Drug-induced gallbladder disease. Incidence, aetiology and management

[New Progress in Longitudinal Research on the Risk Factors for Cholelithiasis]

Cholelithiasis is a common disease of the digestive system. The risk factors for cholelithiasis have been reported and summarized many times in the published literature, which primarily focused on cross-sectional studies. Due to the inherent limitations of the study design, the reported findings still need to be validated in additional longitudinal studies. Moreover, a number of new risk factors for cholelithiasis have been identified in recent years, such as bariatric surgery, hepatitis B virus infection, hepatitis C virus infection, kidney stones, colectomy, osteoporosis, etc. These new findings have not yet been included in published reviews. Herein, we reviewed the 101 cholelithiasis-associated risk factors identified through research based on longitudinal investigations, including cohort studies, randomized controlled trials, and nested case control studies. The risk factors associated with the pathogenesis of cholelithiasis were categorized as unmodifiable and modifiable factors. The unmodifiable factors consist of age, sex, race, and family history, while the modifiable factors include 37 biological environmental factors, 25 socioenvironmental factors, and 35 physiochemical environmental factors. This study provides thorough and comprehensive ideas for research concerning the pathogenesis of cholelithiasis, supplying the basis for identifying high-risk groups and formulating relevant prevention strategies.

Low skeletal muscle mass and high visceral adiposity are associated with recurrence of acute cholecystitis after conservative management: A propensity score-matched cohort study

BACKGROUND

Recurrent acute cholecystitis (RAC) can occur after non-surgical treatment for acute cholecystitis (AC), and can be more severe in comparison to the first episode of AC. Low skeletal muscle mass or adiposity have various effects in several diseases. We aimed to clarify the relationship between RAC and body parameters.

METHODS

Patients with AC who were treated at our hospital between January 2011 and March 2022 were enrolled. The psoas muscle mass and adipose tissue area at the third lumbar level were measured using computed tomography at the first episode of AC. The areas were divided by height to obtain the psoas muscle mass index (PMI) and subcutaneous/visceral adipose tissue index (SATI/VATI). According to median VATI, SATI and PMI values by sex, patients were divided into the high and low PMI groups. We performed propensity score matching to eliminate the baseline differences between the high PMI and low PMI groups and analyzed the cumulative incidence and predictors of RAC.

RESULTS

The entire cohort was divided into the high PMI (n = 81) and low PMI (n = 80) groups. In the propensity score-matched cohort there were 57 patients in each group. In Kaplan-Meier analysis, the low PMI group and the high VATI group had a significantly higher cumulative incidence of RAC than their counterparts (log-rank P = 0.001 and 0.015, respectively). In a multivariate Cox regression analysis, the hazard ratios of low PMI and low VATI for RAC were 5.250 (95% confidence interval 1.083-25.450, P = 0.039) and 0.158 (95% confidence interval: 0.026-0.937, P = 0.042), respectively.

CONCLUSIONS

Low skeletal muscle mass and high visceral adiposity were independent risk factors for RAC.

Prevalence of Symptomatic Gallbladder Disease After Bariatric Surgery: A Literature Review

