key: cord-0767242-ka4lqhk8
authors: Culebras, Mario; Loor, Karina; Sansano, Irene; Persiva, Óscar; Clofent, David; Polverino, Eva; Felipe, Almudena; Osorio, Jeisson; Muñoz, Xavier; Álvarez, Antonio
title: HISTOLOGICAL FINDINGS IN TRANSBRONCHIAL CRYOBIOPSIES OBTAINED FROM PATIENTS AFTER COVID-19
date: 2021-09-25
journal: Chest
DOI: 10.1016/j.chest.2021.09.016
sha: 4a518284d344a53df13d7bd4a36632aed7a9b2ca
doc_id: 767242
cord_uid: ka4lqhk8

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Mario Culebras has written the manuscript and is the guarantor of it.

Karina Loor has carried out the statistical study. In cases of severe acute respiratory syndrome (SARS) caused by coronavirus disease (COVID-19) a broad spectrum of pulmonary sequelae can be observed. 1 Some preliminary reports described radiological and histological findings suggestive of pneumonitis and organizing pneumonia (OP), 2-4 two diffuse interstitial lung diseases (DILD) that can lead to pulmonary fibrosis (PF). However, only one report describes the long-term radiological evolution of pulmonary sequelae of COVID-19. 5 Similarly, followup studies after middle eastern respiratory syndrome-CoV and SARS-CoV described a prevalence of residual PF between 33% and 62%, 6,7 although the diagnosis of PF was never histologically confirmed.

We report the results of a complete investigation of patients with suspicion of DILD following COVID-19 including radiology (computerized tomography -CT-scan) and We describe the histological findings of the first 50 patients with suspected DILD who were requested to perform TBC through FB. None of the patients had received corticosteroids since hospital discharge.

All procedures were performed as previously described. 9 Single-use Ambu® aScope™ 4

Broncho Large (Ambu Corp,Ballerup,Denmark) and 2.4-mm single-use Erbe® cryoprobes were employed, using cryosurgical technology ERBEKRYO® 2 (ERBE Medizintechnik,Tuebingen,Germany). According to radiological findings, the most affected lung was chosen for the TBC. After the histological confirmation of DILD, corticosteroid therapy was initiated in 30(60%) patients, following an internal multidisciplinary protocol, and are currently on follow-up. In the remaining patients only follow-up was decided due to clinical improvement (n, 3) or to normal or unspecific histological findings (n,17).

To our knowledge, this is the first study based on histological assessment of patients with suspected DILD following COVID-19. The observed findings can support the existence of interstitial involvement after some cases of severe SARS-CoV-2 pneumonia, and the need to initiate a specific therapy or intervention in order to prevent disease progression.

OP following a viral infection has been previously described and often improves with corticosteroid treatment. 10 However, long-term, high dose steroid regimen is usually J o u r n a l P r e -p r o o f required, which can induce serious side effects. For this reason, we believe that a histological confirmation can likely avoid an empirical corticosteroid treatment when it is not evidence-based. Notably, in our study 17(34%) patients with initial empirical indication to corticosteroid treatment in the first visit, were not initiated after results of CBT.

This study has also confirmed safety and usefulness of TBC in expert hands. All obtained samples were of high quality, allowing a histological description of findings in all cases. Additionally, all procedures were performed using single-use material, avoiding the possibility of cross-contamination. However, a potential limitation of this kind of study is that none of the patients had a CT scan prior to COVID-19 making impossible to discard eventual pre-existing DILD, although unlikely.

In summary, in case of severe SARS-CoV-2 pneumonia, some patients show pulmonary clinical, radiology, and functional criteria consistent with DILD with different histological patterns. Moreover, the TBC based on single-use FB and cryoprobe has shown to be a safe technique with a high diagnostic yield to investigate DILD during the current and likely future pandemics. Table   Table 1 . Clinical, demographic and biopsies characteristics of the 50 patients included in the study.

Women, n (%) 24 (48%)

Characteristics of and important lessons from the coronavirus disease 2019 (COVID-19) outbreak in China: summary of a report of 72 314 cases from the Chinese center for disease control and prevention

COVID-19): Relationship to duration of infection

Covid-19 Interstitial Pneumonia: Histological and Immunohistochemical Features on Cryobiopsies

The pathogenic role of epithelial and endothelial cells in early-phase COVID-19 pneumonia: victims and partners in crime

Six-month Follow-up Chest CT Findings after Severe COVID-19 Pneumonia

Thin-section CT in patients with severe acute respiratory syndrome following hospital discharge: preliminary experience

Follow-up chest radiographic findings in patients with MERS-CoV after recovery

Optimization of transbronchial cryobiopsy in lung transplant recipients

Organizing pneumonia: a kaleidoscope of concepts and morphologies

Age (years), mean (range)

Smoker or former smoker; non-smoker, n (%) 18 (36%)

ICU time (n = 33) (days), mean (range)

Time from diagnosis of COVID-19 to FB (days), median

Time from discharge to FB (days), median

RESPIRATORY FUNCTION TEST FVC (%)