Biomedica : revista del Instituto Nacional de Salud最新文献

{"title":"Ten years of the immunogenetics laboratory performance assessment programme and its impact on the donor and transplant network","authors":"Yazmin Rocio Arias-Murillo, María Angélica Salinas-Nova, Yesith Guillermo Toloza-Pérez, Miguel Ángel Castro-Jiménez","doi":"10.7705/biomedica.7589","DOIUrl":"10.7705/biomedica.7589","url":null,"abstract":"<p><p>Introduction. The use of immunological tests before solid organ transplantation is essential to reduce the risk of rejection and post-transplant complications. Therefore, quality control systems in laboratories performing them are necessary for clinical practice. The Colombian Instituto Nacional de Salud implemented the external evaluation program of transplant immunogenetics laboratory performance in 2014.\u0000Objective. To evaluate the performance of the laboratories that carried out five of the immunological tests for transplants in Colombia between 2014 and 2023, according to information from the external evaluation program of transplant immunogenetics laboratory performance.\u0000Materials and methods. We conducted a study of laboratory performance considering five immunological tests for transplantation: HLA, qualitative and quantitative PRA (Panel Reactive Antibodies), isolated antigen, and cross-matching tests. We collected data from reports of each laboratory. Based on the comparisons between laboratories, their performance was rated as “good”, “acceptable”, or “unacceptable” for each test. We calculated proportions and an analysis of predicted values with a 95% confidence interval.\u0000Results. The number of participating laboratories varied between 5 and 12, depending on the test. The proportion of laboratories with “good” performance was lower in the first year. The best performance was for qualitative PRA, rated as good in all the laboratories for eight years. In HLA (2014), qualitative PRA (2017 and 2019), crossmatch tests (2019), and single antigen (2017 and 2019) tests, the laboratories had a lower percentage of “good” performance than expected.\u0000Conclusion. “Good” performance was observed in all the laboratories in each test during the last three years, except for HLA and quantitative PRA.</p>","PeriodicalId":101322,"journal":{"name":"Biomedica : revista del Instituto Nacional de Salud","volume":"44 Sp. 2","pages":"155-167"},"PeriodicalIF":0.0,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11991689/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143019577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recommendations on vaccination in children and adolescents with inborn errors of immunity according to the expanded Colombian immunization program","authors":"Nathalia Cortés-Marín, Luis Miguel Sosa-Ávila, Andrés Felipe Arias, Leonardo David Escobar-Cortés, Juan Pablo Rojas-Hernández","doi":"10.7705/biomedica.7424","DOIUrl":"10.7705/biomedica.7424","url":null,"abstract":"<p><p>In this manuscript, we carried out an exhaustive analysis of the global recommendations for immunization in inborn errors of immunity patients. We examined the mechanisms of action and types of vaccines, and we described the vaccines included in the Colombian immunization program together with the specific guidelines for immunization in patients with the most frequent inborn errors of immunity in Colombia.\u0000These recommendations were adjusted according to the severity and subclassifications of each immunodeficiency, considering variations in the immune response to offer evidencebased recommendations for vaccination in children with these conditions. We included the most common inborn errors of immunity worldwide and considered the vaccines included in the Colombian immunization program to avoid delays in vaccination schedules.\u0000This work was achieved through a narrative, non-systematic review of articles indexed in Spanish and English, using MeSH terms such as: “inborn errors of immunity”, “primary immunodeficiencies”, “vaccination in inborn errors of immunity, “types of vaccines”, “mechanism of action of vaccines”, and “live vaccines in inborn errors of immunity”.\u0000We used search engines such as: PubMed, Medline, ScienceDirect, and websites of recognized institutions such as the Centers for Disease Control and Prevention (CDC).