Introduction Gallbladder disease (GBD) encompasses several medical conditions, including gallbladder stone formation, biliary colic, and cholecystitis. These conditions may arise following bariatric surgery, including bypass or laparoscopic sleeve gastrectomy (LSG). The development of GBD after surgery may be attributed to various factors, including the formation of stones shortly after the procedure, the exacerbation of existing stones due to the surgery, or inflammation of the gallbladder. Rapid weight loss after surgery has also been proposed as a contributing factor. Methodology This observational study consisted of a review of retrospective hospital patient medical records of 350 adult participants who underwent LSG, with 177 participants included in the study after excluding those with cholecystectomy or GBD prior to surgery. The participants were followed for a median of two years, during which we recorded any hospitalizations, emergency department visits, clinic visits, and incidents of cholecystectomy or abdominal pain due to GBD. The participants were grouped into two: those with GBD and those without GBD after bariatric surgery, and quantitative data were summarized using mean and standard deviations. The data were analyzed using IBM SPSS Statistics for Windows, Version 20.0. (IBM Corp. Released 2020. IBM SPSS Statistics for Windows, Version 27.0. Armonk, NY: IBM Corp), with a statistical significance of P<0.05. Results In our retrospective study of 177 patients who underwent LSG, the incidence of GBD after bariatric surgery was 4.5%. Most patients with GBD after bariatric surgery were White, but this difference was not statistically significant. Patients with type 2 diabetes had a higher incidence of GBD after bariatric surgery than those without diabetes (8.3% vs. 3.6%, P=0.355). Patients with HTN had a lower incidence of GBD after bariatric surgery than those without HTN (1.1% vs. 8.2%, P=0.032). Anti-hyperglycemia medication use did not significantly increase the risk of GBD after bariatric surgery (7.5% vs. 3.8%, P=0.389). None of the patients on weight loss medication developed GBD after bariatric surgery, compared to 5% of patients who did not take weight loss medication. Our sub-data analysis showed that patients who developed GBD after bariatric surgery had a high BMI (above 40 kg/m2) before surgery, which decreased to 35 kg/m2 and below 30 kg/m2 at six months and 12 months post-surgery, respectively. Conclusions Our findings demonstrate that the prevalence of GBD after LSG is low and comparable to the general population without LSG. Thus, LSG does not increase the risk of GBD. We found that rapid weight loss after LSG is a significant risk factor for GBD. These findings suggest that patients who undergo LSG should be informed of the risks of GBD and undergo careful screening before surgery to detect any pre-existing gallbladder issues. Overall, our study highlights the importance of continued research into the factors associated with GBD after bariatric surgery and the need for standardized prophylactic measures to prevent this potentially serious complication.

Demographic, Chemical, and Helicobacter pylori Positivity Assessment in Different Types of Gallstones and the Bile in a Random Sample of Cholecystectomied Iranian Patients with Cholelithiasis

BACKGROUND

The occurrence of stones in the gallbladder or common bile duct and the symptoms and complications they cause is called gallstone disease. The symptoms of gallstone disease range from mild, nonspecific symptoms to a severe right quadrant abdominal pain. Characteristics of gallstone types in an Iranian population have not been well studied before and there are very limited studies on the demographic pattern of stone types in our country, so this study is one of the first studies on its kind on the epidemiology of gallstone types in Iran. As information on chemical components of the stone will help in the management and prevention of gallstones, in this study, we aimed to do chemical component analysis of gallstones including cholesterol, bilirubin, and calcium. Given the conflicting reports about the relationship between H. pylori infections and gallstone formation, this study aimed to investigate the relationship between H. pylori positivity in the bile specimen of Iranian patients with cholelithiasis and formation and type of stone.

METHODS

This prospective study reviewed a total of 196 patients who underwent cholecystectomy for symptomatic cholelithiasis at Shahid Beheshti Training and Research Hospital affiliated to the Yasuj University of Medical Sciences between September 2015 and May 2018. Chemical analysis of gallstone components performed using the colorimetry method. Microbiological analysis for H. pylori was done using the OnSite H. pylori Ag Rapid Test on the bile sample. For the validation test of bile, the H. pylori Rapid Stool Ag Test on stool was used, and Cohen's Kappa statistical analysis was done next.

RESULTS

There were significant associations between the stone types and age, chemical composition of the stones such as calcium, cholesterol, and bilirubin levels, and also H. pylori positivity and cholesterol and bilirubin levels; however, no significant association was found between the stone types and sex, H. pylori positivity and age, sex, stone types, and calcium level. The main bile and validity tests were matched to the substantial agreement according to Cohen's Kappa analysis. The most common drugs used were proton pump inhibitors, nonsteroidal anti-inflammatory drugs, antihypertensive drugs, and oral contraceptives.

