Presence of immunounreactive albumin in the urine of diabetic patients

Usefulness of HPLC assay for early detection of microalbuminuria in chronic kidney disease

BACKGROUND

Since the degree and increase of albuminuria predict cardiovascular and renal diseases even within the range of normoalbuminuria. The high-performance liquid chromatography (HPLC) assay has been reported as a useful tool for earlier detection of microalbuminuria than turbidimetric immunoassay (TIA) in diabetes but has not been evaluated for other common diseases that caused chronic kidney disease (CKD).

METHODS

We measured albumin in spot urine by TIA and HPLC assay in 119 patients with diabetes, hypertension, IgA nephropathy in complete remission, or autosomal-dominant polycystic kidney disease whose dipstick screening tests were negative.

RESULTS

There were significant correlations (r = 0.946) between TIA and HPLC assay, and the ratios of urine albumin/creatinine (ACR) measured by HPLC assay were always higher than those measured by TIA. The value of microalbuminuria was highest in IgA nephropathy patients, and higher in diabetic patients with hypertension than in those without hypertension. Fifty-one patients were classified as having normoalbuminuria and 42 as having microalbuminuria by both TIA and HPLC assay. However, 26 patients (21.8%) were classified having as normoalbuminuria by TIA but microalbumnuria by HPLC assay. Three of these patients were reclassified as microalbuminuria by both assays within 1 year.

CONCLUSION

These results suggest that ACR measurements by HPLC assay are better than TIA for early detection and monitoring of microalbuminuria in patients with diabetes and hypertension.

Efficient generation of human hepatocytes by the intrahepatic delivery of clonal human mesenchymal stem cells in fetal sheep

Alternative methods to whole liver transplantation require a suitable cell that can be expanded to obtain sufficient numbers required for successful transplantation while maintaining the ability to differentiate into hepatocytes. Mesenchymal stem cells (MSCs) possess several advantageous characteristics for cell-based therapy and have been shown to be able to differentiate into hepatocytes. Thus, we investigated whether the intrahepatic delivery of human MSCs is a safe and effective method for generating human hepatocytes and whether the route of administration influences the levels of donor-derived hepatocytes and their pattern of distribution throughout the parenchyma of the recipient's liver. Human clonally derived MSCs were transplanted by an intraperitoneal (n = 6) or intrahepatic (n = 6) route into preimmune fetal sheep. The animals were analyzed 56-70 days after transplantation by immunohistochemistry, enzyme-linked immunosorbent assay, and flow cytometry. The intrahepatic injection of human MSCs was safe and resulted in more efficient generation of hepatocytes (12.5% +/- 3.5% versus 2.6% +/- 0.4%). The animals that received an intrahepatic injection exhibited a widespread distribution of hepatocytes throughout the liver parenchyma, whereas an intraperitoneal injection resulted in a preferential periportal distribution of human hepatocytes that produced higher amounts of albumin. Furthermore, hepatocytes were generated from MSCs without the need to first migrate/lodge to the bone marrow and give rise to hematopoietic cells.

CONCLUSION

Our studies provide evidence that MSCs are a valuable source of cells for liver repair and regeneration and that, by the alteration of the site of injection, the generation of hepatocytes occurs in different hepatic zones, suggesting that a combined transplantation approach may be necessary to successfully repopulate the liver with these cells.