Editorial : Updates on the pathogenesis of common variable immunodeficiency (CVID)

Non peer reviewe

CORYNOSOMA AUSTRALE JOHNSTON, 1937 AND C. CETACEUM JOHNSTON & BEST, 1942 (ACANTHOCEPHALA: POLYMORPHIDAE) FROM MARINE MAMMALS AND FISH IN ARGENTINIAN WATERS: ALLOZYME MARKERS AND TAXONOMIC STATUS

Genetic and morphological studies were carried out on acanthocephalans belonging to Corynosoma Luhe, 1904 and referable to the species C. cetaceum Johnston & Best, 1942 and C. australe Johnston, 1937, which were recovered from both definitive and intermediate hosts in Argentinian waters. The aims were to estimate the level of genetic differentiation between the two taxa at any stage of their life-cycle, to provide genetic ( allozyme) markers for their recognition and to analyse the systematic status of both taxa. Acanthocephalans were collected from the stomach and intestine of Arctocephalus australis (Zimmerman), the intestine of Mirounga leonina (Linnaeus) and the stomach of Pontoporia blainvillei Gervais & D'Orbigny (definitive hosts) in Argentinian waters. Alternative alleles at all the 13 enzymatic loci studied were observed for C. australe and C. cetaceum. The specimens from the stomach of both P. blainvillei and A. australis were identified, on the basis of the great number of diagnostic loci found, as C. cetaceum; those from intestine of both A. australis and M. leonina as C. australe. A high level of genetic differentiation (D-Nei= infinity: I-Nei= 0.00) between the two taxa was found, suggesting a generic distinction between the two species. Cystacanths of the two species from the body-cavity of the fish Cynoscion guatucupa (Cuvier) collected from the same geographical area were identified genetically. Morphological patterns, such as the number of hooks and hook rows on the proboscis, the distribution of somatic and genital armature, and other morphometric and meristic differences, in addition to ecological data, enabled the identification of these two species at cystacanth, juvenile and adult stages. However, a number of morphological and morphometric features of the Argentinian material were different to those of C. australe and C. cetaceum described from other regions of the world

La Asociación Parasitológica Argentina en tiempos de virtualidad : ¿Una oportunidad para repensarnos?

Desde hace unos meses, y como consecuencia de las medidas sanitarias de aislamiento para prevenir la expansión de la pandemia de COVID-19, fue necesario buscar e implementar estrategias para comunicarnos con nuestros afectos, nuestros colegas y nuestra sociedad. Así, la virtualidad irrumpió en nuestras vidas de una manera inesperadamente potente y, con el paso del tiempo, la estamos naturalizando como la manera de mantenernos comunicados y en sociedad. Desde la Asociación Parasitológica Argentina (APA), la primera respuesta a estos desafíos recientes fue capitalizar los nuevos usos y capacidades. Así, implementamos el ciclo de charlas virtuales “Parasitología en la Nube”, propendiendo a estar cada vez más cerca de una APA inclusiva y participativa. El exitoso desarrollo del ciclo ha propiciado el contacto y la comunicación entre los/las socios/as, así como la promoción y difusión de la parasitología. A su vez, las discusiones e intercambios establecidos entre las/los participantes, pusieron de manifiesto la importancia y la necesidad de profundizar la comunicación entre las y los miembros de nuestra comunidad, en pos de fomentar el espíritu de solidaridad, colaboración y asistencia recíproca. Sin embargo, para establecer estrategias de integración, comunicación y colaboración entre nuestras/ os asociadas/os, se requiere de datos que necesitan ser recabados. En estos tiempos en que la palabra “diagnóstico” ha tomado especial relevancia como primera medida para diseñar y poner en práctica acciones, consideramos imprescindible responder una serie de preguntas sobre nuestra Asociación, su representatividad entre el total de las/los parasitólogas/os del país, su distribución geográfica y disciplinar, el grado de interacción entre socias/os, etc. Por estos motivos, el presente análisis representa un primer paso para conocernos como Asociación y luego repensarnos como comunidad y así contar con herramientas para diseñar, desde la virtualidad, las estrategias necesarias para honrar nuestros fines y objetivos.Asociación Parasitológica Argentin

