Summary

[Posted 23/Nov/2022]

AUDIENCE: Gastroenterology, Internal Medicine

KEY FINDINGS: Identified and characterised a subpopulation of unconventional Crohn-associated invariant T (CAIT) cells. Multiple evidence suggests these cells to be part of the NKT type II population. The potential implications of this population for CD or a subset thereof remain to be elucidated, and the immunophenotype and antigen reactivity of CAIT cells need further investigations in future studies.

BACKGROUND: One of the current hypotheses to explain the proinflammatory immune response in IBD is a dysregulated T cell reaction to yet unknown intestinal antigens. As such, it may be possible to identify disease-associated T cell clonotypes by analysing the peripheral and intestinal T-cell receptor (TCR) repertoire of patients with IBD and controls.

DETAILS: Bulk TCR repertoire profiling of both the TCR alpha and beta chains was performed using high-throughput sequencing in peripheral blood samples of a total of 244 patients with IBD and healthy controls as well as from matched blood and intestinal tissue of 59 patients with IBD and disease controls. It was further characterised specific T cell clonotypes via single-cell RNAseq. Identified a group of clonotypes, characterised by semi-invariant TCR alpha chains, to be significantly enriched in the blood of patients with Crohn's disease (CD) and particularly expanded in the CD8+ T cell population. Single-cell RNAseq data showed an innate-like phenotype of these cells, with a comparable gene expression to unconventional T cells such as mucosal associated invariant T and natural killer T (NKT) cells, but with distinct TCRs.

Copyright © BMJ Publishing Group Ltd & British Society of Gastroenterology. All rights reserved.

Source: Rosati, E., Rios Martini G., Pogorelyy, M. V., et al. (2022). A Novel Unconventional T Cell Population Enriched In Crohn's Disease. Gut. 2022; 71(11): 2194-2204. Published: November, 2022. DOI: XXXXXXXX.

Summary

A Randomized Controlled Comparative Study

[Posted 19/May/2026]

AUDIENCE: General Surgery, Family Medicine

KEY FINDINGS: Early active treatment with isotretinoin and FMRF is safe and better than isotretinoin monotherapy over 44 weeks regarding severity, reduced erythema, and improved surface roughness in moderate-to-severe acne vulgaris. This encourages early and effective treatment of acne to mitigate acne scarring and improve patients' quality of life.

BACKGROUND: Oral isotretinoin is the standard therapy for severe acne. However, scarring may persist. Fractional microneedling radiofrequency (FMRF) improves both inflammatory lesions and scars with minimal downtime. In this study, we compare isotretinoin monotherapy and concurrent isotretinoin and FMRF for active acne regarding clinical outcomes. The GAGS scores of isotretinoin and FMRF were significantly lower than those of isotretinoin monotherapy from weeks 12-44 (-79.69% vs. -60.34% at week 44, respectively; p < 0.001). Isotretinoin and FMRF showed significantly greater lesion count reductions than isotretinoin monotherapy at follow-up visits from weeks 12-44. Isotretinoin and FMRF showed significantly lower hemoglobin levels than isotretinoin monotherapy at weeks 32 and 44 (p = 0.029 and p < 0.001, respectively). Skin surface roughness improved substantially and persistently from week 12-44.

DETAILS: In this parallel two-group comparative study, patients received either low-dose isotretinoin monotherapy for 20 weeks (n = 34) or low-dose isotretinoin concurrently with 5 monthly FMRF sessions (n = 36). Outcomes were assessed at baseline and weeks 12, 20, 24, 32, and 44. The primary endpoints were Global Acne Grading System (GAGS) scores and inflammatory/non-inflammatory lesion counts. Secondary endpoints were hemoglobin indices and skin roughness.

Copyright © Wiley Periodicals LLC. All rights reserved

Source: Disphanurat, W., Leeyangyuen, P,, and Srisantithum, B. Efficacy of Low-Dose Oral Isotretinoin Combined With Fractional Microneedle Radiofrequency Versus Low-Dose Oral Isotretinoin Monotherapy in the Treatment of Moderate-To-Severe Acne Vulgaris: A Randomized Controlled Comparative Study. Lasers in Surgery and Medicine. 2026; 58(4): 321-330. Published: April, 2026. DOI: 10.1002/lsm.70120.

Summary

An Updated Systematic Review and Meta-analysis of Randomized Controlled Trials.

