Porcine-derived pancreatic enzyme replacement therapy may be linked to chronic hepatitis E virus infection in cystic fibrosis lung transplant recipients.

OBJECTIVES: In high-income countries hepatitis E virus (HEV) is an uncommonly diagnosed porcine-derived zoonoses. After identifying disproportionate chronic HEV infections in persons with cystic fibrosis (pwCF) postlung transplant, we sought to understand its epidemiology and potential drivers. DESIGN: All pwCF post-transplant attending our regional CF centre were screened for HEV. HEV prevalence was compared against non-transplanted pwCF and with all persons screened for suspected HEV infection from 2016 to 2022 in Alberta, Canada. Those with chronic HEV infection underwent genomic sequencing and phylogenetic analysis. Owing to their swine derivation, independently sourced pancreatic enzyme replacement therapy (PERT) capsules were screened for HEV. RESULTS: HEV seropositivity was similar between transplanted and non-transplanted pwCF (6/29 (21%) vs 16/83 (19%); p=0.89). Relative to all other Albertans investigated for HEV as a cause of hepatitis (n=115/1079, 10.7%), pwCF had a twofold higher seropositivity relative risk and this was four times higher than the Canadian average. Only three chronic HEV infection cases were identified in all of Alberta, all in CF lung transplant recipients (n=3/29, 10.3%). Phylogenetics confirmed cases were unrelated porcine-derived HEV genotype 3a. Ninety-one per cent of pwCF were taking PERT (median 8760 capsules/person/year). HEV RNA was detected by RT-qPCR in 44% (47/107) of PERT capsules, and sequences clustered with chronic HEV cases. CONCLUSION: PwCF had disproportionate rates of HEV seropositivity, regardless of transplant status. Chronic HEV infection was evident only in CF transplant recipients. HEV may represent a significant risk for pwCF, particularly post-transplant. Studies to assess HEV incidence and prevalence in pwCF, and potential role of PERT are required.

A case of hypercalcemia from Pneumocystis jirovecii in an immunosuppressed non-HIV patient.

BACKGROUND: The prevalence of non-HIV related Pneumocystis jirovecii pneumonia (PJP) is increasing with use of immunosuppressive therapies. There are case reports of solid organ transplant recipients on immunosuppressive therapy presenting with mild hypercalcemia, leading to a diagnosis of PJP. Recent studies have shown efficacy of PJP prophylaxis for patients treated with rituximab with a favourable adverse effect profile. CASE PRESENTATION: A 78-year-old male with a history of PR3-ANCA vasculitis, chronic kidney disease and heart failure with reduced ejection fraction presented to our tertiary care hospital with a two-week history of confusion and non-productive cough. Background immunosuppression with rituximab was completed every six months. The patient was found to have hypercalcemia and new infiltrates and ground glass opacities on cross-sectional imaging. Bronchoscopy was performed that was positive for Pneumocystis jirovecii. He was treated with 21 days of trimethoprim-sulfamethoxazole and prednisone with resolution of symptoms and hypercalcemia. CONCLUSIONS: Herein, we present a novel case of PJP in a non-transplant recipient preceded by hypercalcemia. Our case demonstrates the importance for a high suspicion for PJP in chronically immunosuppressed patients on rituximab presenting with PTH-independent hypercalcemia.

Evaluating Sinus Microbiology by Transplant Status in Persons With Cystic Fibrosis: A Matched Cohort Study.

