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Blom M, Bredius RGM, van der Burg M. Efficient screening strategies for severe combined immunodeficiencies in newborns. Expert Rev Mol Diagn 2023; 23:815-825. [PMID: 37599592 DOI: 10.1080/14737159.2023.2244879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 08/02/2023] [Indexed: 08/22/2023]
Abstract
INTRODUCTION Severe combined immunodeficiency (SCID) is one of the most severe forms of inborn errors of immunity (IEI), affecting both cellular and humoral immunity. Without curative treatment such as hematopoietic stem cell transplantation or gene therapy, affected infants die within the first year of life. Due to the severity of the disease, asymptomatic status early in life, and improved survival in the absence of pretransplant infections, SCID was considered a suitable candidate for newborn screening (NBS). AREAS COVERED Many countries have introduced SCID screening based on T-cell receptor excision circle (TREC) detection in their NBS programs. Screening an entire population is a radical departure from previous paradigms in the field of immunology. Efficient screening strategies are cost-efficient and balance high sensitivity while preventing high numbers of referrals. NBS for SCID is accompanied by (actionable) secondary findings, but many NBS programs have optimized their screening strategy by adjusting algorithms or including second-tier tests. Harmonization of screening terminology is of great importance for international shared learning. EXPERT OPINION The expansion of NBS is driven by the development of new test modalities and treatment options. In the near future, other techniques such as next-generation sequencing will pave the way for NBS of other IEI. Exciting times await for population-based screening programs.
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Affiliation(s)
- Maartje Blom
- Laboratory for Pediatric Immunology, Willem-Alexander Children's Hospital, Leiden University Medical Center, Leiden, The Netherlands
| | - Robbert G M Bredius
- Department of Pediatrics, Willem-Alexander Children's Hospital, Leiden University Medical Center, Leiden, The Netherlands
| | - Miriam van der Burg
- Laboratory for Pediatric Immunology, Willem-Alexander Children's Hospital, Leiden University Medical Center, Leiden, The Netherlands
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El Allam A, El Fakihi S, Tahoune H, Sahmoudi K, Bousserhane H, Bakri Y, El Hafidi N, Seghrouchni F. Cytometric analysis and clinical features in a Moroccan cohort with severe combined immunodeficiency. Hum Antibodies 2022; 30:67-77. [PMID: 35094990 DOI: 10.3233/hab-211510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Severe combined immunodeficiency (SCID) is a form of primary immunodeficiency disease (PID). It is characterized by a serious abnormality of the cellular and sometimes humoral system due to a deficiency in development of T cells, B cells and/or NK cells. The early diagnosis of SCID improves the prognosis. Typically, the initial consideration of SCID is made based on low lymphocyte counts. Notwithstanding, the heterogeneity of lymphocyte count presentation makes the diagnosis of SCID a significant challenge. The objective of this cross-sectional retrospective study was to analyze the lymphocyte subpopulation counts along with clinical manifestations within a Moroccan cohort diagnosed as SCID compared to children diagnosed with non-PID diseases. Thirty-five SCID confirmed patients were selected in the period between 2008 and 2018 and compared with non-PID patients. Results of peripheral blood T, B, and NK lymphocyte subpopulation counts were measured by flow cytometry for each SCID subtype. As expected, T cell count was less than 300 cells/μL in most patients with SCID (85.5%). Unexpectedly, significantly higher T cell counts were detected in some patients with a confirmed clinical diagnosis and family history of SCID. 5.7% of our SCID Moroccan cohort had T cell numbers in the range between 300 and 500 cells/μL. 8.7% of our SCID Moroccan cohort had T cell numbers higher than 500 cells/μL. Of the SCID subtypes, the proportion of SCID with B cell deficiencies was highly represented in our cohort. 71.4% of Moroccan SCID patients (25 out of 35 patients) were of T-B-subtype. Furthermore, 40% of the patients (14 out of 35 patients) had a T-B-NK+ profile and 31.4% had a T-B-NK- profile (11 out of 35 patients). The most common clinical manifestations observed in our SCID cohort were pneumonia, failure to thrive, candidiasis, diarrhea, bronchitis and urinary tract infections. Our results not only highlight the relatively frequent presence of atypical SCID in the Moroccan population with unexpectedly high T cell numbers, but also describes the incidence pattern of common SCID subtypes in Morocco. Physicians in Morocco may find this local region-specific difference in SCID important for making improved early diagnosis of this disease.