[Posted 18/May/2026]

AUDIENCE: Gastroenterology, Internal Medicine

KEY FINDINGS: NTZ-based therapy significantly improved eradication rates, with risk ratios of 1.40 and 1.36 in different patient analyses, indicating better outcomes than standard therapy. While NTZ showed non-significant reductions in symptoms like abdominal pain and nausea, the certainty of evidence was consistently high, although the risk of bias varied from low to high. Further research is needed on NTZ's optimal use and safety.

BACKGROUND: Helicobacter pylori infections are the major cause of gastrointestinal disease, mainly chronic gastritis, peptic ulcer, and gastric carcinomas, affecting half of the population globally. Due to the emergence of antibiotic resistance, the efficacy of current standard therapies, particularly clarithromycin and metronidazole, has been reduced.

DETAILS: Nitazoxanide (NTZ), a broad-spectrum antimicrobial drug, has shown promising efficacy against H. pylori infections. This study aims to assess the comparative efficacy and safety of NTZ-based regimens versus standard triple therapy in H. pylori infections. A comprehensive literature search was conducted across 4 databases. Eight randomized controlled trials, comprising 1286 participants, comparing NTZ-based regimens with standard triple therapy, were included. A random-effects model was used to estimate pooled risk ratios (RRs) with 95% confidence intervals (CIs). NTZ-based therapy showed significant improvement in primary outcome, which includes H. pylori eradication rate compared to standard triple therapy. In per-protocol (PP) and intention-to-treat patients, durational analysis showed significant improvement in H. pylori eradication rates (RR=1.40; 95% CI: 1.19-1.56; P<0.0001) and (RR=1.36; 95% CI: 1.19-1.56; P<0.0001), respectively. In addition, post follow-up assessment also shows significant effects in both patients per-protocol (RR= 1.40; 95% CI: 1.21-1.62; P<0.0001) and intention-to-treat (RR=1.36; 95% CI: 1.19-1.56; P<0.0001). In secondary outcomes, NTZ-based therapy showed non-significant reduction in abdominal pain (RR=0.50) and nausea (RR=0.78). Risk of bias was reported as low to high, although certainty of evidence was consistently high. Egger’s test shows non-significant publication bias (P=0.161). Future research should focus on NTZ’s optimal duration, resistance pattern, safety, and symptom relief.

Copyright © Wolters Kluwer Health, Inc. All rights reserved.

Source: Ali, S. H., Shaikh, U. A., Shahzad, A., et al. Comparative Efficacy and Safety of Nitazoxanide-based Triple Therapy Versus Standard Triple Therapy in Treating Helicobacter Pylori Infections: An Updated Systematic Review and Meta-analysis of Randomized Controlled Trials. Journal of Clinical Gastroenterology. 2026; 60(5): 373-384. Published: May/June 2026. DOI: 10.1097/MCG.0000000000002328

Summary

[Posted 11/May/2026]

AUDIENCE: All Healthcare Professionals

KEY FINDINGS:

• Hantaviruses are a family of viruses that cause serious illness and sometimes death in people worldwide.
• The viruses are spread by infected rodents through their urine, feces, and saliva.
• Some hantaviruses cause hantavirus pulmonary syndrome (HPS).
• Early symptoms of HPS in people resemble many other respiratory illnesses, making HPS difficult to diagnose at illness onset.
• Healthcare providers should test a person for hantavirus if they have HPS-compatible symptoms and have had contact with rodents.

BACKGROUND: Hantaviruses are spread by rodents' body fluids and excrement. People mostly contract hantavirus by breathing in the virus. Most hantaviruses found in North, Central, and South America can cause hantavirus pulmonary syndrome (HPS). Andes virus, which is found in South America, has reportedly had person-to-person transmission.

DETAILS: Different hantaviruses are found in the United States. Most of these cause HPS, which primarily affects the lungs. Non-HPS hantavirus infection can also occur, where patients experience non-specific viral symptoms, but no cardiopulmonary symptoms. The hantaviruses that are found throughout the United States are not known to spread between people.

HPS initially causes flu-like symptoms that can progress to more severe illness where people have trouble breathing. It's important for people with HPS to begin treatment as early as possible to improve their chances of recovery. HPS is fatal in nearly 4 in 10 people who are infected.

Exposure risks

Anyone who has contact with hantavirus-carrying rodents, or their droppings, urine, saliva or nesting material is at risk of HPS. Rodent infestation in and around the home remains the primary risk for hantavirus exposure. Even healthy individuals are at risk for HPS infection if they have contact with the virus.

Andes virus can cause HPS and is the only type of hantavirus that is known to spread person-to-person.

How it spreads

Each hantavirus has one primary rodent that carries the disease. The most common hantavirus that causes HPS in the U.S. is spread by the deer mouse.