Objective: Sinus disease is prevalent in persons with cystic fibrosis (PwCF) and may be a reservoir of airway infection in postlung transplant (pTx) patients. The microbial composition of cystic fibrosis sinuses and its associations with chronic rhinosinusitis (CRS) is relatively unexplored. We aimed to examine the sinus and lower airway microbiome and their associations with CRS in PwCF and pTxPwCF. Study Design: Prospective single-centre study. Setting: A total of 31 sex and age (±2 years) matched PwCF and pTxPwCF. Methods: Demographic and clinical data along with sinus swabs and sputum were collected. CRS was assessed using Sinonasal Outcome Test-22 (SNOT-22) (patient reported outcome) and Lund-McKay (computed tomography sinus) scores. Samples underwent MiSeq Illumina sequencing of the universal 16S ribosomal RNA gene. Results: A total of 31 PwCF (15 pTxPwCF) were included. Aggregate airways microbiome composition was dominated by Pseudomonas (46%), Haemophilus (14%), Staphylococcus (11%), Streptococcus (10%), and Fusobacterium (6%). α-diversity was significantly lower in post-Tx samples across both sputum and sinus samples (P = .005). ß-diversity was significantly different between sputum (P = .004), but not sinus (P = .75) samples by transplant status. While there was a trend in higher ß-diversity associated with lower SNOT-22 score at time of first visit, this did not reach significance (P = .05). Conclusion: Sinus and airway microbiomes differed in PwCF and pTxPwCF, but the prevalent organisms remained consistent. Elucidating the relationship of the microbiome with clinical status to better understand when to intervene accordingly is needed to optimize sinus disease management in PwCF.

Prevalence and Clinical Impact of Respiratory Viral Infections from the STOP2 Study of Cystic Fibrosis Pulmonary Exacerbations.

RATIONALE: Rates of viral respiratory infection (VRI) are similar in people with cystic fibrosis (CF) and the general population; however, the associations between VRI and CF pulmonary exacerbations (PEx) require further elucidation. OBJECTIVES: To determine VRI prevalence during CF PEx and evaluate associations between VRI, clinical presentation, and treatment response. METHODS: The Standardized Treatment of Pulmonary Exacerbations II (STOP2) study was a multicenter, randomized trial to evaluate different durations of intravenous antibiotic therapy for PEx. In this ancillary study, participant sputum samples from up to three study visits were tested for respiratory viruses using multiplex PCR. Baselines and treatment associated changes in mean lung function (percent predicted forced expiratory volume in one second; ppFEV1), respiratory symptoms (Chronic Respiratory Infection Symptom Score; CRISS), weight, and C-reactive protein (CRP) were compared as a function of virus detection. Odds of PEx retreatment within 30 days and future PEx hazard were modeled by logistic and Cox proportional hazards regression, respectively. RESULTS: A total of 1,254 sputum samples from 621 study participants were analyzed. One or more respiratory viruses were detected in sputum samples from 245 participants (39.5%). Virus-positive participants were more likely to be receiving CF transmembrane conductance regulator (CFTR) modulator therapy (45% vs. 34%) and/or chronic azithromycin therapy (54% vs. 44%), and more likely to have received treatment for nontuberculous mycobacterium infection in the preceding two years (7% vs. 3%). At study visit 1, virus-positive participants were more symptomatic (mean CRISS score 53.8 vs. 51.1), had evidence of greater systemic inflammation (log10CRP concentration: 1.32 log10 mg/L vs. 1.23 log10 mg/L), and had a greater drop in ppFEV1 from the prior 6-month baseline (5.8 vs 3.6). Virus positivity was associated with reduced risk of future PEx (HR: 0.82, 95% CI: 0.69-0.99; p=0.034) and longer median time to next PEx (255 days vs. 172 days, p=0.021) compared to virus-negativity. CONCLUSIONS: Over one-third of STOP2 participants treated for a PEx tested positive for a respiratory virus with more symptomatic initial presentation compared to virus-negative participants, but favorable long-term outcomes. More refined phenotyping of PEx, taking VRIs into account, may aid in optimizing personalized management of PEx. CLINICAL TRIAL REGISTRATION: NCT02781610 Primary Source of Funding: Cystic Fibrosis Foundation.

A 17-Year-Old Male With Hypoxemia After Long-Bone Fracture.

CASE PRESENTATION: An otherwise healthy 17-year-old male patient presented to a periphery hospital with a compound fracture of the right distal tibia and fibula after a traumatic accident on a ski trip. He was treated empirically with IV cefazolin before undergoing open reduction with internal fixation with intramedullary nail for surgical fixation. Postoperatively, he became febrile, tachypneic, and hypoxemic, requiring up to 6 L/min supplemental oxygen by nasal prongs. He reported mild chest discomfort but denied productive cough, hemoptysis, or calf tenderness. Because of nonresolving oxygen demands, on postoperative day (POD) 4, he was transferred to a tertiary care center for further management.

