Implications of COVID-19 for the busy gastroenterologist.

Coronavirus disease 2019 (COVID-19) is an infection caused by a novel coronavirus (SARS-CoV-2) originated in China in December 2020 and declared pandemic by WHO. This coronavirus mainly spreads through the respiratory tract and enters cells through angiotensin-converting enzyme 2 (ACE2). The clinical symptoms of COVID-19 patients include fever, cough, and fatigue. Gastrointestinal symptoms (diarrhea, anorexia, and vomiting) may be present in 50% of patients and may be associated with worst prognosis. Other risk factors are older age, male gender, and underlying chronic diseases. Mitigation measures are essential to reduce the number of people infected. Hospitals are a place of increased SARS-CoV-2 exposure. This has implications in the organization of healthcare services and specifically endoscopy departments. Patients and healthcare workers safety must be optimized in this new reality. Comprehension of COVID-19 gastrointestinal manifestations and implications of SARS-CoV-2 in the management of patients with gastrointestinal diseases, under or not immunosuppressant therapies, is essential. In this review, we summarized the latest research progress and major societies recommendations regarding the implications of COVID-19 in gastroenterology, namely the adaptations that gastroenterology/endoscopy departments and professionals must do in order to optimize the provided assistance, as well as the implications that this infection will have, in particularly vulnerable patients such as those with chronic liver disease and inflammatory bowel disease under or not immunosuppressant therapies.

Intradermal skin test with mRNA vaccines as a surrogate marker of T cell immunity in immunocompromised patients.

OBJECTIVES: Intradermal skin test (IDT) with mRNA vaccines may represent a simple, reliable, and affordable tool to measure T cell response in immunocompromised patients who failed to mount serological responses following vaccination with mRNA covid-19 vaccines. METHODS: We compared anti-SARS-CoV-2 antibodies and cellular responses in vaccinated immunocompromised patients (n = 58), healthy seronegative naive controls (NC, n = 8), and healthy seropositive vaccinated controls (VC, n = 32) by Luminex, spike-induced IFN-γ Elispot and an IDT. A skin biopsy 24 h after IDT and single-cell RNAseq was performed in three vaccinated volunteers. RESULTS: Twenty-five percent of seronegative NC had a positive Elispot (2/8) and IDT (1/4), compared to 95% (20/21) and 93% (28/30) in seropositive VC, respectively. Single-cell RNAseq data in the skin of VC showed a predominant mixed population of effector helper and cytotoxic T cells. The TCR repertoire revealed 18/1064 clonotypes with known specificities against SARS-CoV-2, among which six were spike-specific. Seronegative immunocompromised patients with positive Elispot and IDT were in 83% (5/6) treated with B cell-depleting reagents, while those with negative IDT were all transplant recipients. CONCLUSIONS: Our results indicate that delayed local reaction to IDT reflects vaccine-induced T-cell immunity opening new perspectives to monitor seronegative patients and elderly populations with waning immunity.

Unknown Circovirus in Immunosuppressed Patient with Hepatitis, France, 2022.

Hepatitis of undetermined origin can be caused by a wide variety of pathogens, sometimes emerging pathogens. We report the discovery, by means of routine shotgun metagenomics, of a new virus belonging to the family Circoviridae, genus Circovirus, in a patient in France who had acute hepatitis of unknown origin.

High-titer convalescent plasma plus nirmatrelvir/ritonavir treatment for non-resolving COVID-19 in six immunocompromised patients.