People can contract hantavirus if they have contact with urine, feces or saliva of a rodent carrying the virus. This can occur when people:

1. Breathe in hantavirus-contaminated air when cleaning up after rodents.
2. Touch contaminated objects and then touch their nose or mouth.
3. Are bitten or scratched by an infected rodent.
4. Eat food contaminated with hantavirus.

Cases normally occur in rural areas where forests, fields, and farms offer habitats for rodents. The animals can get into homes and barns, where they may leave urine or feces.

Dogs and cats are not known to become infected with hantavirus in the United States. Pets may bring infected rodents to people or into homes.

Testing and diagnosis

Assessing patients for hantavirus can be difficult early in the infection because symptoms are non-specific and resemble many other viral infections like influenza, legionnaire's, leptospirosis, mycoplasma, and Q fever. Because hantavirus resembles these infections, a blood test is often the only way to officially diagnose it.

To diagnose hantavirus or HPS, clinicians should understand:

• Disease symptoms and rodent exposure history
• Testing guidelines to identify the virus
• How to request testing support from CDC if needed, and
• How to report cases to CDC

Clinicians with a patient experiencing symptoms compatible with HPS and a potential rodent exposure should contact their state, tribal, local, or territorial health department.

Testing

CDC uses an enzyme-linked immunosorbent assay (ELISA) to detect IgM antibodies and diagnose acute infections with hantaviruses. This diagnostic method is used to diagnose both HPS and HFRS. Diagnostic testing can be performed at:

1. CDC
2. State labs running the CDC-developed assay
3. State public health labs using other diagnostic assays
4. Commercial labs

The criteria to report hantavirus-positive cases are based on the national case definition, which includes clinical symptoms (HPS or non-HPS) and acute laboratory diagnostic results, such as:

1. IgM positive
2. IgG positive with rising titers
3. Immunohistochemistry positive, or
4. PCR positive

Treatment and recovery

There is no specific treatment for hantavirus infection. If HPS is suspected, the patient needs emergency medical care immediately, preferably in the intensive care unit, even before diagnosis.

Early intensive medical care is critical because patients who have sudden acute disease can rapidly become severely sick and die. If a patient is experiencing full distress, it is less likely the treatment will be effective.

Patient management should include:

1. Monitoring and adjustment of cardiac function
2. Carefully administering fluids
3. Providing supplemental oxygen
4. Intubating and ventilating if needed

Suspected HPS patients should receive appropriate broad-spectrum antibiotic therapy, even if you're still waiting for diagnosis. Care should also include fever reducers and pain relievers.

While HPS can be quite severe, it has a short duration of critical disease. The cardiopulmonary dysfunction seen in HPS is most likely due to circulating inflammatory mediators. Autopsies performed on fatal cases did not show significant tissue damage.

Initiating extracorporeal membrane oxygenation (ECMO) at the earliest sign of decompensation has an 80 percent survival rate in patients despite cardiopulmonary collapse.

Within 24 hours of initial evaluation, most HPS patients develop some degree of hypotension. They also experience progressive evidence of pulmonary edema and hypoxia, usually requiring mechanical ventilation.

Patients with fatal infections often appear to have severe myocardial depression that progresses to sinus bradycardia with subsequent electromechanical dissociation, ventricular tachycardia, or fibrillation.

In patients with HPS, poor prognostic indicators include a plasma lactate of greater than 4.0 mmol/L or a cardiac index of less than 2.2 L/min/m2.

Pulmonary edema and pleural effusions are common, but multiorgan dysfunction syndrome is rarely seen. However, HPS patients sometimes have mildly impaired renal function. Survivors frequently become polyuric during convalescence and improve rapidly.

Intravenous ribavirin, a guanosine analogue, has been tested in patients with HPS. However, it was not shown to be effective for treatment of HPS.

Without adequate treatment, most deaths occur in patients with HPS within 24 to 48 hours of the cardiopulmonary phase onset.

Related diseases

Some hantaviruses cause kidney symptoms more than lung damage. When this occurs, it is called hemorrhagic fever with renal syndrome (HFRS).

Source: Clinician Brief: Hantavirus Pulmonary Syndrome (HPS). CDC. Published: May 8, 2026.

Summary

[Posted 8/May/2026]

AUDIENCE: Infectious Disease, Family Medicine

KEY FINDINGS: In two open-label trials, nirmatrelvir-ritonavir did not reduce the incidence of hospitalization or death among vaccinated higher-risk participants with SARS-CoV-2 infection.

