To the Editor:
We read with great interest the response by Drs. Jearn and Kim1 to our letter “Presence of Anti-topoisomerase I Antibody Alone May Not Be Sufficient for the Diagnosis of Systemic Sclerosis”2. We agree with Drs. Jearn and Kim that the antinuclear antibody (ANA)-negative accompanied by antitopoisomerase I antibody (anti-topo I) positivity is not sufficient to diagnose systemic sclerosis (SSc). Although we noted an apparent association between relatively lower anti-topo I antibody levels (median 76 AU/ml, range 42–118 AU/ml) and lung pathology in ANA-negative (6/11) or -positive (5/11) cases, we only suggested that our observation warrants further study. We did not state that the finding is clinically significant or that this pattern predicts pulmonary epithelial damage.
Our article was written to inform clinicians on …
Address correspondence to Dr. T.M. Frech, Department of Rheumatology, University of Utah, 4b200 SOM 30 N. 1900 E., Salt Lake City, Utah 84132, USA. E-mail: tracy.frech{at}hsc.utah.edu