CONCLUSIONS

This study suggested that the chemical composition of the stones could predict the presence of bacteria, there is no correlation between H. pylori and gallstone formation, and some of the drugs could be predisposing factors for gallstones. This work provides an objective basis for further research into gallbladder stone formation; meanwhile, it has great significance in the treatment and prevention of gallbladder stones. Trial registration. The project was found to be in accordance to the ethical principles and the national norms and standards for conducting research in Iran with the approval ID IR.YUMS.REC.1399.147 and date 2020.09.23, and this project is the result of a residency dissertation to obtain the specialty in general surgery, which has been registered with the research project number 960159 in the Vice Chancellor for Research and Technology Development of the Yasuj University of Medical Sciences, Yasuj, Iran, URL: https://ethics.research.ac.ir/EthicsProposalViewEn.php?id=160634.

Acute Cholecystitis Following Allogeneic Hematopoietic Stem Cell Transplantation: Clinical Features, Outcomes, Risk Factors, and Prediction Model

Acute cholecystitis (AC) is a potentially fatal complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT); however, only limited information is available on its clinical features, outcomes, and risk management strategies. This retrospective, nested, case-control study included 6701 patients undergoing allo-HSCT at our center from January 2004 to June 2019. In total, 72 patients (1.1%) were diagnosed with AC; among these, acute acalculous cholecystitis had a slightly higher prevalence (42 patients, 58.3%). Patients with moderate and severe AC exhibited remarkably worse overall survival (P = .001) and non-relapse mortality (P = .011) than others. Survival of haploidentical HSCT recipients with AC was comparable to that for patients with human leukocyte antigen (HLA)-identical donors. Age ≥ 18 years, antecedent stage II to IV acute graft-versus-host disease, and total parenteral nutrition were identified as potential risk factors for AC following allo-HSCT, while haploidentical transplantations were not more susceptible to AC than HLA-identical HSCT. Based on these criteria, a risk score model was developed and validated to estimate the probability of AC following allo-HSCT. The model separates all patients into low-, intermediate-, and high-risk groups and thereby provides a basis for early detection of this complication in the management of allo-HSCT.

The Cumulative Risk Assessment of Hepatotoxic Chemicals: A Hepatic Histopathology Perspective

The increased concern on the consequence of exposure to multiple chemical combinations has led national regulatory authorities to develop different concepts to conduct risk assessments on chemical mixtures. Pesticide residues were identified as "problem formulation" in the respective European regulations and in this context, the European Food and Safety Authority has suggested to group pesticidal active ingredients (AIs) into cumulative assessment groups (CAGs) based on the toxicological properties of each AI. One proposed CAG, on the liver, currently consists of 15 subgroups, each representing a specific hepatotoxic effect observed in toxicity studies. Dietary cumulative risk assessments would then have to be conducted assuming dose additivity of all members of each CAG subgroup. The purpose of this publication is to group AIs based upon the knowledge of the pathogenesis of liver effects to discriminate between primary end points (direct consequence of chemical interaction with a biological target) and secondary end points (which are a consequence of, or that arise out of, a previous pathological change). Focusing on the relevant primary end points strengthens and simplifies the selection of compounds for cumulative risk assessment regarding the liver and better rationalizes the basis for chemical grouping. Relevant dose additivity is to be expected at the level of the primary/leading pathological end points and not at the level of the secondary end points. We recognize, however, that special consideration is needed for substances provoking neoplasia, and this category is included in the group of primary end points for which chemicals inducing them are grouped for risk assessment. Using the pathological basis for defining the respective CAGs, 6 liver subgroups and 2 gallbladder/bile duct groups are proposed. This approach simplifies the cumulative assessment calculation without obviously affecting consumer safety.

Clinical characteristics of patients with newly developed acute cholecystitis after admission to the intensive care unit

INTRODUCTION

Critical care patients have many risk factors for acute cholecystitis (AC). However, less data are available regarding newly developed AC in critically ill patients.

OBJECTIVES

To investigate the clinical features of AC occurring in critically ill patients after admission to an intensive care unit (ICU).

METHODS

We performed a retrospective cohort study from January 2006 to August 2016 at a tertiary care university hospital. We included patients diagnosed with AC with or without gallstones after ICU admission. All cases of AC were confirmed by gastroenterologists or general surgeons. We excluded patients with AC diagnosed before or at the time of ICU admission.

