Toll-like Receptor 9 Inhibition Mitigates Fibroproliferative Responses in Translational Models of Pulmonary Fibrosis.

RATIONALE: Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease for which current treatment options only slow clinical progression. Previously, we identified a subset of patients with IPF with an accelerated disease course associated with fibroblast expression of Toll-Like Receptor 9 (TLR9) mediated by interactions with its ligand mitochondrial DNA (mtDNA). OBJECTIVES: We aimed to show that TLR9 activation induces fibroproliferative responses that are abrogated by its antagonism by using two commercially-available indirect inhibitors and a proprietary, selective direct small molecule inhibitor. METHODS: We employed two independent cohorts of patients with IPF, multiple in vitro fibroblast cell culture platforms, an in vivo mouse model, and an ex vivo human precision cut lung slices system to investigate the clinical and biologic significance of TLR9 in this disease. MEASUREMENTS AND MAIN RESULTS: In two independent IPF cohorts, plasma mtDNA activates TLR9 in a manner associated with the expression of MCP-1, IL-6, TNFα, and IP-10 and worsened transplant-free survival. Our cell culture platform showed that TLR9 mediates fibroblast activation via TGFß1 and stiff substrates, and that its antagonism, particularly direct inhibition, ameliorates this process, including production of these TLR9 associated pharmacodynamic endpoints. We further demonstrated that direct TLR9 inhibition mitigates these fibroproliferative responses in our in vivo and ex vivo models of pulmonary fibrosis. CONCLUSIONS: In this novel study, we found that direct TLR9 inhibition mitigates fibroproliferative responses in preclinical models of pulmonary fibrosis. Our work demonstrates the therapeutic potential of direct TLR9 antagonism in IPF and related fibrotic lung diseases.

Effectiveness of Paxlovid in Reducing Severe Coronavirus Disease 2019 and Mortality in High-Risk Patients.

BACKGROUND: Paxlovid was granted an Emergency Use Authorization for the treatment of mild to moderate coronavirus disease 2019 (COVID-19), based on the interim analysis of the Evaluation of Protease Inhibition for COVID-19 in High-Risk Patients (EPIC-HR) trial. Paxlovid effectiveness needs to be assessed in a noncontrolled setting. In this study we used population-based real-world data to evaluate the effectiveness of Paxlovid. METHODS: The database of the largest healthcare provider in Israel was used to identify all adults aged 18 years or older with first-ever positive test for severe acute respiratory syndrome coronavirus 2 between January and February 2022, who were at high risk for severe COVID-19 and had no contraindications for Paxlovid use. Patients were included irrespective of their COVID-19 vaccination status. Cox hazard regression was used to estimate the 28-day hazard ratio (HR) for severe COVID-19 or mortality with Paxlovid examined as time-dependent variable. RESULTS: Overall, 180 351 eligible patients were included; of these, only 4737 (2.6%) were treated with Paxlovid, and 135 482 (75.1%) had adequate COVID-19 vaccination status. Both Paxlovid and adequate COVID-19 vaccination status were associated with significant decrease in the rate of severe COVID-19 or mortality with adjusted HRs of 0.54 (95% confidence interval [CI], .39-.75) and 0.20 (95% CI, .17-.22), respectively. Paxlovid appears to be more effective in older patients, immunosuppressed patients, and patients with underlying neurological or cardiovascular disease (interaction P < .05 for all). No significant interaction was detected between Paxlovid treatment and COVID-19 vaccination status. CONCLUSIONS: This study suggests that in the era of Omicron and in real-life settings, Paxlovid is highly effective in reducing the risk of severe COVID-19 or mortality.

Effectiveness of Molnupiravir in High-Risk Patients: A Propensity Score Matched Analysis.

