Increased memory phenotypes of CD4+ and CD8+ t cells in children with sickle cell anaemia in Tanzania

Emmanuel Balandya, Teri Reynolds, Said Aboud, Stephen K Obaro, Julie Makani

Research output: Contribution to journalArticle

Abstract

Background: Infection is an important cause of morbidity in children with sickle cell anaemia (SCA). However, little is currently known regarding the spectrum of adaptive immune derangement in SCA, especially of populations in Sub-Saharan Africa. In this study, we investigated the phenotype and activation status of T and B lymphocytes among children with SCA in Tanzania. Methods: We compared 30 children with SCA aged 1-6 years in steady-state with 10 age-matched controls. We assessed white blood cell count, T and B lymphocyte phenotype and activation status using an automated haematology analyser and multiparameter Flow Cytometry. Results: In children with SCA, the absolute lymphocyte, monocyte and granulocyte counts were all increased. There was also an increase in proportion of central/transitional memory (42.4% vs. 33.3%, p = 0.0100), effector memory (7.8% vs. 5.4%, p = 0.0086) and terminally differentiated (2.3% vs. 1.3%, p = 0.0355) CD4+ T cells as well as effector memory CD8+ T cells (21.3% vs. 11.5%, p = 0.0060) in children with SCA. In contrast, there was no difference in naïve, classical memory, atypical memory and IgM memory B-cells between the two groups. The level of activation of both T and B cells were comparable between children with and without SCA. Furthermore, we observed a significant inverse correlation between frequency of the effector memory CD8+ T cells and haematocrit (Spearman rho = -0.3859, p = 0.0352). Conclusions: Children with SCA in Tanzania show an absolute increase in all leukocyte types, including lymphocytes, with skewing of both CD4+ and CD8+ T cells towards the memory phenotypes. These findings provide insights on the development of adaptive immunity which may have implications on vaccine responsiveness, allo-immunisation, auto-immune diseases and transplant immunology in children with SCA.

Original languageEnglish (US)
JournalTanzania Journal of Health Research
Volume19
Issue number2
DOIs
StatePublished - Jan 1 2017

Fingerprint

Tanzania
Sickle Cell Anemia
Phenotype
T-Lymphocytes
B-Lymphocytes
Lymphocytes
Africa South of the Sahara
Immune System Diseases
Adaptive Immunity
Hematology
Lymphocyte Activation
Allergy and Immunology
Leukocyte Count
Hematocrit
Granulocytes
Immunoglobulin M
Monocytes
Immunization
Flow Cytometry
Leukocytes

Keywords

  • Activation
  • B-cell
  • Lymphocyte
  • Phenotype
  • Sickle cell anaemia
  • T-cell
  • Tanzania

ASJC Scopus subject areas

  • Medicine(all)

Cite this

Increased memory phenotypes of CD4+ and CD8+ t cells in children with sickle cell anaemia in Tanzania. / Balandya, Emmanuel; Reynolds, Teri; Aboud, Said; Obaro, Stephen K; Makani, Julie.

In: Tanzania Journal of Health Research, Vol. 19, No. 2, 01.01.2017.

Research output: Contribution to journalArticle

@article{5c01fbe8dd3d4c88a70f8a303cf9bfcf,
title = "Increased memory phenotypes of CD4+ and CD8+ t cells in children with sickle cell anaemia in Tanzania",
abstract = "Background: Infection is an important cause of morbidity in children with sickle cell anaemia (SCA). However, little is currently known regarding the spectrum of adaptive immune derangement in SCA, especially of populations in Sub-Saharan Africa. In this study, we investigated the phenotype and activation status of T and B lymphocytes among children with SCA in Tanzania. Methods: We compared 30 children with SCA aged 1-6 years in steady-state with 10 age-matched controls. We assessed white blood cell count, T and B lymphocyte phenotype and activation status using an automated haematology analyser and multiparameter Flow Cytometry. Results: In children with SCA, the absolute lymphocyte, monocyte and granulocyte counts were all increased. There was also an increase in proportion of central/transitional memory (42.4{\%} vs. 33.3{\%}, p = 0.0100), effector memory (7.8{\%} vs. 5.4{\%}, p = 0.0086) and terminally differentiated (2.3{\%} vs. 1.3{\%}, p = 0.0355) CD4+ T cells as well as effector memory CD8+ T cells (21.3{\%} vs. 11.5{\%}, p = 0.0060) in children with SCA. In contrast, there was no difference in na{\"i}ve, classical memory, atypical memory and IgM memory B-cells between the two groups. The level of activation of both T and B cells were comparable between children with and without SCA. Furthermore, we observed a significant inverse correlation between frequency of the effector memory CD8+ T cells and haematocrit (Spearman rho = -0.3859, p = 0.0352). Conclusions: Children with SCA in Tanzania show an absolute increase in all leukocyte types, including lymphocytes, with skewing of both CD4+ and CD8+ T cells towards the memory phenotypes. These findings provide insights on the development of adaptive immunity which may have implications on vaccine responsiveness, allo-immunisation, auto-immune diseases and transplant immunology in children with SCA.",
keywords = "Activation, B-cell, Lymphocyte, Phenotype, Sickle cell anaemia, T-cell, Tanzania",
author = "Emmanuel Balandya and Teri Reynolds and Said Aboud and Obaro, {Stephen K} and Julie Makani",
year = "2017",
month = "1",
day = "1",
doi = "10.4314/thrb.v19i2.3",
language = "English (US)",
volume = "19",
journal = "Tanzania Journal of Health Research",
issn = "1821-6404",
publisher = "National Institute for Medical Research",
number = "2",