RESULTS

A total of 38 patients were diagnosed with AC after ICU admission between January 2006 and August 2016. Seventeen (44.7%) had acute acalculous cholecystitis, while 21 (55.3%) had acute calculous cholecystitis. The median age was 73 years (interquartile range = 63-81 years), and 22 (57.9%) patients were male. The most common reason for ICU admission was pneumonia or sepsis. The median interval from ICU admission to diagnosis of AC was 11 days (interquartile range = 4.8-22.8 days). Before AC diagnosis, almost 90% of patients used total parenteral nutrition, 68% used opioids, 76% were mechanically ventilated, and 42% received vasoactive drugs. More than half of patients underwent cholecystectomy, and all surgically resected gallbladders had pathology results for cholecystitis. Gangrenous cholecystitis was observed in five patients with acute calculous cholecystitis. The overall mortality was 42.1%, and 1/3 of these deaths were directly associated with AC. The average length of stay in the ICU and hospital was 26.5 and 44.5 days, respectively.

CONCLUSION

The development of AC in the ICU should be carefully monitored, especially in patients who have been infected and admitted to the ICU for more than 10 days. Proper diagnosis and treatment at a critical time could be lifesaving.

Daclatasvir and Asunaprevir Combination Therapy-induced Hepatitis and Cholecystitis with Coagulation Disorder due to Hypersensitivity Reactions

A 70-year-old woman with chronic hepatitis C was admitted to our hospital due to liver injury, cholecystitis, and disseminated intravascular coagulation with a fever and skin rash. She had been on a combination regimen of daclatasvir and asunaprevir for 2 weeks of a 24-week regimen. Because of the symptoms, laboratory findings, results of a drug-induced lymphocyte stimulation test, and pathological findings of liver biopsy, we diagnosed her with drug-induced liver injury. Although daclatasvir and asunaprevir combination therapy is generally well-tolerated, some serious adverse effects have been reported. Our findings indicate that immunoallergic mechanisms were associated with daclatasvir and asunaprevir-induced liver injury.

Review of the impact of antineoplastic therapies on the risk for cholelithiasis and acute cholecystitis

BACKGROUND

Development of cholecystitis in patients with malignancies can potentially disrupt their treatment and alter prognosis. This review aims to identify antineoplastic interventions associated with increased risk of cholecystitis in cancer patients.

METHODS

A comprehensive search strategy was developed to identify articles pertaining to risk factors and complications of cholecystitis in cancer patients. FDA-issued labels of novel antineoplastic drugs released after 2010 were hand-searched to identify more therapies associated with cholecystitis in nonpublished studies.

RESULTS

Of an initial 2,932 articles, 124 were reviewed in the study. Postgastrectomy patients have a high (5-30 %) incidence of gallstone disease, and 1-7 % develop symptomatic disease. One randomized trial addressing the role of cholecystectomy concurrent with gastrectomy is currently underway. Among other risk groups, patients with neuroendocrine tumors treated with somatostatin analogs have a 15 % risk of cholelithiasis, and most are symptomatic. Hepatic artery based therapies carry a risk of cholecystitis (0.02-24 %), although the risk is reduced with selective catheterization. Myelosuppression related to chemotherapeutic agents (0.4 %), bone marrow transplantation, and treatment with novel multikinase inhibitors are associated with high risk of cholecystitis.

CONCLUSIONS

There are several risk factors for gallbladder-related surgical emergencies in patients with advanced malignancies. Incidental cholecystectomy at index operation should be considered in patients planned for gastrectomy, and candidates for regional therapies to the liver or somatostatin analogs. While prophylactic cholecystectomy is currently recommended for patients with cholelithiasis receiving myeloablative therapy, this strategy may have value in patients treated with multikinase inhibitors, immunotherapy, and oncolytic viral therapy based on evolving evidence.