BACKGROUND: Molnupiravir was granted emergency use authorization for the treatment of mild to moderate coronavirus disease 2019 (COVID-19). In this study, we used population-based real-world data to evaluate the effectiveness of molnupiravir. METHODS: The database of the largest healthcare provider in Israel was used to identify all adults with first-ever positive test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) performed in the community during January-February 2022, who were at high risk for severe COVID-19, and had no contraindications for molnupiravir use. Patients were included regardless of SARS-CoV-2 vaccination status. A total of 2661 patients who received molnupiravir were propensity score matched with 2661 patients who have not received molnupiravir (control group). Patients were followed through 10 March 2022 for up to 28 days for the first occurrence of the composite severe COVID-19 or COVID-19-specific mortality. RESULTS: The composite outcome occurred in 50 patients in the molnupiravir group and 60 patients in the control group. Molnupiravir was associated with a nonsignificant reduced risk of the composite outcome: hazard ratio, 0.83 (95% confidence interval, .57-1.21). However, subgroup analyses showed that molnupiravir was associated with a significant decrease in the risk of the composite outcome in older patients 0.54 (0.34-0.86), in females 0.41 (0.22-0.77), and in patients with inadequate COVID-19 vaccination 0.45 (0.25-0.82). The results were similar when each component of the composite outcome was examined separately. CONCLUSIONS: This study suggests that in the era of Omicron and in real-life setting, molnupiravir might be effective in reducing the risk of severe COVID-19 and COVID-19-related mortality, particularly in specific subgroups.

Bronchial epithelium epithelial-mesenchymal plasticity forms aberrant basaloid-like cells in vitro.

Although epithelial-mesenchymal transition (EMT) is a common feature of fibrotic lung disease, its role in fibrogenesis is controversial. Recently, aberrant basaloid cells were identified in fibrotic lung tissue as a novel epithelial cell type displaying a partial EMT phenotype. The developmental origin of these cells remains unknown. To elucidate the role of EMT in the development of aberrant basaloid cells from the bronchial epithelium, we mapped EMT-induced transcriptional changes at the population and single-cell levels. Human bronchial epithelial cells grown as submerged or air-liquid interface (ALI) cultures with or without EMT induction were analyzed by bulk and single-cell RNA-Sequencing. Comparison of submerged and ALI cultures revealed differential expression of 8,247 protein coding (PC) and 1,621 long noncoding RNA (lncRNA) genes and revealed epithelial cell-type-specific lncRNAs. Similarly, EMT induction in ALI cultures resulted in robust transcriptional reprogramming of 6,020 PC and 907 lncRNA genes. Although there was no evidence for fibroblast/myofibroblast conversion following EMT induction, cells displayed a partial EMT gene signature and an aberrant basaloid-like cell phenotype. The substantial transcriptional differences between submerged and ALI cultures highlight that care must be taken when interpreting data from submerged cultures. This work supports that lung epithelial EMT does not generate fibroblasts/myofibroblasts and confirms ALI cultures provide a physiologically relevant system to study aberrant basaloid-like cells and mechanisms of EMT. We provide a catalog of PC and lncRNA genes and an interactive browser (https://bronc-epi-in-vitro.cells.ucsc.edu/) of single-cell RNA-Seq data for further exploration of potential roles in the lung epithelium in health and lung disease.

Cognitive dysfunction following COVID-19 infection.

The coronavirus (COVID-19) pandemic is still evolving, causing hundreds of millions of infections around the world. The long-term sequelae of COVID-19 and neurologic syndromes post COVID remain poorly understood. The present study aims to characterize cognitive performance in patients experiencing cognitive symptoms post-COVID infection. Patients evaluated at a post COVID clinic in Northern Israel who endorsed cognitive symptoms were referred for neurologic consultation. The neurologic work-up included detailed medical history, symptom inventory, neurological examination, the Montreal Cognitive Assessment (MoCA), laboratory tests and brain CT or MRI. Between December 2020 and June 2021, 46 patients were referred for neurological consultation (65% female), mean age 49.5 (19-72 years). On the MoCA test, executive functions, particularly phonemic fluency, and attention, were impaired. In contrast, the total MoCA score, and memory and orientation subscores did not differ from expected ranges. Disease severity, premorbid condition, pulmonary function tests and hypoxia did not contribute to cognitive performance. Cognitive decline may affect otherwise healthy patients post-COVID, independent of disease severity. Our examination identified abnormalities in executive function, attention, and phonemic fluency. These findings occurred despite normal laboratory tests and imaging findings.

Adherence to Guidelines in Heart Failure, Is It Valid for Elderly Patients?

