager, Core Lab York Hospital, York, PA ggaspari@wellspan.org

2. Program Objectives • Enhance knowledge of CKD and the NKF’s guidelines for laboratory diagnosis & monitoring of CKD. • Identify pre-analytic variables of urinalysis testing & analytic variables of manual urine sediment testing. • Understand the technology, software features, and flagging parameters of the Sysmex UF-1000i automated urine sediment analyzer. • Identify the benefits of automated urine sediment analysis.

3. Did You Know . . . “Urinalysis is the most valuable single test of the anatomic integrity of the kidneys that is readily available to the clinician” Schreiner From J. Szwed, The Importance of Microscopic Examination of the Urinary Sediment, American Journal of Medical Technology, 48:2, Feb. 1982

4. Functions of Kidney • Remove waste products & drugs from body. • Balance body’s fluid, release hormones to regulate blood pressure, and produce active vitamin D. • Regulation of body’s salt, potassium, & acid content

5. National Kidney Foundation • http://www.kidney.org/kls/index/cfm • http://www.kidney.org/professionals/kdoqi/guidelines • New Guidelines February 2002 • Addition to Guidelines in 2003, 2005, 2006, 2007, 2008, and 2012.

6. Incidence and Prevalence of End-Stage Renal Disease in the U.S.

7. CHRONIC KIDNEY DISEASE • CKD is a world-wide public health problem that is under-diagnosed and under-treated. • Early diagnosis is critical as kidney disease is often silent in the early stages. • Most common causes of CKD in North America is diabetes, hypertension, and glomerular disease.

8. CHRONIC KIDNEY DISEASE • Presence of excessive amounts of urine protein is most common clinical sign of early kidney dysfunction. • Other markers of kidney damage • abnormal urine sediment • abnormal findings on imaging studies • abnormal blood & urine chemistry results that identify renal tubular syndromes

10. CHRONIC KIDNEY DISEASE • Symptoms • fatigue • difficulty concentrating • poor appetite • sleeplessness • muscle cramping at night • swollen feet and ankles

11. CHRONIC KIDNEY DISEASE • Symptoms (cont.) • Puffiness around the eyes, especially in the morning • Dry, itchy skin • Frequent urination, especially at night

13. Complications of CKD • Result of reduction of GFR, disorder of tubular function, or reduction in endocrine function of the kidney • Hypertension • Malnutrition • Anemia • Low serum albumin and serum calcium

14. Complications of CKD • High serum phosphate concentration and high serum parathyroid hormone concentration • Reduced activities of daily living • Lower quality of life • Increased risk of cardiovascular disease and stroke

15. Laboratory Diagnosis and Monitoring of CKD • Definitive diagnosis of the type of kidney disease is based on biopsy or imaging studies • Biopsy and invasive imaging procedures are associated with a risk or serious complications and are usually avoided unless a definitive diagnosis would change treatment or prognosis

16. Laboratory Diagnosis and Monitoring of CKD • GFR is the best overall index of kidney function • Decreased GFR precedes the onset of kidney failure and persistently reduced GFR is a specific indicator of CKD. • Drug dosing in CKD is based on GFR levels

17. Laboratory Diagnosis and Monitoring of CKD • GFR cannot be measured directly • Serum creatinine is used to measure GFR in most cases • Use of an international standard or traceable standard for creatinine calibration is recommended. • Creatinine clearance is considered too inaccurate due to difficulties in obtaining a correctly timed specimen.

18. Laboratory Diagnosis and Monitoring of CKD • The NKF guidelines recommend that clinical labs report an estimate of GFR using the MDRD prediction equation in addition to the serum creatinine. • Variables that will affect the estimation of GFR include: age, sex, race, diet, body build, medication, and pregnancy. • If the variables are significant, use the creatinine clearance.

19. Laboratory Diagnosis and Monitoring of CKD • Serum creatinine is recommended at least yearly in patients with CKD. • The rate of decline in GFR can be used to estimate the interval until onset of kidney failure and facilitate planning for therapy, diet, or kidney replacement. • An acute decline in GFR may be superimposed on CKD and result in acute deterioration of kidney function.