Prevalence and impact of human papillomavirus (HPV) in adults with cystic fibrosis: A self-reported cross-sectional Canadian survey.

BACKGROUND: In persons with cystic fibrosis (pwCF), little is known about the prevalence or impact of HPV on quality of life and attitudes towards vaccination. METHODS: We conducted a national online survey of adult pwCF. We sought to determine the prevalence of self-reported HPV infection, disease-associated complications and effects on quality of life. Additionally, we investigated factors associated with vaccination status. RESULTS: A total of 235 adult pwCF across Canada (≥18 years, 68% female) completed the survey. Forty-eight percent of female pwCF had a history of abnormal Pap smear, with 62% self-reporting a 'no' or 'low' chance of risk of HPV-associated disease. Across participants, 12% reported at least one HPV-associated complication including anogenital warts (58%), HPV-associated malignancies (34%) and cervical dysplasia requiring colposcopy (69%). Only 19% reported discussions with their CF care provider around HPV complications. Across both sexes, pwCF experienced high psychosocial burden in the domains of 'worries and concerns', 'sexual impact' and 'self-image'. Sixty percent of adult pwCF were unvaccinated for HPV. Eighty-one percent reported never having discussed HPV vaccination with their CF care provider, with similar rates in vaccinated and unvaccinated groups. Barriers to vaccination included: lack of discussions with healthcare providers (31%), insured coverage (based on age) (19%) and perceived side effects/risk (10%). CONCLUSIONS: Across adult pwCF, we found high prevalence of HPV disease and associated HPV-psychosocial burden and low vaccination uptake. Given the limited medical discussions reported, incorporation of HPV prevention and management should be prioritized by CF care providers as part of comprehensive multimodal care.

Stenotrophomonas maltophilia natural history and evolution in the airways of adults with cystic fibrosis.

Introduction: Stenotrophomonas maltophilia is an opportunistic pathogen infecting persons with cystic fibrosis (pwCF) and portends a worse prognosis. Studies of S. maltophilia infection dynamics have been limited by cohort size and follow-up. We investigated the natural history, transmission potential, and evolution of S. maltophilia in a large Canadian cohort of 321 pwCF over a 37-year period. Methods: One-hundred sixty-two isolates from 74 pwCF (23%) were typed by pulsed-field gel electrophoresis, and shared pulsotypes underwent whole-genome sequencing. Results: S. maltophilia was recovered at least once in 82 pwCF (25.5%). Sixty-four pwCF were infected by unique pulsotypes, but shared pulsotypes were observed between 10 pwCF. In chronic carriage, longer time periods between positive sputum cultures increased the likelihood that subsequent isolates were unrelated. Isolates from individual pwCF were largely clonal, with differences in gene content being the primary source of genetic diversity objectified by gene content differences. Disproportionate progression of CF lung disease was not observed amongst those infected with multiple strains over time (versus a single) or amongst those with shared clones (versus strains only infecting one patient). We did not observe evidence of patient-to-patient transmission despite relatedness between isolates. Twenty-four genes with ≥ 2 mutations accumulated over time were identified across 42 sequenced isolates from all 11 pwCF with ≥ 2 sequenced isolates, suggesting a potential role for these genes in adaptation of S. maltophilia to the CF lung. Discussion: Genomic analyses suggested common, indirect sources as the origins of S. maltophilia infections in the clinic population. The information derived from a genomics-based understanding of the natural history of S. maltophilia infection within CF provides unique insight into its potential for in-host evolution.

Quantifying variation in home spirometry in people with cystic fibrosis during baseline health, and associations with clinical outcomes.

