Diagnostic differences in high-resolution esophageal motility in a large Mexican cohort based on geographic distribution.

High-resolution esophageal manometry [HRM] has become the gold standard for the evaluation of esophageal motility disorders. It is unclear whether there are HRM differences in diagnostic outcome based on regional or geographic distribution. The diagnostic outcome of HRM in a diverse geographical population of Mexico was compared and determined if there is variability in diagnostic results among referral centers. Consecutive patients referred for HRM during 2016-2020 were included. Four major referral centers in Mexico participated in the study: northeastern, southeastern, and central (Mexico City, two centers). All studies were interpreted by experienced investigators using Chicago Classification 3 and the same technology. A total of 2293 consecutive patients were included. More abnormal studies were found in the center (61.3%) versus south (45.8%) or north (45.2%) P < 0.001. Higher prevalence of achalasia was noted in the south (21.5%) versus center (12.4%) versus north (9.5%) P < 0.001. Hypercontractile disorders were more common in the north (11.0%) versus the south (5.2%) or the center (3.6%) P.001. A higher frequency of weak peristalsis occurred in the center (76.8%) versus the north (74.2%) or the south (69.2%) P < 0.033. Gastroesophageal junction obstruction was diagnosed in (7.2%) in the center versus the (5.3%) in the north and (4.2%) in the south p.141 (ns). This is the first study to address the diagnostic outcome of HRM in diverse geographical regions of Mexico. We identified several significant diagnostic differences across geographical centers. Our study provides the basis for further analysis of the causes contributing to these differences.

Functional outcomes and quality of life in patients treated with laparoscopic total colectomy for colonic inertia.

PURPOSE: To assess the functional outcomes and quality of life in patients with laparoscopic total colectomy for slow-transit constipation (STC). METHODS: All patients undergoing laparoscopic colectomy with ileorectal anastomosis for colonic inertia at two referral centers were analyzed. Their preoperative, intraoperative and postoperative details were recorded with a one-year follow-up. Their quality of life was assessed using the SF-36 questionnaire. RESULTS: Between 2004 and 2007, 710 patients were evaluated. Eight female patients (1.1 %) fulfilled the criteria for STC without obstructive defecation syndrome. Their mean age was 38 years ± 15 (range from 22 to 62). The conversion rate was 12.5 %. The morbidity rate was 37.5 %, and mortality was nil. The preoperative abdominal pain was 6.6 ± 0.3 and had decreased to 3.6 ± 2.3 postoperatively (P = 0.008). At 1 year, the defecation frequency per week had increased from 0.84 ± 0.24 to 6.75 ± 3.4 (P = 0.001). Three patients developed nocturnal leakage (37.5 %). Eighty-eight percent of the patients recommend the procedure. All parameters of the SF-36 questionnaire had improved at the one-year follow-up examination. CONCLUSION: Laparoscopic colectomy for slow-transit constipation is safe and increased the number of evacuations per week. Although nocturnal leakage may occur, these patients experience improvements in their quality of life.

The Effects of Agave Fructans in a Functional Food Consumed by Patients with Irritable Bowel Syndrome with Constipation: A Randomized, Double-Blind, Placebo-Controlled Trial.

Irritable bowel syndrome displays three different subtypes: constipation (IBS-C), diarrhea (IBS-D), and mixed (IBS-M). Treatment with dietary fiber is used, with consideration given both to the chemical composition of the fiber and to the different subtypes of IBS. The IBS-D subtype is usually treated with a low-FODMAPs diet, whereas the IBS-C subtype suggests prebiotics and probiotics to promote microbiota restoration. The aim of this study was to assess the effects of employing agave fructans as the soluble fiber of a jelly (Gelyfun®gastro) containing 8 g per serving in the IBS-C group (n = 50), using a randomized, double-blind, time-limited trial for four weeks. We evaluated changes in the frequency and types of bowel movements through the Bristol scale, and the improvement of the condition was evaluated using quality of life (IBS-QOL) and anxiety-depression (HADS) scales. The main results were that the number of bowel movements increased by more than 80%, with at least one stool per day from fifteen days onwards, without a laxative effect for the group treated. Finally, the quality of life with the prebiotic jelly was significantly improved compared to the placebo in all specific domains, in addition to significantly reducing anxiety and depression.

[Guidelines for diagnosis and treatment of constipation in Mexico. B) Diagnostic approach]. / Guías de diagnóstico y tratamiento del estreñimiento en México. B) Abordaje diagnóstico.

