Adeno-associated virus type 2 in US children with acute severe hepatitis.

As of August 2022, clusters of acute severe hepatitis of unknown aetiology in children have been reported from 35 countries, including the USA1,2. Previous studies have found human adenoviruses (HAdVs) in the blood from patients in Europe and the USA3-7, although it is unclear whether this virus is causative. Here we used PCR testing, viral enrichment-based sequencing and agnostic metagenomic sequencing to analyse samples from 16 HAdV-positive cases from 1 October 2021 to 22 May 2022, in parallel with 113 controls. In blood from 14 cases, adeno-associated virus type 2 (AAV2) sequences were detected in 93% (13 of 14), compared to 4 (3.5%) of 113 controls (P < 0.001) and to 0 of 30 patients with hepatitis of defined aetiology (P < 0.001). In controls, HAdV type 41 was detected in blood from 9 (39.1%) of the 23 patients with acute gastroenteritis (without hepatitis), including 8 of 9 patients with positive stool HAdV testing, but co-infection with AAV2 was observed in only 3 (13.0%) of these 23 patients versus 93% of cases (P < 0.001). Co-infections by Epstein-Barr virus, human herpesvirus 6 and/or enterovirus A71 were also detected in 12 (85.7%) of 14 cases, with higher herpesvirus detection in cases versus controls (P < 0.001). Our findings suggest that the severity of the disease is related to co-infections involving AAV2 and one or more helper viruses.

Acute liver failure and unique challenges of pediatric liver transplantation amidst a worldwide cluster of adenovirus-associated hepatitis.

Investigation into a recent cluster of acute hepatitis in children from the southeastern United States identified human adenovirus (HAdV) DNAemia in all 9 cases. Molecular genotyping in 5 of 9 (56%) children identified HAdV type 41 in all cases (100%). Importantly, 2 children from this cluster progressed rapidly to pediatric acute liver failure (PALF) and required liver transplantation. HAdV type 41, a known cause of self-limited gastroenteritis, has not previously been associated with severe cholestatic hepatitis and liver failure in healthy children. Adenovirus polymerase chain reaction assay and sequencing of amplicons performed on DNA extracted from formalin-fixed, paraffin-embedded liver tissue also identified adenovirus species F (HAdV type 40 or 41) in these 2 children with PALF. Transplant considerations and successful liver transplantation in such situations remain scarce. In this report, we describe the clinical course, laboratory results, liver pathology, and treatment of 2 children with PALF associated with HAdV type 41, one of whom developed secondary hemophagocytic lymphohistiocytosis. Their successful posttransplant outcomes demonstrate the importance of early multidisciplinary medical management and the feasibility of liver transplantation in some children with PALF and HAdV DNAemia.

RINT1 Bi-allelic Variations Cause Infantile-Onset Recurrent Acute Liver Failure and Skeletal Abnormalities.

Pediatric acute liver failure (ALF) is life threatening with genetic, immunologic, and environmental etiologies. Approximately half of all cases remain unexplained. Recurrent ALF (RALF) in infants describes repeated episodes of severe liver injury with recovery of hepatic function between crises. We describe bi-allelic RINT1 alterations as the cause of a multisystem disorder including RALF and skeletal abnormalities. Three unrelated individuals with RALF onset ≤3 years of age have splice alterations at the same position (c.1333+1G>A or G>T) in trans with a missense (p.Ala368Thr or p.Leu370Pro) or in-frame deletion (p.Val618_Lys619del) in RINT1. ALF episodes are concomitant with fever/infection and not all individuals have complete normalization of liver function testing between episodes. Liver biopsies revealed nonspecific liver damage including fibrosis, steatosis, or mild increases in Kupffer cells. Skeletal imaging revealed abnormalities affecting the vertebrae and pelvis. Dermal fibroblasts showed splice-variant mediated skipping of exon 9 leading to an out-of-frame product and nonsense-mediated transcript decay. Fibroblasts also revealed decreased RINT1 protein, abnormal Golgi morphology, and impaired autophagic flux compared to control. RINT1 interacts with NBAS, recently implicated in RALF, and UVRAG, to facilitate Golgi-to-ER retrograde vesicle transport. During nutrient depletion or infection, Golgi-to-ER transport is suppressed and autophagy is promoted through UVRAG regulation by mTOR. Aberrant autophagy has been associated with the development of similar skeletal abnormalities and also with liver disease, suggesting that disruption of these RINT1 functions may explain the liver and skeletal findings. Clarifying the pathomechanism underlying this gene-disease relationship may inform therapeutic opportunities.

