Vascular Injury Characterizes Doxycycline-induced Upper Gastrointestinal Tract Mucosal Injury

Drug-induced digestive tract injury: decoding some invisible offenders

There is an ever-growing list of pharmacological agents, several of which are attributed to cause clinically significant gastrointestinal (GI) injury. Many patients present with significant but nonspecific symptoms, that in conjunction with the absence of relevant drug history on the requisition slip can make the histopathologic diagnosis challenging. To complicate this, although some drugs have relatively characteristic histopathologic features (such as doxycycline), there exist many other drugs that exhibit wide and varying spectra of histopathologic findings (such as immune checkpoint inhibitors or olmesartan) and have histomorphologic overlap with many other commonly encountered disease entities. This review discusses the histopathologic features of some relatively recently described drugs causing GI tract injury, namely doxycycline, tacrolimus, mycophenolate, immune checkpoint inhibitors, and olmesartan. We also discuss the common mimics in histopathologic differential and some pearls that can help distinguish GI tract injury induced by the aforementioned drugs from its mimics. Awareness of the wide spectra of histopathologic changes associated with these drugs is crucial for practicing pathologists, to avoid misdiagnosis and guiding the clinician for an optimal patient management, which usually involves modifying or discontinuing the offending drug. Needless to say, once a diagnosis of drug-induced injury is suspected, clinicopathologic correlation including corroboration with the drug history is of utmost importance as is the exclusion of dual pathology in these patients.

Biopsy Confirmed Doxycycline Induced Gastric Mucosal Injury

Doxycycline (DOX) is a tetracycline antibiotic that is prescribed for treating a variety of infections involving the skin, respiratory tract, and urogenital system. Adversely, esophageal mucosal injury due to DOX is well described; however, gastric mucosal injury is less commonly reported and may result in severe gastrointestinal hemorrhage and occasionally, perforation. In most reported cases of DOX-induced gastric lesions, patients are symptomatic upon presentation leading to endoscopic evaluation and diagnosis with biopsy. However, severe gastric insults may go unrecognized in rare cases of asymptomatic patients, increasing the risk of mortality.

Isolated Compartment Syndrome of the Hand After Intravenous Doxycycline Infiltration Injury

Isolated compartment syndrome of the hand, although uncommon, can lead to considerable functional deficits if not treated promptly. The most common etiologies are related to trauma, burns, or electric injuries; however, some cases have been reported after intravenous infiltration events, particularly rapid intravenous contrast injection. In this case report, we describe the development of compartment syndrome in the hand of a critically ill patient with COVID-19 pneumonia and sepsis 16 days after doxycycline infiltration injury. She presented with worsening pain, swelling, bullous eruption, and intrinsic minus hand posturing. Emergent surgical release of intrinsic hand compartments and evacuation of a hematoma resolved her symptoms and preserved hand function. Early recognition and surgical intervention of compartment syndrome of the hand after infiltration injury in medically complex patients will reduce morbidity in this patient population.

Data mining for detecting signals of adverse drug reaction of doxycycline using the Korea adverse event reporting system database

BACKGROUND

Doxycycline is one of the most prescribed antibiotics by dermatologists. However, the concern regarding adverse events of doxycyline has been rising.

OBJECTIVE

To detect the adverse events of doxycycline using the Korea Adverse Events Reporting System (KAERS) database from January 2014 to December 2018 through a data mining method.

METHODS

A signal was defined as one satisfying all three indices; a proportional reporting ratio, a reporting odds ratio, and an information component. We further checked whether the detected signals exist in drug labels in Korea and five developed countries, the United States, the United Kingdom, Germany, Canada, and Japan.

RESULTS

A total of 3,365,186 adverse event-drug pairs were reported and of which 3,075 were associated with doxycycline. Among the thirty-seven signals, nineteen (malaise, ileus, confusion, malignant neoplasm, ectopic pregnancy, ovarian hyperstimulation, vaginal hemorrhage, bone necrosis, acne, rosacea, seborrheic dermatitis, folliculitis, skin ulceration, crusting, dry skin, paronychia, mottled skin, application site reaction, and application site edema) were not included on any of the drug labels of the six countries.

CONCLUSION

We identified nineteen new doxycycline signals that did not appear on drug labels in six countries. Further studies are warranted to evaluate the causality of the adverse events with doxycycline.

Beyond Helicobacter: dealing with other variants of gastritis-an algorithmic approach

In daily practice, the presence of inflammation in gastric biopsies prompts a mental algorithm, an early question being whether the lesion present is Helicobacter-associated. If Helicobacter organisms are not found, then there is a further algorithm, governed by the predominant type of inflammatory cells present, and the presence of other features such as intraepithelial lymphocytosis, a subepithelial collagen band, granulomas, coexisting chronic inflammation, focality, and superimposed reactive changes including erosions and ulcers. Each of these generates its own differential diagnosis. If no inflammation is present, then the two major changes specifically looked for are the changes associated with hypergastrinaemia, by far the most common cause of which is treatment with proton pump inhibitors, and reactive changes. These may be present with and without accompanying inflammation, and, when the epithelial changes dominate, the term gastropathy is preferred. In this article, we present an approach to non-Helicobacter inflammation and gastropathies.

