Ascertainment of collagen vascular disease in patients presenting with interstitial lung disease
Received 3 October 2008; accepted 16 February 2009. published online 23 March 2009.
Summary
Introduction
Previous studies of interstitial lung disease (ILD) suggest that prognosis and therapeutic response are influenced by the presence of underlying collagen vascular disease (CVD). Yet, what proportion of patients presenting with ILD have CVD is largely unknown. We sought to determine the frequency of a new CVD diagnosis in an ILD referral population.
Materials/patients and methods
We retrospectively studied 114 consecutive patients evaluated at the Johns Hopkins Interstitial Lung Disease Clinic for the development of CVD.
Results
In this retrospective cohort, nearly one-third of the 114 patients with confirmed ILD satisfied published criteria for a CVD diagnosis. Seventeen (15%) patients were diagnosed with a new CVD as a direct consequence of their ILD evaluation. Patients with new CVD diagnosis were younger than those without new CVD diagnosis: 51.4years (95% CI 45–58years) and 60years (95% CI 57–63), respectively (p=0.01). Moreover, an ANA≥1:640 (p=0.03) and elevated levels of creatine phosphokinase (CPK) or aldolase (p<0.001) were associated with a new CVD diagnosis.
Conclusions
Unrecognized collagen vascular disease may be more common than previously appreciated among patients referred with ILD. High titer ANA and an elevated CPK or aldolase are associated with a CVD diagnosis in this referral population.
aDivision of Rheumatology, University of Manitoba, Winnipeg Rheumatic Disease Unit, RR149 Rehabilitation Hospital, Health Sciences Centre, 800 Sherbrook Street, Winnipeg, MB, R3A 1M4, Canada
bDivision of Rheumatology, Johns Hopkins University School of Medicine, 5200 Eastern Avenue, Mason F. Lord Center Tower, Suite 4100, Baltimore, MD 21224, USA
cDivision of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, 1830 E. Monument St, 5th Floor, Baltimore, MD 21205, USA
ABSTRACT