Acute Hepatitis and Adenovirus Infection Among Children - Alabama, October 2021-February 2022.

During October-November 2021, clinicians at a children's hospital in Alabama identified five pediatric patients with severe hepatitis and adenovirus viremia upon admission. In November 2021, hospital clinicians, the Alabama Department of Public Health, the Jefferson County Department of Health, and CDC began an investigation. This activity was reviewed by CDC and conducted consistent with applicable federal law and CDC policy.

Hepatic macrosteatosis in the US pediatric deceased liver donor population.

INTRODUCTION: The pediatric obesity epidemic is associated with early development of hepatic macrosteatosis, a hallmark of non-alcoholic fatty LI disease, which is thought to be more rapidly progressive in children than adults. Macrosteatosis in adult allografts is associated with allograft loss, but this has not been examined in pediatric donors. METHODS: We studied all pediatric potential whole LI donors (2005-2018) who had a LI biopsy in the SRTR (n = 862) and whose LI was transplanted (n = 862). Macrosteatosis was abstracted from biopsy reports and compared to values in the SRTR standard analytic file. Recipients of macrosteatotic pediatric allografts were matched 1:1 to recipients of non-macrosteatotic pediatric allografts by propensity score matching on donor/recipient variables. All-cause allograft loss was estimated via Kaplan-Meier analysis and Cox proportional hazards model. RESULTS: From 2005 to 2018, the proportion of pediatric donors (age ≥2 years) with obesity increased (14.8% to 21.7%; p < .001), as did the proportion of pediatric deceased whole LI-only donor allografts with macrosteatosis (n = 10 648; 1.8% to 3.9%; p < .001). The median degree of macrosteatosis among macrosteatotic donors was 10% (IQR 5-30). There were no significant differences in all-cause allograft loss between recipients of pediatric LI allografts with and without macrosteatosis at 90 days (p = .11) or 1 year (p = .14) post-transplant in Kaplan-Meier analysis or a Cox proportional hazards model (p > .05). CONCLUSION: Obese pediatric LI donors have increased over time and were more likely to have hepatic macrosteatosis; however, pediatric macrosteatosis did not appear to adversely affect recipient outcomes.

Liver Diseases in the Perinatal Period: Interactions Between Mother and Infant.

Liver diseases affecting the mother and infant dyad may present in the perinatal period from 20 weeks of gestation to 28 days of life. This review will focus on the current approach to neonatal acute liver failure and the progress made in the diagnosis and management of gestational alloimmune liver disease. It will highlight mother-to-child transmission of viral hepatitis, both management and public health implications. Emerging concepts implicating maternal obesity and nutrition in the development of a rapidly progressive nonalcoholic steatohepatitis phenotype in the offspring will be discussed. Finally, the presentation and management of acute fatty liver of pregnancy and intrahepatic cholestasis of pregnancy, and their impact on the fetus, will be reviewed.

Integrin ß1-enriched extracellular vesicles mediate monocyte adhesion and promote liver inflammation in murine NASH.

