[Natural history of mucopolysaccharidosis type III in a series of Colombian patients]. / Historia natural de la mucopolisacaridosis III en una serie de pacientes colombianos.

INTRODUCTION: Mucopolysaccharidosis type III (MPS III), also known as Sanfilippo syndrome, is a lysosomal storage disease with progressive neurodegenerative features, predominantly affecting the central nervous system. Diagnosis is based on clinical features, with neurodevelopmental and neuropsychiatric alterations taking precedence, including over phenotype alterations. The disease is confirmed by biochemical analysis to identify the type of glycosaminoglycans present, enzyme assay and molecular genetic studies. CASE REPORTS: A clinical description was performed for eight patients diagnosed with MPS III in Colombia. Their initial symptoms were related to developmental delay and behavioural disorders presenting between 3 and 8 years of age, associated in all cases with coarse facial features, thick eyebrows, hepatomegaly and progressive hearing loss. One of the patients presented cardiac anomalies; two presented focal epilepsy; and one presented optic atrophy. They all presented neuroimaging alterations, with evidence of parenchymal volume loss, corpus callosum atrophy and cortical thinning; the diagnosis was performed by biochemical glycosaminoglycan chromatography studies, and all patients have a confirmatory genetic study. CONCLUSIONS: MPS III is a challenge for diagnosis, particularly in its early stages and in patients in which the course of the disease is attenuated. This is due to its variable course, non-specific early neuropsychiatric symptoms, and the absence of obvious somatic features compared to other types of MPS. After a definitive diagnosis has been made, interdisciplinary care must be provided for the patient and their family, and support given for the treatment of physical symptoms, ensuring the best possible care and quality of life for the patient and their family, as the condition is neurodegenerative.

TITLE: Historia natural de la mucopolisacaridosis III en una serie de pacientes colombianos.Introducción. La mucopolisacaridosis de tipo III (MPS III), o síndrome de Sanfilippo, es un trastorno de almacenamiento lisosómico con características neurodegenerativas progresivas, predominante del sistema nervioso central. Su diagnóstico se basa en el cuadro clínico, y priman alteraciones en el neurodesarrollo y neuropsiquiátricas, incluso antes de la presencia de alteraciones fenotípicas. El análisis bioquímico para identificar el tipo de glucosaminoglucanos presente, la determinación enzimática y el estudio de genética molecular confirman la enfermedad. Casos clínicos. Se realiza la descripción clínica de ocho pacientes con diagnóstico de MPS III en Colombia, con síntomas iniciales en relación con retraso del desarrollo y trastornos comportamentales evidenciados entre los 3 y 8 años, asociado a facies toscas, cejas pobladas, hepatomegalia y pérdida auditiva progresiva en todos los casos. Uno de los pacientes presentó anomalías cardíacas; dos de ellos, epilepsia focal; y en uno se evidenció atrofia óptica. Todos presentaron alteraciones en las neuroimágenes con evidencia de pérdida del volumen parenquimatoso, atrofia del cuerpo calloso y adelgazamiento cortical; el diagnostico se realizó a través de estudios bioquímicos de cromatografía de glucosaminoglucanos y todos cuentan con un estudio genético confirmatorio. Conclusiones. La MPS III es un desafío diagnóstico, particularmente en pacientes con un curso atenuado de la enfermedad, debido al curso variable, síntomas neuropsiquiátricos tempranos inespecíficos y falta de características somáticas evidentes en comparación con otros tipos de MPS. Cuando se tiene el diagnóstico definitivo, es fundamental brindar atención interdisciplinaria para el paciente y la familia, y apoyar el tratamiento de los síntomas físicos, garantizando ofrecer el mejor cuidado posible y la mejor calidad de vida para el paciente y su familia, al tratarse de una condición neurodegenerativa.

Parkinson's disease: an update on preclinical studies of induced pluripotent stem cells.

Parkinson's disease (PD) is the second most prevalent neurodegenerative disease among adults worldwide. It is characterised by the death of dopaminergic neurons in the substantia nigra pars compacta and, in some cases, presence of intracytoplasmic inclusions of α-synuclein, called Lewy bodies, a pathognomonic sign of the disease. Clinical diagnosis of PD is based on the presence of motor alterations. The treatments currently available have no neuroprotective effect. The exact causes of PD are poorly understood. Therefore, more precise preclinical models have been developed in recent years that use induced pluripotent stem cells (iPSC). In vitro studies can provide new information on PD pathogenesis and may help to identify new therapeutic targets or to develop new drugs.

