Genomics and inclusion of Indigenous peoples in high income countries.

Genomics research related to Indigenous people has been at worst exploitative and at best, retrospectively on a journey to improve effective engagement of Indigenous individuals and communities. Genomics can positively impact all stages of clinical management, and to improve genomic effectiveness researchers aggregate genomic data from diverse global sub-populations, such as shared ancestry groupings, as people within these groupings will have a greater proportion of shared DNA traits. While genomics is already being used worldwide to improve lives, its utility and effectiveness has not been maximized for individuals with Indigenous ancestry. Several large datasets of human genetic variation have been made publicly available, of which the most widely used is the Genome Aggregation Database (gnomAD), but none of these databases currently contain any population-specific data for Indigenous populations. There are many reasons why Indigenous people have been largely left out of genomics research and, because of this, miss out on the benefits offered. It is also clear that if research is to be effective, it needs to be done 'with' and not 'on' Indigenous communities. This systematic review of the literature regarding Indigenous peoples (in high income countries) and genomics aims to review the existing literature and identify areas of strength and weakness in study design and conduct, focusing on the effectiveness of Indigenous community engagement.

Asthma phenotypes, associated comorbidities, and long-term symptoms in COVID-19.

BACKGROUND: It is unclear whether asthma and its allergic phenotype are risk factors for hospitalization or severe disease from SARS-CoV-2. METHODS: All patients over 28 days old testing positive for SARS-CoV-2 between March 1 and September 30, 2020, were retrospectively identified and characterized through electronic analysis at Stanford. A sub-cohort was followed prospectively to evaluate long-term COVID-19 symptoms. RESULTS: 168,190 patients underwent SARS-CoV-2 testing, and 6,976 (4.15%) tested positive. In a multivariate analysis, asthma was not an independent risk factor for hospitalization (OR 1.12 [95% CI 0.86, 1.45], p = .40). Among SARS-CoV-2-positive asthmatics, allergic asthma lowered the risk of hospitalization and had a protective effect compared with non-allergic asthma (OR 0.52 [0.28, 0.91], p = .026); there was no association between baseline medication use as characterized by GINA and hospitalization risk. Patients with severe COVID-19 disease had lower eosinophil levels during hospitalization compared with patients with mild or asymptomatic disease, independent of asthma status (p = .0014). In a patient sub-cohort followed longitudinally, asthmatics and non-asthmatics had similar time to resolution of COVID-19 symptoms, particularly lower respiratory symptoms. CONCLUSIONS: Asthma is not a risk factor for more severe COVID-19 disease. Allergic asthmatics were half as likely to be hospitalized with COVID-19 compared with non-allergic asthmatics. Lower levels of eosinophil counts (allergic biomarkers) were associated with a more severe COVID-19 disease trajectory. Recovery was similar among asthmatics and non-asthmatics with over 50% of patients reporting ongoing lower respiratory symptoms 3 months post-infection.

Increased rates of periprosthetic joint infection in patients with cirrhosis undergoing total joint arthroplasty.