BACKGROUND & AIMS: Hepatic recruitment of monocyte-derived macrophages (MoMFs) contributes to the inflammatory response in non-alcoholic steatohepatitis (NASH). However, how hepatocyte lipotoxicity promotes MoMF inflammation is unclear. Here we demonstrate that lipotoxic hepatocyte-derived extracellular vesicles (LPC-EVs) are enriched with active integrin ß1 (ITGß1), which promotes monocyte adhesion and liver inflammation in murine NASH. METHODS: Hepatocytes were treated with either vehicle or the toxic lipid mediator lysophosphatidylcholine (LPC); EVs were isolated from the conditioned media and subjected to proteomic analysis. C57BL/6J mice were fed a diet rich in fat, fructose, and cholesterol (FFC) to induce NASH. Mice were treated with anti-ITGß1 neutralizing antibody (ITGß1Ab) or control IgG isotype. RESULTS: Ingenuity® Pathway Analysis of the LPC-EV proteome indicated that ITG signaling is an overrepresented canonical pathway. Immunogold electron microscopy and nanoscale flow cytometry confirmed that LPC-EVs were enriched with activated ITGß1. Furthermore, we showed that LPC treatment in hepatocytes activates ITGß1 and mediates its endocytic trafficking and sorting into EVs. LPC-EVs enhanced monocyte adhesion to liver sinusoidal cells, as observed by shear stress adhesion assay. This adhesion was attenuated in the presence of ITGß1Ab. FFC-fed, ITGß1Ab-treated mice displayed reduced inflammation, defined by decreased hepatic infiltration and activation of proinflammatory MoMFs, as assessed by immunohistochemistry, mRNA expression, and flow cytometry. Likewise, mass cytometry by time-of-flight on intrahepatic leukocytes showed that ITGß1Ab reduced levels of infiltrating proinflammatory monocytes. Furthermore, ITGß1Ab treatment significantly ameliorated liver injury and fibrosis. CONCLUSIONS: Lipotoxic EVs mediate monocyte adhesion to LSECs mainly through an ITGß1-dependent mechanism. ITGß1Ab ameliorates diet-induced NASH in mice by reducing MoMF-driven inflammation, suggesting that blocking ITGß1 is a potential anti-inflammatory therapeutic strategy in human NASH. LAY SUMMARY: Herein, we report that a cell adhesion molecule termed integrin ß1 (ITGß1) plays a key role in the progression of non-alcoholic steatohepatitis (NASH). ITGß1 is released from hepatocytes under lipotoxic stress as a cargo of extracellular vesicles, and mediates monocyte adhesion to liver sinusoidal endothelial cells, which is an essential step in hepatic inflammation. In a mouse model of NASH, blocking ITGß1 reduces liver inflammation, injury and fibrosis. Hence, ITGß1 inhibition may serve as a new therapeutic strategy for NASH.

Post-Transplant Lymphoproliferative Disorder Presenting as a Gastrointestinal Fistulous Tract in a Heart Transplant Recipient: Case Report and Literature Review.

We present a challenging case of Epstein-Barr virus-related isolated small bowel post-transplant lymphoproliferative disorder (PTLD) in a pediatric heart transplant recipient presenting as recurrent gastrointestinal (GI) bleeding and subsequently a GI fistulous tract with associated intra-abdominal abscess. Diagnosis was not confirmed until exploratory laparoscopy was performed, with excision of the fistulous tract revealing evidence of PTLD on pathology. Early diagnosis of GI-PTLD remains a challenge, especially if isolated in the small intestine. Diagnosis may rely on positron emission tomography/ computed tomography scan (PET/CT) or invasive intervention to obtain appropriate tissue samples for pathology diagnosis.

Signatures of AAV-2 immunity are enriched in children with severe acute hepatitis of unknown etiology.

Severe acute hepatitis of unknown etiology in children is under investigation in 35 countries. Although several potential etiologic agents have been investigated, a clear cause for the liver damage observed in these cases remains to be identified. Using VirScan, a high-throughput antibody profiling technology, we probed the antibody repertoires of nine cases of severe acute hepatitis of unknown etiology treated at Children's of Alabama and compared their antibody responses with 38 pediatric and 470 adult controls. We report increased adeno-associated dependoparvovirus A (AAV-A) breadth in cases relative to controls and adeno-associated virus 2 (AAV-2) peptide responses that were conserved in seven of nine cases but rarely observed in pediatric and adult controls. These findings suggest that AAV-2 is a likely etiologic agent of severe acute hepatitis of unknown etiology.

Clinicopathologic Features of Severe Acute Hepatitis Associated With Adenovirus Infection in Children.

A recent increase in reports of severe acute hepatitis of unknown etiology in children is under investigation. Although adenovirus has been frequently detected, its role remains unclear, and systematic histopathologic analysis is lacking. We conducted a retrospective study of 11 children hospitalized between October 2021 and May 2022 with unexplained acute hepatitis and concurrent adenovirus infection. Liver biopsies collected shortly after admission demonstrated moderately to severely active hepatitis in 8/11 (73%) cases, characterized by marked portal mixed inflammation, moderate-to-severe interface activity, and milder lobular inflammation. Clusters of plasma cells were present in 6/11 (55%) cases, mimicking autoimmune hepatitis. Semiquantitative scoring of 17 discrete histologic features found that greater degrees of portal inflammation, interface activity, bile duct injury, bile ductular reaction, lobular inflammation, Kupffer cell activation, and hepatocyte focal necrosis were significantly more common in these cases in comparison to the control group of unexplained acute severe hepatitis without adenovirus infection. Liver biopsy immunohistochemistry was negative for adenovirus in all cases. Polymerase chain reaction testing of liver tissue was positive for the enteric adenovirus serotypes 41 (species F) in 10/11 (91%) cases. An immunoprofile study of hepatic infiltrating lymphocytes in 1 patient revealed the presence of large numbers of CD3 + and CD4 + lymphocytes. Nine patients received supportive treatment without steroids and recovered without the need for liver transplantation. In summary, liver injury in children with severe acute hepatitis and adenovirus infection is characterized by a hepatitic pattern that resembles severe autoimmune hepatitis and may represent an immune-mediated process associated with viral infection.