BACKGROUND: Home spirometry is increasingly used to monitor lung function in people with cystic fibrosis (pwCF). Although decreases in lung function in the setting of increased respiratory symptoms are consistent with a pulmonary exacerbation (PEx), the interpretation of home spirometry during asymptomatic periods of baseline health is unclear. The aims of this study were to determine the variation in home spirometry in pwCF during asymptomatic periods of baseline health and to identify associations between this variation and PEx. METHODS: Near-daily home spirometry measurements were obtained from a cohort of pwCF enrolled in a long-term study of the airway microbiome. Associations between the degree of variation in home spirometry and the time to next PEx were evaluated. RESULTS: Thirteen subjects (mean age of 29 years and mean percent predicted forced expiratory volume in one second [ppFEV1] of 60) provided a median of 204 spirometry readings taken during 40 periods of baseline health. The mean week-to-week within-subject level of variation in ppFEV1 was 15.2 ± 6.2%. The degree of variation in ppFEV1 during baseline health was not associated with time to PEx. CONCLUSIONS: Variation in ppFEV1 measured with near-daily home spirometry in pwCF during periods of baseline health exceeded the variation in ppFEV1 expected in clinic spirometry (based on ATS guidelines). The degree of variation in ppFEV1 during baseline health was not associated with time to PEx. These data are relevant for guiding interpretation of home spirometry.

Microbial Epidemiology of the Cystic Fibrosis Airways: Past, Present, and Future.

Progressive obstructive lung disease secondary to chronic airway infection, coupled with impaired host immunity, is the leading cause of morbidity and mortality in cystic fibrosis (CF). Classical pathogens found in the airways of persons with CF (pwCF) include Pseudomonas aeruginosa, Staphylococcus aureus, the Burkholderia cepacia complex, Achromobacter species, and Haemophilus influenzae. While traditional respiratory-tract surveillance culturing has focused on this limited range of pathogens, the use of both comprehensive culture and culture-independent molecular approaches have demonstrated complex highly personalized microbial communities. Loss of bacterial community diversity and richness, counteracted with relative increases in dominant taxa by traditional CF pathogens such as Burkholderia or Pseudomonas, have long been considered the hallmark of disease progression. Acquisition of these classic pathogens is viewed as a harbinger of advanced disease and postulated to be driven in part by recurrent and frequent antibiotic exposure driven by frequent acute pulmonary exacerbations. Recently, CF transmembrane conductance regulator (CFTR) modulators, small molecules designed to potentiate or restore diminished protein levels/function, have been successfully developed and have profoundly influenced disease course. Despite the multitude of clinical benefits, structural lung damage and consequent chronic airway infection persist in pwCF. In this article, we review the microbial epidemiology of pwCF, focus on our evolving understanding of these infections in the era of modulators, and identify future challenges in infection surveillance and clinical management.

Airway bacterial community composition in persons with advanced cystic fibrosis lung disease.

BACKGROUND: The progression of lung disease in people with cystic fibrosis (pwCF) has been associated with a decrease in the diversity of airway bacterial communities. How often low diversity communities occur in advanced CF lung disease and how they may be associated with clinical outcomes is not clear, however. METHODS: We sequenced a region of the bacterial 16S ribosomal RNA gene to characterize bacterial communities in sputum from 190 pwCF with advanced lung disease (FEV1≤40% predicted), with particular attention to the prevalence and relative abundance of dominant genera. We evaluated relationships between community diversity and clinical outcomes. RESULTS: Although most of the 190 pwCF with advanced lung disease had airway bacterial communities characterized by low diversity with a dominant genus, a considerable minority (40%) did not. The absence of a dominant genus, presence of methicillin-susceptible Staphylococcus aureus, and greater bacterial richness positively correlated with lung function. Higher relative abundance of the dominant genus and greater antimicrobial use negatively correlated with lung function. PwCF with a low diversity community and dominant genus had reduced lung transplant-free survival compared to those without (median survival of 1.6 vs 2.9 years). CONCLUSIONS: A considerable proportion of pwCF with advanced lung disease do not have airway bacterial communities characterized by low diversity and a dominant genus and these individuals had better survival. An understanding of the antecedents of low diversity airway communities- and the impact these may have on lung disease trajectory - may provide avenues for improved management strategies.

Assessment of factors and interventions towards therapeutic adherence among persons with non-cystic fibrosis bronchiectasis.