A High Prevalence of Gastrointestinal Manifestations in Common Variable Immunodeficiency

OBJECTIVES: Common variable immunodeficiency (CVID) is associated with a spectrum of autoimmune complications. We studied the prevalence of gastrointestinal (GI) manifestations and infections in patients with CVID. METHODS: Complete clinical data of 132 Finnish patients with CVID (106 probable and 26 possible CVID) followed up between 2007 and 2016 were collected to a structured database. Data on endoscopies, histology, and laboratory studies were retrieved from patient files. RESULTS: Most common referral indications were diarrhea and/or weight loss (47%-67%). Patients with probable CVID had higher fecal calprotectin and a1-antitrypsin and lower blood vitamin B12 than patients with possible CVID. Gastroscopy and colonoscopy were done to 71 (67%) and 63 (59%) patients with probable CVID, respectively. Endoscopies showed that 15% of them had chronic active gastritis and 17% atrophic gastritis and 3% had gastric adenocarcinoma. A celiac sprue-like condition was found in 7 patients (10%), of whom 3 responded to a gluten-free diet. Colonoscopies demonstrated unspecific colitis (14%), ulcerative colitis (8%), microscopic colitis (10%), and Crohn's disease (2%). Colonic polyps were noted in30% of patients, and3% had lower GI malignancies. Thirty-five patients with CVID had bacterial or parasitic gastroenteritis; chronic norovirus was detected in 4 patients with probable CVID. Patients with GI inflammation had higher levels of fecal calprotectin and blood CD81 T lymphocytes but lower counts of CD191CD271 memory B cells and/or CD191 B cells. Immunophenotype with low B-cell counts was associated with higher fecal calprotectin levels. DISCUSSION: Patients with CVID had a high prevalence of GI manifestations and infections of the GI tract. GI inflammation was associated with a distinct immunophenotype and elevated fecal calprotectin.Peer reviewe

Genetic evidence of two sibling species within the Contracoecum ogmorhini Johnson & Mawson 1941 complex (Nematoda; Anisakidae) from otariid seals in boreal and austral regions

Genetic variation of Contracaecum ogmorhini (sensu lato) populations from different otariid seals of the northern and southern hemisphere was studied on the basis of 18 enzyme loci as well as preliminary sequence analysis of the mitochondrial cyt b gene (260 bp). Samples were collected from Zalophus californianus in the boreal region and from Arctocephalus pusillus pusillus, A. pusillus doriferus and A. australis from the austral region. Marked genetic heterogeneity was found between C. ogmorhini (sensu lato) samples from the boreal and austral region, respectively. Two loci (Mdh-2 and NADHdh) showed fixed differences and a further three loci (Iddh, Mdh-1 and 6Pgdh) were highly differentiated between boreal and austral samples. Their average genetic distance was DNei = 0.36 at isozyme level. At mitochondrial DNA level, an average proportion of nucleotide substitution of 3.7% was observed. These findings support the existence of two distinct sibling species, for which the names C. ogmorhini (sensu stricto) and C. margolisi n. sp., respectively, for the austral and boreal taxon, are proposed. A description for C. margolisi n. sp. is provided. No diagnostic morphological characters have so far been detected; on the other hand, two enzyme loci, Mdh-2 and NADHdh, fully diagnostic between the two species, can be used for the routine identification of males, females and larval stages. Mirounga leonina was found to host C. ogmorhini (s.s.) inmixed infections with C. osculatum (s.l.) (of which C. ogmorhini (s.l.) was in the past considered to be a synonym) and C. miroungae; no hybrid genotypes were found,confirming the reproductive isolation of these three anisakid species. The hosts and geographical range so far recorded for C. margolisi n. sp. and C. ogmorhini (s.s.) are given

