HUMAN ANTI-GSTT1 ELISA - FAQ

• 1. What is the GSTT1 gene?

  The GSTT1 gene is involved in cellular detoxification showing high expression levels in liver kidney and erythrocytes. Around 20% of the Caucasian population is deficient in GSTT1 enzyme activity, due to a homozygous deletion in GSTT1 locus.

• 2. How does the Human Anti-GSTT1 ELISA work?

  The Human Anti-GSTT1 ELISA consists of adding samples to a micro plate coated with recombinant human GSTT1. Anti-GSTT1 antibodies present in the sample (or standard) bind to GSTT1 absorbed in the micro wells. After addition and developing of an AP-conjugated anti-human-lgG antibody, a colored product is formed in proportion to the amount of anti-GSTT1 antibodies present in the sample.

• 3. What is de novo immune hepatitis?

  De novo immune hepatitis is an immune disease that emerged de novo in liver grafts among individuals receiving transplantation. It is characterized by histological alterations similar to viral hepatitis, high level of lgG, the presence of non-organ specific antibodies and a positive response to immunosuppresion therapy.

• 4. What patients are susceptible to de novo hepatitis?

Genetic studies in recipient patients developing de novo post transplant hepatitis demonstrated that, in all cases, the recipient harbored the GSTT1 deletion and the donor was positive for GSTT1.

• 5. What are the benefits of the Human Anti-GSTT1 ELISA?

  Anti-GSTT1 antibody detection in transplanted patient sera constitutes a new tool in the diagnosis and monitoring of de novo post-transplant hepatitis. Besides, the titration of these antibodies offers other utilities in patient such as monitoring, prophylaxis, and appropriate therapy choice in the earliest disease stages when clinical symptoms are still not present.

• 6. What is the specificity of the test?

  Controls were made using samples containing the anti-GSTT1 antibody and lacking the anti-GSTT1 antibody. There have no crossreactivity known with any other human antibodies, including antibodies against nuclear antigens (ANA), anti-HLA Class I, anti-HLA Class II, or anti-HLA Class I and anti-HLA Class II.

• 7. What are the limitations of the test?

  A positive value only indicates the presence in the sample of the anti-GSTT1 antibody and does not necessarily indicate the presence of symptoms, because the damage may have not reach the pathological level. However, any patient with the symptoms and with a positive value in the kit is suspected to suffer from de novo post-transplant hepatitis. The presence of the anti-GSTT1 antibodies after kidney and blood transfusion has also been reported. However, the pathology associated to that parameter is not yet determined.

• 8. How sensitive is the test?

  The anti-GSTT1 ELISA has the lowest detection limits compared to Western blot or immunofluorescence, and could detect antibody levels below the pathological level determined in certain individuals. The sera could be diluted 1:500-1:1,000 fold to perform the analysis and even 1:100,000 dilutions of sera could be used to detect the antibodies.

• 9. Other Important Information

  All human source material used in the preparation of controls for this product have been tested and found negative for antibodies of HIV, HbsAg, and HCV by FDA cleared methods. However, no diagnostic method can offer complete assurance that these infectious antibodies are absent. Therefore, the anti-GSTT1 positive and negative controls should be handled I the same manner as potentially infectious material. This product is for in vitro research use only.