BACKGROUND: Total joint arthroplasty (TJA) is becoming more prevalent, with additional increases in procedure rates expected as the US population ages. Small series have suggested increased risk of periprosthetic joint infections in patients with liver cirrhosis after TJA. However, the rates of periprosthetic joint infections and use of TJA for patients with cirrhosis have not been evaluated on a larger scale. QUESTIONS/PURPOSES: The purposes of this study were to (1) measure the rate of periprosthetic joint infections after THAs and TKAs in patients with cirrhosis of the liver; (2) assess mortality, length of hospital stay, readmission rates, and other clinical factors among patients with cirrhosis who have had a TJA; and (3) evaluate the use of TJA in the United States among patients with liver cirrhosis during the past decade. METHODS: National and state-level databases were used to identify patients with and without liver cirrhosis who underwent TJAs. The rate of periprosthetic joint infections within 6 months was assessed using the Statewide Inpatient Database, which identified 306,946 patients undergoing THAs (0.3% with cirrhosis) and 573,840 patients undergoing TKAs (0.2% with cirrhosis). To evaluate trends in the use of TJAs, 16,634 patients with cirrhosis who underwent TJAs were identified from the Nationwide Inpatient Sample from 2000 to 2010. RESULTS: Periprosthetic joint infections after THA were more common in patients with cirrhosis for hip fracture (6.3% versus 1.1%; hazard ratio [HR], 5.8; p < 0.001) and nonhip fracture diagnoses (3.7% versus 0.7%; HR, 5.4; p < 0.001). Periprosthetic joint infections were more common after TKA in patients with cirrhosis (2.7% versus 0.8%; HR, 3.4; p < 0.001). Use of TJA increased faster for patients with cirrhosis than for patients without cirrhosis for THAs (140% versus 80%; p = 0.011) and TKAs (213% versus 128%; p < 0.001), and also increased faster than the general increase in use of TJAs. CONCLUSIONS: Periprosthetic joint infections were more common among patients with cirrhosis who had TJAs. Additionally, patients with cirrhosis had longer length of hospital stay, increased costs, and higher rates of mortality, readmission, and reoperation. Finally, national use of TJAs for patients with cirrhosis has increased during the past decade. LEVEL OF EVIDENCE: Level III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Allergy to Local Anesthetics is a Rarity: Review of Diagnostics and Strategies for Clinical Management.

Local anesthetics (LA) are commonly used in procedures and in topical agents for pain management. With the increasing use of LA drugs, the management of LA reactions is more frequently encountered in the office and in operating rooms. True allergic reactions involving IgE-mediated reactions and anaphylaxis are rare; they have only been identified in case reports and account for less than 1% of adverse LA reactions. Most reactions are non-allergic or are a result of hypersensitivity to other culprits such as preservatives, excipients, or other exposures. LA reactions that are misclassified as true allergies can lead to unnecessary avoidance of LA drugs or delays in surgical procedures that require their use. A detailed history of prior LA reactions is the first and most crucial step for understanding the nature of the reaction. Reactions that are suspicious for an immediate hypersensitivity reaction can be evaluated with skin prick and intradermal testing with subsequent graded challenge. Reactions that are suspicious for a delayed hypersensitivity reaction can be evaluated with patch testing.

Artificial intelligence in endoscopy: Overview, applications, and future directions.

Since the emergence of artificial intelligence (AI) in medicine, endoscopy applications in gastroenterology have been at the forefront of innovations. The ever-increasing number of studies necessitates the need to organize and classify applications in a useful way. Separating AI capabilities by computer aided detection (CADe), diagnosis (CADx), and quality assessment (CADq) allows for a systematic evaluation of each application. CADe studies have shown promise in accurate detection of esophageal, gastric and colonic neoplasia as well as identifying sources of bleeding and Crohn's disease in the small bowel. While more advanced CADx applications employ optical biopsies to give further information to characterize neoplasia and grade inflammatory disease, diverse CADq applications ensure quality and increase the efficiency of procedures. Future applications show promise in advanced therapeutic modalities and integrated systems that provide multimodal capabilities. AI is set to revolutionize clinical decision making and performance of endoscopy.

Acquired Fanconi Syndrome from Tenofovir Treatment in a Patient with Hepatitis B.

Fanconi syndrome is a rare disease of generalized proximal tubule dysfunction which can be acquired secondary to certain medications, including tenofovir, a commonly used hepatitis B treatment. Signs and symptoms of ensuing renal wasting can be severe but vague, leading to potentially avoidable invasive investigations and delays in diagnosis. We present a case of a 62-year-old female with chronic hepatitis B on tenofovir treatment who was found to have subacute weakness, anorexia, and weight loss. She underwent extensive investigations including computed tomography (CT) imaging, bronchoscopy, upper and lower endoscopy, and psychiatric evaluation. Finally, persistent electrolyte derangements led to urine studies, which demonstrated acquired Fanconi syndrome secondary to tenofovir. After discontinuing tenofovir disoproxil fumarate and starting tenofovir alafenamide, her symptoms resolved and her renal function recovered. This case illustrates the importance of maintaining clinical suspicion for tenofovir-induced Fanconi syndrome, given the common use of tenofovir as first-line hepatitis B treatment and the availability of less nephrotoxic alternatives.

