Single-center "Argentine" analysis of post-transplant lymphoproliferative disorders: incidence, histopathological characteristics and EBV status

ABSTRACT Introduction: Post-transplant lymphoproliferative disorders (PTLDs) are a heterogeneous group of lymphoid proliferations occurring after solid organ or bone marrow transplantation. The primary aims of our study were to characterize cumulative incidence of PTLDs, clinical and pathological features according to the Epstein-Barr virus (EBV) status and survival. Methods: This was a retrospective cohort study on adult and pediatric patients, from January 2001 to December 2017. The cumulative incidence of PTLD was calculated by analyzing all the patients transplanted at our hospital, based on the database of the Organ Donation and Ablation Authority of Argentina (INCUCAI). The Kaplan-Meier method was used to plot the survival. Results: Fifty-eight cases of biopsy-confirmed PTLD were identified and 12 cases of clinical data were incomplete and these patients were excluded. The median age at the time of the PTLD diagnosis was 17.5 years (interquartile range [IQR] 9 - 57). The median interval between transplant and PTLD diagnosis was 39 months (IQR 9 - 113). The most commonly transplanted organ was the liver (24 cases, 52.2%), followed by kidney (20 cases, 43.5%). The Epstein-Barr encoding region in situ hybridization (EBER ISH) was positive in 29 (69.8%) of the 43 evaluable biopsies. The PTLD cumulative incidence was 1.84% (95%CI 1.77 - 1.91) for solid organ and 0.84% (95%CI 0.48 - 1.2) for bone marrow transplant patients. The overall survival rate at 5 years was 0.77 (95%CI 0.61 - 0.87). Subgroups by the EBV EBER status, transplant type, PTLD subtype and age group (adult vs. pediatric) showed no statistically significant association with the overall survival. Conclusion: The PTLD incidence was similar to that of previous series and the EBER did not appear as a relevant factor in our patient survival.

Single-center "Argentine" analysis of post-transplant lymphoproliferative disorders: incidence, histopathological characteristics and EBV status.

INTRODUCTION: Post-transplant lymphoproliferative disorders (PTLDs) are a heterogeneous group of lymphoid proliferations occurring after solid organ or bone marrow transplantation. The primary aims of our study were to characterize cumulative incidence of PTLDs, clinical and pathological features according to the Epstein-Barr virus (EBV) status and survival. METHODS: This was a retrospective cohort study on adult and pediatric patients, from January 2001 to December 2017. The cumulative incidence of PTLD was calculated by analyzing all the patients transplanted at our hospital, based on the database of the Organ Donation and Ablation Authority of Argentina (INCUCAI). The Kaplan-Meier method was used to plot the survival. RESULTS: Fifty-eight cases of biopsy-confirmed PTLD were identified and 12 cases of clinical data were incomplete and these patients were excluded. The median age at the time of the PTLD diagnosis was 17.5 years (interquartile range [IQR] 9 - 57). The median interval between transplant and PTLD diagnosis was 39 months (IQR 9 - 113). The most commonly transplanted organ was the liver (24 cases, 52.2%), followed by kidney (20 cases, 43.5%). The Epstein-Barr encoding region in situ hybridization (EBER ISH) was positive in 29 (69.8%) of the 43 evaluable biopsies. The PTLD cumulative incidence was 1.84% (95%CI 1.77 - 1.91) for solid organ and 0.84% (95%CI 0.48 - 1.2) for bone marrow transplant patients. The overall survival rate at 5 years was 0.77 (95%CI 0.61 - 0.87). Subgroups by the EBV EBER status, transplant type, PTLD subtype and age group (adult vs. pediatric) showed no statistically significant association with the overall survival. CONCLUSION: The PTLD incidence was similar to that of previous series and the EBER did not appear as a relevant factor in our patient survival.

Mono- and biallelic germline variants of DNA glycosylase genes in colon adenomatous polyposis families from two continents.