Central nervous system activity of a Tabernaemontana arborea alkaloid extract involves serotonergic and opioidergic neurotransmission in murine models.

Tabernaemontana arborea (Apocynaceae) is a Mexican tree species known to contain ibogan type alkaloids. This study aimed at determining central nervous system-related activities of an alkaloid extract obtained from the root bark of T. arborea. A gas chromatography-mass spectrometry (GC-MS) analysis was performed to describe the alkaloid profile of the extract. A wide dosing range (0.1 to 56.2 mg/kg) of this extract was evaluated in different murine models. Electrical brain activity was examined by electroencephalography (EEG). The extract's effects on motor coordination, ambulatory activity, and memory were analyzed based on the rotarod, open field (OFT), and object recognition tests (ORT), respectively. Antidepressant and antinociceptive activities were determined using the forced swimming test (FST) and the formalin assay, respectively. In order to elucidate the underlying mechanisms of action, the 5-HT1A receptor antagonist WAY100635 (1 mg/kg) or the opioid receptor antagonist naloxone (1 mg/kg) was included in the latter experiments. GC-MS analysis (µg/mg extract) confirmed the presence of the monoterpenoid indole alkaloids (MIAs) voacangine (207.00), ibogaine (106.33), vobasine (72.81), coronaridine (30.72), and ibogamine (24.2) as principal constituents of the extract, which exhibited dose- and receptor-dependent antidepressant (0.1 to 1 mg/kg; 5-HT1A) and antinociceptive (30 and 56.2 mg/kg; opioid) effects, without altering motor coordination, ambulatory activity, and memory. EEG indicated CNS depressant activity at high doses (30 and 56.2 mg/kg). The root bark of T. arborea contains a mixture of alkaloids that may hold therapeutic value in pain relief and the treatment of psychiatric diseases without causing neurotoxic activity at effective doses.

Consultas nutricionales en menores de 9 años en la región del Maule, Chile, entre 2017-2021, efecto de estallido social y pandemia COVID-19

Introducción: La consulta nutricional es la primera línea de atención en niñas y niños en salud pública que presentan condiciones de malnutrición por déficit o exceso. Sin embargo, la atención a estos niños y niñas fue afectada por las movilizaciones sociales y la pandemia por COVID-19. Objetivo: Evaluar la tendencia de las consultas realizadas a menores de 9 años por profesional nutricionista en la región del Maule, Chile, desde el año 2017 a 2021. Métodos: Estudio descriptivo de corte longitudinal histórico basado en los datos de los Registros Estadísticos Mensuales (REM) del Servicio de Salud del Maule, las tendencias fueron analizadas con coeficiente de determinación (R2) mediante la regresión de Prais-Winsten. Resultados: Se analizaron 274.377 consultas nutricionales de niños/as menores de 9 años. 53,8% en clasificación de malnutrición por exceso y 12,1% en déficit. Se registró una disminución de 56,8% en las consultas nutricionales durante las movilizaciones sociales y un 92% al inicio de pandemia. Se observó una tendencia al aumento de las consultas por déficit nutricional, especialmente en menores de 12 meses (R2 0,633, β=4,45, p<0,001). Conclusión: La situación social y epidemiológica afectaron significativamente las atenciones nutricionales en salud pública. Es necesario dar una mayor visibilidad de los profesionales nutricionistas y promover el desarrollo de estrategias innovadoras para afrontar este escenario epidemiológico.

Background: The nutritional appointments is the first line of care for children with malnutrition or overweight in public primary health, but its normal functioning was affected by social mobilizations and the COVID-19 pandemic. Objective: To evaluate trends in consultations among children under 9 years of age in the Maule region, Chile, between 2017 and 2021. Methods: Descriptive longitudinal study based on data from the Monthly Statistical Records (REM) of the Maule Health Service, the trends were analyzed with coefficient of determination (R2) using Prais-Winsten regression. Results: 274,377 nutritional consultations were analyzed, of which 53.8% were overweight and 12.1% with malnutrition. A 56.8% decrease in nutritional consultations was recorded during social mobilizations and 92% at the beginning of the pandemic. A tendency to increase consultations due to malnutrition was observed, especially in children under 12 months of age (R2 0.633, β=4.45, p<0.001). Conclusion: The social and epidemiological situations significantly affected nutritional care in public health. It is necessary to give nutrition professionals greater visibility and promote the development of innovative strategies to deal with this epidemiological scenario.

