A case of wild-type transthyretin amyloidosis associated with organizing pneumonia

Association of subpleural ground-glass opacities with respiratory failure and RNAemia in COVID-19

OBJECTIVES

To examine the radiological patterns specifically associated with hypoxemic respiratory failure in patients with coronavirus disease (COVID-19).

METHODS

We enrolled patients with COVID-19 confirmed by qPCR in this prospective observational cohort study. We explored the association of clinical, radiological, and microbiological data with the development of hypoxemic respiratory failure after COVID-19 onset. Semi-quantitative CT scores and dominant CT patterns were retrospectively determined for each patient. The microbiological evaluation included checking the SARS-CoV-2 viral load by qPCR using nasal swab and serum specimens.

RESULTS

Of the 214 eligible patients, 75 developed hypoxemic respiratory failure and 139 did not. The CT score was significantly higher in patients who developed hypoxemic respiratory failure than in those did not (median [interquartile range]: 9 [6-14] vs 0 [0-3]; p < 0.001). The dominant CT patterns were subpleural ground-glass opacities (GGOs) extending beyond the segmental area (n = 44); defined as "extended GGOs." Multivariable analysis showed that hypoxemic respiratory failure was significantly associated with extended GGOs (odds ratio [OR] 29.6; 95% confidence interval [CI], 9.3-120; p < 0.001), and a CT score  > 4 (OR 12.7; 95% CI, 5.3-33; p < 0.001). The incidence of RNAemia was significantly higher in patients with extended GGOs (58.3%) than in those without any pulmonary lesion (14.7%; p < 0.001).

CONCLUSIONS

Extended GGOs along the subpleural area were strongly associated with hypoxemia and viremia in patients with COVID-19.

KEY POINTS

• Extended ground-glass opacities (GGOs) along the subpleural area and a CT score  > 4, in the early phase of COVID-19, were independently associated with the development of hypoxemic respiratory failure. • The absence of pulmonary lesions on CT in the early phase of COVID-19 was associated with a lower risk of developing hypoxemic respiratory failure. • Compared to patients with other CT findings, the extended GGOs and a higher CT score were also associated with a higher incidence of RNAemia.

Wild-type Transthyretin Amyloidosis with Diffuse Alveolar-septal Amyloidosis Diagnosed by a Transbronchial Lung Biopsy

A 69-year-old man visited our pulmonary medicine department for dyspnea. Chest computed tomography (CT) revealed ground-glass opacity bilaterally in the lungs. Upon performing a transbronchial lung biopsy (TBLB), organizing pneumonia was diagnosed. His electrocardiogram revealed low voltage, and the cardiac ultrasound revealed hypertrophy of the interventricular septum. The patient had bilateral carpal tunnel syndrome, and amyloidosis was suspected. Congo red stain was added to the lung biopsy specimen. Amyloid deposition of transthyretin (ATTR) was positive, mutations with amino acid changes were not observed in the TTR gene. Wild-type ATTR Amyloidosis (ATTRwt amyloidosis) was diagnosed using a TBLB. Chest CT after treatment with steroids revealed diffuse alveolar-septal amyloidosis.