Survey of the Impact of COVID-19 on Chronic Liver Disease Patient Care Experiences and Outcomes.

Background: The COVID-19 pandemic has a secondary impact on the health of patients with chronic liver disease (CLD). Our objective was to study this impact on care provision, telemedicine, and health behaviours in CLD patients. Methods: CLD patients of an urban gastroenterology clinic who attended a telemedicine appointment between March 17, 2020 and September 17, 2020, completed an online survey on care delays, health behaviours, and experience with telemedicine. Chart review was conducted in 400 randomly selected patients: 200 charts from during the pandemic were compared to 200 charts the previous year. Data were extracted for clinicodemographic variables, laboratory investigations, and clinical outcomes. Results: Of 399 patients invited to participate, 135 (34%) completed the online survey. Fifty (39%) patients reported 83 care delays due to the COVID-19 pandemic, with the majority (71%) of delays persisting beyond 2 months. Ninety-five (75%) patients were satisfied with telemedicine appointments. There was a longer delay between lab work and appointments in patients seen during the pandemic compared to 2019 (P = 0.01). Compared to the year prior, during the COVID pandemic, there was a similar number of cases of cirrhosis decompensation (n = 26, 13% versus n = 22, 11%) and hospitalization (n = 12, 6% versus n = 5, 3%). Conclusion: The COVID-19 pandemic has led to care delays for CLD outpatients, with most delays on the scale of months. These patient-reported experiences and clinical observations can direct optimization of CLD care as effects from the pandemic evolve.

Characterization of Immune Infiltrates Associated With Radiation Necrosis in the Setting of Brain Metastases Following Stereotactic Radiosurgery and Immunotherapy: A Retrospective Cohort Analysis.

INTRODUCTION: Radiation necrosis (RN) is caused by vascular damage and brain parenchymal injury resulting in inflammation following radiotherapy (RT) for brain metastases. The impact of immunotherapy (IO) on the immune cellular microenvironment in patients' brain metastases is unknown. The objective of this study was to characterize the inflammatory microenvironment in the setting of RN compared to recurrent metastasis and determine whether IO treatment affects the cellular infiltrates. METHODS: Adult patients with brain metastases from solid tumors who received both systemic IO and RT prior to resection of intracranial lesions were retrospectively analyzed. The resection either showed biopsy-proven RN or recurrent tumor. A group of patients who developed RN and were not on IO was reviewed as well. A total of 18 patients were categorized into one of three groups: necrosis, IO+RT; tumor, IO+RT; and necrosis, RT. Surgical specimens were stained for immune and inflammatory components and reviewed by a neuro-pathologist who remained blinded during the analysis. The presence or absence of lymphocytes, perivascular cuffs, plasma cells, macrophages, and fibrinoid vascular changes was characterized in a semiquantitative manner. RESULTS: The median age was 61.5 years (range 37-82 years). Seventy-seven percent of primary cancers were melanoma. Patients with RN were more likely to exhibit immune infiltrates compared to patients with recurrent metastasis. Limited analysis showed 100% of patients in "necrosis, IO+RT" had quantifiable cell counts; conversely, 83.3% of patients in "tumor, IO+RT" lacked quantifiable cell counts. Additionally, 83.3% of patients in "necrosis, RT" showed immune cells, including lymphocytes, macrophages, plasma cells, and cuffing. CONCLUSION: The immune microenvironment of brain metastasis following RT and IO showed higher levels of cell infiltrates in the RN setting versus the recurrent tumor setting. Patients who received prior IO compared to those with no IO had similar immune cell infiltrates adjacent to RN. Lower levels of immune cells in tumor recurrence following IO and RT raise the possibility that an environment lacking primed immune cells may decrease the efficacy of IO.