Recently, biallelic germline variants of the DNA glycosylase genes MUTYH and NTHL1 were linked to polyposis susceptibility. Significant fractions remain without a molecular explanation, warranting searches for underlying causes. We used exome sequencing to investigate clinically well-defined adenomatous polyposis cases and families from Finland (N=34), Chile (N=21), and Argentina (N=12), all with known susceptibility genes excluded. Nine index cases (13%) revealed germline variants with proven or possible pathogenicity in the DNA glycosylase genes, involving NEIL1 (mono- or biallelic) in 3 cases, MUTYH (monoallelic) in 3 cases, NTHL1 (biallelic) in 1 case, and OGG1 (monoallelic) in 2 cases. NTHL1 was affected with the well-established, pathogenic c.268C>T, p.(Gln90Ter) variant. A recurrent heterozygous NEIL1 c.506G>A, p.(Gly169Asp) variant was observed in two families. In a Finnish family, the variant occurred in trans with a truncating NEIL1 variant (c.821delT). In an Argentine family, the variant co-occurred with a genomic deletion of exons 2 - 11 of PMS2. Mutational signatures in tumor tissues complied with biological functions reported for NEIL1. Our results suggest that germline variants in DNA glycosylase genes may occur in a non-negligible proportion of unexplained colon polyposis cases and may predispose to tumor development.

Cervical lymph nodes in rheumatology: A diagnostic dilemma

The case is presented on a 52-year-old male patient, who was seen in the Rheumatology department. He had painless lymph nodes in the cervical, axillary, supraclavicular, and neck region. He also had a fever, and parotid and submaxillary gland enlargement. Complementary studies were performed, showing normocytic-normochromic anemia, thrombocytopenia and eosinophilia, impaired renal function with hypoalbuminaemia and hematuria, ANA 1/5120, Sm+, ACL+. Biopsies were also performed on the compromised tissues, reaching the diagnosis of Rosai-Dorfman Disease and IgG4-related Disease. Differential diagnoses of cervical, axillary and inguinal lymph nodes, with fever, renal and hematological compromise are discussed.

Se describe el caso de un paciente varón de 52 años que consulta al servicio de reumatología por presentar adenopatías indoloras en las regiones cervical, axilar, supraclaviculares y en la nuca, así como fiebre, aumento de tamaño de parótidas y submaxilares. Se realizan estudios complementarios que arrojan como resultado anemia normocítica-normocrómica, trombocitopenia y eosinofilia, alteración de la función renal con hipoalbuminemia y hematuria, FAN 1/5.120, Sm+, ACL+ y biopsia de los tejidos comprometidos, por lo que se arriba al diagnóstico de enfermedad de Rosai-Dorfman y enfermedad relacionada con IgG4. Se discuten diagnósticos diferenciales de adenopatías cervicales, axilares e inguinales, fiebre, compromiso renal y hematológico.

Automatic Integration of Clinical and Genetic Data Using cBioPortal.

Precision medicine seeks to improve the prevention, diagnosis and treatment of patients based on genetic characteristics unique to each person. In oncology, therapeutic decisions have been established based on the genomic characteristics of each patient's tumor. Data integration is key for the successful implementation of precision medicine since it is necessary for both studying a large volume of data from different sources and working with an interdisciplinary and translational vision. In this work, a bioinformatic process was successfully implemented that allows the integration of patients' genomic data, from two molecular biology laboratories, with their clinical data provided by their electronic medical records. For this, the REDCap data capture software, the cBioPortal visualization and analysis software, and a computer tool developed to automate the processing and annotation of the information in REDCap were used to be included in cBioPortal, for the "Map of Tumor Genomic Actionability of Argentina" project.

Building a Genome Archiving and Communication System Integrated into a Health Information Systems.

The use of next-generation sequencing technologies in clinical practice has increased the volume of information that must be stored, processed, and interpreted. In this work, a description of the implementation of a genomic communication and archiving system (GACS) is presented. This GACS will allow us to store, share and search the genomic files and genetic variants obtained as a result of genetic laboratory tests.

