Effect of NOD2/CARD15 variants in T-cell depleted allogeneic stem cell transplantation

Area of Science:

• Immunogenetics
• Transplantation immunology
• Genetics of immune response

Background:

• Single nucleotide polymorphisms (SNPs) in NOD2/CARD15 are linked to graft-versus-host disease (GVHD) after allogeneic stem cell transplantation (SCT).
• The impact of NOD2/CARD15 SNPs may differ in T-cell-depleted (TCD) SCT, where donor T cells are removed.

Purpose of the Study:

• To investigate the clinical effect of NOD2/CARD15 SNPs in patients undergoing TCD allogeneic SCT.
• To determine if NOD2/CARD15 variants influence GVHD incidence, severity, or overall survival in this specific transplant setting.

Main Methods:

• Studied NOD2/CARD15 SNPs (8, 12, 13) using Taqman protocol.
• Analyzed 85 patients undergoing HLA-identical TCD SCT and 71 sibling donors.
• Assessed incidence of acute and chronic GVHD, disease-free survival, and causes of death.

Main Results:

• NOD2/CARD15 variants were found in 11% of patients and 8% of donors.
• No association between NOD2/CARD15 variants and acute or chronic GVHD incidence.
• Variants were linked to significantly lower disease-free survival (17% vs. 48%, p=0.03) and increased death from pulmonary infection.
• Multivariate analysis identified NOD2/CARD15 variants and older age as independent prognostic factors for disease-free survival.

Conclusions:

• NOD2/CARD15 variants adversely affect clinical outcomes in TCD allogeneic SCT, independent of GVHD.
• The detrimental effect likely stems from alterations in the innate immune system rather than adaptive immune activation.
• These findings highlight the role of specific genetic variants in transplant outcomes beyond traditional GVHD mechanisms.