ABSTRACT
Background@#ANCA-associated vasculitis and its subtypes have been associated with pulmonary manifestations, with bronchiectasis being a unique clinical presentation.@*Case Summary@# We report the case of a 26-year-old Filipino male who presented with progressive dyspnea, neuropathic pain, and purpuric rash. Diagnostic evaluation revealed upper lobe bronchiectasis and lower lobe pneumonia, as well as hematuria and proteinuria. ANCA-associated vasculitis (AAV) and tuberculosis were considered. There was improvement of dyspnea, cough and rashes with antibiotics, glucocorticoids (GC), and anti-TB coverage. However, neuropathic pain progressed to the upper and lower extremities with development of weakness. Anti-myeloperoxidase (MPO) Anti-Neutrophil Cytoplasmic Antibody (ANCA) was positive, Electromyography-Nerve Conduction Velocity (EMG-NCV) revealed diffuse sensorimotor axonal polyradiculopathy of both upper and lower extremities. Cyclophosphamide was then given. The patient gradually regained his motor strength while sensory deficits persisted. He was referred to rehabilitation medicine for physical therapy and eventually discharged. This case highlights vasculitis as an associated extrapulmonary manifestation of bronchiectasis, and the possible role of bronchiectasis in the immune-mediated pathogenesis of ANCA- associated vasculitides.
Subject(s)
Bronchiectasis , Anti-Neutrophil Cytoplasmic Antibody-Associated VasculitisABSTRACT
To elucidate the prevalence and clinical implications of antineutrophil cytoplasmic antibody(ANCA) in lupus nephritis(LN), we examined ANCA by indirect immunofluorescence and by ELISA against anti-MPO antibody and anti-lactoferrin antibody. To discriminate pANCA with antinuclear antibody(ANA), all the ANCA positive sera were tested again after incubating patients' sera with single stranded(ss) and double stranded(ds) DNA. To exclude possible cross-reactivity of anti-MPO antibody with lactoferrin, we also performed anti-MPO ELISA with sera preincubated with lactoferrin. These results were correlated with clinicopathologic manifestations and clinical courses of LN. ANCA was positive in 19(37.3%) out of the 51 LN patients. Among these LN patients, 3 had cANCA and 16 had pANCA. ANCA were not found in 8 SLE patients without nephritis and 30 normal controls. The presence of ANCA, particularly pANCA, was associated with the presence of nephritis(19/51 cases vs 0/8 cases, P<0.05), especially diffuse proliferative lupus nephritis(WHO class IV)(17/18 cases vs 21/31 cases, P<0.05) as well as the presence of anti-ds DNA antibody(17/19 cases vs 18/30 cases, P<0.05). Patients with ANCA more frequently had deterioration of renal function than those without it(3/16 vs 0/26 cases). Anti-lactoferrin antibody was positive in 13 patients. Among those, 5 didn't have ANCA, 7 had pANCA, and 1 had cANCA. The presence of anti-lactoferrin antibody was correlated to the low initial creatinine level[serum creatinine(mg/dl):0.78(0.6-1.0) vs 1.43(0.5-5.0), P<0.05]. Anti-MPO antibody was positive in one patient with cANCA and 6 patients with pANCA. However, in 6 patients, the anti-MPO activity was inhibited if tested after preincubation of the serum with lactoferrin. These data suggested that compared with lactorerrin, MPO is a rare antigen for ANCA in LN.