Immunoglobulin G4-related retroperitoneal fibrosis / Fibrosis retroperitoneal relacionada con IgG4

Abstract Some patients diagnosed with idiopathic retroperitoneal fibrosis could be reclassified as IgG4-related disease (IgG4-RD). Classification criteria have not been uniform and prevalence of IgG4-related retroperitoneal fibrosis (IgG4-RPF) is unknown in our region. We aimed to describe IgG4-RPF frequency relying on criteria published recently and comparing clinical, histopathologic and radiologic features with non-IgG4-RPF. From January, 2005 to December, 2020, nineteen adults with histopathologic diagnosis of idiopathic retroperitoneal fibrosis were included in a dynamic retrospective cohort at Hospital Italiano de Buenos Aires. Pathology slides were reviewed and immunohistochemistry was performed and assessed for each case. We used classification criteria described in 2019 American College of Rheumatology/European League Against Rheumatism to identify IgG4-RD cases. Ten of 19 patients met criteria for IgG4-RPF. Median age was similar in two subsets (61 versus 55, p = 0.2) and both had male predominance. Three out of 10 patients (p = 0.2) featured other manifestations of IgG4-RD in the IgG4-RPF group, and periaortic fibrosis was the most significant finding in images (p = 0.01). Corticosteroids were mostly used as therapy, followed by azathioprine and rituximab. Most patients did not receive specific treatment. IgG4-RPF patients had dense lymphocytic infiltrate and 8 out of 10 showed storiform fibrosis (p = 0.02). IgG4+ cells/hpf and IgG4/IgG ratio were significantly higher (p = 0.01). Over half of the patients in our cohort met the criteria of IgG4-RPF. New criteria may harmonize the identification of IgG4-RD. As IgG4-RD may be reversible at initial stages, these findings may lead to early recognition, treatment and integral follow-up.

Resumen Muchos pacientes con diagnóstico de fibrosis retroperitoneal idiopática (FRI) pueden ser reclasificados como enfermedad relacionada con IgG4 (ER- IgG4). Los criterios diagnósticos no han sido uniformes y la frecuencia de fibrosis retroperitoneal relacionada con IgG4 en nuestra región es desconocida. El objetivo fue describir la frecuencia de ER-IgG4 en pacientes clasificados como FRI y comparar características clínicas, histopatológicas y de laboratorio con aquellos que no reunían criterios de la enfermedad. Se incluyeron 19 adultos en un estudio de cohorte retrospectiva dinámica con diagnóstico anatomopatológico de FRI, en el Hospital Italiano de Buenos Aires, desde enero de 2005 hasta diciembre de 2020. Se revisaron las biopsias y se realizó inmun ohistoquímica en cada una. Se consideró caso al paciente que reunía los criterios de la American College of Rheumatology/European League Against Rheumatism 2019. Diez pacientes reunieron criterios de ER-IgG4. La mediana de edad fue similar en ambos grupos (61 vs. 55, p = 0.2) y en ambos hubo predominio masculino. Tres de 10 pacientes (p = 0.2) tuvieron otras manifestaciones de ER-IgG4 y la fibrosis periaórtica fue el hallazgo más significativo en los estudios por imágenes (p = 0.01). Los corticoides fueron las drogas más utilizadas seguidos por azatioprina y rituximab, pero la mayoría no reci bió tratamiento específico. Todos los pacientes con fibrosis retroperitoneal relacionada con IgG4 presentaron infiltrado linfocitario denso y 8/10 fibrosis estoriforme (p = 0.01), así como las células IgG4+/hpf y ratio IgG4/ IgG fueron significativamente mayores (p = 0.01). Más de la mitad de los pacientes con FRI cumplieron criterios de ER-IgG4. Los nuevos criterios diagnósticos podrían contribuir a homogeneizar la identificación de ER-IgG4. Dado que esta enfermedad puede ser reversible en estadios tempranos, estos resultados promueven aumentar el conocimiento de la entidad para tratamiento precoz y seguimiento integral.

Immunoglobulin G4-related retroperitoneal fibrosis.

