Circulating bullous pemphigoid autoantibodies in the setting of negative direct immunofluorescence findings for bullous pemphigoid: A single-center retrospective review.

BACKGROUND

Bullous pemphigoid (BP) autoantibody levels are generally elevated in patients with BP but can be present nonspecifically in patients without BP.

OBJECTIVE

To analyze the clinical findings of patients with elevated BP180 or BP230 autoantibody levels and negative direct immunofluorescence (DIF) study findings.

METHODS

We retrospectively reviewed records of patients seen at our institution during January 1, 2005-December 31, 2015, who were positive for BP180 or BP230 autoantibodies and had a negative DIF study finding. These patients' demographic characteristics and BP180 and BP230 levels were compared with those of a BP control group who were positive for BP180 or BP230 autoantibodies and had positive DIF study findings.

RESULTS

We identified 208 patients with BP autoantibodies but without positive DIF study findings. These patients' mean age and enzyme-linked immunosorbent assay values were significantly lower than those of the control group. Dermatitis was the most common final clinical diagnosis. Of the 208 patients, 41 (19.7%) had at least 2 years' follow-up. Four patients had positive DIF results upon repeating the test and ultimately received pemphigoid diagnoses.

LIMITATIONS

Retrospective design with limited follow-up.

CONCLUSION

Patients might harbor serum BP autoantibodies in the context of a wide range of dermatoses. Low positive BP180 and BP230 autoantibody levels should not be overinterpreted as evidence for BP in the setting of a negative DIF.