TG13 current terminology, etiology, and epidemiology of acute cholangitis and cholecystitis

While referring to the evidence adopted in the Tokyo Guidelines 2007 (TG07) as well as subsequently obtained evidence, further discussion took place on terminology, etiology, and epidemiological data. In particular, new findings have accumulated on the occurrence of symptoms in patients with gallstones, frequency of severe cholecystitis and cholangitis, onset of cholecystitis and cholangitis after endoscopic retrograde cholangiopancreatography and medications, mortality rate, and recurrence rate. The primary etiology of acute cholangitis/cholecystitis is the presence of stones. Next to stones, the most significant etiology of acute cholangitis is benign/malignant stenosis of the biliary tract. On the other hand, there is another type of acute cholecystitis, acute acalculous cholecystitis, in which stones are not involved as causative factors. Risk factors for acute acalculous cholecystitis include surgery, trauma, burn, and parenteral nutrition. After 2000, the mortality rate of acute cholangitis has been about 10 %, while that of acute cholecystitis has generally been less than 1 %. After the publication of TG07, diagnostic criteria and severity assessment criteria were standardized, and the distribution of cases according to severity and comparison of clinical data among target populations have become more subjective. The concept of healthcare-associated infections is important in the current treatment of infection. The treatment of acute cholangitis and cholecystitis substantially differs from that of community-acquired infections. Cholangitis and cholecystitis as healthcare-associated infections are clearly described in the updated Tokyo Guidelines (TG13). Free full-text articles and a mobile application of TG13 are available via http://www.jshbps.jp/en/guideline/tg13.html.

Ceftriaxone associated nephrolithiasis: a prospective study in 284 children

Urinary tract calculi have been reported to account for between 1 in 1,000 and 1 in 7,600 hospital admissions in children in the USA. The annual incidence of urolithiasis in patients older than 10 years is 109 per 100,000 of the population in men and 36 per 100,000 of the population in women in Minnesota. The use of various medications is considered to be one of the etiologic factors of nephrolithiasis. Ceftriaxone is a widely used third-generation cephalosporin that is generally considered very safe, but complications such as biliary pseudolithiasis, and rarely, nephrolithiasis have been reported in children. There is limited information about urolithiasis as a side effect of ceftriaxone. The aim of this study was evaluation of the incidence of nephrolithiasis following ceftriaxone therapy in children. This quasi-experimental before and after study was conducted in Mofid Children's Hospital between 2003 and 2005. All patients were treated with 75 mg/kg intravenous ceftriaxone. Diagnosis of pyelonephritis was based on standard criteria. The first renal ultrasonography was performed on the first or second day of admission and was repeated on the last day of treatment. We also evaluated complicated patients for the third time with renal ultrasonography 3 months after treatment. Stone-forming patients underwent metabolic kidney stone risk factor evaluation. We evaluated 284 patients with pyelonephritis, 185 girls and 99 boys. The first ultrasonography was normal in all of our patients. On the second ultrasonography renal stones were reported in 4 out of 284 cases (1.4% and CI=0.96-1.83%). Underlying metabolic risk factors could not be identified in stone-forming patients. Follow-up ultrasonography 3 months later was normal. The results of our study suggest that ceftriaxone-treated patients may be at an increased risk of kidney stone formation. Stones passed spontaneously in all affected patients so the use of this effective drug can be safely continued. Close monitoring of ceftriaxone-treated patients with regard to kidney stone formation is recommended.

Definitions, pathophysiology, and epidemiology of acute cholangitis and cholecystitis: Tokyo Guidelines