Some patients diagnosed with idiopathic retroperitoneal fibrosis could be reclassified as IgG4-related disease (IgG4-RD). Classification criteria have not been uniform and prevalence of IgG4-related retroperitoneal fibrosis (IgG4-RPF) is unknown in our region. We aimed to describe IgG4-RPF frequency relying on criteria published recently and comparing clinical, histopathologic and radiologic features with non-IgG4-RPF. From January, 2005 to December, 2020, nineteen adults with histopathologic diagnosis of idiopathic retroperitoneal fibrosis were included in a dynamic retrospective cohort at Hospital Italiano de Buenos Aires. Pathology slides were reviewed and immunohistochemistry was performed and assessed for each case. We used classification criteria described in 2019 American College of Rheumatology/European League Against Rheumatism to identify IgG4-RD cases. Ten of 19 patients met criteria for IgG4-RPF. Median age was similar in two subsets (61 versus 55, p = 0.2) and both had male predominance. Three out of 10 patients (p = 0.2) featured other manifestations of IgG4-RD in the IgG4-RPF group, and periaortic fibrosis was the most significant finding in images (p = 0.01). Corticosteroids were mostly used as therapy, followed by azathioprine and rituximab. Most patients did not receive specific treatment. IgG4-RPF patients had dense lymphocytic infiltrate and 8 out of 10 showed storiform fibrosis (p = 0.02). IgG4+ cells/hpf and IgG4/IgG ratio were significantly higher (p = 0.01). Over half of the patients in our cohort met the criteria of IgG4-RPF. New criteria may harmonize the identification of IgG4-RD. As IgG4-RD may be reversible at initial stages, these findings may lead to early recognition, treatment and integral follow-up.

Muchos pacientes con diagnóstico de fibrosis retroperitoneal idiopática (FRI) pueden ser reclasificados como enfermedad relacionada con IgG4 (ER- IgG4). Los criterios diagnósticos no han sido uniformes y la frecuencia de fibrosis retroperitoneal relacionada con IgG4 en nuestra región es desconocida. El objetivo fue describir la frecuencia de ER-IgG4 en pacientes clasificados como FRI y comparar características clínicas, histopatológicas y de laboratorio con aquellos que no reunían criterios de la enfermedad. Se incluyeron 19 adultos en un estudio de cohorte retrospectiva dinámica con diagnóstico anatomopatológico de FRI, en el Hospital Italiano de Buenos Aires, desde enero de 2005 hasta diciembre de 2020. Se revisaron las biopsias y se realizó inmun ohistoquímica en cada una. Se consideró caso al paciente que reunía los criterios de la American College of Rheumatology/European League Against Rheumatism 2019. Diez pacientes reunieron criterios de ER-IgG4. La mediana de edad fue similar en ambos grupos (61 vs. 55, p = 0.2) y en ambos hubo predominio masculino. Tres de 10 pacientes (p = 0.2) tuvieron otras manifestaciones de ER-IgG4 y la fibrosis periaórtica fue el hallazgo más significativo en los estudios por imágenes (p = 0.01). Los corticoides fueron las drogas más utilizadas seguidos por azatioprina y rituximab, pero la mayoría no recibió tratamiento específico. Todos los pacientes con fibrosis retroperitoneal relacionada con IgG4 presentaron infiltrado linfocitario denso y 8/10 fibrosis estoriforme (p = 0.01), así como las células IgG4+/hpf y ratio IgG4/IgG fueron significativamente mayores (p = 0.01). Más de la mitad de los pacientes con FRI cumplieron criterios de ER-IgG4. Los nuevos criterios diagnósticos podrían contribuir a homogeneizar la identificación de ER-IgG4. Dado que esta enfermedad puede ser reversible en estadios tempranos, estos resultados promueven aumentar el conocimiento de la entidad para tratamiento precoz y seguimiento integral.

Primary lymphoma of the entire esophagus diagnosed by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA).

