EBMT 2019 | Influence of inflammatory bowel disease on the outcome of allogeneic stem cell transplantation: a matched-pair analysis

Allogeneic stem cell transplantation (allo-SCT) is a curative treatment option for leukemia and lymphoma patients. In patients with concomitant inflammatory bowel disease (IBD) an increased risk of aGvHD after SCT has been suspected and related to the inflammatory state of the gut. On 25 March 2019, at the 45^th Annual Meeting of the European Society for Blood and Marrow Transplantation, in Frankfurt, Germany, Zinaida Peric from the University Hospital Centre Zagreb, Hematology, Zagreb, Croatia, presented results of a pair-matched controlled, retrospective study of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with IBD; the largest conducted so far.¹ The team analyzed and compared the incidence of GvHD, non-relapse mortality (NRM) and overall survival (OS) after allo-HSCT in patients with and without IBD.

Patient characteristics

• IBD patients, n = 175
• 54% male, median age 53 years, range 18—69
• 61% acute leukemia (n = 106), 24% myelodysplastic/myeloproliferative neoplasm (n = 42)
• 38% matched related donors (n = 66), 32% matched unrelated donors (n = 56)
• 53% received a myeloablative conditioning regimen (n = 93); 47% received a reduced-intensity conditioning regimen (n = 82)

Methods

• Retrospective pair-matched analysis based on EBMT registry data between 2011 and 2015
• Patients with IBD were matched with three controls based on patient age, patient sex, disease, intensity of conditioning, donor type and HLA disparity, cell source and year of transplant
• Median follow-up of 37 months in IBD group (range 32—45) and 36 months for controls (range 33—39)

Results

	IBD patients	Controls	HR (95% CI)	P-value
Cumulative incidence of grade II-IV aGvHD	27%	28%	0.95	0.77
Cumulative incidence of cGvHD at 36 months	25%	17%	1.54	0.03
NRM at 36 months	27%	25%	1.07	0.68
Relapse incidence at 36 months	32%	33%	1.19	0.82
OS at 36 months	47%	49%	1.04	0.79
GvHD-free relapse survival at 36 months	29%	34%	1.19	0.14

Table 1: Results of pair-matched controlled analysis

Key findings

Dr. Peric concluded that no significant difference was found between the IBD and control groups in aGvHD, NRM or OS, however IBD patients had significantly more extensive cGvHD than the control group. Despite it being the largest matched-pair comparison of IBD patients and controls, the study was retrospective and so the status of IBD and its outcome is unknown. Results suggest that IBD as a comorbidity should not be a contraindication for conducting allo-HSCT in affected patients. However, IBD patients have a higher risk of developing severe forms of cGvHD, impairing their long-term quality of life.