OBJECTIVES: Immunocompromised patients have an increased risk of severe or prolonged COVID-19. Currently available drugs are registered to treat COVID-19 during the first 5 to 7 days after symptom onset. Data on the effectivity in immunocompromised patients with chronic non-resolving COVID-19 are urgently needed. Here, we report the outcome of patients treated with nirmatrelvir/ritonavir together with high-titer convalescent plasma (CP) in six immunocompromised patients with non-resolving COVID-19. METHODS: Immunocompromised patients with persisting COVID-19 (positive PCR with Ct values <30 for ≥20 days) received off-label therapy with nirmatrelvir/ritonavir. It was combined with CP containing BA.5 neutralizing titers of ≥1/640 whenever available. Follow-up was done by PCR and sequencing on nasopharyngeal swabs on a weekly basis until viral genome was undetectable consecutively. RESULTS: Five immunocompromised patients were treated with high-titer CP and 5 days of nirmatrelvir/ritonavir. One patient received nirmatrelvir/ritonavir monotherapy. Median duration of SARS-CoV-2 PCR positivity was 70 (range 20-231) days before nirmatrelvir/ritonavir treatment. In four patients receiving combination therapy, no viral genome of SARS-CoV-2 was detected on day 7 and 14 after treatment while the patient receiving nirmatrelvir/ritonavir monotherapy, the day 7 Ct value increased to 34 and viral genome was undetectable thereafter. Treatment was unsuccessful in one patient. In this patient, sequencing after nirmatrelvir/ritonavir treatment did not show protease gene mutations. CONCLUSIONS: In immunocompromised patients with non-resolving COVID-19, the combination of nirmatrelvir/ritonavir and CP may be an effective treatment. Larger prospective studies are needed to confirm these preliminary results and should compare different treatment durations.

Efficacy of Remdesivir and Neutralizing Monoclonal Antibodies in Monotherapy or Combination Therapy in Reducing the Risk of Disease Progression in Elderly or Immunocompromised Hosts Hospitalized for COVID-19: A Single Center Retrospective Study.

INTRODUCTION: Remdesivir (REM) and monoclonal antibodies (mAbs) could alleviate severe COVID-19 in at-risk outpatients. However, data on their use in hospitalized patients, particularly in elderly or immunocompromised hosts, are lacking. METHODS: All consecutive patients hospitalized with COVID-19 at our unit from 1 July 2021 to 15 March 2022 were retrospectively enrolled. The primary outcome was the progression to severe COVID-19 (P/F < 200). Descriptive statistics, a Cox univariate-multivariate model, and an inverse probability treatment-weighted (IPTW) analysis were performed. RESULTS: Overall, 331 subjects were included; their median (q1-q3) age was 71 (51-80) years, and they were males in 52% of the cases. Of them, 78 (23%) developed severe COVID-19. All-cause in-hospital mortality was 14%; it was higher in those with disease progression (36% vs. 7%, p < 0.001). REM and mAbs resulted in a 7% (95%CI = 3-11%) and 14% (95%CI = 3-25%) reduction in the risk of severe COVID-19, respectively, after adjusting the analysis with the IPTW. In addition, by evaluating only immunocompromised hosts, the combination of REM and mAbs was associated with a significantly lower incidence of severe COVID-19 (aHR = 0.06, 95%CI = 0.02-0.77) when compared with monotherapy. CONCLUSIONS: REM and mAbs may reduce the risk of COVID-19 progression in hospitalized patients. Importantly, in immunocompromised hosts, the combination of mAbs and REM may be beneficial.

Within-Host Evolution of SARS-CoV-2 in a B-Cell Depleted Patient With Successful Treatment.

Prolonged viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in an immunocompromised host is a challenge as the treatment and infection control for chronic coronavirus disease 2019 infection is not well established and there is a potential risk of new variants emerging. A 48-year-old woman who underwent chemotherapy, including rituximab and steroid, had reactivation of SARS-CoV-2 68 days after the virus was first detected. She successfully recovered after receiving convalescent plasma and intravenous immunoglobulin. Genomic analysis demonstrated that viruses collected from the nasopharyngeal specimens at day 0 and day 68 had 18 different nucleotide mutations, implying within-host evolution after in-depth epidemiologic investigation.

Borrelia miyamotoi Infection in Immunocompromised Man, California, USA, 2021.

Infection with Borrelia miyamotoi in California, USA, has been suggested by serologic studies. We diagnosed B. miyamotoi infection in an immunocompromised man in California. Diagnosis was aided by plasma microbial cell-free DNA sequencing. We conclude that the infection was acquired in California.

Delayed organising pneumonia in an immunocompromised host after a mild COVID-19 infection.

