Glutathione S-transferase T1-null seems to be associated with graft failure in hematopoietic SCT

Pre-existing non-human leukocyte antigen antibodies are associated with allograft rejection after thoracic transplantation

BACKGROUND

There is growing evidence on the important role of non-human leukocyte antigen (HLA) antibodies in lung and heart transplant rejection. Since data on the prevalence and clinical significance of non-HLA antibodies in the Asian population are scarce, we analyzed non-HLA antibodies in heart and lung transplant patients.

METHODS

We used the Luminex method to measure non-HLA antibodies in patients who underwent heart transplantation (N = 28) or lung transplantation (N = 36) between 2016 and 2019. We evaluated the association between pre-existing non-HLA antibodies and acute rejection-free days in these recipients.

RESULTS

Of 64 patients, 27 (42.2%) patients underwent rejection, with 26 (40.6%) acute cellular rejection and one (1.6%) acute antibody-mediated rejection. Among 33 identified different non-HLA antibodies, only the anti-glutathione S-transferase theta-1 (GSTT1) antibody positive rate was significantly higher in patients with acute rejection compared to those without rejection (14.8% vs. 0%, p = 0.016). The angiotensin II type I receptor positive rate was not significantly different between the two groups (40% vs. 18.5%, p = 0.129). In the multivariate Cox regression analysis, anti-GSTT1 antibody-positive patients had a higher risk of acute allograft rejection (hazard ratio, 4.19; 95% confidence interval [CI], 1.41-12.49; p = 0.010). The Kaplan-Meier curve showed that anti-GSTT1 antibody-positive patients had fewer acute rejection-free days (χ² = 7.892; p = 0.005). Additionally, patients who underwent platelet transfusion (odds ratio, 1.49; 95% CI, 1.16-1.91; p = 0.002) before transplantation were more likely to be positive for anti-GSTT1 antibody.

CONCLUSION

Patients with antibodies against GSTT1 before heart or lung transplantation have an increased risk of acute rejection.

Gene expression profiles for predicting antibody‑mediated kidney allograft rejection: Analysis of GEO datasets

Antibody‑mediated rejections (AMRs) are one of the most challenging complications that result in the deterioration of renal allograft function and graft loss in a large majority of cases. The purpose of the present study was to characterize a meta‑signature of differentially expressed RNAs associated with AMR in cases of kidney transplantation. Gene Expression Omnibus (GEO) dataset searches up to September 11, 2017, using Medical Subject Heading terms and keywords associated with kidney transplantation, AMR and mRNA arrays were downloaded from the GEO dataset. Using a computational analysis, a meta‑signature was determined that characterized the significant intersection of differentially expressed genes (DEGs). Gene‑set and network analyses were also performed to identify gene sets and sub‑networks associated with the AMR‑related traits. A statistically significant mRNA meta‑signature of upregulated and downregulated gene expression levels that were significantly associated with AMR was identified. C‑X‑C motif chemokine ligand 10 (CXCL10), CXCL9 and guanylate binding protein 1 were the most significantly associated with AMR. DEGs were efficiently identified and were found to be able to predict the occurrence of AMR according to a meta‑analysis approach from publicly available datasets. These methods and results can be applied for a more accurate diagnosis of AMR in transplant cases.

Non-Jewish Israeli IBD patients have significantly higher glutathione S-transferase GSTT1-null frequency

BACKGROUND

The involvement of oxidant/antioxidant imbalance in the development of inflammatory bowel disease (IBD) is well documented. Two members of the glutathione S-transferase (GST) family of enzymes, GSTM1 and GSTT1, known to take part in cellular protection against electrophiles, demonstrate common deletion variants (termed null) associated with impaired enzyme function.

AIM

To evaluate the effect of GSTM1/GSTT1 genotype on IBD susceptibility in a Israeli cohort and to study the correlation between GSTM1/GSTT1 genotype, smoking status, and a variety of clinical characteristics of IBD.

METHODS

A cohort of 606 Israeli IBD patients (453 with Crohn's disease [CD] and 153 with ulcerative colitis [UC]) and 528 ethnically matched healthy controls were genotyped for the null variants of GSTM1 and GSTT1. In patients, phenotype-genotype correlations were examined.

RESULTS

Ethnic stratification of healthy controls revealed a higher frequency of GSTT1-null in Jewish and Arab Moslem individuals compared to Druze individuals (P < 0.0005), but no difference in GSTM1-null was found. Comparing IBD patients (both CD and UC) to healthy controls revealed a pattern of lower GSTM1-null and higher GSTT1-null frequencies, which reached significance in Arab Moslem patients. No association was found between NOD2/CARD15 mutation carriage and GSTM1/GSTT1 genotype. No statistically significant association was found between GSTT1-null or GSTM1-null, smoking status, and other phenotypes of CD/UC.

CONCLUSIONS

GSTT1-null appears to be associated with IBD, while GSTM1-null appears to be conversely associated with IBD. No association was found between GSTT1-null or GSTM1-null and specific IBD phenotypes.

Knockout and transgenic mice in glutathione transferase research

Glutathione transferases (GSTs) are a multigene family of ubiquitously expressed, polymorphic enzymes responsible for the metabolism of a wide range of both endogenous and exogenous substrates, play a central role in the adaptive response to chemical and oxidative stress, and are subject to regulation by a range of structurally unrelated chemicals. In this review, we present a current summary of knockout mouse models in the GST field, discussing some of the issues pertaining to orthologous proteins between mice and humans, the potential confounding issues related to genetic background, and also cover new transgenic models in the increasingly important area of humanization.

Influence of glutathione S-transferase A1, P1, M1, T1 polymorphisms on oral busulfan pharmacokinetics in children with congenital hemoglobinopathies undergoing hematopoietic stem cell transplantation

BACKGROUND

Busulfan (BU), often used in high dose for myeloablation before hematopoietic stem cell transplantation (HSCT), has been implicated in certain HSCT toxicities, including the occurrence of hepatic veno-occlusive disease (HVOD). In addition to weight and age, gene polymorphisms in specific members of the glutathione-transferase (GST) gene family (A1, P1, M1, and T1), involved in BU metabolism, may play a role in the wide inter-patient variability in systemic BU concentrations.

PROCEDURE

The present study integrated clinical data regarding the occurrence of HVOD, graft versus host disease (GVHD), BU pharmacokinetics and GSTA1, GSTP1, GSTM1, and GSTT1 genotypes of 18 children who received BU in their pre-HSCT conditioning regimen. The children were all treated for congenital hemoglobinopathies and were all of Arab Moslem descent.

RESULTS

The data demonstrate an association between GSTA1 and GSTP1 genotypes and BU-maximal concentration (C(max)) (P = 0.01, P = 0.02, respectively), area under the concentration-time curve (AUC) (P = 0.02, P = 0.01, respectively) and oral BU clearance/kg body weight (P < 0.02, P = 0.08, respectively). GSTM1-null individuals demonstrated lower BU-AUC/Kg compared to GSTM1-positive individuals. In addition, an association between GVHD and GSTM1-null genotype was found.

CONCLUSIONS

GSTA1, GSTP1, and GSTM1 genotyping prior to HSCT in children with congenital hemoglobinopathies may allow better prediction of oral BU kinetics and the need for BU dose adjustment, as well as prediction of transplant related toxicity such as GVHD, thereby improving clinical outcome.