B) Diffuse pulmonary capillaritis
in case-patient 4.
Regardless of etiology, all cases of DAH appear similar histologically and are usually accompanied by capillaritis
in the alveolar walls.
Patients typically present with fever, arthralgias or weight loss (61-78%), cutaneous manifestations (30-62%, mostly leukocytoclastic angiitis), peripheral neuropathy (37-72%), pulmonary disease (25-55%, capillaritis
reported in 12-55%) and most importantly, renal involvement, characterized by crescentic necrotizing glomerulonephritis (80-100%) (2).
Allograft biopsy revealed TMA with glomerulitis (g3), mild peritubular capillaritis
(ptc1), and acute tubular injury, together with C4d staining (C4d2) (Figure 2).
The 2013 classification system grades renal allograft biopsies based on glomerulitis score, criterion for allograft glomerulopathy, tubulitis score, intimal arteritis score, classification of peritubular capillaritis
(PTC), and interstitial inflammation score (Haas et al, 2014).
Pulmonary physicians are well aware of drug-induced acute and chronic pulmonary toxicities; inhaled or systemically administered drugs can affect airway tone and cause cough, dyspnoea due to airspace disease, diffuse alveolar damage, pulmonary capillaritis
or interstitial lung fibrosis, to name a few presentations and tissue manifestations.
Here, we report a patient who had a previous MPA diagnosis with pulmonary capillaritis
, no renal involvement and positive p-ANCA testing and new developing coexistence of RA with this vasculitis.
The definitive diagnosis can be confirmed through skin biopsy, which shows capillaritis
of dermal vessels.
Most cases of DAH are caused by capillaritis
associated with systemic autoimmune diseases such as ANCA-associated vasculitis, anti-GBM disease, and systemic lupus erythematosus.
Many causes of DAH have been described to have pulmonary capillaritis
that include systemic vasculitis, collagen vascular diseases, antiphospholipid syndrome, Gooodpasture's syndrome and Behcet's syndrome, (4) whereas ENL has not been previously described as a cause.
Postmortem examination found infarction in the upper lobe of the left lung with active capillaritis
and haemorrhage into the trachea.