Inverse Hartmann test for radius of curvature measurement in a corneal topography calibration sphere.

In this article, the use of a square Hartmann screen test to measure the radius of curvature of a corneal topography calibration test sphere is presented. The proposed technique is based on the image formation principle by specular reflection on convex reflective surfaces. Applying an inverse Hartmann test, a de-magnified virtual image (Hartmanngram) is obtained; considering their own scaled reference screen plate, a zonal wavefront retrieval approach is used and the radius of curvature obtained. Experimental setup along the obtained results is presented. A simulated spherical wavefront is used as a method to evaluate the error in the wavefront reconstruction. Since the measurements of radius of curvature fits in to ISO 10343, through suitable modifications the proposed method is potentially applicable in small F/# convex specular surfaces, as is the case in keratometry and corneal topography measurements.

Monitoring of RAS mutant clones in plasma of patients with RAS mutant metastatic colorectal cancer.

PURPOSE: Some patients with histologically confirmed primary mCRC and mutated RAS reported undetectable RAS mutant clones in plasma after receiving anti-VEGF treatment. The aim was to prospectively assess it with its potential therapeutic implications. METHODS: RAS mutant genes in solid biopsy (before first-line treatment: FOLFOX/CAPOX + bevacizumab) were compared in liquid biopsy (before second-line treatment: panitumumab + FOLFIRI), using Idylla™ system. Discordant results between solid/liquid biopsies were assessed by the next-generation sequencing (NGS) test (solid/liquid biopsies). RESULTS: Twenty-three patients were assessed (seven had RAS mutant discrepancies between solid/liquid biopsies). The NGS test confirmed that 3/23 (13%) patients had undetectable RAS mutant clones in liquid biopsy and 3/23 (13%) presented discrepancies in solid biopsy (Idylla™ system vs. NGS test). CONCLUSION: Thirteen percentage of patients had undetectable RAS mutant clones in liquid biopsy after first-line treatment. However, some discrepancies between solid and liquid biopsies have been observed. These results suggest a need to improve accuracy of RAS analyses, especially in solid biopsies.

Antibacterial Activity Analysis of Hydroxyapatite Based Materials with Fluorine and Silver / Análisis de la Actividad Antibacteriana de Materiales a Base de Hidroxiapatita con Flúor y Plata

ABSTRACT This investigation aims to evaluate the antibacterial activity of nanostructured hydroxyapatite based materials doped with silver and fluorine, to be used as a biomaterial with antibacterial activity. Four different formulations were prepared by combustion method: hydroxyapatite, hydroxyapatite-fluorine, hydroxyapatite-silver-fluorine and hydroxyapatite-silver, with 2% of the doping agents. X-ray diffraction technique was used to determine the mineralogy, identifying the presence of Ca5(PO4)3OH, Ca2P2O7, Ag3PO4, AgCa10(PO4)7 Ca5(PO4)3F and CaF2 phases for the studied samples. Scanning electron microscopy was used to study the morphological structure and it showed homogeneous crystallization of the hydroxyapatite and the inclusion of dopant agents. The antibacterial activity was determined using a modified inhibition test zone to observe if the bacteria (E. faecalis) was susceptible to the antimicrobial agent by the appearance of the zone of inhibition on the agar plate. Both the hydroxyapatite-silver and the hydroxyapatite-silver-fluorine materials generated an inhibition zone. It was possible to determine the minimum inhibitory concentration needed to kill most viable organisms after 48 hours of incubation using the broth microdilution method, resulting in 75 µg/ml and 200 µg/ml for the hydroxyapatite-silver and the hydroxyapatite-silver-fluorine formulation, respectively. These materials could be used for the development of new biomaterials that can be used in dental applications.