20. Laboratory Diagnosis and Monitoring of CKD • Most common causes of deterioration of kidney function are: • Reduced blood flow to the kidney, usually related to volume depletion. • Toxic insult • Obstruction from tumors, stones, or blood. • Inflammation and infection

21. Cystatin C • 13 kDa cysteine protease inhibitor constantly produced by all nucleated cells • Advantages over creatinine • Constant rate of production, freely filtered by the glomerulus • Unaffected by muscle mass, diet or gender • No renal tubular secretion • Good assay precision (~3% CV throughout assay range) • Assay unaffected by spectral interferences

22. NKF Guidelines for Adults and Children • Under most circumstances, untimed (“spot”) urine samples should be used to detect and monitor proteinuria. • First morning urines preferred but random specimens are acceptable. Timed urine collection (overnight or 24 hr) is not necessary.

23. NKF Guidelines (cont.) • In most cases, screening with urine dipsticks is acceptable for detecting proteinuria • Standard urine dipsticks are acceptable for detecting increased total urine protein. • Albumin-specific dipsticks are acceptable for detecting albuminuria

24. NKF Guidelines (cont.) • Patients with a positive dipstick (1+ or greater): confirm proteinuria by a quantitative measurement (protein-to-creatinine ratio >200 mg/g or albumin-to-creatinine ratio >30 mg/g) within 3 mos. • Patients with 2 or more positive quantitative tests temporally spaced by 1-2 weeks: diagnosed as persistent proteinuria; further evaluation needed

25. NKF Guidelines (cont.) • Monitoring proteinuria in patients with CKD should be performed using quantitative measurements. • Children Without Diabetes: • orthostatic proteinuria must be excluded by repeat measurement on a first morning specimen if the initial proteinuria was obtained on a random specimen.

26. NKF Guidelines (cont.) • Children Without Diabetes: • Screen spot urine sample for total urine protein using either: standard urine dipstick or total protein-to-creatinine ratio • When monitoring proteinuria for CKD, total protein-to-creatinine ratio should be measured in spot urine specimens.

27. NKF Guidelines (cont.) • Children With Diabetes: • Screening and monitoring of post-pubertal children with diabetes of 5+ years duration should follow the adult guidelines. • Screening and monitoring other children with diabetes should follow the guidelines for children without diabetes.

28. 2005 Additions to NKF Guidelines • Bone Metabolism & Disease in Children with Chronic Kidney Disease: 10/05 • Warns that bone disease begins early in the course of CKD in children & calcium balance must be in order for growth & cardiovascular development • Physicians need to place greater emphasis on vitamin D nutrition, levels of parathyroid hormone, & excesses of calcium intake which can lead to development of vascular calcifications.

29. 2005 Additions to NKF Guidelines • Cardiovascular Disease in Dialysis Patients: 4/05 • Warns that CVD is leading cause of death among dialysis patients but treatment is not as effective as in general population • Dialysis patients are more prone to side-effects of treatment • More research is needed to better manage CVD in dialysis patients

30. 2006 Additions to NKF Guidelines • Treatment of Anemia in Chronic Kidney Disease: 5/06 • Patients with all stages of CKD should be evaluated for anemia • Definition of anemia is <13.5 g/dL for males & <12.0 g/dL for females • Treat patients with ESA(erythropoiesis stimulating agent) &/or iron when Hgb is <11g/dL

31. 2007 Additions to NKF Guidelines • Chronic Kidney Disease and Diabetes: 2/07 • Emphasizes diabetes prevention, screening & management of kidney disease • New term: diabetic kidney disease (DKD)

32. 2012 Additions to NKF Guidelines • Diabetes and Chronic Kidney Disease • Target HbA1c of ~7.0% to prevent or delay progression of microvascular complications of diabetes, including DKD. • Lipid-lowering treatment with statins suggested for patients with diabetes and CKD, including kidney transplant recipients

33. 2012 Additions to NKF Guidelines (cont.) • Diabetes and Chronic Kidney Disease • Withholding statin treatment initiation in dialysis patients is suggested. • Treatment of normotensive patients with diabetes & elevated levels of albuminuria by ACE inhibitors or angiotensin receptor blockers (ARB). • Statin combination therapy reduces risk of CVD events.