Primary esophageal lymphoma is extremely rare, with fewer than 30 cases reported in the literature. Presentation is nonspecific with multiple radiological and endoscopic appearances, posing its diagnosis a challenge. We report a case of a primary esophageal lymphoma diagnosed by endoscopic ultrasound-fine needle aspiration in a 68-year-old woman referred to our hospital for evaluation of a submucosal tumor spreading all over the esophageal wall. We describe its clinical and imaging features and stand out the importance of having a specific preoperatory diagnosis in order to avoid a major surgery.

Maternal ancestry and hematological cancer risk: case-control study in an Argentinean population.

Aim: We investigated the role of maternal ancestry in neoplastic hematological malignancies (HMs) risk in a population from Central Argentina. Materials & methods: We analyzed 125 cases with HMs and 310 controls from a public hospital, and a set of 202 colorectal, breast, lung, and hematologic cancer patients from a private hospital. Results: A decreased risk for HMs was associated with the Native American haplogroup B2 (odds ratio = 0.49; 95% CI: 0.25-0.92; p = 0.02). The sub-Saharan African parahaplogroup L was associated with higher susceptibility for disease (odds ratio = 3.10; 95% CI: 1.04-9.31; p = 0.043). Although the mean ancestral proportions in the total studied population was as published (61.7% Native American, 34.6% European and 3.7% African), an unequal distribution was observed between hospitals. Conclusion: We confirmed the tri-hybrid nature of the Argentinean population, with proportions varying within the country. Our finding supports the notion that associated haplogroup is population and cancer specific.

Apoptotic regulator BCL-2 blockade as a potential therapy in classical Hodgkin Lymphoma.

The challenge in classical Hodgkin Lymphoma (cHL) management is the 30-40% of refractory/relapsed cases. AIMS: The aim of this work was to determine whether NIK and BCL-2 could be useful as prognosis biomarkers in cHL. In addition, we evaluated BCL-2 as a directed-therapy in cHL cell lines using venetoclax. MAIN METHODS: We evaluated NIK and BCL-2 expression in 112 untreated cHL patients' lymph-node biopsies by immunohistochemistry. cHL cell lines were treated with venetoclax alone or combined with vincristine or doxorubicin. Cell viability, metabolic activity and cell death were analyzed by trypan-blue exclusion method, MTS assay and FDA/IP staining respectively. KEY FINDINGS: No correlation between NIK or BCL-2 expression and the majority of the clinical parameters was found. Patients with ≥60% BCL-2+ HRS-cells had a shorter disease-free survival (DFS) and overall survival (OS) (p = 0.002, p = 0.02 respectively). A decision tree analysis, in a 30 patients subgroup, showed that patients with <60% NIK+ HRS-cells but with ≥60% BCL-2+ HRS-cells had a worse outcome in terms of DFS and OS. These parameters performed better as prognosis indicators as compared to the diagnosis bone marrow status. Human cHL cell lines U-H01, KM-H2, L1236, SUPHD1, L540 showed sensitivity to venetoclax. The co-treatment effect of venetoclax and vincristine or doxorubicin on cell viability was diverse depending on the cell line evaluated. SIGNIFICANCE: BCL-2 should be considered as a prognosis biomarker as well as a potential new therapeutic target in cHL. We report for the first time the cytotoxic effect of venetoclax in human cHL cell lines.

Genetic diversity and phylogeographic analysis of human herpesvirus type 8 (HHV-8) in two distant regions of Argentina: Association with the genetic ancestry of the population.