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Affiliation(s)
- Aicha El Allam
- Laboratory of Cellular Immunology, National Institute of Hygiene, Rabat, Morocco
- Laboratory of Biology and Human Pathology, Faculty of Sciences, University Mohammed V, Rabat, Morocco
| | - Sara El Fakihi
- Laboratory of Cellular Immunology, National Institute of Hygiene, Rabat, Morocco
- Med Biotech Laboratory, Faculty of Medicine and Pharmacy, University Mohammed V, Rabat, Morocco
| | - Hicham Tahoune
- Department of Biology, Faculty of Sciences, University Ibn Tofail, Kenitra, Morocco
| | - Karima Sahmoudi
- Laboratory of Cellular Immunology, National Institute of Hygiene, Rabat, Morocco
- Department of Biology, Faculty of Sciences, University Mohammed V, Rabat, Morocco
| | - Houria Bousserhane
- Laboratory of Cellular Immunology, National Institute of Hygiene, Rabat, Morocco
- Med Biotech Laboratory, Faculty of Medicine and Pharmacy, University Mohammed V, Rabat, Morocco
| | - Youssef Bakri
- Laboratory of Biology and Human Pathology, Faculty of Sciences, University Mohammed V, Rabat, Morocco
- Centre of Human Pathology Genomic, Faculty of Medicine and Pharmacy, University Mohammed V, Rabat, Morocco
| | - Naima El Hafidi
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT, USA
- Immunology, Allergic and Respiratory Diseases Unit, Children's Hospital of Rabat, Ibn Sina University Hospital Centre, Rabat, Morocco
| | - Fouad Seghrouchni
- Laboratory of Cellular Immunology, National Institute of Hygiene, Rabat, Morocco
- Med Biotech Laboratory, Faculty of Medicine and Pharmacy, University Mohammed V, Rabat, Morocco
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Godsell J, Chan S, Slade C, Bryant V, Douglass JA, Sasadeusz J, Yong MK. Cytomegalovirus in primary immunodeficiency. Curr Opin Infect Dis 2021; 34:663-671. [PMID: 34608876 DOI: 10.1097/qco.0000000000000797] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
PURPOSE OF REVIEW Cytomegalovirus (CMV) infection and disease are well described in the setting of secondary immunodeficiency. Less is known about CMV in the context of primary immunodeficiencies (PIDs), where inborn errors in one or more arms of the immune system result in variable degrees of CMV susceptibility. RECENT FINDINGS PID presents unique challenges in the diagnosis and management of CMV disease. The clinical presentation of CMV in PID is often severe, accelerated by underlying immune dysregulation and iatrogenic immunosuppression. Here we describe the clinical significance of CMV infection in PID, the key components of immune defence against CMV and how these are affected in specific PIDs. CMV disease is under-recognized as a complication of common variable immunodeficiency (CVID). High rates of CMV end-organ disease, mortality, development of CMV resistance and prolonged antiviral use have been observed in individuals with CVID. SUMMARY We recommend that clinicians tailor their approach to the individual based on their underlying immune deficit and maintain a high index of suspicion and low threshold for treatment. More research is required to improve stratification of CMV risk in PID, develop new diagnostic tools and manage end-organ disease in this cohort.