BACKGROUND: Nirmatrelvir-ritonavir has been shown to reduce progression to severe illness from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in unvaccinated high-risk outpatients. The effectiveness of nirmatrelvir-ritonavir in persons who have been vaccinated, infected naturally, or both is unclear.

DETAILS: In two open-label platform trials (PANORAMIC in the United Kingdom and CanTreatCOVID in Canada), we enrolled higher-risk adults (>=50 years of age or >=18 years of age with coexisting conditions) in the community who tested positive for SARS-CoV-2 and had been unwell for 5 days or less. The participants were randomly assigned to receive usual care plus nirmatrelvir (300 mg)-ritonavir (100 mg) twice a day for 5 days or to receive usual care alone. The primary outcome was hospitalization or death from any cause within 28 days after randomization. From December 8, 2021, to September 30, 2024, a total of 3516 participants in the PANORAMIC trial and 716 participants in the CanTreatCOVID trial underwent randomization. In the PANORAMIC trial, 14 of 1698 participants (0.8%) in the nirmatrelvir-ritonavir group and 11 of 1673 participants (0.7%) in the usual-care group were hospitalized or died (adjusted odds ratio, 1.18; 95% Bayesian credible interval, 0.55 to 2.62; probability of superiority, 0.334). In the CanTreatCOVID trial, 2 of 343 participants (0.6%) in the nirmatrelvir-ritonavir group and 4 of 324 participants (1.2%) in the usual-care group were hospitalized or died (adjusted odds ratio, 0.48; 95% Bayesian credible interval, 0.08 to 2.23; probability of superiority, 0.830). In a substudy involving 634 participants, viral load was reduced by the end of treatment with nirmatrelvir-ritonavir. Serious adverse events with nirmatrelvir-ritonavir were reported in 9 participants in the PANORAMIC trial and in 4 participants in the CanTreatCOVID trial.

Copyright © Massachusetts Medical Society. All rights reserved.

Source: Butler, C. C., Pinto, A. D., Harris, V., et al. Oral Nirmatrelvir-Ritonavir for Covid-19 in Higher-Risk Outpatients. N Engl J Med. 2026; 394(16): 1583-1594. Published: April 22, 2026. DOI: 10.1056/NEJMoa2502457

Summary

[Posted 4/May/2026]

AUDIENCE: Gastroenterology, Internal Medicine

KEY FINDINGS: The addition of endoscopic clipping prior to cyanoacrylate injection significantly reduces the risk of ectopic embolism without compromising procedural success, rebleeding rates, or survival outcomes. This approach offers a safer modification of conventional therapy, particularly in patients with gastric varices associated with portosystemic shunts.

BACKGROUND: Endoscopic cyanoacrylate injection (ECI) is a well-established treatment for gastric varices; however, it carries a significant risk of ectopic embolism due to migration of the adhesive material, particularly in patients with portosystemic shunts. This complication can lead to severe outcomes, including pulmonary embolism. The study was designed to evaluate whether the addition of endoscopic clipping prior to cyanoacrylate injection could reduce embolic complications while maintaining procedural efficacy.

DETAILS: This multicenter, open-label, randomized controlled trial included patients with fundal gastric varices and gastrorenal shunts. Participants were randomized into two groups: clip-assisted endoscopic cyanoacrylate injection (Clip-ECI, n=35) and conventional endoscopic cyanoacrylate injection (Con-ECI, n=35). The primary outcome was the occurrence of ectopic embolism detected by computed tomography within 48 hours after the procedure. Secondary outcomes included technical success, rebleeding rates, and survival during follow-up. The technical success rate was 100% in both groups. The incidence of cyanoacrylate embolism was significantly lower in the Clip-ECI group compared with the conventional group (11.4% vs 42.9%, p = 0.003). Symptomatic pulmonary embolism occurred in four patients in the conventional group, including one death, whereas no symptomatic embolism events were observed in the clip-assisted group (11.4% vs 0%, p = 0.114). There were no clip-related bleeding complications. The total rebleeding rate was identical between groups (14.3% vs 14.3%), and survival rates were comparable (97.1% vs 93.9%) over a median follow-up of approximately 10 months.

Copyright © The American College of Gastroenterology. All rights reserved.

Source: Wang, G., Peng, L., Li, P., et al. Adding Clip Before Endoscopic Cyanoacrylate Injection Decreases Ectopic Embolisms in Gastric Varices: A Randomized Controlled Trial. American Journal of Gastroenterology. 2026; 121(5): 1106-1115. Published: May, 2026. DOI: 10.14309/ajg.0000000000003629