BACKGROUND: Current guidelines for the treatment of heart failure with reduced ejection fraction (HFrEF) are based on studies that have excluded or underrepresented older patients. OBJECTIVES: To assess the value of guideline directed medical therapy (GDMT) in HFrEF patients 80 years of age and older. METHODS: A single-center retrospective study included patients hospitalized with a first and primary diagnosis of acute decompensated heart failure (ADHF) and ejection fraction (EF) of ≤ 40%. Patients 80 years of age and older were stratified into two groups: GDMT, defined as treatment at hospital discharge with at least two drugs of the following groups: beta-blockers, angiotensin converting enzyme inhibitor (ACEI), angiotensin receptor blocker (ARB), or mineralocorticoid antagonists; and a personalized medicine group, which included patients who were treated with up to one of these drug groups. The primary outcomes were 90-day all-cause mortality, 90-day rehospitalization, and 3-years mortality. RESULTS: The study included 1152 patients with HFrEF. 254 (22%) patients who were at least 80 years old. Of the group, 123 were GDMT at discharge. When GDMT group was compared to the personalized medicine group, there were no statistically significant differences in terms 90-day mortality (17% vs. 13%, P = 0.169), 90-day readmission (51 % vs. 45.6%, P = 0.27), or 3-year mortality (64.5% vs. 63.3%, P = 0.915). CONCLUSIONS: Adherence to guidelines in the older adult population may not have the same effect as in younger patients who were studied in the randomized clinical trials. Larger prospective studies are needed to further address this issue.

Point Shear Wave Elastography for Assessing Liver Stiffness in Chronic Liver Diseases of Different Etiologies Compared to Biopsy.

BACKGROUND: Point shear-wave elastography (pSWE) is a new method to assess the degree of liver fibrosis. It has been shown to be effective in detecting stiffness in viral hepatitis. OBJECTIVES: To determine the feasibility of pSWE for assessing liver stiffness and fibrosis in liver diseases of different etiologies. METHODS: This prospective single-center study included a population of adult patients with chronic liver diseases from different etiologies, who were scheduled for liver biopsy, and a control group of healthy adults who prospectively underwent pSWE. Ten consecutive pSWE measurements of the liver were performed using a Philips iU22 ultrasound system. Stiffness degree was compared to liver biopsy results. Fibrosis degree was staged according to METAVIR scoring system. RESULTS: The study group was comprised of 202 patients who underwent liver biopsy and pSWE test and a control group consisting of 14 healthy adults who underwent pSWE for validation. In the study group, the median stiffness was 5.35 ± 3.37 kilopascal (kPa). The median stiffness for F0-1, F2, F3, and F4 as determined by liver biopsy results were 4.9 kPa, 5.4 kPa, 5.7 kPa, and 8 kPa, respectively. The median stiffness in the control group was 3.7 ± 0.6 kPa. Subgroup analyses were conducted for viral hepatitis vs. non-viral hepatitis and steatohepatitis vs. non-steatohepatitis groups. CONCLUSIONS: pSWE is a reproducible method for assessing liver stiffness and is in a linear relationship with fibrosis degree as seen in pathology. Compared with patients with non-significant fibrosis, healthy controls showed significantly lower values.

Histomorphometric Findings May Help Predicting Response in Patients with Chronic Liver Disease.

BACKGROUND: Hepatitis C virus (HCV) is a leading cause of cirrhosis and hepatocellular carcinoma worldwide. Several viral and host factors related to viral response have been reported in the era of treatment with pegylated (PEG)-interferon and ribavirin. OBJECTIVES: To quantify histological findings from patients with chronic HCV using computerized morphometry and to investigate whether the results can predict response to medical treatment with peg-interferon and ribavirin. METHODS: We followed 58 patients with chronic HCV infection with METAVIR score F1 and F2 in our liver unit who were grouped according to treatment response sustained viral response (SVR) and non-SVR. Liver needle biopsies from these patients were evaluated and histological variables, such as inflammatory cells, collagen fibers and liver architecture, were quantified using computerized morphometrics. The pathologist who performed the histomorphometric analysis was blinded to previous patient clinical and histological information. RESULTS: Histomorphometric variables including the density of collagen fibers were collected. The number of inflammatory cells in the portal space and textural variable were found to be statistically significant and could be used together in a formula to predict response to treatment, with a sensitivity of 93% and a 100% specificity. CONCLUSIONS: Histomorphometry may help to predict a patient's response to treatment at an early stage.

The association between fluconazole dose and MIC with mortality and persistence in candidemia.

