Background Diffuse alveolar hemorrhage (DAH), which has the mortality rate of higher than 50%, is a rare but serious manifestation in the immune-mediated systemic vasculitides including ANCA-associated vasculitis (AAV) and systemic lupus erythematosus (SLE). AAV and SLE share the common clinical features such as frequent involvement of the lung and kidney. Up to date, however, studies that compare the clinical features of DAH between AAV and SLE have not been reported.
Objectives To compare the mortality rate and cause of death (COD) between AAV and SLE patients complicated with DAH.
Methods A retrospective study was conducted in 18 AAV and 16 SLE patients who were complicated with DAH. The clinical diagnostic criteria of DAH were at least three of the following: respiratory symptoms including hemoptysis, hypoxemia or dyspnea, new infiltration on chest radiograph or CT scan, a drop of hemoglobin of at least 1.5 g/dL, and characteristic bronchoscopic findings of DAH. We compared the demographic and clinical presentation, laboratory findings, treatment modalities, and the outcome.
Results Demographic and laboratory characteristics revealed significant differences in sex (female of SLE vs. AAV, 93.8% vs. 61.1%, p=0.043) and in platelet count (SLE vs. AAV, 51,310±50,194 vs. 278,780±112,393/mm3, p<0.001) between AAV and SLE patients. The mean age was different in both groups (SLE vs. AAV, 38.7±18.6 vs. 50.9±19.1) but showed only a marginal significance (p=0.067). The number of involved organs was higher in SLE patients (SLE vs. AAV, 4.3±1.1 vs. 3.1±0.7, p=0.005), whereas the frequency of renal involvement and renal insufficiency (peak creatinine threshold≥150umol/L), and intensity of proteinuria were similar in both groups. There were no differences in the therapeutic modalities (intravenous immunoglobulin, cyclophosphamide pulse therapy, steroid pulse therapy, and plasmapheresis) and frequency of mechanical ventilation in both groups. The mortality rate was 66.7% (12/18) and 56.3% (9/16) in AAV and SLE patients with DAH, respectively (p=0.725). Among the deceased patients, respiratory failure directly caused by DAH was the COD in 3 patients with SLE, but in no patients with AAV (SLE vs. AAV, p=0.063). Mortality rate of DAH-related pneumonia was significantly higher in AAV patients, compared to SLE patients with DAH (AAV vs. SLE, 61.1% vs. 12.5%, p<0.01). Pneumonia was the predominant COD in 12 AAV patients compared with 9 SLE patients (91.7% vs 22.2%, p=0.002). The intervals between DAH and onset of pneumonia in these patients were 50.8±36.0 days in AAV patients and 3.0±1.4 days in SLE patients.
Conclusions The present data indicate that pneumonia secondary to DAH is the more significant factor in determining mortality of AAV patients with DAH, compared to SLE patients with DAH. Further studies are warranted to determine the mechanism of higher incidence and severity of pneumonia in AAV patients with DAH.
West S, et al. Diffuse alveolar haemorrhage in ANCA-associated vasculitis. Intern Med. 2013;52:5-13.
Shen M, et al. Diffuse alveolar hemorrhage in systemic lupus erythematosus: a retrospective study in China. Lupus 2010;19:1326-1330.
Disclosure of Interest None declared