Stereotactic radiosurgery and anti-PD-1 + CTLA-4 therapy, anti-PD-1 therapy, anti-CTLA-4 therapy, BRAF/MEK inhibitors, BRAF inhibitors, or conventional chemotherapy for the management of melanoma brain metastases.

BACKGROUND: Immunotherapy and targeted BRAF/MEK inhibitors (i) have revolutionised the systemic management of advanced melanoma. Given the role of stereotactic radiosurgery (SRS) in the local management of brain metastases, we sought to evaluate clinical outcomes in patients with melanoma brain metastases (MBM) treated with SRS and various systemic therapies. METHODS: Patients were included if MBM were diagnosed and treated with SRS within 3 months of receiving anti-PD-1+CTLA-4 therapy, anti-PD-1 therapy, anti-CTLA-4 therapy, BRAF/MEK-i, BRAF-i, or conventional chemotherapy. Comparisons between groups were made for overall survival (OS), distant MBM control, local MBM, systemic progression-free survival (sPFS), and neurotoxicity. RESULTS: In total, 257 patients with 1048 MBM treated over 368 SRS sessions between 2011 and 2020 were identified. On MVA, treatment with anti-PD1+anti-CTLA-4, anti-PD-1, and BRAF/MEK-i improved distant intracranial control over conventional chemotherapy. No significant differences were noted in local control (LC) between groups (p = 0.78). Kaplan-Meier OS at 12 months for anti-PD-1 + CTLA-4 therapy, anti-PD-1 therapy, anti-CTLA-4 therapy, BRAF/MEK-i, BRAF-i, and conventional chemotherapy was 68%, 59%, 45%, 62%, 21%, and 15%, respectively (p = <0.0001). The sPFS rates at 12 months were 57%, 53%, 42%, 45%, 14%, and 6% (p = <0.0001). No significant differences were noted in rates of radiation necrosis (p = 0.93). CONCLUSIONS: This is among the largest series evaluating MBM treated with SRS and various systemic therapy regimens. Our analysis noted significant differences in OS, distant MBM control, and sPFS by systemic therapy. No differences in LC or radiation necrosis risk were noted.

N-acetylcysteine for non-acetaminophen induced acute liver failure: A review.

The use of N-acetylcysteine (NAC) for non-acetaminophen-induced acute liver failure (NAI-ALF) has been increasing despite controversy in its efficacy. National guidelines are in disagreement for NAC use as standard of care; however, many healthcare centers continue to adopt the use of NAC outside of acetaminophen poisoning. While NAC may have multiple mechanisms of action in treatment of ALF, this has not translated to clinical benefit. Murine models have reported antioxidant and anti-inflammatory properties, as well as improvement in liver-specific microcirculation. Multiple case studies and series have reported positive outcomes of NAC treatment for ALF of various etiologies. While prospective studies suggested the benefit of NAC treatment, these studies have methodological and statistical shortcomings that affect the validity of the results. In this review, we aimed to summarize the existing literature on the efficacy of NAC for NAI-ALF including mechanism of action, case studies and series demonstrating outcomes, and prospective studies that have led to its current widespread use, along with the reported rate of adverse events.

Hemostatic powders for gastrointestinal bleeding: a review of old, new, and emerging agents in a rapidly advancing field.