To evaluate the association between fluconazole exposure parameters and clinical outcomes in patients with candidemia. We retrospectively included all adults with candidemia in a single center from January 2009 to December 2017, treated initially with fluconazole for fluconazole-susceptible candidemia. We assessed the association between fluconazole exposure parameters and 30-day mortality or 14-day clinical failure, a composite of mortality at day 14 or persistent candidemia ≥ 72 h, in all patients and in patients with C. glabrata candidemia. During the study period, 158 patients fulfilled the inclusion criteria. Main species were C. albicans 66 (41.8%), C. glabrata 35 (22.2%), and C. parapsilosis 31 (19.6%). Sixty patients (38%) died within 30 days. Sixty-one patients (38.6%) experienced 14-day failure. In 30-day survivors, the median AUC24/MIC was 2279 [398, 5989] versus 1764 [238, 6714] h in non-survivors, p = 0.75. Median fluconazole MIC was 0.75 [0.25, 4] and 1 [0.22, 5.50] mg/L, p = 0.54, respectively. Similar non-significant differences were found for other fluconazole exposure parameters and in the 14-day clinical failure analysis. For C. glabrata, a higher AUC24/MIC was observed among 30-day survivors with a median of 230 [77, 539] compared to 96 [75, 164] h in non-survivors, p = 0.008, in parallel with a trend for lower MIC values (median 7 [1, 2] versus 16 [8, 24] mg/L, p = 0.06, respectively). Currently used fluconazole dosing has no association with clinical outcome in Candida with low MIC values. For Candida species with high MICs, attention to dosing is needed.

Risk Factors for Non-Albicans Candidemia Focusing on Prior Antifungal and Immunosuppressive Therapy.

BACKGROUND: With the widespread use of antifungal agents, the frequency of non-albicans Candida (NAC) blood-stream infections (BSI) is increasing. OBJECTIVES: To describe the epidemiology, clinical manifestations, and risk factors for NAC BSI, focusing on prior antifungal and immunosuppressive therapy. METHODS: The authors conducted an observational, retrospective cohort study among adult patients with candidemia at the Rambam Health Care Campus, a tertiary medical center in Israel, between 2009 and 2015. Comparisons between patients with Candidemia albicans and NAC candidemia were performed. Regression analysis, with NAC BSI as the dependent variable and significant risk factors for NAC as independent variables, was performed. RESULTS: A total of 308 episodes of candidemia were included. C. albicans was isolated in 30.8% of patients (95/308), while NAC spp. were isolated in the rest. Significant independent risk factors for NAC included immunosuppression therapy (odds ratio [OR] 0.38, 95% confidence interval [95%CI] 0.19-0.76) and previous azole use (OR 0.2, 95%CI 0.06-0.710). The interaction between prior azole and immunosuppression therapy in the model was not significant, and after its inclusion in the model only immunosuppression remained significantly associated with NAC. In the subgroup of patients who did not receive prior azoles, immunosuppression therapy, neutropenia, and bone marrow transplantation were significantly associated with NAC. CONCLUSIONS: Independent of previous azole treatment, immunosuppressive therapy was a significant risk factor for NAC in our cohort.

Non-invasive evaluation of a liver mass in a patient post splenectomy.

INTRODUCTION: Numerous conditions may cause liver lesions, solitary or multiple, benign or malignant. It can be crucial to establish the correct diagnosis. Splenosis is a rare condition that may result from the spillage of cells from the splenic pulp following abdominal trauma, accidental lesions to the spleen during operation or elective splenectomy. These splenic 'implants', which are often multiple, can be located anywhere in the peritoneal cavity, although they are most often found in the left upper quadrant of the abdomen. They may be confused with neoplasms or endometriosis, and may rarely be the cause of small bowel obstruction. CASE PRESENTATION: A 35-year-old man presented with a hepatic mass, and malignancy was suspected. After extensive investigation, it was diagnosed as splenosis using Tc-99m-labelled heat-denaturated red blood cells scintigraphy, without the need for liver biopsy. We consider this the most effective method for diagnosing splenosis. CONCLUSION: When splenosis is suspected, Tc-99m-labelled heat-denaturated red blood cells scintigraphy can be used to confirm the diagnosis, and may avoid invasive investigation.

The association between treatment appropriateness according to EUCAST and CLSI breakpoints and mortality among patients with candidemia: a retrospective observational study.