BACKGROUND: The genetic diversity of persistent infectious agents, such as HHV-8, correlates closely with the migration of modern humans out of East Africa which makes them useful to trace human migrations. However, there is scarce data about the evolutionary history of HHV-8 particularly in multiethnic Latin American populations. OBJECTIVES: The aims of this study were to characterize the genetic diversity and the phylogeography of HHV-8 in two distant geographic regions of Argentina, and to establish potential associations with pathogenic conditions and the genetic ancestry of the population. STUDY DESIGN: A total of 101 HIV-1 infected subjects, 93 Kaposi's Sarcoma (KS) patients and 411 blood donors were recruited in the metropolitan (MET) and north-western regions of Argentina (NWA). HHV-8 DNA was detected by ORF-26 PCR in whole blood, saliva and FFPE tissues. Then, ORF-26 and ORF-K1 were analyzed for subtype assignment. Mitochondrial DNA and Y chromosome haplogroups, as well as autosomal ancestry markers were evaluated in samples in which subtypes could be assigned. Phylogeographic analysis was performed in the ORF-K1 sequences from this study combined with 388 GenBank sequences. RESULTS: HHV-8 was detected in 50.7%, 59.2% and 8% of samples from HIV-1 infected subjects, KS patients and blood donors, respectively. ORF-K1 phylogenetic analyses showed that subtypes A (A1-A5), B1, C (C1-C3) and F were present in 46.9%, 6.25%, 43.75% and 3.1% of cases, respectively. Analyses of ORF-26 fragment revealed that 81.95% of strains were subtypes A/C followed by J, B2, R, and K. The prevalence of subtype J was more commonly observed among KS patients when compared to the other groups. Among KS patients, subtype A/C was more commonly detected in MET whereas subtype J was the most frequent in NWA. Subtypes A/C was significantly associated with Native American maternal haplogroups (p = 0.004), whereas subtype J was related to non-Native American haplogroups (p < 0.0001). Sub-Saharan Africa, Europe and Latin America were the most probable locations from where HHV-8 was introduced to Argentina. CONCLUSIONS: These results give evidence of the geographic circulation of HHV-8 in Argentina, suggest the association of ORF-26 subtype J with KS development and provide new insights about its relationship with ancient and modern human migrations and identify the possible origins of this virus in Argentina.

Policondritis recidivante asociada a enfermedad por IgG4 / Relapsing polychondritis associated with IgG4-related disease

La policondritis recidivante (RP) es un trastorno autoinmune sistémico poco frecuente que se caracteriza por episodio y deterioro progresivo de la inflamación del cartílago. Aproximadamente el 30% de los pacientes con RP tienen enfermedad concurrente. Sin embargo, hay tres casos previos reportados de RP relacionado con enfermedad relacionada con la inmunoglobulina G4 (IgG4-RD). Nosotros presentamos otro caso de una mujer de 37 años que desarrolló RP aproximadamente 1 año antes del diagnóstico de IgG4-RD. La asociación entre ER-IgG4 y RP sigue sin estar clara.

Relapsing polychondritis (RP) is a rare systemic autoimmune disorder characterized by the episodic and progressive deterioration of cartilage inflammation. Approximately 30% patients with RP have concurrent disease. However, there are three cases reports of RP complicated by immunoglobulin G4-related disease (IgG4-RD). Here we report another case of a 37-year-old female who developed RP approximately 1 years before IgG4-RD diagnosis. The association between IgG4-RD and RP remains unclear.

Investigación traslacional en microbioma (InTraMic): un área de interés común y creciente en el IMTIB, Hospital Italiano e Instituto Universitario / Translational research in microbiome (InTraMic): an area of common and growing interest at IMTIB, Hospital Italiano and Instituto Universitario