BACKGROUND: Constipation is a heterogeneous symptom so an accurate diagnosis requires an appropriate approach. OBJECTIVE AND METHODS: To establish the clinical guidelines for diagnosis and treatment of chronic constipation in Mexico we have reviewed the diagnostic aspects of constipation according to the availability of resources in our country. In addition, evidence-based recommendations have been provided. RESULTS: The symptoms that best define constipation in our population are infrequent stool, hard stool expulsion, excessive effort and sensation of incomplete evacuation. Digital rectal examination is a useful diagnostic tool to discard organic diseases and pelvic floor dyssynergia. Patients with risk factors such as recent onset of constipation, family history of inflammatory bowel disease or colon cancer and those with alarm signs (unintentional weight loss and significant anemia, blood in stool) should undergo endoscopic diagnostic studies. If they are available, the most useful tests in evaluating patients with functional constipation are colonic transit with radiopaque markers and anorectal manometry with balloon expulsion test. CONCLUSIONS: Patients with symptoms of chronic constipation should undergo advanced colorectal physiological studies to try to establish the cause of constipation.

Prevalence of burnout syndrome in gastroenterologists and endoscopists: results of a national survey in Mexico.

BACKGROUND: Burnout syndrome (BOS) is characterized by emotional exhaustion, depersonalization and reduced personal accomplishment. It affects doctors, patients and their inter-relationship. There is a lack of data on BOS in Mexico. The main objective of the present study is to evaluate the prevalence of BOS in physician members of the Mexican gastroenterological association (MGA) and Mexican association for gastrointestinal endoscopy (MAGE). MATERIALS AND METHODS: Cross sectional, prospective study through anonymous electronic survey via e-mail, sent to members of the MGA (n = 1192) and MAGE (n = 600). The survey included questions about basic sociodemographic information, Maslach Burnout Inventory, and factors potentially associated with BOS. Continuous variables were summarized as means and ANOVA or Kruskal-Wallis test were used to compare groups. Nominal variables were summarized as proportions and Fisher's exact test or Χ2 test were used, as appropriate. RESULTS: A total of 1792 e-mail invitations were delivered and 411 answers were received with a response rate of 22.9%. The prevalence of BOS according to the Maslach Burnout Inventory was 26.3% (108/411). The prevalence of BOS according to the single-item self-defined burnout question (SISDBOQ) was 32.6% (134/411). The Kappa coefficient for emotional exhaustion between the SISDBOQ and Maslach inventory was 0.48 (p = 0.0001). Factors associated with BOS included performing endoscopic procedures (OR 2.9 (1.2-6.6); p = 0.008), lack of support from colleagues upon complications (OR 0.2 (0.1-0.4); p = 0.0001), receiving frequent reprimands from superiors (OR 2.4 (1.5-3.8); p = 0.0001), work unrelated to medicine (OR 2.4 (1.4-3.9); p = 0.0001), work violence/harassment (OR 3.0 (1.9-4.9); p = 0.0001) and living in a big city (OR 1.9 (1.2-3); p = 0.005). CONCLUSION: BOS is a frequent entity in Mexican gastroenterologists and endoscopists. There are potentially modifiable factors associated with BOS.

Maximum tolerated volume in drinking tests with water and a nutritional beverage for the diagnosis of functional dyspepsia.

AIM: Recently, drinking load tests with water or nutritional beverages have been proposed as diagnostic tools for functional dyspepsia (FD), therefore we sought to reproduce if these tests can discriminate between FD patients and controls in a Mexican population. METHODS: Twenty FD-Rome II patients were matched by age and gender with 20 healthy controls. All underwent both drinking tests at a 15 mL/min rate, randomly, 7 d apart. Every 5 min within each test, four symptoms were evaluated (satiety, bloating, nausea and pain) by Likert scales. Maximum tolerated volume (MTV) was defined as the ingested volume when a score of 5 was reached for any symptom or when the test had to be stopped because the patients could not tolerate more volume. Sensitivity and specificity were analyzed. RESULTS: FD patients had higher symptom scores for both tests compared to controls (water: t = 4.1, P = 0.001<0.01; Nutren: t = 5.2, P = 0.001<0.01). The MTV for water and Nutren were significantly lower in FD (water: 1 014+/-288 vs 1 749+/-275 mL; t = 7.9, P = 0.001<0.01; Nutren: 652+/-168 vs 1 278+/-286 mL; t = 6.7, P = 0.001<0.01). With the volume tolerated by the controls, the percentile 10 was determined as the lower limit for tolerance. Sensitivity and specificity were 0.90, 0.95 for water and 0.95, 0.95 for Nutren tests. CONCLUSION: A drinking test with water or a nutritional beverage can discriminate between FD patients and healthy subjects in Mexico, with high sensitivity and specificity. These tests could be used as objective, noninvasive, and safe diagnostic approaches for FD patients.

