NAG, hexosaminidase
NAG (HEX) is measured in urine as a non-invasive marker of renal damage
and disease. Renal disease causes a progressive deterioration in function
which eventually results in renal failure which necessitates either renal
dialysis or transplantation. The young are often affected and treatment
may therefore be necessary for long periods of time. The kidney is also
susceptible to secondary damage resulting from hypertension, diabetes,
arthritis and urinary tract infection as well as being vulnerable to nephrotoxic
drugs and environmental pollutants. However, the high reserve capacity
of the kidney means that over 50% of active renal mass can be lost before
there is a measurable change in renal function. Definitive diagnosis of
renal disease is often based on the examination of renal biopsy samples
or the measurement of serum creatinine which is modified after the disease
is well established. However, this procedure is not without risk. There
is therefore a need for, sensitive, non-invasive tests, as early detection
improves the possibility of successful treatment, and at the same time
reduces medical costs while improving the prospects of the patients. Such
tests are also required for the assessment of new drugs for potential
nephrotoxicity, and monitoring for the effect of environmental or occupational
toxins (for example, heavy metals or solvents).
Hexosaminidase (NAG) isoenzymes are present in different organs and
tissues. The acidic A and basic B forms are present in the liver, kidney
and spleen. However, in serum the major form is the As-form but two additional
intermediate forms I1 and I2 are also present. The latter resembles the
P-form which is found in the serum of pregnant women. Hexosaminidase is
assayed in Laboratories monitoring genetic disease in suspected cases
of Tay-Sach disease and Sandhoff’s disease. The A-form of HEX is
absent from Tay-Sach disease which is most commonly found in Ashkenasi
Jews.
Key Benefits
- Early warning of renal damage
- Colorimetric procedure adaptable to any laboratory
- Can be used in conjunction with heat treatment or ion-exchange chromatography
in the quantitation of the A and B-forms of hexosaminidase
- 3 Kits available in various sizes to suit type of investigation
Ordering Information
References
Method Sheets
Method sheets are available for the manual assay of N-acetyl-ß-D-glucosaminidase
in urine or if required serum are supplied. In addition the assay procedure
can be used to detect the isoenzymes of NAG particularly the A and B forms.
If the assay is to be carried out in the routine laboratory, method sheets
for most of the commonly used autoanalysers are available on request.
View method sheet for NAG Calibrant procedure
Method sheet immediately available
Bayer Diagnostics
Hitachi
- Hitachi 704 as well as Hitachi 705
- Hitachi 717
- Hitachi 917
International Laboratories Monarch
- Multistat III
- I.L. Monarch
Roche Products
- Cobas Bio
- Cobas Fara II
- Cobas Mira S
- Modular 1
Other
- Ilab 900
- Konelab 6.5.4
- A procedure is available which enables the NAG kit to be used in conjunction
with 96-well plate readers.
We are in discussions with the above and other manufacturers to provide
methodology for the latest additions to their range. Please email
for details if your instrument is not listed. |