</p>","PeriodicalId":101322,"journal":{"name":"Biomedica : revista del Instituto Nacional de Salud","volume":"44 Sp. 2","pages":"220-235"},"PeriodicalIF":0.0,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12014215/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143019482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Loss-of-function variant in MAGT1 leading to XMEN disease in a Colombian patient with a common variable immunodeficiency","authors":"Sebastián Gutiérrez-Hincapié, Julio César Orrego, José Luis Franco, Claudia M Trujillo-Vargas","doi":"10.7705/biomedica.7636","DOIUrl":"10.7705/biomedica.7636","url":null,"abstract":"<p><strong>Introduction: </strong>Common variable immunodeficiency is a diagnosis of exclusion in immunodeficient patients with increased susceptibility to infections, hypogammaglobulinemia, deficient response to vaccination, or low percentages of switched memory B cells. In low- and middle-income countries, the elucidation and study of molecular defects in these patients may take decades.</p><p><strong>Objective: </strong>To elucidate the genetic defect conferring impaired immunity in a patient diagnosed with common variable immunodeficiency.</p><p><strong>Materials and methods: </strong>The clinical phenotype was extracted from the clinical records. NKG2D expression in natural killer cells was evaluated by flow cytometry. The whole exome sequencing was performed in the patient and his parents. Sanger sequencing confirmed the pathogenic variant.</p><p><strong>Results: </strong>The patient suffered from upper respiratory and urinary tract infections, autoimmune hemolytic anemia, and hepatopathy. NKG2D was decreased in the different blood subpopulations of natural killer cells. Serologic and viral load studies for Epstein-Barr virus were positive, but no B-cell malignancies have been documented. The patient presented a nonsense variant in the exon 3 of the MAGT1 gen (c.409C>T, rs387906724) in the X chromosome, resulting in an amino acid substitution of arginine for a stop codon in the position 137 of the protein (R137X). The mother also carried the pathogenic variant in a heterozygous state.</p><p><strong>Conclusions: </strong>We report the clinical case of the first Colombian male patient with a pathogenic variant in MAGT1 associated with XMEN disease. Genetic counseling and followup are recommended for families with similar cases to allow prompt detection of new cases.</p>","PeriodicalId":101322,"journal":{"name":"Biomedica : revista del Instituto Nacional de Salud","volume":"44 Sp. 2","pages":"39-47"},"PeriodicalIF":0.0,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11913215/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143019566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Autoimmunity against cytokines: Double strike in autoimmune disease, a historical perspective","authors":"Iván Insignares, Luis E Rodríguez, Óscar Correa-Jiménez, Alberto Alfaro-Murillo, Laura Rincón-Arenas, Andrés Sánchez, Marlon Múnera","doi":"10.7705/biomedica.7570","DOIUrl":"10.7705/biomedica.7570","url":null,"abstract":"<p><p>Autoimmune responses are characterized by the development of antibodies and the activation of T lymphocytes against self-antigens. This leads to an effector immune response against tissues expressing antigens, which are later recognized by the host immune system. Host antigens attacked by antibodies are called \"autoantigens\" and are of different kinds, including receptors, enzymes, and channel proteins. The autoimmune response is potentiated by cytokines that mediate the activation of Th1, Th2, or Th17 lymphocytes. The released cytokines can also be recognized as autoantigens, meaning they can be targets of the autoimmune response. The effects of autoimmunity on cytokines or their receptors are diverse, and the mechanisms of this type of autoimmune response are discussed in this review.</p>","PeriodicalId":101322,"journal":{"name":"Biomedica : revista del Instituto Nacional de Salud","volume":"44 Sp. 2","pages":"209-219"},"PeriodicalIF":0.0,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12014211/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143019548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Standardization of the use of opsonized zymosan as stimulus in the 1,2,3-dihydrorhodamine technique for the assessment of neutrophil respiratory burst","authors":"Uriel Pérez-Blanco, Jenniffer Yissel Girón, Guillermo Juárez-Vega, María Jiménez, Carlos Sánchez, Ricardo Rioja, Sara Espinosa-Padilla, Lizbeth Blancas-Galicia","doi":"10.7705/biomedica.7461","DOIUrl":"10.7705/biomedica.7461","url":null,"abstract":"<p><strong>Introduction: </strong>Chronic granulomatous disease is a defect in phagocytosis due to deficiency of gp91phox, p22phox, p47phox, p40phox, and p67phox (classic form of the disease). Recently, EROS and p40phox deficiency were described as responsible for the non-classical form of the disease. The 1,2,3-dihydrorhodamine oxidation technique, with phorbol-12-myristate-13-acetate as a stimulus, is performed to diagnose the classic chronic granulomatous disease. However, oxidation mediated by EROS and p40phox requires stimuli such as zymosan, Escherichia coli, or Staphylococcus aureus.