Organising pneumonia after a mild COVID-19 infection has been increasingly reported and poses a diagnostic challenge to physicians especially in immunocompromised patients. We report a patient with a background of lymphoma in remission on rituximab who presented with prolonged and persistent fever after recovering from a mild COVID-19 infection. The initial workup showed bilateral lower zone lung consolidation; however, the infective and autoimmune workup were unremarkable. Subsequently, a bronchoscopy with transbronchial lung biopsy confirmed the diagnosis of organising pneumonia. A tapering glucocorticoid regimen was commenced with prompt resolution of the patient's clinical symptoms, and subsequent resolution of biochemical markers and radiological lung changes 3 months later. This case highlights the importance of early recognition of the diagnosis of organising pneumonia in immunocompromised populations after a mild COVID-19 infection as it shows promising response to glucocorticoid therapy.

SARS-COV-2 antibodies after booster vaccination. Identification of subgroups with poor response.

OBJECTIVE: To determine which patients within the high-risk group are most likely to have insufficient post-vaccination immunity. METHODS: Determination of IgG titers against SARS-CoV-2 after the booster dose. Vaccine response was categorized as negative (IgG titers < 34 BAU/ml), indeterminate (titers 34-259 BAU/ml) or positive (≥260 BAU/ml). RESULTS: 765 patients were included (31.25% of those vaccinated). 54 (7.1%) on treatment with biologics, 90 (11.8%) with hematologic disease, 299 (39.1%) with oncologic pathology, 304 (39.7%) with solid organ transplant and 18 (2.4%) with immunosuppression for other reasons. 74 patients (9.7%) had negative serology and 45 (5.9%) had indeterminate titers. By diagnostic group, the patients with the highest proportion of negative or indeterminate serology were patients with biologic treatment (55.6%, mainly at expense of antiCD20), hematologic (35.4%) and transplant patients (17.8%, mainly lung and kidney). Oncology and other immunosuppressed patients had a favorable response to vaccination. CONCLUSION: Patients treated with antiCD20 drugs, hematologic patients and transplanted patients (mainly lung and kidney) have a higher risk of not achieving post-vaccination immunity. It is essential to identify them in order to individualize and optimize their management.

Emerging viral infections in immunocompromised patients: A great challenge to better define the role of immune response.

The immune response to invading pathogens is characterized by the rapid establishment of a complex network of cellular interactions and soluble signals. The correct balancing of activating and regulating pathways and tissue-homing signals determines its effectiveness and persistence over time. Emerging viral pathogens have always represented a great challenge to the immune system and an often uncontrolled/imbalanced immune response has been described (e.g. cytokine storm, immune paralysis), contributing to the severity of the disease. Several immune biomarkers and cell subsets have been identified as major players in the cascade of events leading to severe diseases, highlighting the rationale for host-directed intervention strategy. There are millions of immunocompromised pediatric and adult patients worldwide (e.g. transplant recipients, hematologic patients, subjects with primary immune-deficiencies), experiencing an impaired immune reactivity, due to diseases and/or to the medical treatments. The reduced immune reactivity could have two paradoxical non-exclusive effects: a weak protective immunity on one hand, and a reduced contribution to immune-mediated pathogenetic processes on the other hand. In these sensitive contexts, the impact of emerging infections represents a still open issue to be explored with several challenges for immunologists, virologists, physicians and epidemiologists. In this review, we will address emerging infections in immunocompromised hosts, to summarize the available data concerning the immune response profile, its influence on the clinical presentation, the possible contribution of persistent viral shedding in generating new viral variants with improved immune escape features, and the key role of vaccination.

[Disseminated infection caused by the bacillus Calmette-Guérin vaccine and SARS-CoV-2 coinfection in a patient with IL-12 receptor ß1 subunit deficiency]. / Infección diseminada por vacuna con bacilo de Calmette-Guérin y coinfección por SARS-CoV-2 en paciente con deficiencia de la subunidad ß1 del receptor de IL-12.

