Many thanks to Lekshmi, our awesome pulm fellow, for the following DAH framework:
Approach to DAH: 5 main categories:
- Vasculitis: Ddx includes MPA, less likely GPA and Churg-Strauss
- Pulmonary-Renal Syndrome: Goodpasture’s, connective tissue dz, IgA nephropathy
- Autoimmune diseases: SLE & APLS
- Medications: Complications of anticoagulation, drug-induced thrombocytopenia
- Idiopathic pulmonary hemosiderosis (or in women, consider pulmonary endometriosis)
A few more take away pearls from our discussion:
- The classic DAH presentation is acute onset cough, hemoptysis fever and dyspnea, but up to 33% of patients may not have hemoptysis, even when hemorrhage is severe
- CXR for DAH classic shows patchy or diffuse infiltrates, and serial lavages on BAL will become progressively more hemorrhagic
- Whether ANCA levels correlate with disease flare is controversial and most studies are for PR3-ANCA (anti-GMC disease rather than MPA), but increased/rising ANCA titers do not consistently correlate with disease flares, at least within a meaningful time frame. Elevated titers may be associated with future relapse, but when this will occur cannot be predicted in a way that helps guide treatment
- While some guidelines suggest that suspected pseudomonas infections should be “double covered” for HAP with a combination of a quinolone, beta lactam or aminoglycoside, most recent IDSA guidelines show limited benefit of this. In practice at UCSF, double coverage is given for CF patients, though with severe bronchiectasis and patients with a history of recurrent pseudomonal infection.
- Rituximab is primarily associated with increased risk of viral infections, including JC virus], HBV and HCV, viral infections such as HSV, CMV, VZV, though PCP and crypto meningitis have been reported.
Collard HR, King TE Jr, Schwarz MI. Diffuse alveolar hemorrhage and rare infiltrative disorders of the lung. In: Murray & Nadel’s Textbook of Respiratory Medicine, 6th, Broaddus VC, Mason RJ, Ernst JD, et al. (Eds), Elsevier, New York 2016. p.1207
Birck R, Schmitt WH, Kaelsch IA, van der Woude FJ. Serial ANCA determinations for monitoring disease activity in patients with ANCA-associated vasculitis: systematic review. Am J Kidney Dis 2006; 47:15.