A 59-year-old lady with underlying hypothyroidism presented with acute contact dermatitis progressed to cellulitis with superimposed bacterial infection and acute kidney injury. She responded to initial management with antibiotics, but a week later, she had cutaneous and systemic vasculitis. Her skin biopsy consistent with immune-mediated leuko-cytoclastic vasculitis and her blood test was positive for cytoplasmic-anti-neutrophil cytoplasmic antibody (c-ANCA). A diagnosis of ANCA-associated vasculitis was made and she was treated with immunosuppressant with plasmapheresis and hemodialysis support for her kidney failure. Despite aggressive measures, the patient succumbed to her illness. This case report demonstrates that soft tissue infection could trigger the development of ANCA-associated vasculitis whilst a background of hypothyroidism serves as a predisposing factor as both condition were reported separately in a couple of case studies before.
Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) are a group of uncommon diseases. Given its rarity and multisystem clinical presentation which are usually serious and potentially fatal, prompt recognition and early treatment are of utmost importance. We report a case of AAV that presented with digital infarcts, cutaneous vasculitis, rapidly progressive glomerulonephritis, mononeuritis multiplex, eosinophilia and positive myeloperoxidase (MPO)-ANCA antibody. Apart from renal damage, there was complete recovery in other systems following intravenous cyclophosphamide and high-dose glucocorticoids albeit the response was delayed. This response obviates the need for second-line therapy with newer agent such as rituximab (anti-CD20 monoclonal antibody). We would also like to highlight that this is the first case of AAV that is associated with autoimmune thyroid disease to be reported from Malaysia.
Autoreactivity to myeloperoxidase (MPO) causes anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), with rapidly progressive glomerulonephritis. Here, we show that a Staphylococcus aureus peptide, homologous to an immunodominant MPO T-cell epitope (MPO409-428), can induce anti-MPO autoimmunity. The peptide (6PGD391-410) is part of a plasmid-encoded 6-phosphogluconate dehydrogenase found in some S. aureus strains. It induces anti-MPO T-cell autoimmunity and MPO-ANCA in mice, whereas related sequences do not. Mice immunized with 6PGD391-410, or with S. aureus containing a plasmid expressing 6PGD391-410, develop glomerulonephritis when MPO is deposited in glomeruli. The peptide induces anti-MPO autoreactivity in the context of three MHC class II allomorphs. Furthermore, we show that 6PGD391-410 is immunogenic in humans, as healthy human and AAV patient sera contain anti-6PGD and anti-6PGD391-410 antibodies. Therefore, our results support the idea that bacterial plasmids might have a function in autoimmune disease.
Antineutrophil cytoplasmic antibodies (ANCA) are autoantibodies directed against primary granules of neutrophils and monocytes' lysosomes. In general, c-ANCA is strongly associated with vasculitic disorders mainly in ANCA-associated systemic vasculitis (AASV). p-ANCA have been identified in several diseases such as primary (AASV) and secondary vasculitis such as collagen vascular diseases, rheumatoid arthritis and inflammatory bowel diseases given the term 'ANCA-associated disease.' The objective of this study was to determine the rate of ANCA positivity by indirect immunofluorescent (IF) and enzyme linked immunosorbent assay (ELISA) and its association with AASV and ANCA associated diseases. Serum from patients with history suspicion of systemic vasculitis were tested for ANCA by IF. Those samples positive for ANCA by IF were further tested for antibodies against myeloperoxidase (MPO) and proteinase 3 (PR3) using the ELISA. Clinical data from medical records were obtained and analyzed. Of 468 samples, a total of 110 were positive for ANCA by IF. IF results showed a p-ANCA pattern in 96 patients and c-ANCA in 14. Of 110 IF positive ANCA, 45 patients were positive by ELISA. Seventeen were positive for MPO-ANCA, 9 were PR3-ANCA positive and 19 were both MPO and PR3 positive. Only 2 patients were classified AASV ie Wegener granulomatosis and the other with microscopic polyangiitis. The remaining patients (n = 108) may be classified as ANCA associated diseases. Our study showed that pANCA (87.3%) was the more common ANCA pattern and 40.9% of IF positive samples were positive for PR3- and MPOANCA.
This article aims to report a case of a young female patient with anti-neutrophil cytoplasmic antibodies-associated vasculitis complicated with pulmonary renal syndrome, multiple relapses, and who later developed venous thromboembolism. Pulmonary renal syndrome is a well- recognized and lethal complication; however, incidence of venous thromboembolism has not been well-described. In this article, we described a 38-year-old Malay female patient admitted in 2008 with three-month history of peripheral neuropathy of lower limbs and right ankle ulcers. Initial inflammatory markers were high and perinuclear Anti-Neutrophil Cytoplasmic Antibodies were positive. She was diagnosed as anti-neutrophil cytoplasmic antibodies-associated vasculitis and started on intravenous methylprednisolone with methotrexate. She presented with relapse of skin vasculitis complicated with pulmonary renal syndrome after being stable for one year. She was intubated and proceeded with plasmapheresis and hemodialysis. She completed six cycles of cyclophosphamide. Renal biopsy revealed chronic changes consistent with end stage renal disease. She further relapsed in 2011 with nasal blockage, epistaxis, and nasal deviation. Chest X-ray revealed lung nodules. Prednisolone was increased, her symptoms settled, and she was discharged with azathioprine. She was readmitted at the end of the same year due to two-day history of right deep vein thrombosis and she later succumbed to methicillin-resistant Staphylococcus aureus sepsis.