Background and study aims Hemostatic powders are increasingly used to address limitations in conventional endoscopic techniques for gastrointestinal bleeding. Various agents exist with different compositions, characteristics, efficacy, and adverse events (AEs). We sought to review existing hemostatic powders, from preclinical to established agents. Methods A literature review on hemostatic powders for gastrointestinal bleeding was undertaken through a MEDLINE search from 2000-2021 and hand searching of articles. Relevant literature was critically appraised and reviewed for mechanism of action, hemostasis and rebleeding rate, factors associated with hemostatic failure, and AEs. Results The most established agents are TC-325 (Hemospray), EndoClot, and Ankaferd Blood Stopper (ABS). These agents have been successfully applied to a variety of upper and lower gastrointestinal bleeding etiologies, in the form of primary, combination, salvage, and bridging therapy. Few AEs have been reported, including visceral perforation, venous embolism, and self-limited abdominal pain. Newer agents include CEGP-003 and UI-EWD, which have shown results similar to those for the older agents in initial clinical studies. All aforementioned powders have high immediate hemostasis rates, particularly in scenarios not amenable to conventional endoscopic methods, but are limited by significant rates of rebleeding. Other treatments include TDM-621 (PuraStat) consisting of a liquid hemostatic agent newly applied to endoscopy and self-propelling thrombin powder (CounterFlow Powder), a preclinical but promising agent. Conclusions Rapid development of hemostatic powders and growing clinical expertise has established these agents as a valuable strategy in gastrointestinal bleeding. Further research will continue to refine the efficacy and applicability of these agents.

Non-alcoholic fatty liver disease (NAFLD) in Filipino North American patients: Results from a multi-ethnic cohort.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is more prevalent in certain ethnicities due to a combination of genetic, environmental, and metabolic factors. North American Filipino populations may have lifestyle and metabolic risk factors for NAFLD; however, the prevalence of NAFLD in this group is unknown. We sought to determine whether Filipino patients are over-represented in a multi-ethnic NAFLD cohort and describe their clinical presentation, primarily compared to other ethnicities in the same geographical region and secondarily compared to Manila-based Filipino patients. METHODS: A cross-sectional study was conducted with patients with NAFLD who were followed at the Hepatology Clinic at Vancouver General Hospital, Canada, from January 2015 to August 2018. Data were extracted for clinicodemographic data, ethnicity, anthropometric measures, blood work, and transient elastography (TE). External comparison data was obtained online from the Metro Vancouver census and a NAFLD study conducted in Manila, Philippines. RESULTS: Of 317 patients meeting inclusion criteria for the study, 224 patients had complete datasets. The mean age was 51.1 years, and 50% were female. There were 139 (62%) Caucasian and other ethnicity patients, 55 (25%) Asian patients, and 30 (13%) Filipino patients. Compared to other ethnic groups, the Filipino group had similar clinical characteristics, including NAFLD fibrosis scores and TE. Of included NAFLD patients, the proportion of Filipino patients (13.39%) was significantly greater than the proportion of Filipino residents in Metro Vancouver (5.52%, p <0.01). Our Filipino Canadians seemed to be younger, with fewer females and a lower proportion of diabetes mellitus, but a higher proportion of hypertension than the previously reported cohort from Manila. CONCLUSIONS: While Filipino patients have not previously been examined in multi-ethnic NAFLD studies, they may represent a high-risk population. Further research is needed to clarify the prevalence and presentation of NAFLD in Filipino Canadian patients, as this appears to be a significant health issue in this community.

Liver Transplant Recipients Speak Out on Public Awareness and Education Surrounding Alcohol-Related Health Effects: A Survey Study.

