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Updated: Jun 22, 2026
05:20
A Colorimetric Assay that Specifically Measures Granzyme B Proteolytic Activity: Hydrolysis of Boc-Ala-Ala-Asp-S-Bzl
Published on: November 28, 2014
Genotypic variation and phenotypic characterization of granzyme B gene polymorphisms
Diana M Girnita1, Steven A Webber, Maria M Brooks
1Department of Pathology, Thomas E Starzl Transplant Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA.
Transplantation
|June 23, 2009
Summary
The Q/Q genotype of granzyme B is linked to higher granzyme B expression in vitro. This finding is relevant for understanding allograft rejection in pediatric heart transplant recipients.
Area of Science:
- Immunology
- Transplantation Science
- Genetics
Background:
- Granzyme B is implicated in allograft rejection following solid organ transplantation.
- Single nucleotide polymorphisms (SNPs) in the granzyme B gene may influence its expression levels.
- Investigating granzyme B SNPs is crucial for understanding transplant outcomes.
Purpose of the Study:
- To determine the frequency of two granzyme B SNPs (A-295G and Q-55R) in pediatric heart transplant (PHTx) recipients.
- To assess the phenotypic expression of these granzyme B SNPs in healthy individuals.
Main Methods:
- Genotyping for Q-55R and A-295G SNPs was performed on 396 PHTx recipients and 52 healthy controls.
- Granzyme B-expressing cells were quantified in control samples using ELISPOT assay post-mitogen stimulation.
Main Results:
- The Q/Q genotype was present in 57% of PHTx recipients, while R/R homozygotes comprised 6%.
- R/R homozygotes were more frequent in Black non-Hispanics (14%) compared to White non-Hispanics (5%) and Hispanics (6%) (P=0.02).
- The Q/Q genotype was associated with significantly higher in vitro granzyme B expression compared to R/R carriers (P=0.006).
Conclusions:
- The 55 Q/Q genotype is associated with increased in vitro granzyme B expression.
- These findings may have implications for managing allograft rejection in PHTx.
- Further research is warranted to explore the clinical significance of these genetic variations.
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