[Utility of rabeprazole as a diagnostic test in non-erosive gastroesophageal reflux disease]. / Utilidad del rabeprazol como prueba diagnóstica en la enfermedad por reflujo gastroesofágico no erosiva.

BACKGROUND: Proton pump inhibitor test (PPIt) has been shown adequate diagnostic usefulness and cost-effectiveness in the evaluation of patients with gastroesophageal reflux disease (GERD). However, comparative studies of PPIt with 24 hr esophageal pH-metry (24-pH) in non erosive GERD (NERD) are scarce and the utility of rabeprazole as a PPIt has not been evaluated. OBJECTIVE: To investigate the diagnostic utility of rabeprazole test in patients with NERD. MATERIAL AND METHODS: An open label trial was performed, and NERD patients with heartburn at least 3 times per week were included. Symptomatic evaluation before, during and after rabeprazole 20 mg bid for 7 days was performed. All patients underwent 24-pH before treatment with rabeprazole. Patients were classified in three groups: 1) abnormal pH, 2) normal pH and symptom index (SI) positive, and 3) normal pH and SI negative. A positive rabrepazole test was considered when symptoms improvement was higher than 50% at the end of the test. Sensitivity, specificity, negative predictive value, positive predictive value and positive likelihood ratio were calculated considering the 24-pH as gold standard. RESULTS: Sixty four patients, 47 (72%) female were studied. Forty four percent of the patients had normal pH, 29% with SI positive and 71% with SI negative. Sensitivity, specificity, positive predictive value, negative predictive value and positive likelihood ratio were 82%, 47%, 78%, 52% and 1.406 respectively. No adverse events were reported. CONCLUSION: PPI test with rabeprazole 20 mg bid for 7 days is a simple and useful test in the diagnostic approach of patients with NERD.

[Usefulness of botulinum toxin in gastrointestinal disorders]. / Utilidad de la toxina botulínica en los trastornos gastrointestinales.

Botulinum toxin (Botox) produced by Clostridium botulinum is a potent neuromuscular blocker agent that inhibits acetylcholine release from presynaptic nerve endings. This effect was confirmed in the smooth muscle of the gastrointestinal tract and led to clinical trials investigating the efficacy of Botox for treatment of several gastrointestinal disorders. Multiple controlled studies have shown that Botox is effective in short-term management of achalasia. Botox reduces lower esophageal sphincter pressure, improves esophageal clearance, and alleviates symptoms in up to 70% of patients; however, its long-term efficacy decreases to 30% and repeated injections are often necessary. Botox is reserved for older patients and with high surgical risk. The main predictors of a good response are older age and presence of vigorous achalasia. Biliary or pancreatic sphincter of Oddi dysfunction (SOD) has been another indication for Botox administration. Transendoscopic injection of Botox in the papilla of Vater has shown relief of symptoms in more than 50% of cases of SOD. Furthermore, a Botox clinical response in this condition can predict a long-term benefit with endoscopic sphincterotomy. Botox decreases resting anal pressure, has healing rates of approximately 80% at six months after injection in patients with chronic anal fissure, and has a better outcome than topic nitroglycerine. Case reports have shown good results with Botox administration in treatment of diffuse esophageal spasm, anismus, oropharyngeal dysphagia, anterior rectocele, and secondary achalasia. Administration of botulinum toxin has a low rate of adverse reactions and complications.

[Post-infectious irritable bowel syndrome. A review based on current evidence]. / Síndrome de intestino irritable postinfeccioso. Una revisión basada en evidencias.