To evaluate the association between appropriate antifungal treatment and mortality among patients with candidemia using different breakpoint definitions. In a retrospective study, we included all adults with candidemia in a tertiary center between 2009 and 2015. We defined three versions of appropriate (covering) antifungal treatment, according to Clinical and Laboratory Standards Institute (CLSI) 2008, CLSI 2012, and European Committee on Antimicrobial Susceptibility Testing (EUCAST) (2017 update) breakpoints. For empiric treatment, we evaluated the association with 30-day mortality. For definitive treatment, we evaluated the association with 90-day mortality among patients surviving the first week after candidemia onset. Adjusted odds ratios (OR) from a bivariate logistic regression with 95% confidence intervals are reported. We identified 302 patients with 308 separate candidemia episodes. The crude 30-day mortality was 55% (168/308). Resistance to anidulafungin increased from 3.5 to 51.6% and to fluconazole from 15.2 to 44.1%, when applying CLSI 2008 and EUCAST definitions, respectively. Appropriate empirical treatment was significantly associated with lower 30-day mortality using the CLSI 2008 definitions, adjusted OR 0.56 (0.33-0.96). The associations were similar, though not statistically significant for EUCAST, 0.58 (0.33-1.00), and CLSI 2012, OR 0.62 (0.37-1.04). Appropriate definitive treatment according to CLSI 2012 and EUCAST was independently associated with lower 90-day mortality, ORs 0.31 (0.13-0.75) and 0.44 (0.23-0.8), respectively. With CLSI 2008, the association was similar but not statistically significant, OR 0.4 (0.11-1.41), with few isolates classified as resistant. Considering the major shift in resistance prevalence when applying CLSI 2008, CLSI 2012, and EUCAST breakpoint definitions, no major differences were observed in their association with mortality.

Is There a Relationship Between Treatment With Direct Antiviral Agents for HCV Infection and the Development of Malignancies?

BACKGROUND AND AIMS: Direct antiviral agents (DAAs) have become the treatment of choice for patients with chronic hepatitis C virus (HCV) infection. As these drugs are new, it is important to learn the adverse events of these drugs in the short and long terms. We report on 7 patients who developed malignancies during treatment with DAAs or a short time after finishing treatment. METHODS: We treated 133 patients with DAAs in our unit between January 2015 and June 2016, 100 (75%) of whom were treated with the combination of paritaprevir/ritonavir/ombitasvir with/without dasabuvir (PrOD). The distribution of HCV genotypes was as follow: G1b 114 (85.7%), G1a 3 (2.2%), G2 3 (2.2%), G3 10 (7.5%), G4 2 (1.5%). One hundred ten (82.7%) patients finished treatment. Adverse events were recorded during treatment and after finishing treatment. Efficacy was determined by assessment of serum HCV RNA. RESULTS: We observed malignancies in 7 patients: 1 developed laryngeal carcinoma, 1 developed pancreatic adenocarcinoma, 1 developed oropharyngeal lymphoma, 1 developed recurrent aggressive transitional cell carcinoma of the urinary bladder, 1 developed recurrent aggressive hepatocellular carcinoma, and 2 patients developed de novo hepatocellular carcinoma. All of these patients had advanced liver disease. CONCLUSIONS: This report raises questions about DAAs and the possible development of malignancies. It will be important to look at large clinical trial data and real-world experience to determine if this relationship is real.

Unexpected bleeding after Exenatide treatment: a causative relationship or a coincidence?

OBJECTIVES: Diabetes mellitus is an endemic disease of the current era. It is important to treat it properly. All antidiabetic medications have side effects and various safety profiles. CASE REPORT: Fifty-two years old patient with type II diabetes mellitus, who had spontaneous cutaneous and intra muscular bleeding after starting treatment with Exenatide. The patient's history did not include any kind of spontaneous bleeding. Investigations did not reveal abnormal platelets count and function or coagulation profile. The use of the Exenatide was discontinued and during one year of follow-up, the patient did not experience an additional occurrence of spontaneous bleeding. CONCLUSIONS: To the best of our knowledge, this is the first report of spontaneous bleeding probably caused by Exenatide. The exact pathophysiology, by which the drug can cause spontaneous bleeding, is still not clear and has to be revealed.

Glycogenic hepatopathy.