Ivacaftor-elexacaftor-tezacaftor and tacrolimus combination in cystic fibrosis.

The CFTR modulator combination elexacaftor/tezacaftor/ivacaftor (ETI) is a genetic mutation-targeted treatment in cystic fibrosis that results in profound improvements in clinical outcomes. Each of the compounds are substrates of CYP3A4/5, the cytochrome P450 enzyme family for which tacrolimus is also a substrate. The use of these compounds in an individual with a solid organ transplant has not been previously studied and there is potential for a drug interaction. In this report, we describe a pediatric liver transplant recipient with clinical decline related to cystic fibrosis who improved substantially with ETI, without significant impact on the systemic exposure of either ETI or tacrolimus.

Acute Liver Failure in a Healthy Young Female With COVID-19.

Several well-described manifestations of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been reported. Among them, a transient elevation of liver enzymes is the typical presentation of coronavirus disease 2019 (COVID-19) liver-related injury. The mechanism of liver involvement is likely a combination of viral injury and immune-mediated inflammation. In contrast, acute liver failure in the setting of COVID-19 has rarely been reported. Herein, we report a case of pediatric acute liver failure in a previously healthy female adolescent infected with SARS-CoV-2 with biopsy evidence of replicating virus in hepatocytes, which has not been previously reported.

Perinatal Nutritional Reprogramming of the Epigenome Promotes Subsequent Development of Nonalcoholic Steatohepatitis.

With the epidemic of obesity, nonalcoholic fatty liver disease (NAFLD) has become the most common pediatric liver disease. The influence of a perinatal obesity-inducing diet (OID) on the development and progression of NAFLD in offspring is important but incompletely studied. Hence, we fed breeding pairs of C57BL/6J mice during gestation and lactation (perinatally) either chow or an OID rich in fat, fructose, and cholesterol (FFC). The offspring were weaned to either chow or an FFC diet, generating four groups: perinatal (p)Chow-Chow, pChow-FFC, pFFC-Chow, and pFFC-FFC. Mice were sacrificed at 10 weeks of age. We examined the whole-liver transcriptome by RNA sequencing (RNA-seq) and whole-liver genome methylation by reduced representation bisulfite sequencing (RRBS). Our results indicated that the pFFC-FFC mice had a significant increase in hepatic steatosis, injury, inflammation, and fibrosis, as assessed histologically and biochemically. We identified 189 genes that were differentially expressed and methylated in the pFFC-FFC mice versus the pChow-FFC mice. Gene set enrichment analysis identified hepatic fibrosis/hepatic stellate cell activation as the top canonical pathway, suggesting that the differential DNA methylation events in the mice exposed to the FFC diet perinatally were associated with a profibrogenic transcriptome. To verify that this finding was consistent with perinatal nutritional reprogramming of the methylome, we exposed pFFC-Chow mice to an FFC diet in adulthood. These mice developed significant hepatic steatosis, injury, inflammation, and more importantly fibrosis when compared to the appropriate controls. Conclusion: Perinatal exposure to an OID primes the immature liver for an accentuated fibrosing nonalcoholic steatohepatitis (NASH) phenotype, likely through nutritional reprogramming of the offspring methylome. These data have potential clinical implications for monitoring children of obese mothers and risk stratification of children with NAFLD.

Laboratory genetic-based reference values for cholinesterase activity in a Colombian population: A step forward in personalized diagnostics.