34. International Classification of Diseases, 9th Revision Clinical Modification (ICD-9-CM) • Diagnosis codes for CKD to be based on NKF’s KDOQI Guidelines • Codes allow medical professionals to clearly note the stage of kidney disease • Ability to identify CKD patients who are kidney transplant recipients • Ability to link specific treatments to appropriate CKD stage

35. Legislative Mandate for Labs to Report eGFR • States with laws requiring reporting of eGFR • New Jersey, Tennessee, Michigan, Louisiana, Connecticut, and Pennsylvania • PA General Assembly House Bill 2639 • Passed into PA state law in November, 2006 • eGFR must be calculated for serum creatinine for patients > 18 years • All labs had to comply within 2 years of passage

36. Facts of Kidney Disease • More than 26 million Americans have CKD. More than 20 million more are at increased risk for developing kidney disease and most do not know it. • At the end of 2010, there were 651,000 Americans receiving treatment for kidney failure (end stage renal disease or ESRD).

37. Facts of Kidney Disease • Each year, more than 70,000 Americans die from causes related to kidney failure. • Every month, the number of Americans waiting for kidney transplants increases. Approximately 96,292 patients are awaiting kidney transplants and >2,500 are waiting for kidney-pancreas transplants.

38. Facts of Kidney Disease • Shortage of organ donations is major contributing factor to the growing number of people on the waiting list. A new name is added every 12 minutes and eighteen people die daily while waiting. • CKD has a disproportionate impact on minority populations, especially African Americans, Hispanics, Asians, and American Indians.

39. Facts of Kidney Disease • Diabetes is the leading cause of kidney failure: 51% of new cases and 45% of all cases of kidney failure in U.S. • Uncontrolled or poorly controlled high blood pressure is the second leading cause of kidney failure in U.S: 28% of new cases and 25% of kidney failure in U.S.

40. Facts of Kidney Disease • Third & fourth leading causes of kidney failure in U.S. are glomerulonephritis and polycystic kidney disease: 8.2% and 2.2% of new cases in U.S. • Kidney and urologic diseases continue to be major causes of work loss, physician visits, and hospitalizations among men and women.

41. Laboratory’s Involvement With NKF Guidelines • Good creatinine calibration • Add GFR prediction equation to report • Understand limits of urine test strip protein • Add urine test with good low end sensitivity to urine albumin (microalbumin) • Improve urine sediment testing

42. Preventing Kidney Disease • Blood glucose & blood pressure checks • Regular physician check-ups • Taking medications as prescribed by physician • Regular exercise; lose weight if overweight; low-fat diet • Avoid tobacco use; moderate alcohol consumption • Cholesterol levels in target range

43. Siemens Clinitek Microalbumin 2 Reagent Strips • Provide albumin, creatinine, and albumin to creatinine ratio results in 1 minute • Can be used by POC or physicians’ offices • Use with Clinitek 50 or Clinitek Status analyzers • Sensitivity as low as 2mg/dL for urine protein • More reliable; less affected by interferences (e.g. specific gravity and pH)

44. Siemens Clinitek Microalbumin 9 Reagent Strips • Provide albumin, blood, creatinine, glucose, ketone, leukocyte, nitrite, pH, & protein and albumin to creatinine ratio & protein to creatinine ratio • Use with Clinitek Status or Advantis analyzers • Random sample; no timed or 24 hr urine sample required • Accurate identification of microalbuminuria

45. Urinalysis Testing • Pre-analytic variables • Specimen collection: need written or clear-cut oral instructions on specimen collection • Type of specimen collection (random, clean catch, cath) • Delay in specimen delivery • Specimen storage conditions

46. Manual Urine Sediment Analysis • Analytic variables • Mixing of samples by inversion, not swirling • Standardized volume for centrifugation; note volume if less than 12mL • Time and G force for centrifugation; do not use brake • Inconsistent decantation and re-suspension steps after centrifugation

47. Manual Urine Sediment Analysis • Analytical variables (cont.) • Reduced recovery rate of urine elements after centrifugation • Variability in concentration ratio • Supernatant removal • Mixing of suspension • Filling of chamber; technique-dependent • Distributional errors

48. Manual Urine Sediment Analysis • Commercial slide systems • Provide some standardization • Technique-dependent • Vary in concentration ratios: 1:5 to 1:48 • Addition of drop of stain also varies concentration ratio • Low & high power fields of view are microscope dependent; reporting unit inequity

49. Manual Urine Sediment Microscopy • Subjective element identification • Poor reproducibility • Lack of standardization • Time consuming/labor intensive

50. Sysmex UF-1000i