</p><p><strong>Objective: </strong>To optimize the 1,2,3-dihydrorhodamine technique using zymosan to assess neutrophil respiratory burst and detect the non-classical chronic granulomatous disease.</p><p><strong>Materials and method: </strong>Blood was obtained from five healthy subjects after the signature of the informed consent. The 1,2,3-dihydrorhodamine technique was performed with phorbol-12-myristate-13-acetate as control and different quantities of opsonized zymosan (150, 100, 50, 20, and 10 μg). We obtained through flow cytometry the mean fluorescence intensity of rhodamine 1,2,3 oxidated in the neutrophil population and calculated the oxidation index. The Kolmogorov-Smirnov test, ANOVA, and Tukey’s post-hoc analysis were used. We considered a p value ≤ 0.05 as statistically significant.</p><p><strong>Results: </strong>The phorbol-12-myristate-13-acetate increased the rhodamine 1,2,3 mean fluorescence intensity in healthy subjects. Among the different zymosan conditions tested, we selected 50 μg as the optimal and reproducible amount in all controls according to the statistical analysis and cytometric findings.</p><p><strong>Conclusions: </strong>We present the optimization of the 1,2,3-dihydrorhodamine technique using zymosan. We propose its implementation in clinical diagnostic laboratories to expand the diagnosis of chronic granulomatous disease.</p>","PeriodicalId":101322,"journal":{"name":"Biomedica : revista del Instituto Nacional de Salud","volume":"44 Sp. 2","pages":"198-208"},"PeriodicalIF":0.0,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12014214/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143019473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Haploidentical hematopoietic stem cell transplantation using post-transplant cyclophosphamide in patients with inborn errors of immunity: Experience in a reference center in Colombia","authors":"Diego Medina, Jhonier Orlando Castro, David Esteban Castro, Estefanía Beltrán, Eliana Manzi, Alexis Antonio Franco, Manuela Olaya","doi":"10.7705/biomedica.7560","DOIUrl":"10.7705/biomedica.7560","url":null,"abstract":"<p><strong>Introduction: </strong>Inborn errors of immunity is a diverse group of rare diseases caused by over 400 genetic mutations affecting the immune system and increasing infection susceptibility, autoimmunity, and malignancy. Hematopoietic stem cell transplantation offers a curative option for some inborn errors of immunity, with haploidentical donors providing a viable alternative when identical donors are unavailable.</p><p><strong>Objective: </strong>To determine survival, usefulness of weekly chimerism monitoring, immune reconstitution, and complications in patients with inborn errors of immunity who underwent haploidentical hematopoietic stem cell transplantation at a reference center in Colombia.</p><p><strong>Materials and methods: </strong>We conducted a retrospective and observational study of a case series of pediatric patients who underwent haploidentical hematopoietic stem cell transplantation with post-transplant cyclophosphamide and follow-up with weekly chimerism. Survival analysis was performed using the Kaplan-Meier method.</p><p><strong>Results: </strong>Sixteen patients with haploidentical familial donor transplantation were included. The most frequent diagnosis was severe combined immunodeficiency (n=5). Eleven out of seventeen patients received a non-myeloablative conditioning regimen. Twelve out of sixteen patients developed acute graft-versus-host disease. Out of these, 3 corresponded to grades III-IV. Post-transplant infections affected 14 of the subjects, predominating bacterial agents. Median T-cell chimerism was greater than 80% during the follow-up. Reconstitution of B and T lymphocytes was achieved in more than 80%. Overall survival at five years was 81%. Survival at 100 days was 94%.</p><p><strong>Conclusion: </strong>Haploidentical hematopoietic stem cell transplantation using post-transplant cyclophosphamide is a viable alternative for inborn errors of immunity when an identical donor is unavailable. Serial chimerism monitoring is useful for graft follow-up.