Se estima que aproximadamente 100 trillones de microorganismos (incluidos bacterias, virus y hongos) residen en el intestino humano adulto y que el total del material genético del microbioma es 100 veces superior al del genoma humano. Esta comunidad, conocida como microbioma se adquiere al momento del nacimiento a través de la flora comensal de la piel, vagina y heces de la madre y se mantiene relativamente estable a partir de los dos años desempeñando un papel crítico tanto en el estado de salud como en la enfermedad. El desarrollo de nuevas tecnologías, como los secuenciadores de próxima generación (NGS), permiten actualmente realizar un estudio mucho más preciso de ella que en décadas pasadas cuando se limitaba a su cultivo. Si bien esto ha llevado a un crecimiento exponencial en las publicaciones, los datos sobre las poblaciones Latinoamérica son casi inexistentes. La investigación traslacional en microbioma (InTraMic) es una de las líneas que se desarrollan en el Instituto de Medicina Traslacional e Ingeniería Biomédica (IMTIB). Esta se inició en 2018 con la línea de cáncer colorrectal (CCR) en una colaboración con el Colorectal Cancer Research Group del Leeds Institute of Medical Research en el proyecto Large bowel microbiome disease network: Creation of a proof of principle exemplar in colorectal cancer across three continents. A fines de 2019 se cumplió el objetivo de comprobar la factibilidad de la recolección, envío y análisis de muestras de MBF en 5 continentes, incluyendo muestras provenientes de la Argentina, Chile, India y Vietnam. Luego de haber participado de capacitaciones en Inglaterra, se ha cumplido con el objetivo de la etapa piloto, logrando efectivizar la recolección, envío y análisis metagenómico a partir de la secuenciación de la región V4 del ARNr 16S. En 2019, la línea de enfermedad de hígado graso no alcohólico se sumó a la InTraMic iniciando una caracterización piloto en el marco de una colaboración con el laboratorio Novartis. Los resultados de ese estudio, así como el de cáncer colorrectal, están siendo enviados a publicación. En 2020, con la incorporación de la línea de trasplante alogénico de células progenitoras hematopoyéticas, fue presentado un proyecto para un subsidio del CONICET que ha superado la primera etapa de evaluación. En el presente artículo se brinda una actualización sobre la caracterización taxonómica de microbioma y se describen las líneas de investigación en curso. (AU)

It is estimated that approximately 100 trillion microorganisms (including bacteria, viruses, and fungi) reside in the adult human intestine, and that the total genetic material of the microbiome is 100 times greater than that of the human genome. This community, known as the microbiome, is acquired at birth through the commensal flora of the mother's skin, vagina, and feces and remains relatively stable after two years, playing a critical role in both the state of health and in disease. The development of new technologies, such as next-generation sequencers (NGS), currently allow for a much more precise study of it than in past decades when it was limited to cultivation. Although this has led to exponential growth in publications, data on Latin American populations is almost non-existent. Translational research in microbiome (InTraMic) is one of the lines developed at the Instituto de Medicina Traslacional e Ingeniería Biomédica (IMTIB). This started in 2018 with the Colorectal Cancer Line (CRC) in a collaboration with the Colorectal Cancer Research Group of the Leeds Institute of Medical Research in the project "Large bowel microbiome disease network: Creation of a proof of principle exemplar in colorectal cancer across three continents". At the end of 2019, the objective of verifying the feasibility of collecting, sending and analyzing MBF samples on 5 continents, including samples from Argentina, Chile, India and Vietnam, was met. After having participated in training in England, the objective of the pilot stage has been met, achieving the collection, delivery and metagenomic analysis from the sequencing of the V4 region of the 16S rRNA. In 2019, the non-alcoholic fatty liver disease line joined InTraMic, initiating a pilot characterization in the framework of a collaboration with the Novartis laboratory. The results of that study, as well as that of colorectal cancer, are being published. In 2020, with the incorporation of the allogeneic hematopoietic stem cell transplantation line, a project was presented for a grant from the CONICET that has passed the first stage of evaluation. This article provides an update on the taxonomic characterization of the microbiome and describes the lines of ongoing research. (AU)

Policondritis recidivante asociada a enfermedad por IgG4 / Recurrent Polychondritis Associated with IgG4 Disease

La policondritis recidivante (RP) es un trastorno autoinmune sistémico poco frecuente que se caracteriza por episodio y deterioro progresivo de la inflamación del cartílago. Aproximadamente el 30% de los pacientes con RP tienen enfermedad concurrente. Sin embargo, hay tres casos previos reportados de RP relacionado con enfermedad relacionada con la inmunoglobulina G4 (IgG4-RD). Nosotros presentamos otro caso de una mujer de 37 años que desarrolló RP aproximadamente 1 año antes del diagnóstico de IgG4-RD. La asociación entre ER- IgG4 y RP sigue sin estar clara.

