Dubini, Alessandra

Abstract Accumulating evidence suggests dysregulated immune checkpoint (IC) signaling can exacerbate COVID-19 severity, but the role of these molecules in the pathogenesis of fatal COVID-19-related diffuse alveolar damage (DAD) remains elusive. Understanding how IC proteins influence acute lung injury due to COVID-19 can provide insights into potential therapeutic strategies to modulate immune responses and improve patient outcomes. Here, in a single-center autopsy cohort, we determined the cellular localization of ICs in lung tissue from cases of fatal COVID-19, DAD-comparators, and non-fibrotic controls by using immunohistochemistry, and investigated their association with clinical outcomes. We expanded our findings by performing analyses of publicly available single-cell RNA sequencing datasets from patients with fatal COVID-19 and non-fibrotic controls. We demonstrated the presence of protein-protein interaction networks of ICs in the lung cellular niche by performing transcriptomic profiling of lung tissue-derived RNA counts from patients with fatal COVID-19. Further, we leveraged data from the largest international, multi-center COVID-19 autopsy cohort and validated that, among patients with fatal COVID-19, those with higher PD-L1/CD274 expression in lung endothelial cells had more rapid clinical deterioration. Lastly, in a cohort of individuals with early COVID-19, IC plasma protein levels were elevated in those with persistent SARS-CoV-2 RNAemia and adverse clinical outcomes. Collectively, our data provide unique pathological insights into the role of IC dysregulation and differential disease severity in COVID-19.

Abstract Rationale Lung biopsy (LBx) has a relevant role in the prediction of prognosis of interstitial lung diseases (ILDs), but its impact on the clinical management of patients remains unexplored. Objectives This study evaluates whether LBx may change the therapeutic strategy and assesses the effect of diagnostic reclassification after LBx on long-term prognosis. Methods We evaluated the LBx of 426 consecutive patients with ILDs, without a definite usual interstitial pneumonia pattern on high-resolution computed tomographic imaging. A total of 266 patients underwent transbronchial lung cryobiopsy (TBLC), and 160 patients underwent surgical lung biopsy (SLB). The multidisciplinary team (MDT) determined a diagnosis with high or low confidence, and a management strategy, both before and after the LBx data. Results Final MDT diagnoses were 189 idiopathic pulmonary fibrosis (IPF), 143 non-IPF fibrotic ILDs, and 94 nonfibrotic ILDs. LBx data changed the management strategy in 145 cases (34%), with similar results for TBLC and SLB (the treatment strategy changed in 31.5% of TBLC cases, 84/266, P < 0.001, and in 38% of SLB, 61/160, P < 0.001). After LBx, the MDT was less inclined to “wait and see” (from 15% to 4% of cases, P < 0.001) or to prescribe steroids only (from 54% to 37%, P < 0.001) and was more confident to treat with antifibrotics (from 23% to 44%, P < 0.001) or immunosuppressive drugs (from 7% to 14%, P < 0.001). The therapeutic strategy changed in 70% of reclassified cases (60/85) and in 59% of cases in which LBx increased the MDT confidence (84/142). Reclassification significantly impacted the outcome. The cases classified as non-IPF by clinician and radiologist and then reclassified to be IPF after LBx showed a significantly worse survival compared with non-IPF confirmed cases (adjusted hazard ratio [HR], 3.8; 95% confidence interval [CI], 1.75–8.3); P = 0.001. Cases initially classified as IPF and then reclassified as non-IPF after LBx showed a better prognosis compared with IPF confirmed cases (HR, 0.41; 95% CI, 0.18–0.94; P = 0.03). Conclusions Reclassification of cases with LBx data increased diagnostic confidence and changed the therapeutic strategy in one-third of cases. Pathologic reclassification of cases refined prognosis prediction. Patients classified as non-IPF by clinician and radiologist and then reclassified IPF after LBx had worse prognosis compared with the non-IPF confirmed cases.

Context.— Transbronchial cryobiopsy has recently been proposed as an alternative to surgical biopsy in the diagnosis of diffuse lung disease. Objective.— To familiarize pathologists with transbronchial cryobiopsy, including what it is, how it is performed, how it compares to other techniques of lung biopsy in diffuse lung disease, what are the technical issues relating to it, what the complications are, how cryobiopsies should be interpreted, and the clinical usefulness of cryobiopsy. Data Sources.— All the available literature on cryobiopsy in diffuse lung disease through May 2016, primarily in the last 5 years, was reviewed, and some unpublished data known to the authors were included. Conclusions.— Cryobiopsies are considerably larger than forceps biopsies and allow pattern recognition approaching that of a surgical lung biopsy in many cases. Artifacts associated with cryobiopsy are minimal. In comparison with surgical lung biopsies, the diagnosis rate with cryobiopsies is lower, in the neighborhood of 80%, versus higher than 90% for surgical lung biopsies. Cryobiopsy is proposed as an alternative to surgical lung biopsy and a technique that may appreciably decrease the number of patients who require surgical lung biopsy for diagnosis. This is important because the mortality from cryobiopsy is very small (0.1% to date) compared with surgical lung biopsy (1.7% for elective procedures and considerably higher for nonelective procedures).

Abstract Rationale Surgical lung biopsy is often required for a confident multidisciplinary diagnosis of idiopathic pulmonary fibrosis (IPF). Alternative, less-invasive biopsy methods, such as bronchoscopic lung cryobiopsy (BLC), are highly desirable. Objectives To address the impact of BLC on diagnostic confidence in the multidisciplinary diagnosis of IPF. Methods In this cross-sectional study we selected 117 patients with fibrotic interstitial lung disease without a typical usual interstitial pneumonia pattern on high-resolution computed tomography. All cases underwent lung biopsies: 58 were BLC, and 59 were surgical lung biopsy (SLB). Two clinicians, two radiologists, and two pathologists sequentially reviewed clinical-radiologic findings and biopsy results, recording at each step in the process their diagnostic impressions and confidence levels. Measurements and Main Results We observed a major increase in diagnostic confidence after the addition of BLC, similar to SLB (from 29 to 63%, P = 0.0003 and from 30 to 65%, P = 0.0016 of high confidence IPF diagnosis, in the BLC group and SLB group, respectively). The overall interobserver agreement in IPF diagnosis was similar for both approaches (BLC overall kappa, 0.96; SLB overall kappa, 0.93). IPF was the most frequent diagnosis (50 and 39% in the BLC and SLB group, respectively; P = 0.23). After the addition of histopathologic information, 17% of cases in the BLC group and 19% of cases in the SLB group, mostly idiopathic nonspecific interstitial pneumonia and hypersensitivity pneumonitis, were reclassified as IPF. Conclusions BLC is a new biopsy method that has a meaningful impact on diagnostic confidence in the multidisciplinary diagnosis of interstitial lung disease and may prove useful in the diagnosis of IPF. This study provides a robust rationale for future studies investigating the diagnostic accuracy of BLC compared with SLB.