</p>","PeriodicalId":101322,"journal":{"name":"Biomedica : revista del Instituto Nacional de Salud","volume":"44 Sp. 2","pages":"118-130"},"PeriodicalIF":0.0,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12014220/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143019561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lymphoproliferation and hyper-IgM as the first manifestation of activated phosphoinositide 3-kinase δ syndrome: A case report.","authors":"Mónica Fernandes-Pineda, Andrés F Zea-Vera","doi":"10.7705/biomedica.7436","DOIUrl":"10.7705/biomedica.7436","url":null,"abstract":"<p><p>Activated phosphoinositide 3-kinase δ syndrome is an inborn error of immunity due to mutations within the genes responsible for encoding PI3Kδ subunits. This syndrome results in an excessive activation of the phosphoinositide 3-kinase signaling pathway. Gainof-function mutations in the gene PIK3R1 (encoding p85α, p55α, and p50α) lead to the development of the activated PI3K δ syndrome. Notably, the clinical presentations of this syndrome often closely resemble those of other primary immunodeficiencies. We present a case involving a 15-year-old male who displayed an immunological phenotype that bore a striking resemblance to hyper-IgM syndrome. Whole exome sequencing was undertaken to pinpoint the underlying genetic mutation. Our investigation successfully identified a heterozygous splice site mutation previously reported within the well-established hotspot of the PIK3R1 gene (GRCh37, c.1425+1 G>T). The diverse spectrum of inborn errors of immunity underscores the pivotal role of identifying gene mutations, particularly in patients presenting clinical manifestations spanning autoimmune disorders, lymphoproliferative conditions, and antibody deficiencies. Such precise genetic diagnoses hold significant potential for improving patient care and management.</p>","PeriodicalId":101322,"journal":{"name":"Biomedica : revista del Instituto Nacional de Salud","volume":"44 Sp. 2","pages":"10-15"},"PeriodicalIF":0.0,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11949422/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143019567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From phenotypic to molecular diagnosis: Insights from a clinical immunology service focused on inborn errors of immunity in Colombia","authors":"Mónica Fernandes Pineda, Andrés F Zea-Vera","doi":"10.7705/biomedica.7533","DOIUrl":"10.7705/biomedica.7533","url":null,"abstract":"<p><strong>Introduction: </strong>Inborn errors of immunity include a broad spectrum of genetic diseases, in which a specific gene mutation might alter the entire emphasis and approach for an individual patient.</p><p><strong>Objective: </strong>To conduct a comprehensive analysis of the correlation between phenotypic and molecular diagnoses in patients with confirmed inborn errors of immunity at a tertiary hospital in Cali, Colombia.</p><p><strong>Materials and methods: </strong>We conducted a retrospective study in which we sequentially evaluated all available institutional medical records with a diagnosis of inborn errors of immunity.</p><p><strong>Results: </strong>In the Clinical Immunology Service of the Hospital Universitario del Valle, 517 patients were evaluated. According to the IUIS-2022 classification, 92 patients (17.35%) were definitively diagnosed with an inborn error of immunity. Of these, 38 patients underwent genetic studies. The most prevalent category was predominantly antibody deficiencies (group III) (38/92 - 41.3%). A broad spectrum of genetic defects, novel and previously reported, were described, including mutations in the following genes: ATM, BTK, ERBIN, MAB21L2, RAG2, SAVI, SH2D1A, STAT1, SYK, and TMEM173. Less frequent findings included cases of the WHIM syndrome, SYK gain-of-function, and IL-7 deficiency.</p><p><strong>Conclusions: </strong>The establishment of the Clinical Immunology Service in the Hospital Universitario del Valle has emerged as a pivotal resource, catering to individuals with limited financial means and covered by public health insurance within the southwest region of Colombia. Molecular genetics confirmatory diagnosis was achieved in 38 patients (41.3%) with inborn errors of immunity and changed the diagnosis in 24 cases (26%).</p>","PeriodicalId":101322,"journal":{"name":"Biomedica : revista del Instituto Nacional de Salud","volume":"44 Sp. 2","pages":"168-177"},"PeriodicalIF":0.0,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12014219/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143019558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A hidden enemy: Understanding the hemophagocytic syndrome in children under five years of age in a high-complexity institution in southwestern Colombia","authors":"Sofía Martínez, Jacobo Triviño, Oriana Arias, Diego Medina, Alexis Franco, Jaime Patiño, Paola Pérez, Harry Pachajoa, Pamela Rodríguez, Manuela Olaya-Hernández","doi":"10.7705/biomedica.7526","DOIUrl":"10.7705/biomedica.7526","url":null,"abstract":"<p><p>Introduction. Hemophagocytic syndrome is an under-recognized condition with high mortality in the pediatric population. It is characterized by excessive activation of immune cells and cytokine release, leading to persistent inflammation. Hemophagocytic syndrome can be primary or secondary and associated with different triggers.