Category Archives: Pulmonary

Morning Report 8/15/22 – TPO

Date
Posted by
Comments0

Thanks to David Kidd for presenting a cool IP case:

A nice resource provided by Tim:

Naranje, P., & Das, A. (2018). Approach to Airway Infections. Clinico Radiological Series: Imaging of Chest Infections, 418.

 

Thanks, David!

David Kidd, MD, Medicine

 

Diffuse pleural thickening review

Date
Posted by
Comments0

 

Morning Report 8/3/22 – Cavitary Lung Diseases

Date
Posted by
Comments0

Wednesday’s Morning Report featured first year Emily Olson (@EmilyOlsonMD) leading a discussion of cavitary lung disease. Let’s review some of her learning points together!

First off, how much better of a mnemonic can you get for cavitary lung diseases than “CAVITY”?

 

It’s always helpful to look at previous chest imaging, and this is especially true in cavitary lung diseases! An important early diagnostic branch point is chronicity of process (12 weeks as the cutoff for a chronic process)

 

 

Histoplasmosis is one differential consideration for subacute/chronic cavitary lung disease which we commonly test for non-invasively.

We learned that the performance characteristics of testing depends on stage of disease.

 

 

Thanks for leading a great discussion, Emily!

 

Sources cited

  1. Chest. 2018 Jun;153(6):1443-1465. doi: 10.1016/j.chest.2018.02.026 
  2. J Clinical Microbiology.2017 Jun;55(6):1612-1620. doi: 10.1128/JCM.02430-16

Pulmonary Report 8/1/22 – Diffuse pleural thickening

Date
Posted by
Comments1

Today’s Morning Report featured a case of restrictive lung disease related to diffuse pleural thickening. Below are some of the points I hope you take away from the discussion:

I. Differential diagnosis of diffuse pleural thickening (DPT)

History is essential for differential diagnosis. 2 general categories:

  • Pleuritis-related
    • Recurrent PNA, empyema
    • Asbestos-related
    • TB
    • Connective tissue disease
    • Drugs
    • Post-radiation
    • Post-CABG
    • Post-traumatic
    • Fibrosing pleuritis
  • Pleural thickening mimickers
    • Pleural plaques
    • Mesothelioma
    • Other pleural-based malignancies

II. Timeline of asbestos-related pulmonary disease

Legend – BAPE (Benign Asbestos-related Pleural Effusion), DPT (Diffuse Pleural Thickening) Clockwise from top left: DPT, pleural plaques, mesothelioma, ILD/asbestosis, BAPE

Remember that timeline is fluid, not absolute!

III. 3 distinct benign responses to asbestos exposure

Asbestos plaques involve parietal pleura only – lung sliding remains intact

 

Asbestosis – pulmonary fibrosis does not involve the pleura; septal thickening, reticulations (left) & honeycombing (center) are observed.

 

Diffuse pleural thickening involves inflammation at the visceral pleural border. Several findings associated with this, clockwise from top left; parenchymal bands “crow’s feet” associated with volume loss, a prominent parenchymal band, rounded atelectasis

 

IV. PET-CT may have utility in diagnostic evaluation of pleural thickening

 

 

Sources cited:

  1. Radiopaedia
  2. Journal of Occupational Medicine and Toxicology 2008, 3:20
  3. Eur Respir J 1998; 11: 1021–1027
  4. J Nucl Med 2004; 45:995–998

Alpha-1 antitrypsin (AAT) deficiency, by PD Clara Schroedl

Date
Posted by
Comments0

Alpha-1 antitrypsin (AAT) deficiency

AAT = protease inhibitor (PI), synthesized in hepatocytes

Emphysema results from an imbalance between neutrophil elastase in the lung (destroys elastin), and the elastase inhibitor AAT = “toxic loss of function”

  • Lung degradation occurs with increased elastase burden in the lungs (smoking)

Liver disease: “toxic gain of function”; accumulation within the hepatocytes of unsecreted variant AAT protein; almost always PI*ZZ

Genetics: autosomal co-dominant; 150 alleles of AAT

  • Normal = M -> PI*MM
  • AAT = Z (most common) -> PI*ZZ
  • AAT = S (compound heterozygote) -> PI*SZ
  • Heterozygotes (PI*MZ): conflicting data re emphysema risk

AAT phenotypes: protective threshold 11 micromol/L (57 mg/dL)

  • Normal: MM
  • Deficient: AAT level < 35% normal
  • Null: no detectable AAT (rare, most severe lung disease, no liver disease)
  • Dysfunctional: normal levels but dysfunctional (PI*F)

Epidemiology: 2-3% of patients with COPD; 80-100K individuals in the US

Clinical manifestations:

  • Emphysema onset at young age, basilar-predominant (although substantial variability), PTX, bronchiectasis
  • Hepatitis, cirrhosis, HCC, panniculitis, IBD, intracranial and inta-abdominal aneurysms, fibromuscular dysplasia, glomerulonephritis

From: https://radiopaedia.org/cases/alpha-1-antitrypsin-deficiency-15?lang=us

Diagnosis: screen all adults with persistent airflow obstruction, emphysema, FH or emphysema/liver disease, adult onset asthma, panniculitis, unexplained liver disease

  •  Send Alpha-1 Antitrypsin Phenotype and Quant

Monitoring:

  • Asymptomatic with normal spiro: spiro Q6-12 mths; augment if/when FEV1 < 80%
  • LFTs annually, +/- CBC (Plts) and liver US Q6-12 mths
  • Lung function decline strongly affected by smoking

Treatment (i.e., Augmentation)

  • Pooled human AAT intravenous infusion (weekly) -> goal is to slow disease progression
  • Never or ex-smokers, > 18 y/o, with low serum AAT and high-risk genetic variant
  • FEV1 35-65% (other societies suggest FEV1 25-80%); uncertainty regarding a lower limit of FEV1 – probably protecting additional lung function decline is favorable although study do not demonstrate clinical improvement
  • Check pre-treatment IgA levels, vaccinate for Hep A and B
  • Efficacy: modest effect in slowing lung function decline (23% slower decline); greatest benefit for those with moderate obstruction.  Achieving a “protective” serum threshold is not necessary.
  • Cost: > $100,000 per year

Screening of Family:

  • Genotype first-degree relatives: siblings, parents, children of PI*ZZ individuals; first degree relatives of individulas with other PI*MZ can be offered testing

Good reference: https://www.alpha1.org/alphas-friends-family/resources/find-an-alpha-1-specialist/

Thank you, Dr. Schroedl, our fearless Program Director, for summarizing!

Clara Schroedl, MD, MSc, Medicine – Pulmonary/Critical Care