INTRODUCTION: Pathophysiology of irritable bowel syndrome (IBS) is multifactorial. Recent investigations have associated episodes of infectious gastroenteritis with development of IBS. This condition is named post-infectious IBS (PI-IBS). The role of inflammation-infection in IBS pathogenesis is not well understood. AIM: To review published scientific evidence on PI-IBS regarding risk factors, causal agents, histopathological changes, and treatment. MATERIALS AND METHODS: An electronic search in MEDLINE and abstracts presented at national and international GI meetings was performed, looking for information published in the past 50 years including animal studies, cohort studies, case-control studies, and series of cases and case reports, using the key words post-infectious enteritis, post-dysenteric or post-infectious irritable bowel syndrome (PI-IBS), and post-infectious colitis. RESULTS: Fifty one papers were included. These studies were classified according to pathophysiologic mechanisms, infectious agents involved, animal or human studies, and treatment. CONCLUSIONS: Current evidence shows a strong association between colonic infection and inflammation with development of IBS. Approximately 25% of patients with IBS have a history of infectious enteritis. Microbial agents related with PI-IBS include bacteria (Campylobacter, Salmonella) and parasites (Trichinella spiralis). Increased number of enteroendocrine cells, CD3 lymphocytes and mast cells within the colonic muscle wall, release of pro-inflammatory substances, and increased number of inflammatory cells with intestinal nervous endings are the most common histopathologic findings. Patients developing PI-IBS have a higher frequency of psychological disorders and stressful events prior to the gastroenteritis episode. Therapeutic interventions with steroids, COX-2 inhibitors, antibiotics and probiotics require further investigation.

[Diagnostic usefulness of the Carlsson-Dent questionnaire in gastroesophageal reflux disease (GERD)]. / Utilidad diagnóstica del cuestionario de Carlsson-Dent en la enfermedad por reflujo gastroesofágico (ERGE).

BACKGROUND: Diagnosis of GERD is based on presence of symptoms (heartburn) associated to abnormal esophageal acid exposure or esophageal erosions determined by 24-hr pH monitoring and/or endoscopy, respectively. Different instruments have been evaluated in order to diagnose GERD without invasive studies. Carlsson-Dent questionnaire (CDQ), validated among European patients, have shown good sensitivity and positive predictive values for detection of GERD. Diagnostic usefulness of the CDQ in Mexican patients is unknown. OBJECTIVE: To evaluate usefulness of CDQ among patients with erosive GERD (EG) and non-erosive GERD (NERD). PATIENTS AND METHODS: Consecutive patients with heartburn at least twice per week during the last three months and previous endoscopy were included. All patients answered a self-administered Spanish version of the CDQ, previously evaluated for its content validity and easy application. A score of > or = 4 was considered as positive for GERD. All patients underwent 24-hr pH esophageal monitoring to determine the presence of pathologic reflux (% time pH < 4, > 4.2), as well as the symptom index (SI). Questionnaire's sensitivity (S), specificity (E), positive and negative predictive values (PPV, NPV) were calculated using 24-hr pH monitoring and endoscopic oesophagitis as gold-standard tests. RESULTS: A total of 125 patients were evaluated, 81 women (65%) and 44 men (35%) with an age of 47.9 (21-83). Eighty-six patients (69%) had NERD and 39 (31%) EG. Among patients with NERD, 28 (32%) had abnormal pH study, 10 (12%) had normal pH study with positive SI (> 50%), and 48 (65%) had normal pH study with negative SI. Most common symptom was a burning feeling rising from the stomach or lower chest up towards the neck (classic definition of heartburn) in 53%, noncardiac chest pain in 14%, and nausea in 5%. In 44 patients (35%) the main discomfort occurred within 2 hours of taking food, and in 77% it worsed with larger meals and food rich in fat, as well as in 77% after taking spicy food. One hundred and seven patients (86%) scored > or = 4 on CDQ and there was no significantly difference between CDQ score among groups. CDQ's sensitivity compared to pH monitoring was 89%, and PPV 55%. When compared to endoscopic findings, sensitivity was 94% and PPV 90. There was strong and significative correlation between esophageal acid exposure and higher CDQ's scores. CONCLUSIONS: CDQ in Spanish is an useful instrument for detection of GERD, and its score correlates with the degree of esophageal acid exposure.

[Perception of symptoms with minimal reductions of esophageal pH in patients with erosive and non-erosive GERD]. / Percepción de síntomas con descensos mínimos en el pH esofágico en pacientes con ERGE erosiva y no erosiva.