BACKGROUND: Inborn errors of immunity manifest with a greater susceptibility to infections, autoimmunity, autoinflammatory diseases, allergies, or malignancies. One of these is the mendelian susceptibility to mycobacterial disease. The most frequent etiology is the complete autosomal recessive deficiency of the ß1 subunit of the interleukin 12 receptor. CASE REPORT: A female patient who, by the age of six months, started with a nodular lesion in the right shoulder and ipsilateral axillary adenitis after the bacillus Calmette-Guérin vaccine was applied. Later, she developed a cutaneous fistula in the anterior thorax, the inframammary region, and chronic recidivant suppurative lymphadenitis. A disseminated infection caused by Mycobacterium bovis was diagnosed, therefore, individualized pharmacological treatment was required due to failure with the primary treatment. The patient was diagnosed with deficiency in the ß1 subunit of the interleukin 12 receptor at age six. During her last hospitalization, she presented fever, cough, and tachypnea, and SARS-CoV-2 was detected by quantitative polymerase chain reaction. The patient has had a favorable evolution. CONCLUSION: In patients with disseminated infections caused by bacillus Calmette-Guérin vaccination or by environmental mycobacteria, there should be suspicion of an inborn error of immunity and the patient should be referred to a third level hospital for an early immunological assessment.

Antecedentes: Los errores innatos de la inmunidad se manifiestan con una mayor susceptibilidad a infecciones, autoinmunidad, enfermedades autoinflamatorias, alergia o malignidad. Uno de estos es la susceptibilidad mendeliana a infecciones micobacterianas. La etiología más frecuente es la deficiencia completa autosómica recesiva de la subunidad ß1 del receptor de interleucina 12. Caso clínico: Paciente que comenzó a los seis meses de edad con una lesión nodular en hombro derecho y adenitis axilar ipsolateral posterior a la vacuna con bacilo de Calmette-Guérin. Posteriormente desarrolló una fistula cutánea en tórax anterior, región inframamaria y linfadenitis supurativa crónica recidivante. Se diagnosticó infección diseminada por Mycobacterium bovis, por lo que requirió tratamiento farmacológico individualizado debido al fracaso con el tratamiento primario. La paciente fue diagnosticada con deficiencia de la subunidad ß1 del receptor de interleucina 12 a los seis años. Durante su última hospitalización presentó fiebre, tos y taquipnea, detectándose SARS-CoV-2 por reacción en cadena de la polimerasa cuantitativa. La paciente evolucionó favorablemente. Conclusión: En los pacientes con infecciones diseminadas por la vacuna con bacilo de Calmette-Guérin o micobacterias ambientales, debe sospecharse un error innato de la inmunidad y derivarlos a tercer nivel de atención para la evaluación inmunológica temprana.

Humoral response after a fourth dose of SARS-CoV-2 vaccine in immunocompromised patients. Results of a systematic review.

Background and objective: The fourth dose the COVID-19 vaccine was first proposed to immunocompromised patients. The aim of the article is to systematically review the literature and report the humoral response and outcomes after the fourth dose administration in people with impaired immune system. Methods: Published studies on the humoral response, efficacy and safety of the fourth dose of the COVID-19 vaccine were analyzed in various settings of immunocompromised patients. We conducted systematic searches of PubMed, Cochrane Library and WHO COVID-19 Research Database for series published through January 31, 2023, using the search terms "fourth dose" or "second booster" or "4th dose" and "Coronavirus" or "COVID-19" or "SARS-CoV-2." All articles were selected according to the PRISMA guidelines. Results: A total of 24 articles including 2,838 patients were comprised in the systematic review. All the studies involved immunocompromised patients, including solid organ transplant recipients, patients with autoimmune rheumatic disease, patients with human immunodeficiency virus (HIV) and patients with blood cancers or diseases. Almost all patients received BNT162b2 or mRNA-1273 as fourth dose. All the studies demonstrated the increase of antibody titers after the fourth dose, both in patients who had a serological strong response and in those who had a weak response after the third dose. No serious adverse events after the 4th dose have been reported by 13 studies. COVID-19 infection after the fourth dose ranged from 0 to 21%. Conclusion: The present review highlights the importance of the fourth dose of covid-19 vaccines for immunocompromised patients. Across the included studies, a fourth dose was associated with improved seroconversion and antibody titer levels. In particular, a fourth dose was associated with increasing immunogenicity in organ transplant recipients and patients with hematological cancers, with a very low rate of serious side effects.