Somatic mutations and T-cell clonality in patients with immunodeficiency

Common variable immunodeficiency (CVID) and other late-onset immunodeficiencies often co-manifest with autoimmunity and lymphoproliferation. The pathogenesis of most cases is elusive, as only a minor subset harbors known monogenic germline causes. The involvement of both B and T cells is, however, implicated. To study whether somatic mutations in CD4(+) and CD8(+) T cells associate with immunodeficiency, we recruited 17 patients and 21 healthy controls. Eight patients had late-onset CVID and nine patients other immunodeficiency and/or severe autoimmunity. In total, autoimmunity occurred in 94% and lymphoproliferation in 65%. We performed deep sequencing of 2,533 immune-associated genes from CD4(+) and CD8(+) cells. Deep T-cell receptor b-sequencing was used to characterize CD4(+) and CD8(+) T-cell receptor repertoires. The prevalence of somatic mutations was 65% in all immunodeficiency patients, 75% in CVID, and 48% in controls. Clonal hematopoiesis-associated variants in both CD4(+)and CD8(+) cells occurred in 24% of immunodeficiency patients. Results demonstrated mutations in known tumor suppressors, oncogenes, and genes that are critical for immuneand proliferative functions, such as STAT5B (2 patients), C5AR1 (2 patients), KRAS (one patient), and NOD2 (one patient). Additionally, as a marker of T-cell receptor repertoire perturbation, CVID patients harbored increased frequencies of clones with identical complementarity determining region 3 sequences despite unique nucleotide sequences when compared to controls. In conclusion, somatic mutations in genes implicated for autoimmunity and lymphoproliferation are common in CD4(+) and CD8(+) cells of patients with immunodeficiency. They may contribute to immune dysregulation in a subset of immunodeficiency patients.Peer reviewe

Patrones de distribución de dos especies de Corynosoma (Acanthocephala: Polymorphidae) en peces del Atlántico sudoccidental

Corynosoma australe Johnston, 1937 y C. cetaceum Johnston and Best, 1942 son los acantocéfalos más frecuentemente reportados en peces del Mar Argentino. Sus hospedadores definitivos son otáridos y cetáceos respectivamente, aunque también han sido reportados en otros mamíferos, aves e, incluso, en humanos. Los peces, por su parte, actúan como hospedadores intermediarios de los mismos alojando a las larvas cistacantas. Dada su amplia distribución, el género Corynosoma es útil para la determinación de stocks y estudios zoogeográficos.Asociación Parasitológica Argentin

RUBY-1: a randomized, double-blind, placebo-controlled trial of the safety and tolerability of the novel oral factor Xa inhibitor darexaban (YM150) following acute coronary syndrome

AIMS: To establish the safety, tolerability and most promising regimen of darexaban (YM150), a novel, oral, direct factor Xa inhibitor, for prevention of ischaemic events in acute coronary syndrome (ACS). METHODS: In a 26-week, multi-centre, double-blind, randomized, parallel-group study, 1279 patients with recent high-risk non-ST-segment or ST-segment elevation ACS received one of six darexaban regimens: 5 mg b.i.d., 10 mg o.d., 15 mg b.i.d., 30 mg o.d., 30 mg b.i.d., or 60 mg o.d. or placebo, on top of dual antiplatelet treatment. Primary outcome was incidence of major or clinically relevant non-major bleeding events. The main efficacy outcome was a composite of death, stroke, myocardial infarction, systemic thromboembolism, and severe recurrent ischaemia. RESULTS: Bleeding rates were numerically higher in all darexaban arms vs. placebo (pooled HR: 2.275; 95% CI: 1.13–4.60, P = 0.022). Using placebo as reference (bleeding rate 3.1%), there was a dose–response relationship (P = 0.009) for increased bleeding with increasing darexaban dose (6.2, 6.5, and 9.3% for 10, 30, and 60 mg daily, respectively), which was statistically significant for 30 mg b.i.d. (P = 0.002). There was no decrease (indeed a numerical increase in the 30 and 60 mg dose arms) in efficacy event rates with darexaban, but the study was underpowered for efficacy. Darexaban showed good tolerability without signs of liver toxicity. CONCLUSIONS: Darexaban when added to dual antiplatelet therapy after ACS produces an expected dose-related two- to four-fold increase in bleeding, with no other safety concerns but no signal of efficacy. Establishing the potential of low-dose darexaban in preventing major cardiac events after ACS requires a large phase III trial. ClinicalTrials.gov Identifier: NCT0099429