}

TY - JOUR

T1 - Increased memory phenotypes of CD4+ and CD8+ t cells in children with sickle cell anaemia in Tanzania

AU - Balandya, Emmanuel

AU - Reynolds, Teri

AU - Aboud, Said

AU - Obaro, Stephen K

AU - Makani, Julie

PY - 2017/1/1

Y1 - 2017/1/1

N2 - Background: Infection is an important cause of morbidity in children with sickle cell anaemia (SCA). However, little is currently known regarding the spectrum of adaptive immune derangement in SCA, especially of populations in Sub-Saharan Africa. In this study, we investigated the phenotype and activation status of T and B lymphocytes among children with SCA in Tanzania. Methods: We compared 30 children with SCA aged 1-6 years in steady-state with 10 age-matched controls. We assessed white blood cell count, T and B lymphocyte phenotype and activation status using an automated haematology analyser and multiparameter Flow Cytometry. Results: In children with SCA, the absolute lymphocyte, monocyte and granulocyte counts were all increased. There was also an increase in proportion of central/transitional memory (42.4% vs. 33.3%, p = 0.0100), effector memory (7.8% vs. 5.4%, p = 0.0086) and terminally differentiated (2.3% vs. 1.3%, p = 0.0355) CD4+ T cells as well as effector memory CD8+ T cells (21.3% vs. 11.5%, p = 0.0060) in children with SCA. In contrast, there was no difference in naïve, classical memory, atypical memory and IgM memory B-cells between the two groups. The level of activation of both T and B cells were comparable between children with and without SCA. Furthermore, we observed a significant inverse correlation between frequency of the effector memory CD8+ T cells and haematocrit (Spearman rho = -0.3859, p = 0.0352). Conclusions: Children with SCA in Tanzania show an absolute increase in all leukocyte types, including lymphocytes, with skewing of both CD4+ and CD8+ T cells towards the memory phenotypes. These findings provide insights on the development of adaptive immunity which may have implications on vaccine responsiveness, allo-immunisation, auto-immune diseases and transplant immunology in children with SCA.

AB - Background: Infection is an important cause of morbidity in children with sickle cell anaemia (SCA). However, little is currently known regarding the spectrum of adaptive immune derangement in SCA, especially of populations in Sub-Saharan Africa. In this study, we investigated the phenotype and activation status of T and B lymphocytes among children with SCA in Tanzania. Methods: We compared 30 children with SCA aged 1-6 years in steady-state with 10 age-matched controls. We assessed white blood cell count, T and B lymphocyte phenotype and activation status using an automated haematology analyser and multiparameter Flow Cytometry. Results: In children with SCA, the absolute lymphocyte, monocyte and granulocyte counts were all increased. There was also an increase in proportion of central/transitional memory (42.4% vs. 33.3%, p = 0.0100), effector memory (7.8% vs. 5.4%, p = 0.0086) and terminally differentiated (2.3% vs. 1.3%, p = 0.0355) CD4+ T cells as well as effector memory CD8+ T cells (21.3% vs. 11.5%, p = 0.0060) in children with SCA. In contrast, there was no difference in naïve, classical memory, atypical memory and IgM memory B-cells between the two groups. The level of activation of both T and B cells were comparable between children with and without SCA. Furthermore, we observed a significant inverse correlation between frequency of the effector memory CD8+ T cells and haematocrit (Spearman rho = -0.3859, p = 0.0352). Conclusions: Children with SCA in Tanzania show an absolute increase in all leukocyte types, including lymphocytes, with skewing of both CD4+ and CD8+ T cells towards the memory phenotypes. These findings provide insights on the development of adaptive immunity which may have implications on vaccine responsiveness, allo-immunisation, auto-immune diseases and transplant immunology in children with SCA.

KW - Activation

KW - B-cell

KW - Lymphocyte

KW - Phenotype

KW - Sickle cell anaemia

KW - T-cell

KW - Tanzania

UR - http://www.scopus.com/inward/record.url?scp=85018549132&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85018549132&partnerID=8YFLogxK

U2 - 10.4314/thrb.v19i2.3

DO - 10.4314/thrb.v19i2.3

M3 - Article

AN - SCOPUS:85018549132

VL - 19

JO - Tanzania Journal of Health Research

JF - Tanzania Journal of Health Research

SN - 1821-6404

IS - 2

ER -