BACKGROUND: Patients with gastrointestinal reflux disease GERD perceive < 5% of acid reflux episodes, independently of GERD type. The role of minimal changes on esophageal pH (1 or 2 units) on development of symptoms is unknown. OBJECTIVE: To evaluate symptom perception and its relationship with minimal changes on esophageal pH in patients with erosive and non-erosive GERD (NERD). PATIENTS AND METHODS: We evaluated consecutive patients with symptomatic GERD. All patients had endoscopy in the previous 8 weeks. All patients underwent 24-h esophageal pH-monitoring. Abnormal pH-metry was defined as % time of pH < 4 > 4.2. Symptom index (SI) was considered positive when > or = 50. We also calculated SI at pH 5 and pH 6. Patients with GERD were classified into three groups: 1) abnormal pH and negative SI. For statistical analysis, we used the test-Student, chi 2, and ANOVA test. P < 0.05 was considered statistically significant. RESULTS: We evaluated 120 patients, 79 (66%) females and 41 (34%) males with mean age of 47.8 years (range 21-83 years). Eighty three (69%) patients had NERD and 37 (31%), erosive esophagitis (EE). Seventy two patients (87%) with NERD and 36 (97%) with erosive GERD developed symptoms during the study. NERD patients had mean of 69 reflux episodes compared with 184 of patients with EE. Perception of reflux symptoms was significantly higher in the group with EE (3.4 vs. 1.02 p < 0.0001). Among patients with NERD, 33% had abnormal pH-metry and 67%, a normal test. Of these patients, nine (16%) had normal pH test and positive SI, and 47 (83%) normal pH test and negative SI. There was no difference in symptom perception among the three groups. Patients with NERD and abnormal pH had similar SI patients with EE; 4% of patients with normal pH and negative SI at pH 4 had positive SI when calculated at pH 5, and 68% when SI was calculated at pH 6. CONCLUSIONS: The majority of acid reflux episodes are not perceived and this phenomenon is independent of erosive or non-erosive GERD. Patients with erosive esophagitis had significantly higher esophageal acid exposure than patients with NERD. Minimal changes in esophageal pH (1 or 2 pH units) increases SI in patients with GERD, especially in those with normal esophageal acid exposure.

Early gastric cancer in Menetrier's disease.

Uncommon conditions such as pernicious anaemia and hypertrophic gastropathies have been considered as risk factors for gastric cancer; however, the exact increase in risk is unknown. Menetrier's disease is a rare hyperproliferative disorder of the stomach caused by an overexpression of tumour growth factor α, a ligand for the tyrokinase epidermal growth factor receptor, resulting in a selective expansion of surface mucous cells in the body and fundus of the stomach. There have been nearly 200 cases of Menetrier's disease reported in the literature yet less than 15 have been associated with gastric adenocarcinoma. Here, we report an early stage gastric adenocarcinoma detected incidentally in a patient recently diagnosed with Menetrier's disease.

Drinking capacity and severity of dyspeptic symptoms during a water load test after Nissen fundoplication.

Up to 30% of subjects undergoing Nissen fundoplication develop dyspeptic symptoms. Previous studies using the water load test have shown that functional dyspepsia patients have a diminished drinking capacity due to increased visceral sensitivity. Here we investigate drinking capacity and severity of symptoms in 9 patients with dyspeptic symptoms after fundoplication, 9 patients without symptoms after surgery, 18 functional dyspepsia patients, and 18 controls. The water load test was performed by having subjects drinking room-temperature tap water at a predetermined rate of 15 ml/min. The presence and severity of symptoms during the test were evaluated every 5 min using a Likert scale. We found that patients with dyspeptic symptoms after fundoplication had a significantly lower drinking capacity and higher symptoms scores than controls (P<0.05) but values similar to those of functional dyspepsia patients (P>0.05). In contrast, drinking capacity in patients without symptoms after surgery was similar to that in controls (P>0.05). These findings suggest that, as in functional dyspepsia, severe dyspeptic symptoms after Nissen fundoplication are associated with an impaired drinking capacity, reflecting visceral hypersensitivity or impaired gastric accommodation or both.