INTRODUCTION: The determination of cholinesterase (ChE) activity has been commonly applied in the biomonitoring of exposure to organophosphate and carbamate pesticides. However, ChE activity is influenced by genetic factors. Integrating genotype and phenotype information in clinical laboratory tests would increase the accuracy of the reference values in well-defined populations. OBJECTIVE: To establish genetic-based reference values for acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity in a Colombian population. MATERIALS AND METHODS: A total of 397 healthy adults from Bucaramanga were included in the study. AChE and BChE activities were measured in blood samples by potentiometry and spectrophotometry, respectively. Genotyping for ACHE rs17880573 and BCHE rs1803274 was performed using the TaqMan allelic discrimination assay. The statistical analyses to obtain the reference values were performed with the MedCalc® software. RESULTS: Allele frequencies were 10.58% for rs17880573 A and 8.82% for rs1803274 A. People with genotypes rs1803274 AA and AG showed a reduction of 20.69% and 10.92% respectively in mean BChE activity compared to people with genotype GG. No significant differences were identified in AChE activity between rs17880573 alleles or genotypes. In the overall sample, the corresponding reference values were as follows: for AChE activity, 0.62-0.98 D pH/h and for BChE activity, 4796.3-10321.1 U/L for people carrying the allele rs1803274A and 5768.2-11180.4 U/L for people carrying the genotype rs1803274 GG. CONCLUSION: We strongly recommend using these genetic-based reference values for ChE enzymes in our well-defined population in daily clinical practice.

[Human mercury exposure and irregular menstrual cycles in relation to artisanal gold mining in Colombia]. / Irregularidad menstrual y exposición a mercurio en la minería artesanal del oro en Colombia.

INTRODUCTION: Artisanal mining commonly extracts gold with an amalgamation process that uses mercury. The reproductive effects from exposure to elemental mercury used in gold mining have not been sufficiently studied. OBJECTIVE: To evaluate the effect of the exposure to elemental mercury used in gold mining on menstrual cycle regularity and the occurrence of miscarriages in Colombia. MATERIALS AND METHODS: An analytical cross-sectional study was conducted. The participants were female residents of gold mining districts, with a history of exposure to elemental mercury. Menstrual regularity and the occurrence of miscarriages were compared between these women and an unexposed group. Exposure and outcome variables were registered based on a questionnaire which was evaluated for its test-retest reproducibility. Prevalence rates were calculated using a binomial model and goodness-of-fit was evaluated. RESULTS: A total of 72 women exposed to mercury and 121 unexposed women participated. The average time of exposure to mercury among exposed women was 19.58 ± 9.53 years. The adjusted prevalence of irregular menstruation over the last six months was higher in the group of women chronically exposed to mercury vapors (PR=1.59, 95% CI 0.93-2.73), while there was no difference in the proportion of women with a history of miscarriages. CONCLUSIONS: Exposure to elemental mercury used in artisanal gold mining may be associated with a higher prevalence of irregular menstrual cycles but not with the occurrence of miscarriage.

Tiempo para quedar en embarazo: Evaluación de su reproducibilidad en una cohorte retrospectiva / Time to pregnancy: reproducibility assessment in a retrospective cohort study

Introducción: El tiempo para quedar en embarazo (TPE) es una medida clínica de la fecundidad útil en la evaluación de efectos reproductivos relacionados con exposiciones ambientales u ocupacionales. Estudios con mujeres europeas evidencian que su uso tiene una adecuada recordación y reproducibilidad; sin embargo, estas propiedades no han sido evaluadas en Latinoamérica. Objetivos: Evaluar la reproducibilidad de la medida TPE en una población de mujeres colombianas como una aproximación clínica de la fecundidad. Metodología: Estudio de reproducibilidad prueba-reprueba de un cuestionario para determinar el tiempo al primer embarazo en una sub-muestra de 27 mujeres, anidado en una cohorte retrospectiva de evaluación de los efectos reproductivos de la exposición al mercurio metálico en la minería artesanal de oro. El cuestionario fue administrado de forma repetida por un evaluador entrenado, en el primer momento en una entrevista presencial y 12 meses después en una entrevista telefónica. La reproducibilidad del cuestionario fue evaluada usando el coeficiente de correlación intraclase (CCI). Resultados: La mediana de tiempo al embarazo fue de 4 meses (rango intercuartil 1-12). El rango de tiempo transcurrido desde el primer embarazo estuvo entre 1 y 15 años. El CCI (2,k) fue 0.726 (IC 95% 0.39, 0.88), demostrando una buena reproducibilidad de la variable después de un año de separación entre la primera y segunda entrevista. Conclusiones: El TPE para el primer embarazo mostró ser una medida clínica de fecundidad sencilla y reproducible, con un tiempo de recordación de hasta 15 años y en evaluación presencial o telefónica en una población de mujeres colombianas.