Non-cystic fibrosis bronchiectasis (NCFB) is a highly prevalent chronic respiratory disease with substantial burden to both patients and healthcare systems. Persons with NCFB (pwNCFB) are often given complex acute and chronic treatment regimens consisting of medications, airway clearance techniques and exercise. Accordingly, the high burden in NCFB has contributed to lower therapy adherence, with estimates of 53% to medications, 41% to airway clearance and only 16% to all prescribed therapy. Consequent clinical outcomes from lower adherence include reduced quality of life, accelerated lung function decline and recurrent pulmonary exacerbations. In this narrative review, we explore the impact of multifactorial mechanisms underpinning adherence in NCFB and evaluate the available evidence towards interventions to improve uptake of therapy as demonstrated in other chronic respiratory diseases. A holistic approach, starting with a careful review of patient adherence at regular intervals, may increase the success of multidimensional therapeutic interventions in pwNCFB, but robust ongoing studies are an area of need in this population.

Exploring the Cystic Fibrosis Lung Microbiome: Making the Most of a Sticky Situation.

Chronic lower respiratory tract infections are a leading contributor to morbidity and mortality in persons with cystic fibrosis (pwCF). Traditional respiratory tract surveillance culturing has focused on a limited range of classic pathogens; however, comprehensive culture and culture-independent molecular approaches have demonstrated complex communities highly unique to each individual. Microbial community structure evolves through the lifetime of pwCF and is associated with baseline disease state and rates of disease progression including occurrence of pulmonary exacerbations. While molecular analysis of the airway microbiome has provided insight into these dynamics, challenges remain including discerning not only "who is there" but "what they are doing" in relation to disease progression. Moreover, the microbiome can be leveraged as a multi-modal biomarker for both disease activity and prognostication. In this article, we review our evolving understanding of the role these communities play in pwCF and identify challenges in translating microbiome data to clinical practice.

Impact of wait times for treatment on clinical outcomes in patients with obstructive sleep apnoea: protocol for a randomised controlled trial.

Background: Obstructive sleep apnoea (OSA) is a common chronic condition that is associated with significant morbidity and economic cost. Prolonged wait times are increasingly being recognised as a barrier to diagnosis and treatment of many chronic diseases; however, no study to date has prospectively evaluated the impact of wait times on health outcomes in OSA. Objective: The purpose of this study is to determine whether treatment outcomes for individuals with OSA differ between patients managed using an expedited versus standard pathway. Methods: A pragmatic randomised controlled trial design will be used with a target sample size of 200 adults. Participants with clinically significant uncomplicated OSA will be recruited through referrals to a large tertiary care sleep centre (Calgary, AB, Canada) and randomised to either early management (within 1 month) or usual care (∼6 months) with a 1:1 allocation using a concealed computer-generated randomisation sequence. The primary outcome will be adherence to positive airway pressure (PAP) therapy at 3 months after treatment initiation. Secondary outcomes will include change in sleepiness, quality of life, patient satisfaction, and patient engagement with therapy from baseline to 3 months after PAP initiation, measured using validated questionnaires and qualitative methods. Anticipated results: This study will determine whether expedited care for OSA leads to differences in PAP adherence and/or patient-reported outcomes. More broadly, the findings of this study may improve the understanding of how wait time reductions impact health outcomes for other chronic diseases.

Prolonged SARS-CoV-2 infection following rituximab treatment: clinical course and response to therapeutic interventions correlated with quantitative viral cultures and cycle threshold values.

BACKGROUND: Detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA is completed through reverse transcriptase-PCR (RT-PCR) from either oropharyngeal or nasopharyngeal swabs, critically important for diagnostics but also from an infection control lens. Recent studies have suggested that COVID-19 patients can demonstrate prolonged viral shedding with immunosuppression as a key risk factor. CASE PRESENTATION: We present a case of an immunocompromised patient with SARS-CoV-2 infection demonstrating prolonged infectious viral shedding for 189 days with virus cultivability and clinical relapse with an identical strain based on whole genome sequencing, requiring a multi-modal therapeutic approach. We correlated clinical parameters, PCR cycle thresholds and viral culture until eventual resolution. CONCLUSIONS: We successfully demonstrate resolution of viral shedding, administration of COVID-19 vaccination and maintenance of viral clearance. This case highlights implications in the immunosuppressed patient towards infection prevention and control that should consider those with prolonged viral shedding and may require ancillary testing to fully elucidate viral activity. Furthermore, this case raises several stimulating questions around complex COVID-19 patients around the role of steroids, effect of antiviral therapies in absence of B-cells, role for vaccination and the requirement of a multi-modal approach to eventually have successful clearance of the virus.