Chronic Nephropathies

Chronic Nephropathies - DiaPat®-N test

Diagnosis of chronic kidney disease is established at a late stage, when substantial organ damage occurred. The analysis of the urine proteome through the DiaPat®-N test enables detecting chronic kidney diseases (CKD) at a very early stage with an accuracy of approximately 94%.

Differential diagnosis - DiaPat®-NDif test

The differential diagnosis of most kidney diseases normally requires a renal biopsy. Due to the considerable risks and adverse side-effects of this surgical procedure, biopsy is carried out at a hospital.

The DiaPat®-NDif test enables differential diagnosis of CKD, supersedes hospitalisation and avoids side-effects. This is particular helpful, whenever kidney biopsy is associated with great risks, this applies especially for children (avoiding anaesthetics), patients with only one kidney, or a deformed kidney (e.g. horse shoe kidney) or transplanted kidney as well as patients with an increased risk of bleeding. The test is a highly valuable complement of routine diagnostics facilitating the evaluation of the necessity for kidney biopsy.

Advantages of the DiaPat®-N and DiaPat®-NDif test

• Painless (from urine)
• Riskless sampling
• Reliable (highly reliable detection of CKD with >95% accuracy)
• Long-term (monitoring therapy success and individually adapted treatment)

In addition to the detection of CKD, at present, the DiaPat®-NDif test enables differentiation between the following renal diseases:

1. Minimal Change Disease (MCD)
2. Membranous Glomerulonephritis (MNGN)
3. Focal Segmental Glomerulosclerosis (FSGS)
4. Immunoglobulin-A-Nephropathy (IgA-Nephropathy)
5. Lupus Nephritis (SLE)
6. Vascular Nephropathy
7. Diabetic Nephropathy

References:

Weissinger EM, Wittke S, Kaiser T et al.
Proteomic patterns established with capillary electrophoresis and mass spectrometry for diagnostic purposes.
Kidney Int 2004; 65: 2426-2434

Julian BA, Wittke S, Novak J et al.
Electrophoretic methods for analysis of urinary polypeptides in IgA-associated renal diseases.
Electrophoresis 2007; 28: 4469-4483

Rossing K, Mischak H, Dakna M et al.
Urinary Proteomics in Diabetes and CKD.
J Am Soc Nephrol 2008; 19: 1283-1290

Haubitz M, Good DM, Woywodt A et al.
Identification and Validation of Urinary Biomarkers for Differential Diagnosis and Evaluation of Therapeutic Intervention in ANCA associated Vasculitis.
Molecular & Cellular Proteomics 2009; 8: 2296-2307

Background information:

Chronic kidney disease (CKD) and renal damage is characterized by a slow, progressive loss of renal function over a period of months or years that finally leads to end-stage renal disease (ESRD). Patients with ESRD require renal replacement therapy (dialysis and/or kidney transplantation). The most common causes of chronic kidney disease in North America, Europe, and Japan are diabetic nephropathy, hypertension, and glomerulonephritis. Together, these diseases account for approximately 75% of all adult cases of ESRD.

Historically, kidney diseases were classified according to the anatomical compartment of the kidney that is involved. Glomerular diseases comprise a diverse group of histologically defined glomerulopathies, e.g. focal segmental glomerulosclerosis (FSGS), membranous glomerulonephritis (MGN), minimal change disease (MCD), IgA nephropathy (IgAN), diabetic nephropathy (DN) or systemic lupus erythematosus (SLE).

In clinical practice, renal damage associated to CKD is generally detected by proteinuria and/or changes in serum creatinine for estimation of glomerular filtration rate. However, there are major limitations to the use of both methods, as they are quite imprecise and a generally late sign of renal damage. In some cases, however, kidney biopsy for histological analysis is necessary to decide on therapeutic measures.