Temporal Control of the Helicobacter pylori Cag Type IV Secretion System in a Mongolian Gerbil Model of Gastric Carcinogenesis

The Helicobacter pylori Cag type IV secretion system (T4SS) translocates the effector protein CagA and nonprotein bacterial constituents into host cells. In this study, we infected Mongolian gerbils with an H. pylori strain in which expression of the cagUT operon (required for Cag T4SS activity) is controlled by a TetR/tetO system. Transcript levels of cagU were significantly higher in gastric tissue from H. pylori-infected animals receiving doxycycline-containing chow (to derepress Cag T4SS activity) than in tissue from infected control animals receiving drug-free chow. At 3 months postinfection, infected animals receiving doxycycline had significantly increased gastric inflammation compared to infected control animals. Dysplasia (a premalignant histologic lesion) and/or invasive gastric adenocarcinoma were detected only in infected gerbils receiving doxycycline, not in infected control animals. We then conducted experiments in which Cag T4SS activity was derepressed during defined stages of infection. Continuous Cag T4SS activity throughout a 3-month time period resulted in higher rates of dysplasia and/or gastric cancer than observed when Cag T4SS activity was limited to early or late stages of infection. Cag T4SS activity for the initial 6 weeks of infection was sufficient for the development of gastric inflammation at the 3-month time point, with gastric cancer detected in a small proportion of animals. These experimental results, together with previous studies of cag mutant strains, provide strong evidence that Cag T4SS activity contributes to gastric carcinogenesis and help to define the stages of H. pylori infection during which Cag T4SS activity causes gastric alterations relevant for cancer pathogenesis.IMPORTANCE The "hit-and-run model" of carcinogenesis proposes that an infectious agent triggers carcinogenesis during initial stages of infection and that the ongoing presence of the infectious agent is not required for development of cancer. H. pylori infection and actions of CagA (an effector protein designated a bacterial oncoprotein, secreted by the Cag T4SS) are proposed to constitute a paradigm for hit-and-run carcinogenesis. In this study, we report the development of methods for controlling H. pylori Cag T4SS activity in vivo and demonstrate that Cag T4SS activity contributes to gastric carcinogenesis. We also show that Cag T4SS activity during an early stage of infection is sufficient to initiate a cascade of cellular alterations leading to gastric inflammation and gastric cancer at later time points.

Modified-release oral pellets for duodenum delivery of doxycycline hyclate

To minimize the gastric and esophageal injury effect, a system to deliver doxycycline hyclate (DOXY) to the duodenum area is needed. DOXY-containing modified-release oral pellets (DMOP) coated with hydroxypropyl methylcellulose phthalate HP-55 (HPMCP HP-55) and hydroxypropyl methylcellulose E15 (HPMC E15) appear to be a reasonable choice. This coating layer dissolves at pH 5.5, which is the pH of the duodenum, but not at a gastric pH (1.2). The formulation and preparation of DMOP were optimized, and a scale-up test was performed. The results showed that the production reproducibility was acceptable, and the quality of DMOP well met the standards of Chinese Pharmacopeia (Ch.P, 2015 edition). Notably, the accumulated DOXY release was lower than 50% at pH 1.2 (20 min) and higher than 85% at pH 5.5, which met the USP40-NF35 standard for DOXY modified-release formulations. Moreover, the storage stability of DMOP with different packages was investigated by stress testing, accelerated and long-term testings. The stability of DMOP was maintained up to 12 months, in terms of DOXY content and in vitro release behavior. The results seem to suggest that DMOP could be a promising duodenum delivery system.

Review of Drug-induced Injury in Mucosal Biopsies From the Tubular Gastrointestinal Tract

The use of prescription and over-the-counter medications is on the rise in the US population, especially among those aged 65 and over, with over 46% of the population taking at least 1 prescription medication. Given the frequency of medication use, and that the majority of these medications are taken orally, it has become increasingly relevant for pathologist examining endoscopically obtained gastrointestinal tract mucosal biopsies to consider and recognize patterns of mucosal injury associated with various drugs. Reports on injuries associated with certain classes of drugs can be scattered among different sources, making a comprehensive view of various injury patterns and the drugs known to cause them difficult to obtain. Herein, we provide a comprehensive overview of the drugs known to cause mucosal injuries in the tubular gastrointestinal tract organized by the organ involved and the prominent pattern of injury.

The Many Faces of Medication-Related Injury in the Gastrointestinal Tract

Every year many new medications are approved for clinical use, several of which can cause clinically significant gastrointestinal tract toxicity. This article emphasizes the histologic features and differential diagnosis of drug-induced injury to the gastrointestinal mucosa. Ultimately, clinical correlation and cessation of a drug with resolution of symptoms are needed to definitively confirm a drug as a causative factor in mucosal injury. Recognizing histologic features in gastrointestinal biopsies, however, can allow surgical pathologists to play a key role in establishing a diagnosis of drug-induced gastrointestinal toxicity.