When Anti-Neutrophil Cytoplasmic Antibody Fails: A Case of Anti-Neutrophil Cytoplasmic Antibody Negative Granulomatosis With Polyangiitis

Dynamically changing antineutrophil cytoplasmic antibodies in granulomatosis with polyangiitis: A case report

BACKGROUND

Granulomatosis with polyangiitis (GPA) is one of the most prevalent forms of the antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. GPA is characterized histologically by necrotizing granulomatous inflammation in addition to vasculitis. The diagnosis of GPA depends on clinical presentation, serological evidence of a positive ANCA, and/or histological evidence of necrotizing vasculitis or granulomatous destructive parenchymal inflammation. Cytoplasmic ANCA (c-ANCA) is positive in 65%-75% of GPA patients, accompanied by proteinase 3 (PR3), the main target antigen of c-ANCA, another 5% of GPA patients had negative ANCA.

CASE SUMMARY

The patient, a 52-year-old male, presented with unexplained nasal congestion, tinnitus, and hearing loss. After a duration of 4 months experiencing these symptoms, the patient subsequently developed fever and headache. The imaging examination revealed the presence of bilateral auricular mastoiditis and partial paranasal sinusitis, and the ANCA results were negative. The anti-infective therapy proved to be ineffective, but the patient's symptoms and fever were quickly relieved after 1 wk of treatment with methylprednisolone 40 mg once a day. However, after continuous use of methylprednisolone tablets for 3 months, the patient experienced a recurrence of fever accompanied by right-sided migraine, positive c-ANCA and PR3, and increased total protein in cerebrospinal fluid. The patient was diagnosed with GPA. After receiving a treatment regimen of intravenous methylprednisolone 40 mg/d and cyclophosphamide 0.8 g monthly, the patient experienced alleviation of fever and headache. Additionally, the ANCA levels became negative and there has been no recurrence.

CONCLUSION

For GPA patients with negative ANCA, there is a potential for early missed diagnosis. The integration of histopathological results and multidisciplinary communication plays a crucial role in facilitating ANCA-negative GPA.

Bilateral Scleritis with Heterogeneous Etiologies: A Diagnostic Dilemma

PURPOSE

To report a patient with bilateral scleritis who was initially treated for infectious scleritis, and subsequently diagnosed as granulomatosis with polyangiitis (GPA).

METHOD

Retrospective chart review.

RESULT

A 48-year-old female with a known history of diabetes presented with pain, redness, and blurring of vision in the right eye. She was diagnosed as scleritis with retinal detachment and underwent vitrectomy, with silicone oil tamponade and intravitreal injections of antibiotics, and antifungal agents. She presented with active scleritis with additional multiple pus points. Several scleral biopsies failed to yield any microorganism and finally, the painful blind eye was enucleated. The enucleated specimen grew gram-positive bacteria which were identified as Staphylococcus arlettae by polymerase chain reaction (PCR)-based sequencing of the 16S rRNA gene. Nine months after the onset of symptoms in the right eye, the patient developed necrotizing scleritis in the left eye. Laboratory investigation revealed a positive cytoplasmic- anti-neutrophil cytoplasmic autoantibody, which was previously negative during the right eye involvement. She was diagnosed with GPA by a rheumatologist and treated accordingly.

CONCLUSION

Retinal detachment may be associated with scleritis, and ANCA testing may not detect GPA in its early stages. Once infection has been excluded, clinicians should not be afraid to use high-dose immunosuppression instead of surgery to treat retinal detachment associated with scleritis.