Relapsing polychondritis (RP) is a rare systemic autoimmune disorder characterized by the episodic and progressive deterioration of cartilage inflammation. Approximately 30% patients with RP have concurrent disease. However, there are three cases reports of RP complicated by immunoglobulin G4-related disease (IgG4-RD). Here we report another case of a 37-year-old female who developed RP approximately 1 years before IgG4-RD diagnosis. The association between IgG4-RD and RP remains unclear

Latin American Study of Hereditary Breast and Ovarian Cancer LACAM: A Genomic Epidemiology Approach.

Purpose: Hereditary Breast and Ovarian Cancer (HBOC) syndrome is responsible for ~5-10% of all diagnosed breast and ovarian cancers. Breast cancer is the most common malignancy and the leading cause of cancer-related mortality among women in Latin America (LA). The main objective of this study was to develop a comprehensive understanding of the genomic epidemiology of HBOC throughout the establishment of The Latin American consortium for HBOC-LACAM, consisting of specialists from 5 countries in LA and the description of the genomic results from the first phase of the study. Methods: We have recruited 403 individuals that fulfilled the criteria for HBOC from 11 health institutions of Argentina, Colombia, Guatemala, Mexico and Peru. A pilot cohort of 222 individuals was analyzed by NGS gene panels. One hundred forty-three genes were selected on the basis of their putative role in susceptibility to different hereditary cancers. Libraries were sequenced in MiSeq (Illumina, Inc.) and PGM (Ion Torrent-Thermo Fisher Scientific) platforms. Results: The overall prevalence of pathogenic variants was 17% (38/222); the distribution spanned 14 genes and varied by country. The highest relative prevalence of pathogenic variants was found in patients from Argentina (25%, 14/57), followed by Mexico (18%, 12/68), Guatemala (16%, 3/19), and Colombia (13%, 10/78). Pathogenic variants were found in BRCA1 (20%) and BRCA2 (29%) genes. Pathogenic variants were found in other 12 genes, including high and moderate risk genes such as MSH2, MSH6, MUTYH, and PALB2. Additional pathogenic variants were found in HBOC unrelated genes such as DCLRE1C, WRN, PDE11A, and PDGFB. Conclusion: In this first phase of the project, we recruited 403 individuals and evaluated the germline genetic alterations in an initial cohort of 222 patients among 4 countries. Our data show for the first time in LA the distribution of pathogenic variants in a broad set of cancer susceptibility genes in HBOC. Even though we used extended gene panels, there was still a high proportion of patients without any detectable pathogenic variant, which emphasizes the larger, unexplored genetic nature of the disease in these populations.

Denosumab-treated giant cell tumor of bone. Its histologic spectrum and potential diagnostic pitfalls.

Giant cell tumor (GCT) of bone is a locally aggressive, rarely metastasizing primary bone neoplasm that occurs most frequently in the epiphysis of long bones of young adults. It is composed of round, oval, or elongated mononuclear cells admixed with osteoclast-like giant cells that express receptor activator of nuclear factor κB (RANK). The mononuclear stromal cells express RANK ligand, a mediator of osteoclast activation. Denosumab, a monoclonal antibody that reduces tumor associated bone lysis by inhibiting the action of RANK ligand, has been used to treat selected cases of GCT. We reviewed the clinical records and histologic slides of 9 patients with GCT who had received denosumab therapy and were subsequently surgically treated. There were 5 men and 4 women aged 20 to 66 years (mean, 36 years). Duration of treatment varied from 2.5 to 13months (mean, 5.9 months). In all cases, different degrees of ossification, fibrosis, depletion of giant cells, and proliferation of mononuclear cells were seen. With this combination of changes, denosumab-treated GCT may mimic other lesions such as fibrous dysplasia, juvenile ossifying fibroma, nonossifying fibroma, and osteoblastoma. Less frequent but more relevant is the presence of cellular atypia or patterns of ossification that resemble an undifferentiated pleomorphic sarcoma, a conventional osteosarcoma, or a low-grade central osteosarcoma. The presence of clinical and radiologic response to denosumab, along with the lack of high mitotic activity, atypical mitotic figures, extensive necrosis, or a permeative pattern of growth, represents clues to achieve a correct diagnosis.