Wegener's granulomatosis: false positive anti-neutrophil cytoplasmic antibody test

Oral manifestations of Wegener's granulomatosis: a report of three cases and a literature review

BACKGROUND

Hyperplastic granular gingivitis or "strawberry gingivitis" is a rare manifestation of Wegener's granulomatosis (WG), but it is nearly pathognomonic for this multisystem autoimmune vasculitis. The dentist may be the first health care professional to see patients with symptoms and findings of this condition. Early diagnosis and treatment is the most important factor in the management of this potentially fatal disease.

METHODS

The authors present three case reports that demonstrate the disease spectrum and conducted a literature review focused on current understanding of this disease.

RESULTS

The first patient had only the classic gingival manifestations of the disease. The second patient had simultaneous typical gingival lesions, as well as dermatologic findings. The third patient had an atypical oral presentation of aphthous ulcers and erythematous gingiva, as well as respiratory and genital involvement. Reaching a definitive diagnosis sometimes is challenging owing to the subtle onset of the disease and variable clinical and laboratory findings.

CONCLUSION AND CLINICAL IMPLICATIONS

Clinicians should be familiar with the broad variety of oral and systemic components of WG, as well as strategies to facilitate prompt disease recognition and to provide continued oral health care to these medically complex patients.

A prospective study of antineutrophil cytoplasmic antibody (c-ANCA) and clinical criteria in diagnosing Wegener's granulomatosis

Antineutrophil cytoplasmic antibody (c-ANCA) has a reported sensitivity and specificity greater than 90% for active Wegener's granulomatosis in selected patients with previously-defined disease. Because of these reports, some clinicians believe that a positive c-ANCA result provides strong circumstantial evidence for the diagnosis of Wegener's granulomatosis in patients with compatible clinical symptoms. However, this approach has not been examined prospectively. We prospectively studied 346 consecutive patients suspected of having vasculitis; those with previously established Wegener's granulomatosis (n = 29) or receiving immunosuppressives other than corticosteroids (n = 65) at baseline were excluded. Measures included a baseline c-ANCA, blinded chart reviews to record symptoms, physical findings, and corticosteroid use at baseline, and 2 to 8 months later to record final diagnoses and biopsy results. Wegener's granulomatosis was defined using the 1990 American College of Rheumatology (ACR) criteria, which does not require a biopsy. Follow-up information was available for 212 (84%) of the 252 patients eligible for this study (no corticosteroids: n = 174; corticosteroids: n = 78). 25 patients with compatible symptoms were classified with Wegener's granulomatosis by ACR criteria; only 6 of the 25 had biopsy-proven disease. 14 of these 212 patients had positive c-ANCA results. The overall sensitivity and specificity of c-ANCA for ACR-defined Wegener's granulomatosis were 28% (95% CI, 10%-46%) and 96% (93%-99%) respectively. The positive and negative predictive values were 0.50 and 0.91. The specificity remained greater than 90% regardless of baseline corticosteroid use or disease activity; however, the sensitivity and positive predictive value remained poor. For Wegener's granulomatosis defined by biopsy criteria and compatible clinical symptoms, the sensitivity was 83% (53%-100%); however, the positive predictive value was 36%. These results raise serious questions about the use of positive c-ANCA tests in diagnosing Wegener's granulomatosis in patients with clinical symptoms alone.

Negative ANCA in Wegener's granulomatosis

Wegener's granulomatosis is a systemic vasculitis characterized by necrotizing granulomata and without treatment is associated with a poor prognosis. Antineutrophil cytoplasmic antibodies (ANCA) have proved to be a useful serological marker allowing for early diagnosis and treatment of this condition. We report two cases of patients who were ANCA-negative on presentation despite clinical suspicion of Wegener's granulomatosis. In both cases the patients developed a positive ANCA titre as the disease progressed.

Wegener's granulomatosis in two siblings: a family study

Two brothers with Wegener's granulomatosis are presented. HLA status and associated genes in the brothers and the immediate family are explored. No specific association could be found with tissue types within the family.

Wegener's granulomatosis, subglottic stenosis and antineutrophil cytoplasm antibodies

Wegener's granulomatosis is difficult to diagnose, especially when the presentation is unusual, restricted to an isolated region. We report four cases of recurrent subglottic stenosis posing difficulty in diagnosis. In each case the finding of anti-neutrophil cytoplasm antibodies (ANCA) strongly suggested an underlying vasculitic pathology, Wegener's granulomatosis. We discuss reasons for the difficulty in diagnosis in the past, the possible role of the ANCA assay in such patients, and suggest it should be more widely used in the future.