Undiagnosed connective tissue disease common in iPAH
medwireNews: Around one-third of patients with idiopathic pulmonary arterial hypertension (iPAH) may have an undiagnosed connective tissue disease (CTD), according to Italian researchers.
Of the 49 patients with confirmed iPAH and no prior rheumatological assessment included in the study, 17 (34.7%) were reclassified as CTD-PAH following clinical, laboratory, and instrumental evaluation by a rheumatologist.
The most common CTD was systemic sclerosis (SSc), found in 12 patients. Systemic lupus erythematosus and undifferentiated connective tissue disease were diagnosed in two patients each and one patient had Sjö̈gren syndrome.
Roberto Caporali (University and IRCCS Foundation Policlinico S. Matteo, Pavia) and colleagues say that the findings “stress the importance of a rheumatological assessment in PAH.”
The most common signs and symptoms of CTD in the study population were anti-nuclear antibody (ANA) positivity (n=16), sclerodactyly (n=11), and Raynaud phenomenon (n=10).
Of note, Raynaud phenomenon was uniquely associated with SSc, giving it 100.0% specificity and 83.3% sensitivity for the diagnosis of SSc. In addition, ANA positivity had 94.0% sensitivity and 78.1% specificity for a diagnosis of CTD-PAH overall.
During a median follow-up period of 44 months, 18 (36.7%) patients died: 31.2% in the iPAH group; 58.3% in the SSc-PAH group; and 20.0% in the other CTD-PAH group.
Compared with patients with iPAH, those with SSc-PAH had a significant 3.32-fold higher risk of death in unadjusted analyses (p<0.05). However, when the data were corrected for the significantly higher mean age among the patients with SSc-PAH (73 vs 58 years, p=0.01), the association, although still positive, was no longer statistically significant.
Caporali and team suggest that the small sample size, and consequently small number of events during follow-up, may be responsible for this lack of significance.
Writing in Medicine they conclude that their findings “highlight the importance of a multidisciplinary approach, which may result helpful with regards to classification and follow-up/therapeutic implications.”
By Laura Cowen
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