This article discusses the definitions, pathophysiology, and epidemiology of acute cholangitis and cholecystitis. Acute cholangitis and cholecystitis mostly originate from stones in the bile ducts and gallbladder. Acute cholecystitis also has other causes, such as ischemia; chemicals that enter biliary secretions; motility disorders associated with drugs; infections with microorganisms, protozoa, and parasites; collagen disease; and allergic reactions. Acute acalculous cholecystitis is associated with a recent operation, trauma, burns, multisystem organ failure, and parenteral nutrition. Factors associated with the onset of cholelithiasis include obesity, age, and drugs such as oral contraceptives. The reported mortality of less than 10% for acute cholecystitis gives an impression that it is not a fatal disease, except for the elderly and/or patients with acalculous disease. However, there are reports of high mortality for cholangitis, although the mortality differs greatly depending on the year of the report and the severity of the disease. Even reports published in and after the 1980s indicate high mortality, ranging from 10% to 30% in the patients, with multiorgan failure as a major cause of death. Because many of the reports on acute cholecystitis and cholangitis use different standards, comparisons are difficult. Variations in treatment and risk factors influencing the mortality rates indicate the necessity for standardized diagnostic, treatment, and severity assessment criteria.

Biliary sludge and hyperbilirubinemia associated with ceftriaxone in an adult: case report and review of the literature

Ceftriaxone is a commonly used third-generation cephalosporin that has antimicrobial activity against many gram-positive and gram-negative organisms. Generally, ceftriaxone is a safe antibiotic; however, symptomatic biliary sludge has been reported in rare instances, most of which have involved children. It is uncommon for ceftriaxone to cause increases in laboratory indexes, such as bilirubin levels. We describe the case of a 53-year-old man who was treated with intravenous ceftriaxone 2 g every 12 hours. After 7 days of therapy, the patient's liver function test results, including total, direct, and indirect bilirubin levels, increased significantly from baseline, and the patient became jaundiced. A right upper quadrant ultrasound examination revealed biliary sludge and cholelithiasis without sonographic evidence of cholecystitis. Ceftriaxone was thought to be the responsible agent, and it was discontinued. The patient's jaundice subsided, and his liver function test results improved, returning to baseline within 14 days. Clinicians need to be aware of the association of ceftriaxone and biliary pseudolithiasis and hyperbilirubinemia, and monitor accordingly.

Schmerzloser Ikterus nach Urlaub in Tansania

The side effects caused by malaria prophylaxis with mefloquine (Lariam) are well known. We describe the case of a 42-year-old female Caucasian patient suffering from painless jaundice and showing elevated liver, cholestasis and inflammation laboratory findings 7 days after returning from Tanzania. Acute cholecystitis was diagnosed by ultrasound. Treatment with parenteral nutrition and antibiotic therapy did not show any beneficial effect. Excluding the possibility of infectious diseases, the elevated laboratory and ultrasound findings were normalized after the discontinuation of the malaria prophylaxis.

Identification of biliary metabolites of ifosfamide using 31P magnetic resonance spectroscopy and mass spectrometry

Biliary excretion is a significant component in the metabolism of many drugs, but remains difficult to detect and characterise non-invasively. A previous publication recently described the detection of metabolites of ifosfamide in gall bladder in a guinea pig model using in vivo 1H-decoupled 31P 3-D magnetic resonance spectroscopic imaging and a clinical 1.5 T MR scanner.. Here high-resolution 31P magnetic resonance spectroscopy (MRS) of extracted bile identifies peaks as parent ifosfamide (1.19+/-1.47 mM; mean+/-sd), carboxyifosfamide (2.04+/-1.04 mM) and a major contribution from a previously unreported peak at 16.0 ppm (4.05+/-2.38 mM). The unknown resonance was identified using liquid chromatography-mass spectrometry (LCMS) as the glutathione conjugate of ifosfamide (MW=531). This was confirmed by analysing products from the reaction of glutathione with ifosfamide using LCMS and MRS. These results demonstrate how combined in vivo and analytical MRS, together with mass spectrometry, can help identify visceral routes of drug metabolism, thereby aiding understanding of +/-drug disposition and mechanisms of action and toxicity. In particular, the distribution of ifosfamide and its metabolites into bile may be related to oxazophosphorine-related cholecystitis reported in patients.

Ultrasonographic findings in ceftriaxone: associated biliary sludge and pseudolithiasis in children

PURPOSE

To prospectively evaluate the incidence of biliary sludge and pseudolithiasis in children treated with ceftriaxone.