RESUMEN El objetivo de esta investigación es analizar la actividad antibacteriana de materiales nanoestructurados a base de hidroxiapatita con iones de flúor y plata que le confieran características particulares para que pueda ser utilizado como un biomaterial con actividad antimicrobiana. Se realizaron cuatro formulaciones distintas: hidroxiapatita, hidroxiapatita-flúor, hidroxiapatita-plata-flúor e hidroxiapatita-plata con un 2% de los agentes dopantes. La síntesis del material se realizó a través del método de combustión. La caracterización mineral se realizó a través de difracción de rayos X identificando las siguientes fases en las diversas formulaciones: Ca5(PO4)3OH, Ca2P2O7, Ag3PO4, AgCa10(PO4)7 Ca5(PO4)3F and CaF2. La estructura morfológica se analizó a través de microscopía electrónica de barrido que muestra la formación de estructuras compactas, presencia de cristales y la incrustación de flúor y plata. Se analizó la actividad antimicrobiana utilizando una prueba modificada para la observación del halo de inhibición, encontrándose solamente que los materiales que contenían plata-flúor y plata generaron dicho halo de inhibición. Por otra parte, usando la prueba de microdilución en pozo se encontró que la concentración mínima inhibitoria para el material de HA-Ag fue de 75 μg/ml y para el material de HA-Ag-F fue de 200 μg/ml, después de 48 horas de incubación utilizando E. faecalis.

Metformin protects from oxaliplatin induced peripheral neuropathy in rats.

Oxaliplatin is a commonly used drug to treat cancer, extending the rate of disease-free survival by 20% in colorectal cancer. However, oxaliplatin induces a disabling form of neuropathy resulting in more than 60% of patients having to reduce or discontinue oxaliplatin, negatively impacting their chance of survival. Oxaliplatin-induced neuropathies are accompanied by degeneration of sensory fibers in the epidermis and hyperexcitability of sensory neurons. These morphological and functional changes have been associated with sensory symptoms such as dysesthesia, paresthesia and mechanical and cold allodynia. Various strategies have been proposed to prevent or treat oxaliplatin-induced neuropathies without success. The anti-diabetic drug metformin has been recently shown to exert neuroprotection in other chemotherapy-induced neuropathies, so here we aimed to test if metformin can prevent the development of oxaliplatin-induced neuropathy in a rat model of this condition. Animals treated with oxaliplatin developed significant intraepidermal fiber degeneration, a mild gliosis in the spinal cord, and mechanical and cold hyperalgesia. The concomitant use of metformin prevented degeneration of intraepidermal fibers, gliosis, and the altered sensitivity. Our evidence further supports metformin as a new approach to prevent oxaliplatin-induced neuropathy with a potential important clinical impact.

Unprecedented Potential for Neural Drug Discovery Based on Self-Organizing hiPSC Platforms.

Human induced pluripotent stem cells (hiPSCs) have transformed conventional drug discovery pathways in recent years. In particular, recent advances in hiPSC biology, including organoid technologies, have highlighted a new potential for neural drug discovery with clear advantages over the use of primary tissues. This is important considering the financial and social burden of neurological health care worldwide, directly impacting the life expectancy of many populations. Patient-derived iPSCs-neurons are invaluable tools for novel drug-screening and precision medicine approaches directly aimed at reducing the burden imposed by the increasing prevalence of neurological disorders in an aging population. 3-Dimensional self-assembled or so-called 'organoid' hiPSCs cultures offer key advantages over traditional 2D ones and may well be gamechangers in the drug-discovery quest for neurological disorders in the coming years.

Management strategies to minimize the use of synthetic chemical acaricides in the control of the cattle tick Rhipicephalus (Boophilus) microplus (Canestrini, 1888) in an area highly favourable for its development in Argentina.

The aim of this work was to test the efficacy of winter-spring control strategies against Rhipicephalus (Boophilus) microplus (Canestrini, 1888) (Ixodida: Ixodidae) in an area highly favourable for its development in Argentina. Control schemes using three or four annual applications of synthetic acaricides were evaluated. Furthermore, the dynamics of the non-parasitic phases of R. microplus were analysed to provide a framework for the application of pasture spelling as a tool for tick control. The treatment schemes provided appropriate levels of efficacy against R. microplus and also prevented the occurrence of the major peak in abundance of this tick in autumn. A significant overall effect against R. microplus can be achieved when the control strategies tested in this study are applied within the area most ecologically favourable for this tick in Argentina. Analysis of the dynamics of the non-parasitic phase of R. microplus indicates that the spelling period required to achieve a significant reduction of larvae in pastures fluctuates between 12 and 17 weeks if spelling is initiated in spring or early summer, but between 20 and 28 weeks if spelling is started in late summer, autumn or winter.

Human Mesenchymal Stem Cells: The Present Alternative for High-Incidence Diseases, Even SARS-Cov-2.

