Characteristics and rates of infection by HIV in people receiving non-occupational post-exposure prophylaxis (nPEP) against HIV.

INTRODUCTION/OBJECTIVES: The use of non-occupational post-exposure prophylaxis (nPEP) emerges as a strategic intervention to reduce HIV infection risk following sexual encounters in our setting. Notwithstanding, there is a scarcity of contemporary data regarding adherence to this treatment, its effectiveness and tolerance. Our study aims to delve into these factors among individuals who have resorted to nPEP after high-risk sexual encounters. METHODS: We conducted a retrospective observational study of cases administered nPEP for HIV from 1 January 2018 to 31 December 2021 at a tertiary hospital in Madrid. The study included all adults over 18 years who sought care at the emergency department of the Fundación Jiménez Díaz Hospital following a risky sexual encounter and were subsequently recommended HIV nPEP treatment. RESULTS: 878 individuals received nPEP for HIV and underwent initial serological tests. Of these, 621 had comprehensive follow-ups. The prescribed regimen for all was raltegravir (RAL) 1200 mg combined with tenofovir/emtricitabine (TDF/FTC) 245/200 mg daily for 28 days. The study revealed a 1.1% rate (n=10) of previously undetected infection and a 0.16% (n=1) failure rate of nPEP. Regarding regimen tolerability, 5.6% (n=35) experienced symptoms linked to the treatment, yet none necessitated discontinuation of the regimen. On the contrary, six per cent (n=53) reported symptoms consistent with an STI during one of the medical visits; specifically, 4.4% had urethritis, and 1.6% had proctitis. CONCLUSION: nPEP with RAL/TDF/FTC demonstrates high efficacy and safety, contingent on proper adherence. There is an observed increase in STI prevalence in this cohort, with nearly half of the participants not engaging in appropriate follow-up after initiating nPEP.

An acoustic-based method for locating maternity colonies of rare woodland bats.

Locating colonies of rare bats can be a time consuming process, as it is often difficult to know where to focus survey effort. However, identifying peaks of bat activity via acoustic monitoring may provide insights into whether a colony is locally present, and help screen out sites with low potential. Using a triage approach, we developed a survey methodology for locating colonies of the woodland-specialist barbastelle bat (Barbastella barbastellus). We investigated whether woodland occupancy by a colony could be predicted by acoustic data, and assessed the influence of survey effort (number of acoustic detectors deployed) on detectability. The methodology was then trialled in citizen science surveys of 77 woodlands, with follow-up radio-tracking surveys by specialists being used to confirm presence or absence. Using Receiver Operating Characteristic (ROC) curve analysis, we found that a threshold of four barbastelle passes recorded by at least one detector within one hour of sunset optimised the balance between the true- and false-positive rates. Subsequently, we found that a minimum survey effort of one detector per 6.25 hectares of woodland was needed to ensure a colony would be detected using this threshold, based on a survey sensitivity of 90%. Radio-tracking surveys in a subset of the woodlands, identified as having a high probability of being occupied by a colony based on acoustic monitoring, confirmed the presence of five previously unknown barbastelle maternity colonies. These results demonstrate that a triage system, in which high probability woodland sites are identified based on acoustic survey data, can be used to prioritise sites for future specialist surveys and conservation action.

Déficit de factor XI. A propósito de un caso / Acquired factor XI deficiency. A case reports

La deficiencia de factor XI es un trastorno hereditario de la coagulación en el que existe una reducción cuantitativa o cualitativa del factor XI debido a mutaciones en el gen F11. Es una entidad común entre los asquenazíes, que puede ser subestimada en los caucásicos. Puede debutar a cualquier edad con clínica variable e impredecible, existiendo escasa relación entre los niveles de actividad del factor XI y los síntomas hemorrágicos. Su diagnóstico se basa en la realización de un estudio de coagulación básico (alargamiento del tiempo parcial de tromboplastina activado [TTPA]) y la medición de los niveles del factor XI. Presentamos un caso con el objetivo de difundir esta entidad entre la comunidad pediátrica

Factor XI deficiency is a hereditary coagulation disorder with a quantitative and/or qualitative reduction of factor XI due to F11 gene mutations. This is a common entity in Ashkenazi community, which can be underestimated in Caucasians. It can debut at any age with variable and unpredictable symptoms, showing poor relation between factor XI activity levels and bleeding symptoms. It can be diagnosed after a basic coagulation exam (lengthening activated partial thromboplastin time [APTT]) and factor XI levels measure. We present a factor XI deficiency clinical case for spreading this entity to the pediatric community

Perfil genético hla en familias venezolanas: útil herramienta biomédica / Hla genetic profile in venezuelan families: biomedical useful tool

