Visual abstract | Vitamin A for the prevention of GvHD in pediatric patients undergoing allo-HSCT

The GvHD Hub is happy to present a visual abstract summarizing key findings from a prospective, double-blind trial evaluating the efficacy of high-dose vitamin A for graft-versus-host disease (GvHD) in pediatric patients undergoing an allogeneic hematopoietic stem cell transplant, as presented during the 2023 Transplantation & Cellular Therapy Meetings of ASTCT and CIBMTR.

Baseline patient characteristics are shown in Table 1. Despite a higher proportion of patients in the vitamin A cohort having characteristics that predispose them to GvHD (HLA mismatching, donor relation, and the use of unmanipulated peripheral blood stem cells), patients in the vitamin A cohort had a lower incidence of GvHD.¹

Table 1. Baseline patient characteristics*

GvHD, graft-versus-host disease; HLA, human leukocyte antigen; MMF, mycophenolate mofetil; MTX, methotrexate; PTCy, post-transplant cyclophosphamide; TCR, T-cell receptor. *Adapted from Khandelwal.1
Characteristic, n (unless otherwise stated)	Vitamin A (n = 40)	Placebo (n = 40)	p value
Median age (range), years	6.9 (2–20)	8.5 (1.1–28)	0.2
Underlying diagnosis			0.6
Malignancy	8	9
Primary immune deficiency	8	6
Bone marrow failure	14	17
Hemoglobinopathy	8	8
Metabolic disorder	2	0
Conditioning regimen			0.8
Myeloablative	25	27
Reduced intensity	15	13
Serotherapy	24	28	0.4
Radiation in conditioning	4	2	0.6
HLA match			0.1
≥2 antigen mismatch	5	2
9/10	11	6
10/10	24	32
Donor relation			0.1
Related (excluding ≥2 antigen mismatch)	8	15
Related (≥2 antigen mismatch)	4	1
Unrelated	28	24
GvHD prophylaxis			0.4
Calcineurin inhibitor + MMF	9	5
Calcineurin inhibitor + MTX	1	5
Calcineurin inhibitor + prednisone	2	2
T-cell depletion	12	10
αβ CD19 TCR depletion	0	2
Abatacept to standard prophylaxis	15	14
PTCy	1	1

The use of high-dose vitamin A is already recommended by the World Health Organization (WHO) for treatment of children with acute measles.¹ Vitamin A is involved in gut homeostasis by maintaining barrier function and expression of junction proteins in the intestinal epithelium. The level of CCR9⁺ CD8⁺ effector memory T-cells were significantly higher in the placebo arm at Day 30 posttransplant compared with the vitamin A arm; therefore, this shows that gut T-cell trafficking was reduced in patients treated with vitamin A (p = 0.01).¹