Interstitial pneumonia with autoimmune features: an additional risk factor for ARDS?

BACKGROUND: Interstitial pneumonia with autoimmune features (IPAF) identifies a recently recognized autoimmune syndrome characterized by interstitial lung disease and autoantibodies positivity, but absence of a specific connective tissue disease diagnosis or alternative etiology. We retrospectively reviewed the clinical presentation, diagnostic workup and management of seven critically ill patients who met diagnostic criteria for IPAF. We compared baseline characteristics and clinical outcome of IPAF patients with those of the population of ARDS patients admitted in the same period. RESULTS: Seven consecutive patients with IPAF admitted to intensive care unit for acute respiratory distress syndrome (ARDS) were compared with 78 patients with ARDS secondary to a known risk factor and with eight ARDS patients without recognized risk factors. Five IPAF patients (71%) survived and were discharged alive from ICU: Their survival rate was equal to that of patients with a known risk factor (71%), while the subgroup of patients without risk factors had a markedly lower survival (38%). According to the Berlin definition criteria, ARDS was severe in four IPAF patients and moderate in the remaining three. All had multiple organ dysfunction at presentation. The most frequent autoantibody detected was anti-SSA/Ro52. All patients required prolonged mechanical ventilation (median duration 49 days, range 10-88); four received extracorporeal membrane oxygenation and one received low-flow extracorporeal CO2 removal. All patients received immunosuppressive therapy. CONCLUSIONS: This is the first description of a cohort of critical patients meeting the diagnostic criteria for IPAF presenting with ARDS. This diagnosis should be considered in any critically ill patient with interstitial lung disease of unknown origin. While management is challenging and level of support high, survival appears to be good and comparable to that of patients with ARDS associated with a known clinical insult.

Nonspecific interstitial pneumonia overlaps organizing pneumonia in lung-dominant connective tissue disease.

Here, we reported two cases of nonspecific interstitial pneumonia overlap organizing pneumonia (NSIP/OP) with lung-dominant connective tissue disease (LD-ILD). The first case is a patient with hands of chapped skin, right-sided pleuritic chest discomfort, weakness, positive ANA and antibodies to Ro/SS-A (+++) and Ro-52 (++). In the second case, there were Reynaud's disease, and nucleolus-ANA increased (1:800). Chest high resolution CT scan in both cases showed ground-glass opacifications, predominantly in basal and subpleural region and the pathologic manifestation were correlated with NSIP/OP, which were previously discovered in Sjogren syndrome, PM/DM and other rheumatic diseases. The two cases of NSIP/OP with LD-CTD we reported expand disease spectrum of NSIP/OP pathological types in ILD. However, it is necessary to process large-scale studies.

Interstitial Lung Disease in Connective Tissue Disease

Interstitial lung disease (ILD) is one of the most serious pulmonary complications of connective tissue diseases (CTDs), resulting in significant morbidity and mortality. ILD is frequently seen in CTDs, particularly systemic sclerosis, polymyositis/dermatomyositis, and rheumatoid arthritis; however, determining that ILD is associated with an established CTD requires the exclusion of alternative causes. Non-specific interstitial pneumonia is the most commonly observed histopathological pattern in CTD-associated ILD (CTD-ILD) except for rheumatoid arthritis, characterized by a higher frequency of usual interstitial pneumonia. Although CTD-ILD usually shows a stable or slowly progressive course, a subgroup exhibits a more severe and progressive course and requires pharmacologic intervention. Treatment strategies typically involve empirical use of immunosuppressive therapies, although a large, randomized study has examined the impact of immunosuppressive therapy for systemic sclerosis associated ILD and should also address comorbid conditions considering implementation of adjunctive therapeutic strategies. A subgroup of patients with idiopathic interstitial pneumonia who meet some, but not all, diagnostic criteria for CTDs were identified and well organized prospective studies are needed in to better determine whether evidence of autoimmunity in those plays a part in the evolution to well-defined CTDs or carries prognostic significance.