Nuevos conceptos en fisiopatología, diagnóstico y tratamiento de la acalasia / New concepts on the physiopathology, diagnosis and treatment of achalasia

Objetivos. Revisar las publicaciones más relevantes referentes a la fisiopatología, cuadro clínico, diagnóstico y tratamiento de la acalasia esofágica, asi como la experiencia desarrollada en nuestra institución y proponer una estrategia práctica para el tratamiento de estos pacientes. Fuente de datos. Búsqueda manual y en MEDLINE de artículos fundamentales de enero de 1986 a julio de 1997, así como publicaciones de nuestro instituto en los últimos treinta años. Selección de estudios. Se incluyeron las publicaciones que aportaron experiencia clínica substancial, conocimientos novedosos o establecieron nuevas líneas de investigación. Síntesis de datos. La acalasia es una enfermedad degenerativa del plexo mientérico del esófago. Los principales síntomas son disfagia, regurgitaciones y dolor toráxico. El diagnóstico debe establecerse mediante manometría, aunque la combinación de esofagograma, endoscopía y medición del tránsito esofágico con radioisótopos permiten detectar la enfermedad en etapas tempranas, establecer diagnósticos diferenciales y evaluar la respuesta al tratamiento. La farmacoterapia puede aliviar síntomas leves y es de utilidad en pacientes con alto riesgo quirúrgico. Las dilataciones y la miotomía constituyen tratamientos seguros y casi siempre permanentes. La toxina botulítica puede ser de utilidad en casos selectos. Recientemente se han descrito factores predictivos de respuesta para cada una de las modalidades terapéuticas. Conclusión. Es necesario sistematizar el abordaje terapéutico en los pacientes con acalasia. Nuevas opciones terapeuticas tales como la toxina botulínica y la cirugía de invasión mínima ofrecen otras alternativas de tratamiento. Los fármacos y la toxina botulínica son la primera elección en pacientes de alto riesgo. La dilatación neumática y la cirugía se indican en aquéllos que no presentan riesgo

Utilización de recursos médicos por los pacientes con síndrome de intestino irritable en un hospital de tercer nivel / Utilization of medical resources for patients with irritable bowel syndrome in a third level hospital

Antecedentes: El síndrome de intestino irritable (SII) es un trastorno que produce un alto costo a la sociedad en términos de ausentismo, consultas, exámenes médicos, tratamientos y cirugías innecesarias. Objetivo: Conocer la utilización de recursos médicos por pacientes con SII en un hospital de referencia. Método. Estudio retrospectivo de expedientes de pacientes con SII. Se analizó el número de estudios de laboratorio, gabinete y consultas médicas y número de cirugías abdominales. Resultados: Entre 1987-1996 se identificaron 98 pacientes con edad promedio 40.8 años. El seguimiento fue de 33.4 meses (rango: 1-243) durante los cuales se solicitaron en promedio 22.4 estudios por pacientes (rango: 1.82). Se requirieron 5.0 estudios por paciente (rango: 1-11) previos al diagnóstico de SII. En el 87 por ciento de los pacientes, el diagnóstico de SII se estableció durante la primera consulta. Cada paciente consultó 3.6 veces/año, 44.2 por ciento por síntomas gastrointestinales y 48.6 por ciento por síntomas no gastrointestinales. Las consultas con mayor demanda fueron medicina interna (53.0 por ciento), gastroenterología (38.8 por ciento), proctología (31.6 por ciento), psiquiatría (21.4 por ciento), ginecología (18.4 por ciento) urología (13.3 por ciento). El 17.3 por ciento tenía antecedentes de apendicectomías y 13.3 por ciento colecistectomías. El 1.02 por ciento y el 2.04 por ciento respectivamente fueron practicadas luego del diagnóstico de SII. Conclusiones: A pesar de los reconocidos criterios diagnósticos de Roma, se solicitan numerosos estudios de laboratorio y gabinete para descartar enfermedad orgánica a los pacientes con SII, y estos demandan un elevado promedio de consultas médicas anuales. Además, los pacientes con SII tienen una elevada tasa de apendicectomías y colecistectomías

Hepatitis viral: interpretación clínica de los antígenos y anticuerpos en el suero / Viral hepatitis: clinical interpretation of serum antigens and antibodies

Se hace una revisión de los aspectos clínicos y bioquímicos de la hepatitis viral, con énfasis en las características biológicas y epidemiológicas de los virus A, B, no A - no B (NANB) y Delta, así como de los eventos serológicos que ocurren durante la infección con estos agentes virales. Se presenta también la secuencia de aparición y comportamiento de los diversos antígenos y anticuerpos, las técnicas de laboratorio para detectarlos y su significado clínico. Finalmente, se propone una guía para el estudio y seguimiento serológico de los pacientes con hepatitis viral aguda