Introduction: Time to pregnancy (TTP) is a clinical measurement of fecundity that has been used in occupational and environmental epidemiological research. Previous studies conducted in European women have shown an adequate reliability and reproducibility. However, these characteristics have not been yet evaluated in Latin American women. Objective: To assess the reproducibility of TTP for the first pregnancy as clinical measurement of couple's fecundity in a population of Colombian women. Methods: A test-retest study of TTP in 27 Colombian women was nested in a retrospective cohort study assessing the effect of mercury exposure on reproductive effects. The questionnaire was applied twice by the same trained interviewer (by person at baseline and by phone 12 months later). The TTP's reproducibility was evaluated using the intraclass correlation coefficient (ICC 2,k). Results: The median TTP was 4 months (Interquartile range 1-12). The range of time from the first pregnancy to the first interview was between 1 and 15 years. The ICC (2,k) was 0.726, (CI 95% 0.39 - 0.88), indicating good reproducibility between both measures. Conclusions: Our results suggest that TTP is a useful and reproducible measurement, with a remembrance time up to 15 years. Results were similar when assessed by phone and face-to face interview in a population of Colombian women.

Laboratory genetic-based reference values for cholinesterase activity in a Colombian population: A step forward in personalized diagnostics / Valores de referencia basados en el contexto genético de la actividad enzimática de la colinesterasa en una población colombiana: un paso hacia el diagnóstico personalizado

Introduction: The determination of cholinesterase (ChE) activity has been commonly applied in the biomonitoring of exposure to organophosphate and carbamate pesticides. However, ChE activity is influenced by genetic factors. Integrating genotype and phenotype information in clinical laboratory tests would increase the accuracy of the reference values in well-defined populations. Objective: To establish genetic-based reference values for acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity in a Colombian population. Materials and methods: A total of 397 healthy adults from Bucaramanga were included in the study. AChE and BChE activities were measured in blood samples by potentiometry and spectrophotometry, respectively. Genotyping for ACHE rs17880573 and BCHE rs1803274 was performed using the TaqMan allelic discrimination assay. The statistical analyses to obtain the reference values were performed with the MedCalc® software. Results: Allele frequencies were 10.58% for rs17880573 A and 8.82% for rs1803274 A. People with genotypes rs1803274 AA and AG showed a reduction of 20.69% and 10.92% respectively in mean BChE activity compared to people with genotype GG. No significant differences were identified in AChE activity between rs17880573 alleles or genotypes. In the overall sample, the corresponding reference values were as follows: for AChE activity, 0.62-0.98 D pH/h and for BChE activity, 4796.3-10321.1 U/L for people carrying the allele rs1803274A and 5768.2-11180.4 U/L for people carrying the genotype rs1803274 GG. Conclusion: We strongly recommend using these genetic-based reference values for ChE enzymes in our well-defined population in daily clinical practice.

Introducción. La determinación de la actividad enzimática de la colinesterasa se utiliza comúnmente en la vigilancia biológica de la exposición a pesticidas organofosforados y carbamatos. Sin embargo, los factores genéticos afectan la actividad de la colinesterasa, por lo que la integración de la información sobre genotipos y fenotipos en las pruebas de laboratorio clínico, incrementaría la precisión de los valores de referencia. Objetivo. Establecer los valores de referencia basados en el contexto genético para la actividad enzimática de la acetilcolinesterasa (AChE) y la butirilcolinesterasa (BChE), en una población colombiana. Materiales y métodos. Se incluyeron 397 adultos sanos. La actividad de la acetilcolinesterasa y la de la butirilcolinesterasa, se determinaron en muestras de sangre por potenciometría y espectrofotometría, respectivamente. Los genotipos de los ACHE rs17880573 y BCHE rs1803274 se obtuvieron mediante el ensayo TaqMan y los valores de referencia se estimaron con el programa MedCalc®. Resultados. La frecuencia alélica fue de 10,58 % para rs17880573 A y de 8,82 % para rs1803274 A. Las personas con los genotipos rs1803274 AA y AG, mostraron una reducción en el promedio de la actividad de la butirilcolinesterasa de 20,69 % y de 10,92 %, respectivamente, comparados con aquellas con el genotipo GG. No se encontraron diferencias significativas en la actividad de la acetilcolinesterasa con respecto a los alelos y genotipos del rs17880573. Los valores de referencia determinados para esta población fueron de 0,62-0,98 D pH/h para acetilcolinesterasa y de 4796,3-10321,1 U/L para butirilcolinesterasa, en las personas portadoras del alelo rs1803274 A, y de 5768,2-11180,4 U/L, en las portadoras del genotipo rs1803274 GG. Conclusión. Se recomienda el uso de estos valores de referencia basados en el contexto genético para las colinesterasas, en la práctica clínica diaria en esta población.