Significance of connective tissue disease features in idiopathic interstitial pneumonia

Abstract

In idiopathic interstitial pneumonia (IIP), the significance of connective tissue disease (CTD) features in the absence of a specific CTD diagnosis remains unclear. We studied the clinical and prognostic utility of a diagnosis of undifferentiated CTD (UCTD) in patients with biopsy-proven IIP.IIP patients undergoing surgical lung biopsy were studied (nonspecific interstitial pneumonia (NSIP), n545; idiopathic pulmonary fibrosis, n556). UCTD was considered present when serum autoantibodies were present and symptoms or signs suggested CTD. The relationship between UCTD and NSIP histology was evaluated. A clinical algorithm that best predicted NSIP histology was constructed using a priori variables. The prognostic utility of UCTD, and of this algorithm, was evaluated.UCTD was present in 14 (31%) NSIP and seven (13%) IPF patients. UCTD was not associated with a survival benefit. The algorithm predictive of NSIP (OR 10.4, 95% CI 3.21-33.67; p,0.0001) consisted of the absence of typical high-resolution computed tomography (HRCT) features for IPF and 1) a compatible demographic profile (females aged ,50 yrs) or 2) Raynaud's phenomenon. In patients with an HRCT scan not typical for IPF, this algorithm predicted improved survival (hazard ratio 0.35, 95% CI 0.14-0.85; p50.02) independent of IIP severity.UCTD is associated with NSIP histology. However, the diagnostic and prognostic significance of UCTD in IIP patients remains unclear.

Thyroid Disease Is Prevalent and Predicts Survival in Patients With Idiopathic Pulmonary Fibrosis

“…Patients with a diagnosis of IPF who exhibited features of autoimmunity according to previously suggested criteria [3][4][5] (n 5 38) were excluded from the analysis, as were 13 We then analyzed datasets from two IPFnet randomized clinical trials, Anticoagulant Eff ective in Idiopathic Pulmonary Fibrosis (ACE-IPF) 9 and Prednisone, Azathioprine and N-acetylcysteine for Pulmonary Fibrosis (PANTHER), 10,11 to determine whether our fi ndings could be replicated. HT was recorded when a patient reported the use of thyroid replacement therapy.…”

“…1,2 Individuals with IPF and other ILDs who exhibit the features of autoimmunity, but who fail to meet the established rheumatologic criteria for connective tissue disease (CTD) compose one such group. [3][4][5] Th ose who have interstitial pneumonia with autoimmune features, referred to as undiff erentiated connective tissue disease (UCTD) and autoimmunefeatured ILD (AIF-ILD), account for a signifi cant minority of patients with IPF and other idiopathic interstitial pneumonias. [3][4][5] UCTD and AIF-ILD criteria focus on CTD-related physical signs and serologies but do not address non-CTD autoimmune disease processes, several of which are common in the general population.…”

“…[3][4][5] Th ose who have interstitial pneumonia with autoimmune features, referred to as undiff erentiated connective tissue disease (UCTD) and autoimmunefeatured ILD (AIF-ILD), account for a signifi cant minority of patients with IPF and other idiopathic interstitial pneumonias. [3][4][5] UCTD and AIF-ILD criteria focus on CTD-related physical signs and serologies but do not address non-CTD autoimmune disease processes, several of which are common in the general population. Chronic autoimmune thyroiditis, also known as Hashimoto thyroiditis, is one such process and is characterized by T-cell and autoantibody-mediated destruction of the thyroid gland, leading to hypothyroidism (HT).…”

An official European Respiratory Society/American Thoracic Society research statement: interstitial pneumonia with autoimmune features

“…A number of recent studies have shown that many patients diagnosed with an IIP have certain, often subtle, clinical features that suggest an underlying autoimmune process and yet do not meet established diagnostic criteria for any characterisable CTD [19][20][21][22]. In some patients, these features may occur in the absence of serologic abnormalities, while in others, a highly specific serum autoantibody may be present without typical systemic or extrathoracic findings.…”

Nonspecific interstitial pneumonia: survival is influenced by the underlying cause

“…Whether or not patients with CTD-associated NSIP have a better outcome than those with idiopathic NSIP remains controversial [7]. Similarly, the prognostic impact of UCTD in NSIP patients has not been fully elucidated [8][9][10][11]. Although it is now well known that NSIP can represent the sole histological expression of a percentage of patients with cHP [12][13][14][15][16], no studies have compared the survival of these patients with that of patients with idiopathic NSIP.…”