Interstitial pneumonia with autoimmune features (IPAF) is a term to describe individuals with both interstitial lung disease (ILD) and combinations of other clinical, serologic, and/or pulmonary morphologic features, which presumably originate from an underlying systemic autoimmune condition, but do not meet current rheumatologic criteria for a defined connective tissue disease (CTD). Predominantly, interstitial pneumonia arises in the course of an established CTD, but it is not so rare for the ILD to be the first, and possibly the one and only manifestation of a latent CTD. Lymphocytic Interstitial Pneumonia (LIP) is an uncommon disease, characterized by infiltration of the interstitium and alveolar spaces of the lung by lymphocytes, plasma cells and other lymphoreticular elements. The cause of LIP is still unknown but it could be also a manifestation of CTD. Clinically, it is highly variable, from spontaneous resolution to progressive respiratory failure and death despite glucocorticoid treatment. Since there are no recent standards for the management of LIP, the disease is treated empirically. We report a case of a HIV-negative 54-year-old woman, who was suspected of LIP according to clinical features and radiological findings. Positive laboratory results were highly suggestive of underlying autoimmune process, but did not fulfil the criteria of any particular CTD. Because of severe general condition of the patient, immunosuppressive treatment was started immediately, without further invasive diagnostics including lung biopsy, which is required for a definitive diagnosis. We present two-year observation of the patient with all our doubts concerning clinical proceedings.
Keywords: clinical suspicion; immunosuppressive treatment; interstitial pneumonia with autoimmune features; lymphocytic interstitial pneumonia.