TY - JOUR
T1 - Antibody-secreting cells to diagnose mycobacterium tuberculosis infection in children in Pakistan
AU - Iqbal, Najeeha Talat
AU - Ahmed, Kumail
AU - Qamar, Farah N.
AU - Shaheen, Fariha
AU - Mehnaz, Aisha
AU - Arif, Fehmina
AU - Saeed, Amna Afzal
AU - Yousuf, Aneeq Muhammad
AU - Raza, Syeda Fatima
AU - Sultana, Shazia
AU - Qureshi, Shahida Mumtaz
AU - Siddiqi, Shakil Ahmad
AU - Houpt, Eric
AU - Thomas, Tania
N1 - Funding Information:
We thank all the members of the Aga Khan University Field Research team, without whose hard work and dedication this project could not have been completed, as well as community health workers Farzeen Hirani, Afshan Pyar Ali, and Zohra Sehwani. We also thank the members of the families of the children who participated in this study. We also acknowledge BCG Japan Laboratories for the provision of BCG vaccine. We acknowledge R. Hussain for providing pooled sera for TB patients and endemic controls. N.T.I. and T.T. were principal investigators (PIs) for this project, participated in study design, analyzed the results, performed literature searches, and wrote the first draft and edited the manuscript. K.A. was involved in bench testing and in writing the manuscript. E.H. secured the funding from the University of Virginia (UVA). F.N.Q., A.M., F.A., and S.A.S. were study clinicians and were involved in classifications of TB at different study sites. S.S. supervised field staff for enrollment of cases and controls and followups. A.A.S., S.F.R., and A.M.Y. were involved in bench testing of biomarkers and contributed to the writing of the manuscript. S.M.Q. contributed to the procurement of laboratory supplies and was involved in the writing of the manuscript. F.S. carried out data cleaning and statistical analyses. All of us have declared that we have no conflict of interest. Funding for this work was supported by a seed grant from the University of Virginia (UoV-WH-NI: Evaluation of MASC-51543). The study was partially supported for biomarker work by funds from the Undergraduate Research Module of Aga Khan Medical College.
Publisher Copyright:
© 2020 Iqbal et al.
PY - 2020/1/1
Y1 - 2020/1/1
N2 - Reliance on microbiologic methods to diagnose Mycobacterium tuberculosis infection is a suboptimal approach for children due in part to the paucibacillary nature of the disease. A blood-based biomarker assay, such as the mycobacterial-antibodysecreting cell (MASC) assay, could be a major advance for the field of study of pediatric tuberculosis (TB). Children <15 years of age with clinical concern for TB and agematched children with no concern for TB were enrolled from outpatient clinics in Karachi, Pakistan. MASC, ferritin, and C-reactive protein (CRP) assays were performed, and results were compared among cases and controls, as well as among children with a case definition of "confirmed TB, ""probable TB, "or "possible TB. "MASC responses were significantly higher among children with TB than among controls (0.41 optical density [OD] versus 0.28 OD, respectively, P<0.001), and the differences were largely driven by the data from children with confirmed TB (P<0.002). Ferritin and CRP values were significantly higher among those with confirmed TB than among those with the other disease states and controls (P<0.004 and P<0.019, respectively). The use of the MASC assay as a blood-based biomarker for TB disease shows some promise among children with microbiologically confirmed disease; however, the performance characteristics for the majority of young children with unconfirmed TB were suboptimal in this cohort. IMPORTANCE Tuberculosis (TB) in children represents a missed opportunity for diagnosis and preventive therapy. The magnitude or burden of disease in children is not fully understood due to our limitations with respect to exploring sensitive diagnostic algorithms. In a setting of TB endemicity in Pakistan, we carried out a proofof-concept study to evaluate for the first time the performance of B cell analyses by the use of well-defined diagnostic criteria and NIH consensus guidelines as "cultureconfirmed, ""probable, "and "possible" TB groups. In contrast to detection of serum antibody, we focused on mycobacterial-antibody-secreting cell (MASC) detection as a marker of active disease in children with a strong suspicion of TB. Further work exploring a larger panel of inflammatory biomarkers and enrichment of B cells with the objective of increasing the sensitivity of the current MASC assay would lead to the development of a field-friendly assay for timely diagnosis of childhood TB.
AB - Reliance on microbiologic methods to diagnose Mycobacterium tuberculosis infection is a suboptimal approach for children due in part to the paucibacillary nature of the disease. A blood-based biomarker assay, such as the mycobacterial-antibodysecreting cell (MASC) assay, could be a major advance for the field of study of pediatric tuberculosis (TB). Children <15 years of age with clinical concern for TB and agematched children with no concern for TB were enrolled from outpatient clinics in Karachi, Pakistan. MASC, ferritin, and C-reactive protein (CRP) assays were performed, and results were compared among cases and controls, as well as among children with a case definition of "confirmed TB, ""probable TB, "or "possible TB. "MASC responses were significantly higher among children with TB than among controls (0.41 optical density [OD] versus 0.28 OD, respectively, P<0.001), and the differences were largely driven by the data from children with confirmed TB (P<0.002). Ferritin and CRP values were significantly higher among those with confirmed TB than among those with the other disease states and controls (P<0.004 and P<0.019, respectively). The use of the MASC assay as a blood-based biomarker for TB disease shows some promise among children with microbiologically confirmed disease; however, the performance characteristics for the majority of young children with unconfirmed TB were suboptimal in this cohort. IMPORTANCE Tuberculosis (TB) in children represents a missed opportunity for diagnosis and preventive therapy. The magnitude or burden of disease in children is not fully understood due to our limitations with respect to exploring sensitive diagnostic algorithms. In a setting of TB endemicity in Pakistan, we carried out a proofof-concept study to evaluate for the first time the performance of B cell analyses by the use of well-defined diagnostic criteria and NIH consensus guidelines as "cultureconfirmed, ""probable, "and "possible" TB groups. In contrast to detection of serum antibody, we focused on mycobacterial-antibody-secreting cell (MASC) detection as a marker of active disease in children with a strong suspicion of TB. Further work exploring a larger panel of inflammatory biomarkers and enrichment of B cells with the objective of increasing the sensitivity of the current MASC assay would lead to the development of a field-friendly assay for timely diagnosis of childhood TB.
KW - Antibody-secreting cells
KW - Biomarkers
KW - Tuberculosis
UR - http://www.scopus.com/inward/record.url?scp=85079069055&partnerID=8YFLogxK
U2 - 10.1128/mSphere.0632-19
DO - 10.1128/mSphere.0632-19
M3 - Article
C2 - 32024709
AN - SCOPUS:85079069055
SN - 2379-5042
VL - 5
JO - mSphere
JF - mSphere
IS - 1
M1 - e00632
ER -