\u0000Objective. To describe 12 clinical cases of children under five years of age with hemophagocytic syndrome in a high-complexity institution in southwestern Colombia.\u0000Materials and methods. We present a retrospective series of 12 cases of hemophagocytic syndrome in children under five years of age treated at a high-complexity institution in Colombia between 2019 and 2022.\u0000Results. The median age of the patients was one year and 7 were male. Fever and splenomegaly were the most common clinical manifestations observed in 11 of the\u0000patients. The predominant laboratory findings included hyperferritinemia (n = 11), hypertriglyceridemia (n = 10), bicytopenia (n = 6), and pancytopenia (n = 2). Eleven cases had elevated lactate dehydrogenase levels. Genetic studies were conducted in 7 patients. Regarding treatment, the full HLH-2004 protocol was administered to 5 cases, while 3 underwent hematopoietic stem cell transplantation. Three patients died.\u0000Conclusion. We highlight the complexity of the hemophagocytic syndrome, especially in children under five years old, because the low prevalence and non-specific clinical presentation of the disease contribute to its underdiagnosis. Emphasis is placed on identifying triggers, performing genetic evaluation for accurate and early diagnosis, adopting a multidisciplinary approach, and considering early hematopoietic stem cell transplantation to improve morbidity and mortality outcomes.</p>","PeriodicalId":101322,"journal":{"name":"Biomedica : revista del Instituto Nacional de Salud","volume":"44 Sp. 2","pages":"140-154"},"PeriodicalIF":0.0,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11991687/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143019486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First pilot study for newborn screening of severe T and B lymphopenias in Colombia","authors":"Sebastián Gutiérrez-Hincapié, Carlos Muskus-López, Isaura Pilar Sánchez, José Luis Franco-Restrepo, Claudia M Trujillo-Vargas","doi":"10.7705/biomedica.7568","DOIUrl":"10.7705/biomedica.7568","url":null,"abstract":"<p><strong>Introduction: </strong>Congenital lymphopenias cause increased susceptibility to infections in children apparently healthy at birth. Earlier detection of these conditions would facilitate prompt treatment, prevent potentially serious disease complications and early deaths, and save healthcare resources.</p><p><strong>Objective: </strong>To perform a pilot study for neonatal screening of congenital lymphopenias by the quantification of TREC and KREC –T- and B-cell receptor excision circles– in peripheral blood samples from newborns in Medellín, Colombia.</p><p><strong>Materials and methods: </strong>Blood samples from 1,092 newborns and six referred patients with suspected lymphopenia were collected by heel or toe-finger prick and dropped onto a filter paper. Thereafter, DNA was extracted and levels of TRECs and KRECs were measured by qPCR.</p><p><strong>Results: </strong>The six patients with suspected lymphopenia showed undetectable or very low TREC levels. All newborns screened presented normal TREC and KREC levels. A positive correlation was found between TREC or KREC values quantified from two different filter papers. Detectable levels of the receptor excision circles decrease considerably after 24 weeks of the dried blood spot sample storage. We identified a positive association between low TREC levels and low birth weight; and a negative correlation between KREC values and prematurity. Finally, no statistical differences were found between TREC or KREC levels and delivery method.</p><p><strong>Conclusion: </strong>We describe the first preliminary study for the early detection of lymphopenias in Colombia. We proposed to use a cut-off value of 119 and 69 copies/μl blood of TREC and KREC, respectively for future newborn screening programs in our country.</p>","PeriodicalId":101322,"journal":{"name":"Biomedica : revista del Instituto Nacional de Salud","volume":"44 Sp. 2","pages":"94-106"},"PeriodicalIF":0.0,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12023848/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143019556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}