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Affiliation(s)
- Jack Godsell
- Department of Clinical Immunology & Allergy, Royal Melbourne Hospital
| | - Samantha Chan
- Department of Clinical Immunology & Allergy, Royal Melbourne Hospital
- Immunology Division, Walter & Eliza Hall Institute of Medical Research
- Department of Medicine, University of Melbourne
| | - Charlotte Slade
- Department of Clinical Immunology & Allergy, Royal Melbourne Hospital
- Immunology Division, Walter & Eliza Hall Institute of Medical Research
| | - Vanessa Bryant
- Department of Clinical Immunology & Allergy, Royal Melbourne Hospital
- Immunology Division, Walter & Eliza Hall Institute of Medical Research
| | - Jo Anne Douglass
- Department of Clinical Immunology & Allergy, Royal Melbourne Hospital
- Department of Medicine, University of Melbourne
| | - Joe Sasadeusz
- Victorian Infectious Diseases Service, Royal Melbourne Hospital, Melbourne
| | - Michelle K Yong
- Victorian Infectious Diseases Service, Royal Melbourne Hospital, Melbourne
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville
- National Centre for Infections in Cancer, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
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Blom M, Zetterström RH, Stray-Pedersen A, Gilmour K, Gennery AR, Puck JM, van der Burg M. Recommendations for uniform definitions used in newborn screening for severe combined immunodeficiency. J Allergy Clin Immunol 2021; 149:1428-1436. [PMID: 34537207 DOI: 10.1016/j.jaci.2021.08.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 08/06/2021] [Accepted: 08/23/2021] [Indexed: 01/31/2023]
Abstract
BACKGROUND Public health newborn screening (NBS) programs continuously evolve, taking advantage of international shared learning. NBS for severe combined immunodeficiency (SCID) has recently been introduced in many countries. However, comparison of screening outcomes has been hampered by use of disparate terminology and imprecise or variable case definitions for non-SCID conditions with T-cell lymphopenia. OBJECTIVES This study sought to determine whether standardized screening terminology could overcome a Babylonian confusion and whether improved case definitions would promote international exchange of knowledge. METHODS A systematic literature review highlighted the diverse terminology in SCID NBS programs internationally. While, as expected, individual screening strategies and tests were tailored to each program, we found uniform terminology to be lacking in definitions of disease targets, sensitivity, and specificity required for comparisons across programs. RESULTS The study's recommendations reflect current evidence from literature and existing guidelines coupled with opinion of experts in public health screening and immunology. Terminologies were aligned. The distinction between actionable and nonactionable T-cell lymphopenia among non-SCID cases was clarified, the former being infants with T-cell lymphopenia who could benefit from interventions such as protection from infections, antibiotic prophylaxis, and live-attenuated vaccine avoidance. CONCLUSIONS By bringing together the previously unconnected public health screening community and clinical immunology community, these SCID NBS deliberations bridged the gaps in language and perspective between these disciplines. This study proposes that international specialists in each disorder for which NBS is performed join forces to hone their definitions and recommend uniform registration of outcomes of NBS. Standardization of terminology will promote international exchange of knowledge and optimize each phase of NBS and follow-up care, advancing health outcomes for children worldwide.
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Affiliation(s)
- Maartje Blom
- Department of Pediatrics, Laboratory for Pediatric Immunology, Leiden University Medical Center, Leiden, The Netherlands
| | - Rolf H Zetterström
- Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden; Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Asbjørg Stray-Pedersen
- Norwegian National Unit for Newborn Screening, Division of Pediatric and Adolescent Medicine, Oslo University Hospital, Oslo, Norway; Department of Pediatrics, Division of Pediatric and Adolescent Medicine, Oslo University Hospital, Oslo, Norway
| | - Kimberly Gilmour
- University College London Great Ormond Street Institute of Child Health, London, United Kingdom; Great Ormond Street Hospital for Children National Health Service Foundation Trust, London, United Kingdom; National Institute for Health Research-Great Ormond Street Hospital Biomedical Research Center, London, United Kingdom
| | - Andrew R Gennery
- Children's Bone Marrow Transplant Unit, Great North Children's Hospital, Newcastle upon Tyne, United Kingdom; Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Jennifer M Puck
- Division of Allergy, Immunology, and Blood and Marrow Transplantation, Department of Pediatrics, University of California, San Francisco School of Medicine, San Francisco, Calif; University of California, San Francisco Benioff Children's Hospital San Francisco, San Francisco, Calif
| | - Mirjam van der Burg
- Department of Pediatrics, Laboratory for Pediatric Immunology, Leiden University Medical Center, Leiden, The Netherlands.
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