Mesenchymal stem cells (MSCs), defined as plastic adherent cells with multipotent differentiation capacity in vitro, are an emerging and valuable tool to treat a plethora of diseases due to their therapeutic mechanisms such as their paracrine activity, mitochondrial and organelle transfer, and transfer of therapeutic molecules via exosomes. Nowadays, there are more than a thousand registered clinical trials related to MSC application around the world, highlighting MSC role on difficult-to-treat high-incidence diseases such as the current COVID-19, HIV infections, and autoimmune and metabolic diseases. Here, we summarize a general overview of MSCs and their therapeutic mechanisms; also, we discuss some of the novel clinical trial protocols and their results as well as a comparison between the number of registries, countries, and search portals.

Atypical femoral fracture, case report and literature review.

INTRODUCTION: Bisphosphonates have been the gold standard in the management of osteoporosis. Its antiresorptive effect has reduced the incidence of fractures due to bone fragility, as well as its impact on public health. We present the clinical case of a patient in prolonged treatment with bisphosphonates and atypical bilateral femur fracture. CASE REPORT: A 65-year-old female who presented a fall from her own height, on treatment with risedronate for seven years, and a history of systemic arterial hypertension and hypercholesterolemia, both with medical treatment. Diagnosed with bilateral atypical femoral fracture, treated with closed reduction internal fixation (CRIF) with intramedullary nailing, application of calcium citrate and teriparatide. DISCUSSION: Multiple studies indicate that the benefit of using bisphosphonates for osteoporosis is higher than the risk of presenting atypical fractures.

INTRODUCCIÓN: Los bifosfonatos han sido de gran utilidad en el manejo de la osteoporosis. Su efecto antirresortivo ha disminuido la incidencia de fracturas por fragilidad ósea, así como, su impacto en salud pública. Presentamos el caso clínico de una usuaria en tratamiento prolongado con bifosfonatos y fractura atípica de fémur bilateral. CASO CLÍNICO: Femenino de 65 años, presenta caía de su plano de sustentación, en tratamiento con risedronato desde hace siete años y antecedente de hipertensión arterial sistémica e hipercolesterolemia, ambas con manejo médico. Diagnosticada con fractura bilateral de fémur, tratada con enclavado centro-medular, citrato de calcio y teriparatida. DISCUSIÓN: Múltiples estudios refieren que el beneficio del uso de bifosfonatos en la prevención del riesgo de fracturas es mayor, aunque exista la posibilidad de presentar fracturas atípicas.

Editing the Central Nervous System Through CRISPR/Cas9 Systems.

The translational gap to treatments based on gene therapy has been reduced in recent years because of improvements in gene editing tools, such as the CRISPR/Cas9 system and its variations. This has allowed the development of more precise therapies for neurodegenerative diseases, where access is privileged. As a result, engineering of complexes that can access the central nervous system (CNS) with the least potential inconvenience is fundamental. In this review article, we describe current alternatives to generate systems based on CRISPR/Cas9 that can cross the blood-brain barrier (BBB) and may be used further clinically to improve treatment for neurodegeneration in Parkinson's and Alzheimer's disease (AD).

Atypical femoral fracture, case report and literature review / Fractura atípica del fémur, reporte de caso y revisión de la literatura

Abstract: Introduction: Bisphosphonates have been the gold standard in the management of osteoporosis. Its antiresorptive effect has reduced the incidence of fractures due to bone fragility, as well as its impact on public health. We present the clinical case of a patient in prolonged treatment with bisphosphonates and atypical bilateral femur fracture. Case report: A 65-year-old female who presented a fall from her own height, on treatment with risedronate for seven years, and a history of systemic arterial hypertension and hypercholesterolemia, both with medical treatment. Diagnosed with bilateral atypical femoral fracture, treated with closed reduction internal fixation (CRIF) with intramedullary nailing, application of calcium citrate and teriparatide. Discussion: Multiple studies indicate that the benefit of using bisphosphonates for osteoporosis is higher than the risk of presenting atypical fractures.

Resumen: Introducción: Los bifosfonatos han sido de gran utilidad en el manejo de la osteoporosis. Su efecto antirresortivo ha disminuido la incidencia de fracturas por fragilidad ósea, así como, su impacto en salud pública. Presentamos el caso clínico de una usuaria en tratamiento prolongado con bifosfonatos y fractura atípica de fémur bilateral. Caso clínico: Femenino de 65 años, presenta caía de su plano de sustentación, en tratamiento con risedronato desde hace siete años y antecedente de hipertensión arterial sistémica e hipercolesterolemia, ambas con manejo médico. Diagnosticada con fractura bilateral de fémur, tratada con enclavado centro-medular, citrato de calcio y teriparatida. Discusión: Múltiples estudios refieren que el beneficio del uso de bifosfonatos en la prevención del riesgo de fracturas es mayor, aunque exista la posibilidad de presentar fracturas atípicas.

