# Pattern of Immune Reconstitution Post Allogeneic Stem Cell Transplant: Data From a Resource Constraint Country

## TL;DR

This study examines immune recovery patterns six months after allogeneic stem cell transplants in a resource-limited setting.

## Contribution

The study provides insights into immune reconstitution in a low-resource country, highlighting factors affecting immune recovery.

## Key findings

- Adequate immune reconstitution was observed except for CD4 and CD4:CD8 ratio six months post-transplant.
- Factors like pre-transplant conditioning and GVHD prophylaxis significantly influenced immune cell recovery.
- Patient-donor relationship and gender disparities impacted immunoglobulin levels.

## Abstract

Objective: To determine the Pattern of immune reconstitution (IR) post allogeneic stem cell transplant at six months.

Study design: Prospective observational study.

Place and duration of the study: This study was conducted at The Armed Forces Bone Marrow Transplant Centre (AFMBTC) Rawalpindi, Pakistan, from May 2022 to December 2022.

Methodology: After approval from the institutional review board, informed/written consents were taken from patients. All patients (both genders, irrespective of age) undergoing allogeneic hematopoietic stem cell transplant were included in the study. Patients undergoing haplo-identical or autologous bone marrow transplants were excluded from the study. Innate immune reconstitution was checked by complete blood count and adaptive immune reconstitution at six months was checked lymphocyte subset analysis and serum immunoglobulin levels. Data was entered in pre-designed proforma and was analyzed using IBM Corp. Released 2017. IBM SPSS Statistics for Windows, Version 25.0. Armonk, NY: IBM Corp.

Results: This study analyzes 43 patients, including 67% (n=29) males. The median age at the time of HSCT was 11.19 years. Cellular and humoral reconstitution at six months after transplant was used to assess immune reconstitution. Innate immune reconstitution was checked by complete blood count for count recovery (Neutrophil engraftment), and adaptive immune reconstitution (cellular/humoral) at six months was checked lymphocyte subset analysis and serum immunoglobulin levels. By using chi-square, significant associations were found as pre-transplant condition regimen with CD4 (PChi= 0.001), GVHD prophylaxis with CD4 (PChi= 0.04), source of stem cells with CD19 (PChi= 0.008), patient-donor gender disparity with CD19 (PChi= 0.05), GVHD treatment low CD19 (PChi= 0.04), patient-donor relationship with IgA(PChi= 0.007), IgG (PChi= 0.001), and IgM (PChi= 0.001), gender of the patient with IgA (PChi= 0.04).

Conclusion: Our data suggested that at post-transplant six months, there was adequate immune reconstitution except for CD4 and CD4:CD8 ratio. Therefore, post-transplant, six months in Allo-HSCT could be considered for immunization.