BACKGROUND: Compared to other recreational substances in Canada, alcohol consumption incurs the highest healthcare costs. Liver transplant recipients are unique stakeholders as members of the general public with lived experiences of liver disease. We sought to explore their perspectives on the current state of public education on alcohol-related health effects. METHODS: The most recent 400 liver transplant recipients at Vancouver General Hospital, Canada, were invited to participate in an anonymous online survey on alcohol-related health effects by mail, email, and phone. RESULTS: Of 372 contacted patients, 212 (57%) completed the survey. Most patients were between 60-79 years, 63% were male, and 69% were Caucasian. The most common liver conditions leading to transplant were viral hepatitis (33%), alcohol-related liver disease (16%), autoimmune liver disease (14%), and non-alcoholic fatty liver disease (15%). Most patients knew that alcohol leads to liver failure (85%), but fewer knew about alcohol leading to cancer (54%), heart disease (50%), and damage to other organs (58%). Most common sources of information included public media (61%), family and friends (52%), and physicians (49%), with narrative comments about learning of alcohol-related health effects after liver diagnosis. Most patients believed that public health education at a middle/high school level would have long-term efficacy (72%) compared to health warning labels (33%) and safety messaging in commercials (39%). Current public education was felt to be adequate by only 20% of patients and 73% of patients supported health warning labels. CONCLUSIONS: Liver transplant patients reported a high, but not universal, awareness of alcohol-related health effects. A majority thought that current public health efforts were inadequate; it is critical to implement public health interventions to ensure consumers are able to make an informed decision on alcohol consumption.

The Role of Regulatory T Cells in Pulmonary Arterial Hypertension.

Pulmonary arterial hypertension (PAH) is a chronic, incurable condition characterized by pulmonary vascular remodeling, perivascular inflammation, and right heart failure. Regulatory T cells (Tregs) stave off autoimmunity, and there is increasing evidence for their compromised activity in the inflammatory milieu of PAH. Abnormal Treg function is strongly correlated with a predisposition to PAH in animals and patients. Athymic Treg-depleted rats treated with SU5416, an agent causing pulmonary vascular injury, develop PAH, which is prevented by infusing missing CD4+CD25highFOXP3+ Tregs. Abnormal Treg activity may also explain why PAH disproportionately affects women more than men. This mini review focuses on the role of Tregs in PAH with a special view to sexual dimorphism and the future promise of Treg therapy.

Systemic Inflammatory Markers of Survival in Epidermal Growth Factor-Mutated Non-Small-Cell Lung Cancer: Single-Institution Analysis, Systematic Review, and Meta-analysis.

BACKGROUND: Systemic inflammatory response (SIR) may influence prognosis in epidermal growth factor receptor (EGFR)-mutated (m) non-small-cell lung cancer (NSCLC). Pretreatment SIR markers (neutrophil-to-lymphocyte ratio [NLR], platelet-to-lymphocyte ratio, lymphocyte-to-monocyte ratio [LMR], lactate dehydrogenase [LDH], and lung immune prognostic index [LIPI]) were assessed as prognostic factors in NSCLC survival. PATIENTS AND METHODS: Retrospective survival analysis (overall survival [OS] and progression-free survival [PFS]) of EGFR-mutated NSCLC patients at Princess Margaret Cancer Centre were performed separately for early (I-IIIa) and late (IIIb-IV) stage disease for individual SIR variables, dichotomized by optimal cutoff points by Kaplan-Meier survival analysis and multivariable Cox proportional hazard modeling. A systematic review and meta-analysis of known SIR studies in patients with late-stage EGFR-mutated were also performed. RESULTS: From 2012 to 2019, in 530 patients, significant adjusted hazard ratios (aHR) for OS comparing high versus low NLR were 2.12 for early stage and 1.79 for late stage disease. Additionally, late stage cohorts had significant associations, as follows: high versus low derived NLR, aHR = 1.53; LMR, aHR = 0.62; LDH, aHR = 2.04; and LIPI, aHR = 2.04. Similar patterns were found for PFS in early stage NLR (aHR = 1.96) and late stage NLR (aHR = 1.46), while for PFS, only late stage derived NLR (aHR = 1.34), LDH (aHR = 1.75), and LIPI (aHR = 1.66) were significant. A meta-analysis confirmed that NLR, LMR, LDH, and LIPI were all significantly associated with OS and PFS in the late stage. CONCLUSION: This primary study and meta-analysis demonstrated that LMR and LDH were significantly associated with late stage EGFR-mutated NSCLC outcomes, and the LIPI scoring system was prognostic. NLR remained an independent prognostic factor across all stages and could represent an early marker of immuno-oncology interactions.