Immunogenicity and reactogenicity of COVID-19 Pfizer-BioNTech (Bnt162b2) mRNA vaccination in immunocompromised adolescents and young adults: a systematic review and meta-analyses.

BACKGROUND: This study aimed to evaluate the safety and effectiveness of the BNT162b2 vaccine in immunocompromised adolescents and young adults. RESEARCH DESIGN AND METHODS: The study conducted a meta-analysis of post-marketing studies examining BNT162b2 vaccination efficacy and safety among immunocompromised adolescents and young adults worldwide. The review included nine studies and 513 individuals aged between 12 and 24.3 years. The study used a random effect model to estimate pooled proportions, log relative risk, and mean difference, and assessed heterogeneity using the I2 test. The study also examined publication bias using Egger's regression and Begg's rank correlation and assessed bias risk using ROBINS-I. RESULTS: The pooled proportions of combined local and systemic reactions after the first and second doses were 30% and 32%, respectively. Adverse events following immunization (AEFI) were most frequent in rheumatic diseases (40%) and least frequent in cystic fibrosis (27%), although hospitalizations for AEFIs were rare. The pooled estimations did not show a statistically significant difference between immunocompromised individuals and healthy controls for neutralizing antibodies, measured IgG, or vaccine effectiveness after the primary dose. However, the evidence quality is low to moderate due to a high risk of bias, and no study could rule out the risk of selection bias, ascertainment bias, or selective outcome reporting. CONCLUSIONS: This study provides preliminary evidence that the BNT162b2 vaccine is safe and effective in immunocompromised adolescents and young adults, but with low to moderate evidence quality due to bias risk. The study calls for improved methodological quality in studies involving specific populations.

Kidney Transplant and Dialysis Patients Remain at Increased Risk for Succumbing to COVID-19.

BACKGROUND: Immunocompromised patients have been at an increased risk of succumbing to coronavirus disease 2019 (COVID-19) since the beginning of the pandemic. METHODS: Here, we analyzed mortality and case fatality data from dialysis and kidney transplant patients, and compared each with an age-matched subgroup of the general population. RESULTS: We found that both patients on dialysis and kidney transplant patients remain at increased risk of succumbing to COVID-19 despite all available countermeasures. CONCLUSIONS: The analyses underline the need for additional protection for this vulnerable population.

Cowpox to COVID: History of vaccination in the immunocompromised host.

BACKGROUND: The use of vaccination to prevent infection has a long history, starting in the 1700s with Jenner. New innovations have led to improvements in the safety and efficacy of vaccines, from live attenuated viruses to subunit vaccines, to RNA-based vaccination for SARS-CoV-2. Despite this progress, however, solid organ transplant (SOT) recipients on immunosuppression demonstrate an impaired vaccine response compared with healthy controls. This issue is important given the increased vulnerability to infection in immunocompromised patients, especially in the setting of the Coronavirus Disease 2019 (COVID-19) pandemic. METHODS: We reviewed the literature on key topics in vaccination with significant clinical impact on SOT patients. RESULTS: Prior to COVID-19, a large amount of data has been published demonstrating impaired humoral and T-cell responses to multiple vaccinations targeting influenza, hepatitis B, VZV, and Pneumococcus. Poor immunogenicity can be addressed through the use of adjuvants to boost the immune response, even in the setting of senescence related to age or immunosuppression. New vaccines provide hope for preventing infection due to hepatitis C and Cytomegalovirus, and to the emerging infection, monkeypox. The data on the impact of the COVID-19 vaccine in SOT patients is reviewed, with a focus on seroconversion, antibody titer, and antigen-specific T cells. Factors associated with impaired response, including mycophenolate, are described. CONCLUSION: The history of vaccination demonstrates how scientific breakthroughs can be applied to clinical challenges. New approaches using adjuvants, strategic antigen selection, and RNA-based vaccines offer the potential to improve immune response in SOT recipients. Future innovations are needed to better protect the vulnerable immunocompromised host.