MATERIAL AND METHODS

Thirty-three children (14 girls, 19 boys) treated with ceftriaxone for prophylaxis (n=13) or for an infection (n=20) were included in this study. The incidences of biliary sludge and pseudolithiasis were investigated using ultrasonography. The ultrasonographic evaluations were performed prior to and on the 4th-5th days and on the 8th-10th days of treatment. The patients who had biliary sludge or pseudolithiasis were followed up with ultrasonographic evaluation periodically until these pathological phenomena disappeared.

RESULTS

Ceftriaxone was administrated intravenously at a dosage of 100 mg kg(-1) day(-1). Serial gallbladder sonograms were performed before treatment and on the 4th-5th and 8th-10th days of therapy. Nineteen children developed pseudolithiasis and sludge in the gallbladder, and all were asymptomatic. No significant differences were found between the patients with normal versus abnormal sonographic findings in regard to gender, age, duration of the therapy, oral restriction except the presence of surgery (P< 0.005).

CONCLUSION

The combination of oral restriction and surgical procedures may be a causal factor in ceftriaxone-associated biliary pseudolithiasis. It is emphasized that when gallstone and/or sludge are detected in the gallbladder in children by ultrasonographic examination, the administration of ceftriaxone must be sought beyond other causative factors.

Myocardial infarction and acute cholecystitis: an application of sequence symmetry analysis

Using a statewide hospital discharge database and a novel epidemiology method, sequence symmetry analysis (Epidemiology. 1996;7:478-84), I examined the relative risk for hospital admission for acute cholecystitis after admission for myocardial infarction. In sequence symmetry analysis, the ratio of the number of subjects in a fixed population who experienced two events in a "causal" vs "noncausal" temporal sequence estimates the incidence rate ratio (IRR). Of 514 patients admitted for both myocardial infarction and acute cholecystitis during a 3-year window period, 295 were admitted for myocardial infarction first and 219 for acute cholecystitis first, yielding a null sequence-adjusted IRR of 1.45 [95% confidence interval (CI) = 1.28-1.64]. A similar analysis for a known relation (myocardial infarction-->congestive heart failure, N = 27,850) showed the expected association [adjusted IRR = 1.92 (95% CI = 1.88-1.95)], whereas an analysis for a relation hypothesized not to be strong (congestive heart failure-->acute cholecystitis, N = 775) showed only a small association [adjusted IRR = 1.16 (95% CI = 1.05-1.28)]. Subgroup analysis revealed time courses that supported each relation as causal. Hospitalization for myocardial infarction may increase the risk for subsequent hospitalization for acute cholecystitis.

Update on the management of intestinal cryptosporidiosis in AIDS

OBJECTIVE

To update readers on the pharmacotherapeutic management of cryptosporidiosis in patients with AIDS.

DATA SOURCES

A MEDLINE search was used to identify pertinent literature. Additionally, programs and abstracts from the 33rd Interscience Conference on Antimicrobial Agents and Chemotherapy; the 1st International Conference on Macrolides, Azalides, and Streptogramins; the 93rd American Society for Microbiology Meeting; and the 6th and 7th International Conferences on AIDS were used.

DATA EXTRACTION

Available data from in vitro, animal, and human experiments were reviewed.

DATA SYNTHESIS

Intestinal cryptosporidiosis in patients with AIDS can be a life-threatening opportunistic infection. However, there can be significant variability in disease expression, including spontaneous remission. Supportive care with hydration and nutritional supplementation remains a hallmark of therapy. Unfortunately, there is no proven specific pharmacotherapy of cryptosporidiosis in patients with AIDS. Numerous agents have been analyzed for in vitro activity and efficacy in experimental animal models and actual human cases of the infection, including paromomycin, azithromycin, clarithromycin, octreotide, hyperimmune bovine colostrum, bovine transfer factor, and many others. Because limited numbers of controlled trials have been conducted with potential therapeutic agents, the majority of the information to date is preliminary in nature.

CONCLUSIONS

Despite the availability of some evolving and potentially promising treatment modalities, further controlled clinical trials are necessary to evaluate the role of pharmacotherapy for intestinal cryptosporidiosis in patients with AIDS.