El sistema de antígenos leucocitarios Humano (Human Leukocyte Antigen, HLA) regula la respuesta inmune mediante su unión a moléculas como el receptor de células T, participando en la presentación de antígenos y el reconocimiento de lo propio en el organismo. La caracterización genética del sistema HLA en determinada población es de gran utilidad para la comprensión de mecanismos asociados a susceptibilidad o resistencia a enfermedades y en la selección de donantes/receptores en trasplantes de órganos. En este estudio se planteó determinar la frecuencia de los Haplotipos HLA de clase I presentes en individuos sanos, relacionados familiarmente y venezolanos de tercera generación y su correspondiente desequilibrio de ligamiento. Se incluyeron 765 individuos pertenecientes a 218 familias a los cuales se les realizó tipificación HLA A y HLA B por PCR-SSOP (polymerase chain reaction-sequence specific oligonucleotide probe) en baja resolución. Se identificaron 265 haplotipos de los cuales los más frecuentes fueron HLA A*24 B*35 (11,98 %), A*02 B*51 (9,7%) y A*02 B*35 (8,6 %).Para los cálculos de desequilibrio de ligamiento se consideraron las frecuencias mayores al 1% (28,7%) y no arrojaron valores estadísticamente significativos el 6,78% de estos haplotipos. Los resultados obtenidos corroboran la composición triétnica históricamente conocida de nuestra población, en la cual predominan genes caucásicos, amerindios y afrodescendientes; y su porcentaje marca la diferencia con otras poblaciones americanas estudiadas. Estos resultados representan una aproximación de la conformación genética establecida en Venezuela y aporta datos que podrán ser usados como referencia en programas de salud para la población.

The system of Human leukocyte antigens (HLA) is the most polymorphic in humans. Its function is performed by regulating the immune response by binding to molecules such as T-cell receptor, involved in antigen presentation and recognition of the same in the body. Genetic characterization of HLA system in a given population is useful for understanding the mechanisms associated with susceptibility or resistance to various diseases and selection of donors and recipients in organ transplants, among others. The objective of the present study is to determine the frequency of HLA Class I Haplotypes present in healthy individuals, family relationships and third-generation Venezuelan and their corresponding linkage disequilibrium. We included 765 individuals belonging to 218 families who underwent HLA typing HLA A and B by PCR-SSOP (polymerase chain reaction-sequence specific oligonucleotide probe) in low resolution. 265 haplotypes were identified of which the most frequent were HLA A * 24 B * 35 (11.98%), A * 02 B * 51 (9.7%) and A * 02 B * 35 (8.6%). Calculations of linkage disequilibrium were considered frequencies above 1% (28.7%) and did not show statistically significant the 6.78% of these haplotypes. The results support the historically known tri-ethnic composition of our population, in which genes predominantly Caucasian, Mongoloid and Negroid, and make a difference with other American populations studied. These data can be used as reference to applications of benefit to this population.

Allele and haplotype frequencies at human leukocyte antigen class I and II genes in Venezuela's population.

Population studies represent an integral part and link in understanding the complex chain of host-pathogen interactions, disease pathogenesis, and MHC gene polymorphisms. Genes of Mongoloid, Caucasoid, and Negroid populations have created a distinctive HLA genetic profile in the Venezuelan population. Our objective was to determine the predominant HLA class I and II alleles and haplotype frequencies in the hybrid population of Venezuela. The study population consisted of 486 healthy unrelated native Venezuelans and 180 families. We examined the frequency of HLA A-B-C, HLA-DQ and HLA-DR genes by polymerase chain reaction and subsequent hybridization with sequence-specific oligonucleotide probes. Phenotypic, allelic and haplotype frequencies were estimated by direct counting and using the maximum-likelihood method. The predominant HLA class I alleles were A*02, A*24, A*68, B*35, B*44, B*51, B*07, B*15 and Cw*07. Regarding HLA class II, the most frequent alleles were DQB1*03 and DRB1*04, DRB1*15, DRB1*13, DRB1*07. The prevailing haplotype was HLA-A*02B*35 DQB1*03 DRB1*04. Some of these alleles and haplotype frequencies were predominantly present in Amerindians (A*02, A*24, B*35, Cw*07, DRB1*04, A*24 B*35). Previous reports have shown high incidence of A*02, B*44, B*51, DRB1*15, DRB1*13, DRB1*07 alleles in several European populations and A*68, B*07, B*15 alleles in African Americans, which could have contributed to the ethnic admixture of the Venezuelan population. We conclude that our results provide strong evidence that Venezuela's population represents an admixture of the primitive Mongoloid Aborigines, Caucasoid Europeans and Western African Negroid migrants.

Inmunogenético clínica y transplante renal: diez años de experiencia en Venezuela / Clinical immunogenetics and kidney transplantation: a 10-year experience in Venezuela

En Venezuela, entre 1974 y 1983 se realizaron 224 transplantes de riñón. De ellos, 122 provenían de donante vivo familiar consanguíneo y 102 de cadáver. La sobrevida actuarial para los transplantes intrafamilia fue de 82% en los casos con compatibilidad de dos haplotipos y de 41% en los casos con compatibilidad de un haplotipo, ambas a los siete años. Para los injertos provenientes de cadáver la sobrevida fue de 33% a los nueve años. Además, en 73 transplantes de órganos de cadáver se estableció la correlación entre sobrevida actuarial y presencia de linfocitotoxinas en el receptor; para 49 pacientes que no generaron linfocitotoxinas la sobrevida del injerto al tecer año fue de 74%, contra 40% para los 24 receptores en los que se detectaron linfocitotoxinas. Estos resultados se discuten y se comparan con los obtenidos por otros investigadores. Se destaca, por último, la necesidad de aclarar en forma definitiva la función que desempeñan los anticuerpos que se inducen por transfusión en los receptores, para la sobrevida de los injertos