The comparison of clinical, laboratory, and radiological findings in immunocompromised and immunocompetent patients with COVID-19: A case-control study.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19) with significant morbidity and mortality. We reported and compared the clinical and para-clinical findings of immunocompromised and immunocompetent COVID-19 patients in a case-control study at the Imam Khomeini hospital in Tehran, Iran. METHODS: In this study, 107 immunocompromised COVID-19 patients were recruited as the case group, and 107 immunocompetent COVID-19 patients as the control group. The participants were matched based on age and sex. The patients' information was retrieved from the hospital records in an information sheet. Associations between clinical and para-clinical findings with the immune status were assessed using bivariate and multivariate analyses. RESULTS: The initial pulse rate and recovery time were significantly higher in immunocompromised patients (p < .05). Myalgia, nausea/vomiting, loss of appetite, headache, and dizziness were more frequently reported by the control group (p < .05). Regarding the prescribed medications' duration, Sofosbovir was used longer in the case group, while Ribavirin was used longer in the control groups (p < .05). The most common complication in the case group was acute respiratory distress syndrome, although no major complications were observed in the control group. According to the multivariate analysis, recovery time and Lopinavir/Ritonavir (Kaletra) prescription were significantly higher in the immunocompromised compared to the immunocompetent group. CONCLUSION: Recovery time was significantly longer in the immunocompromised compared to the immunocompetent group, which emphasizes the necessity of prolonged care in these high-risk patients. Also, it is recommended to investigate the effect of novel therapeutic interventions to reduce the recovery time in addition to improving the prognosis of immunodeficient patients with COVID-19.

Anti-spike protein to determine SARS-CoV-2 antibody levels: Is there a specific threshold conferring protection in immunocompromised patients?

BACKGROUND: Identifying a specific threshold level of SARS-CoV-2 antibodies that confers protection in immunocompromised patients has been very challenging. The aim was to assess the threshold of 264 binding antibody units (BAU)/ml using four different SARS-CoV-2 antibody assays (Abbott, Beckman, Roche, and Siemens) and to establish a new optimal threshold of protection for each of the four antibody assays. METHODS: This study was performed on data retrieved from 69 individuals, who received at least one dose of the Pfizer/BioNTech BNT162b2 or Moderna COVID-19 vaccine (Spikevax) at the Alphabio Laboratory in Marseille, France (European Hospital, Alphabio-Biogroup). The results were compared to the percent inhibition calculated using a functional surrogate of a standardized virus neutralization test (Genscript). RESULTS: Samples from 69 patients were analyzed. For a reference cutoff of 264 BAU/ml, assays showed moderate to good overall concordance with Genscript: 87% concordance for Abbott, 78% for Beckman, 75% for Roche, and 88% for Siemens. Overall concordance increased consistently after applying new thresholds, i.e., 148 BAU/ml (Abbott), 48 (Beckman), 559 (Roche), and 270 (Siemens). CONCLUSION: We suggest specific adjusted thresholds (BAU/ml) for the four commercial antibody assays that are used to assess pre-exposure prophylaxis in immunocompromised patients.

Total escape of SARS-CoV-2 from dual monoclonal antibody therapy in an immunocompromised patient.

Monoclonal antibodies (mAbs) directed against the spike of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are effective therapeutic options to combat infections in high-risk patients. Here, we report the adaptation of SARS-CoV-2 to the mAb cocktail REGN-COV in a kidney transplant patient with hypogammaglobulinemia. Following mAb treatment, the patient did not clear the infection. During viral persistence, SARS-CoV-2 acquired three novel spike mutations. Neutralization and mouse protection analyses demonstrate a complete viral escape from REGN-COV at the expense of ACE-2 binding. Final clearance of the virus occurred upon reduction of the immunosuppressive regimen and total IgG substitution. Serology suggests that the development of highly neutralizing IgM rather than IgG substitution aids clearance. Our findings emphasise that selection pressure by mAbs on SARS-CoV-2 can lead to development of escape variants in immunocompromised patients. Thus, modification of immunosuppressive therapy, if possible, might be preferable to control and clearance of the viral infection.