BACKGROUND: Glycogenic hepatopathy (GH) is a disorder associated with uncontrolled diabetes mellitus, most commonly type 1, expressed as right upper quadrant abdominal pain, hepatomegaly and increased liver enzymes. The diagnosis may be difficult, because laboratory and imaging tests are not pathognomonic. Although GH may be suggested based on clinical presentation and imaging studies, the gold standard for diagnosis is a liver biopsy, showing a significant accumulation of glycogen within the hepatocytes. GH may be diagnosed also after elevated liver enzymes in routine blood tests. GH usually regresses after tight glycemic control. Progression to end-stage liver disease has never been reported. This review aims to increase the awareness to this disease, to suggest a pathway for investigation that may reduce the use of unnecessary tests, especially invasive ones. DATA SOURCES: A PubMed database search (up to July 1, 2017) was done with the words "glycogenic hepatopathy", "hepatic glycogenosis", "liver glycogenosis" and "diabetes mellitus-associated glycogen storage hepatopathy". Articles in which diabetes mellitus-associated liver glycogen accumulation was described were included in this review. RESULTS: A total of 47 articles were found, describing 126 patients with GH. Hepatocellular disturbance was more profound than cholestatic disturbance. No synthetic failure was reported. CONCLUSIONS: GH may be diagnosed conservatively, based on corroborating medical history, physical examination, laboratory tests, imaging studies and response to treatment, even without liver biopsy. In case of doubt about the diagnosis or lack of clinical response to treatment, a liver biopsy may be considered. There is no role for noninvasive tests like fibroscan or fibrotest for the diagnosis of GH or for differentiation of this situation from nonalcoholic fatty liver disease.

Alkaline phosphatase level change in patients with osteosarcoma: its role as a predictive factor of tumor necrosis and clinical outcome.

BACKGROUND: In osteosarcoma the histological response, measured by the percentage of tumor necrosis, constitutes one of the most significant predictive factors, with better survival in patients whose tumor necrosis is > or = 90%. OBJECTIVES: To determine if the decrease rate of serum alkaline phosphatase (SAP) levels during the first month of neoadjuvant chemotherapy could serve as a predictive indicator of tumor necrosis and clinical outcome. METHODS: We analyzed the medical files of 53 osteosarcoma patients (19 females, 34 males) (median age 16 years, range 8-24); the disease was metastatic in 12 and localized in the other 41. RESULTS: The histological responses were good in 38 patients (71.7%) and poor in 15 (28.3%). At a median follow-up of 50 months, 34 patients (64.2%) had no evidence of disease and 19 (35.8%) had died from the disease. High levels of SAP at diagnosis correlated with worse survival (P = 0.002). There was no difference in overall survival between patients whose SAP decrease rate was > 25% and those with a rate < 25% (P = 0.14). Among female patients, "rapid" SAP responders had better survival than "slow" responders (P= 0.026). In patients with metastases the SAP decrease rate was positively correlated with survival (P = 0.042). CONCLUSIONS: There was no evidence that "rapid" SAP responders had a higher percentage of tumor necrosis than "slow" responders, although female "rapid" SAP responders had a better prognosis than "slow" responders. Patients with metastases at presentation and "rapid" SAP response had better prognoses.

Association Between COVID-19 Infection and Pulmonary Fibrosis: A Nested Case-Control Study.

BACKGROUND: Pulmonary fibrosis is associated with significant morbidity. Data are scarce on the link between coronavirus disease (COVID-19) and pulmonary fibrosis. We aimed to assess the association between COVID-19 with pulmonary fibrosis. METHODS: We conducted a nested case-control study in a cohort of 2,894,801 adults without a diagnosis of pulmonary fibrosis. The underlying cohort consisted of members of the largest healthcare provider in Israel aged 18 years or older as of May 1, 2020. Subjects were followed up from cohort entry until June 30, 2022, for the occurrence of pulmonary fibrosis. Ten randomly selected controls were matched to each case of pulmonary fibrosis on age, sex, and calendar time. To account for surveillance bias a lag time of 60 days was used for ascertainment of prior COVID-19 and COVID-19 severity. RESULTS: During follow-up 1284 patients were newly diagnosed with pulmonary fibrosis and matched with 12,840 controls. Multivariable conditional logistic-regression models showed that the odds ratio for pulmonary fibrosis was 1.80 (95% confidence interval, 1.47-2.19) in patients with COVID-19 compared with no COVID-19. The multivariable odds ratio for pulmonary fibrosis was 1.33 (1.06-1.68), 2.98 (1.16-7.65), and 9.30 (5.77-14.98) for mild, moderate, and severe COVID-19, respectively, compared with no COVID-19. The magnitude of the association was attenuated but remained statistically significant for severe disease when the lag time was extended to 180 days (1.08 [0.78-1.49], 2.37 [0.75-7.46], and 5.34 [2.75-10.36] for mild, moderate, and severe COVID-19, respectively). CONCLUSIONS: COVID-19 appears to be associated with an increased risk of pulmonary fibrosis and the magnitude of the association increases with COVID-19 severity.