Propagating the "SEAD": Exploring the Value of an Overnight Call Shift in the Surgical Exploration and Discovery (SEAD) Program.

OBJECTIVE: Attrition of general surgery residents highlights a need to support well-informed specialty selection. This study evaluated preclerkship medical students' perception of overnight call shifts in surgical career exploration. DESIGN: A mixed-methods design was used, involving entry and postcall shift surveys and focus groups. Survey data characterized the population and call shift, guided focus group segmentation by baseline interest in surgery, and provided context for interpretation of qualitative data. Focus groups were transcribed and analyzed with a phenomenological approach using thematic analysis. SETTING: Call shifts took place at the University of Toronto's Sunnybrook Health Sciences Centre and St. Michael's Hospital, 2 Level 1 trauma centers in Toronto, Canada. PARTICIPANTS: Twenty-five first-year medical students participating in the Surgical Exploration and Discovery program. RESULTS: Sixty-four percent (n = 16) of the participants were male. Students in the high interest group (n = 9) had more prior operating room exposure than students in the moderate (n = 12) and low (n = 4) interest groups (p = 0.039). Most students valued participating in a call shift; 80% (n = 20) rated the experience "positive" or "very positive." Thematic analysis yielded 2 categories of themes: (1) Valuable aspects of the experience, including being part of a team, mentorship, understanding the clerk's role, dispelling misconceptions, trial of working overnight, and influencing interest in a surgical career; and (2) Determinants of an enjoyable experience, including resident engagement and number of traumas. CONCLUSIONS: An overnight call shift experience was valuable to preclerkship medical students regardless of baseline interest in surgery. While it only influenced a few students' specialty preferences, exposure facilitated a better understanding of a unique component of surgical careers and provided valuable mentorship. These findings support implementing calls shifts in other curricular or extracurricular programs to make the experience more widely available and enable earlier, informed career decision-making.

MPEG1/Perforin-2 Haploinsufficiency Associated Polymicrobial Skin Infections and Considerations for Interferon-γ Therapy.

Introduction: Macrophage expressed gene 1 (MPEG1) is highly expressed in macrophages and other phagocytes. The gene encodes a bactericidal pore-forming protein, dubbed Perforin-2. Structural-, animal-, and cell-based studies have established that perforin-2 facilitates the destruction of phagocytosed microbes upon its activation within acidic phagosomes. Relative to wild-type controls, Mpeg1 knockout mice suffer significantly higher mortality rates when challenged with gram-negative or -positive pathogens. Only four variants of MPEG1 have been functionally characterized, each in association with pulmonary infections. Here we report a new MPEG1 non-sense variant in a patient with the a newly described association with persistent polymicrobial infections of the skin and soft tissue. Case Description: A young adult female patient was evaluated for recurrent abscesses and cellulitis of the breast and demonstrated a heterozygous, rare variant in MPEG1 p.Tyr430*. Multiple courses of broad-spectrum antimicrobials and surgical incision and drainage failed to resolve the infection. Functional studies revealed that the truncation variant resulted in significantly reduced capacity of the patient's phagocytes to kill intracellular bacteria. Patient-derived macrophages responded to interferon gamma (IFN-γ) by significantly increasing the expression of MPEG1. IFN-γ treatment supported perforin-2 dependent bactericidal activity and wound healing. Conclusions: This case expands the phenotype of MPEG1 deficiency to include severe skin and soft tissue infection. We showed that haploinsufficiency of perforin-2 reduced the bactericidal capacity of human phagocytes. Interferon-gamma therapy increases expression of perforin-2, which may compensate for such variants. Thus, treatment with IFN-γ could help prevent infections.