Implications of human induced pluripotent stem cells in metabolic disorders: from drug discovery toward precision medicine.

Human induced pluripotent stem cells (hiPSCs) enable in vitro high-throughput pharmacological screening assays of diseased tissue. Together with recent genome-wide association studies (GWAS), hiPSCs enable the identification of key mutations for the development of effective treatments based on precise drugs. In concert with CRISPR/Cas9 systems, hiPSC technology can reveal therapeutic targets in metabolic disorders. The ex vivo CRISPR correction of autologous patient-derived hiPSCs has led to the development of replacement cell therapies, providing better patient prognoses.

A combination of hydroxytyrosol, omega-3 fatty acids and curcumin improves pain and inflammation among early stage breast cancer patients receiving adjuvant hormonal therapy: results of a pilot study.

PURPOSE: Breast cancer patients receiving hormonal therapies face risks of relapse, increased rates of cardiovascular events, and toxicities of therapy such as aromatase inhibitor (AI)-associated musculoskeletal symptoms (AIMSS). C-reactive protein (CRP), a marker for inflammation, is associated with breast cancer outcomes. We evaluated whether the olive-derived polyphenol hydroxytyrosol combined with omega-3 fatty acids and curcumin would reduce CRP and musculoskeletal symptoms in breast cancer patients receiving adjuvant hormonal therapies. EXPERIMENTAL DESIGN: This prospective, multicenter, open-label, single arm, clinical trial enrolled post-menopausal breast cancer patients (n = 45) with elevated C-reactive protein (CRP) taking predominantly aromatase inhibitors to receive a combination of hydroxytyrosol, omega-3 fatty acids, and curcumin for 1 month. CRP, other inflammation-associated cytokines, and pain scores on the Brief Pain Inventory were measured before therapy, at the end of therapy and 1 month after completion of therapy. RESULTS: CRP levels declined during the therapy [from 8.2 ± 6.4 mg/L at baseline to 5.3 ± 3.2 mg/L (p = 0.014) at 30 days of treatment], and remained decreased during the additional 1 month off therapy. Subjects with the highest baseline CRP levels had the greatest decrease with the therapy. Pain scores also decreased during the therapy. There were no significant adverse events. CONCLUSIONS: The combination of hydroxytyrosol, omega-3 fatty acids, and curcumin reduced inflammation as indicated by a reduction in CRP and reduced pain in patients with aromatase-induced musculoskeletal symptoms. Longer studies comparing this combination to other anti-inflammatories in larger groups of patients with clinical outcome endpoints are warranted.

Microdeletion 22q11.2 syndrome: Does thymus incidental surgical resection affect its immunological profile?

BACKGROUND: The del22q11 syndrome patients present immunological abnormalities associated to thymus alterations. Up to 75% of them present cardiopathies and thymus is frequently removed during surgery. The thymectomy per se has a deleterious effect concerning lymphocyte subpopulations, and T cell function. When compared to healthy controls, these patients have higher infections propensity of variable severity. The factors behind these variations are unknown. We compared immunological profiles of del22q11.2 Syndrome patients with and without thymectomy to establish its effect in the immune profile. METHODS: Forty-six del22q11.2 syndrome patients from 1 to 16 years old, 19 of them with partial or total thymectomy were included. Heart disease type, heart surgery, infections events and thymus resection were identified. Immunoglobulin levels, flow cytometry for lymphocytes subpopulations and TREC levels were determined, and statistical analyses were performed. RESULTS: The thymectomy group had a lower lymphocyte index, both regarding total cell count and when comparing age-adjusted Z scores. Also, CD3+, CD4+ and CD8+ lower levels were observed in this group, the lowest count in those patients who had undergone thymus resection during the first year of life. Their TREC level median was 23.6/µL vs 16.1µL in the non-thymus group (p=0.22). No differences were identified regarding immunoglobulin levels or infection events frequencies over the previous year. CONCLUSION: Patients with del22q11.2 syndrome subjected to thymus resection present lower lymphocyte and TREC indexes when compared to patients without thymectomy. This situation may be influenced by the age at the surgery and the time elapsed since the procedure.