Case report: Fibrotic interstitial lung disease as the initial manifestation of hereditary pulmonary alveolar proteinosis caused by CSF2RB mutation

A 50-year-old male was admitted to the hospital with a 3-year history of dyspnea and cough. Chest high-resolution computed tomography (HRCT) did not show typical features of pulmonary alveolar proteinosis (PAP), but rather atypical features of interstitial lung disease with fibrosis. The diagnosis of PAP was confirmed through transbronchial lung cryobiopsy. Whole exome sequencing identified a rare homozygous frame shift mutation (c.304_305del:p.S102Ffs*5) in exon 3 of the CSF2RB gene in our patient. This case represents a rare occurrence of fibrotic interstitial lung disease in PAP.

Primary SARS-CoV-2 Pneumonia Screening in Adults: Analysis of the Correlation between High-Resolution Computed Tomography Pulmonary Patterns and Initial Oxygen Saturation Levels

BACKGROUND

Chest high-resolution computed tomography (HRCT) is mandatory for patients with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and a high respiratory rate (RR) because sublobar consolidation is the likely pathological pattern in addition to ground glass opacities (GGOs).

OBJECTIVE

The present study determined the correlation between the percentage extent of typical pulmonary lesions on HRCT, as a representation of severity, and the RR and peripheral oxygen saturation level (SpO2), as measured through pulse oximetry, in patients with reverse transcriptase polymerase chain reaction (RT-PCR)-confirmed primary (noncomplicated) SARS-CoV-2 pneumonia.

METHODS

The present retrospective study was conducted in 332 adult patients who presented withzdyspnea and hypoxemia and were admitted to Prince Mohammed bin Abdulaziz Hospital, Riyadh, Saudi Arabia between May 15, 2020 and December 15, 2020. All the patients underwent chest HRCT. Of the total, 198 patients with primary noncomplicated SARS-CoV-2 pneumonia were finally selected based on the typical chest HRCT patterns. The main CT patterns, GGO and sublobar consolidation, were individually quantified as a percentage of the total pulmonary involvement through algebraic summation of the percentage of the 19 pulmonary segments affected. Additionally, the statistical correlation strength between the total percentage pulmonary involvement and the age, initial RR, and percentage SpO2 of the patients was determined.

RESULTS

The mean ± standard deviation (SD) age of the 198 patients was 48.9 ± 11.4 years. GGO magnitude alone exhibited a significant weak positive correlation with patients' age (r = 0.2; p = 0.04). Sublobar consolidation extent exhibited a relatively stronger positive correlation with RR than GGO magnitude (r = 0.23; p = 0.002). A relatively stronger negative correlation was observed between the GGO extent and SpO2 (r = - 0.38; p = 0.002) than that between sublobar consolidation and SpO2 (r = - 0.2; p = 0.04). An increase in the correlation strength was demonstrated with increased case segregation with GGO extent (r = - 0.34; p = 0.01).

CONCLUSION

The correlation between the magnitudes of typical pulmonary lesion patterns, particularly GGO, which exhibited an incremental correlation pattern on chest HRCT, and the SpO2 percentage, may allow the establishment of an artificial intelligence program to differentiate primary SARS-CoV-2 pneumonia from other complications and associated pathology influencing SpO2.

Effectiveness of corticosteroids on chest high-resolution computed tomography features of COVID-19 pneumonia

Objective:

The aim of our study was to assess the effect of a short-term treatment with low-moderate corticosteroid (CS) doses by both a quantitative and qualitative assessment of chest HRCT of COVID-19 pneumonia.

Methods:

CORTICOVID is a single-center, cross-sectional, retrospective study involving severe/critical COVID-19 patients with mild/moderate ARDS. Lung total severity score was obtained according to Chung and colleagues. Moreover, the relative percentages of lung total severity score by ground glass opacities, consolidations, crazy paving, and linear bands were computed. Chest HRCT scores, P/F ratio, and laboratory parameters were evaluated before (pre-CS) and 7–10 days after (post-CS) methylprednisolone of 0.5–0.8 mg/kg/day.

Findings:

A total of 34 severe/critical COVID-19 patients were included in the study, of which 17 received Standard of Care (SoC) and 17 CS therapy in add-on. CS treatment disclosed a significant decrease in HRCT total severity score [median = 6 (IQR: 5–7.5) versus 10 (IQR: 9–13) in SoC, p < 0.001], as well in single consolidations [median = 0.33 (IQR: 0–0.92) versus 6.73 (IQR: 2.49–8.03) in SoC, p < 0.001] and crazy paving scores [mean = 0.19 (SD = 0.53) versus 1.79 (SD = 2.71) in SoC, p = 0.010], along with a significant increase in linear bands [mean = 2.56 (SD = 1.65) versus 0.97 (SD = 1.30) in SoC, p = 0.006]. GGO score instead did not significantly differ at the end of treatment between the two groups. Most post-CS GGO, however, derived from previous consolidations and crazy paving [median = 1.5 (0.35–3.81) versus 2 (1.25–3.8) pre-CS; p = 0.579], while pre-CS GGO significantly decreased after methylprednisolone therapy [median = 0.66 (0.05–1.33) versus 1.5 (0.35–3.81) pre-CS; p = 0.004]. CS therapy further determined a significant improvement in P/F levels [median P/F = 310 (IQR: 235.5–370) versus 136 (IQR: 98.5–211.75) in SoC; p < 0.001], and a significant increase in white blood cells, lymphocytes, and neutrophils absolute values.

Conclusion:

The improvement of all chest HRCT findings further supports the role of CS adjunctive therapy in severe/critical COVID-19 pneumonia.

The reliability of lung ultrasound in assessment of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is the severest form of idiopathic interstitial pneumonia, with a median survival time estimated at 2–5 years from the time of diagnosis. It occurs mainly in elderly adults, suggesting a strong link between the fibrosis process and aging. Although chest high-resolution computed tomography (HRCT) is currently the method of choice in IPF assessment, diagnostic imaging with typical usual interstitial pneumonia (UIP) provides definitive results in only 55%, requiring an invasive surgical procedure such as lung biopsy or cryobiopsy for the final diagnostic analysis. Lung ultrasound (LUS) as a noninvasive, non-radiating examination is very sensitive to detect subtle changes in the subpleural space. The evidence of diffuse, multiple B-lines defined as vertical, hyperechoic artifacts is the hallmark of interstitial syndrome. A thick, irregular, fragmented pleura line is associated with subpleural fibrotic scars. The total numbers of B-lines are correlated with the extension of pulmonary fibrosis on HRCT, being an LUS marker of severity. The average distance between two adjacent B-lines is an indicator of a particular pattern on HRCT. It is used to appreciate a pure reticular fibrotic pattern as in IPF compared with a predominant ground glass pattern seen in fibrotic nonspecific interstitial pattern. The distribution of the LUS artifacts has a diagnostic value. An upper predominance of multiple B-lines associated with the thickening of pleura line is an LUS feature of an inconsistent UIP pattern, excluding the IPF diagnosis. LUS is a repeatable, totally radiation-free procedure, well tolerated by patients, very sensitive in detecting early changes of fibrotic lung, and therefore a useful imaging technique in monitoring disease progression in the natural course or after initiation of treatment.