Neonatal microscopic polyangiitis secondary to transfer of maternal myeloperoxidase-antineutrophil cytoplasmic antibody resulting in neonatal pulmonary hemorrhage and renal involvement.
BACKGROUND
Microscopic polyangiitis is a systemic vasculitis characterized by small vessel involvement. Studies suggest myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) is involved in its pathogenesis, and the titer may reflect disease activity.


OBJECTIVE
To report a case of transplacental transfer of MPO-ANCA from a mother to a 33-week gestational age neonate that resulted in neonatal pulmonary hemorrhage and renal involvement that was successfully treated with high-dose steroid therapy and exchange transfusion.


METHODS
MPO-ANCA titers from the cord blood and the neonate on the 8th, 15th, and 25th days of life (DOLs) were obtained. Metabolic panels and chest x-ray examinations were performed for the neonate and mother and the following values were measured: ANCA, erythrocyte sedimentation rate, C-reactive protein, antinuclear antibody, serial urinalysis, and complete blood cell count. Anti-glomerular basement membrane, quantitative immunoglobulins, anticardiolipin antibody, and rheumatoid factor were also measured for the neonate.


RESULTS
The neonate had elevated MPO-ANCA titers at birth. Pulmonary hemorrhage and renal involvement were seen on DOL 2. High-dose steroid therapy decreased symptoms within 1.5 hours of initiation. Exchange transfusion performed on DOL 5 removed all of the remaining MPO-ANCA by DOL 25. The child remains asymptomatic to date.


CONCLUSIONS
To our knowledge, this is the first reported case of transplacental transfer of MPO-ANCA resulting in pulmonary-renal syndrome that was successfully treated with high-dose steroid therapy and exchange transfusion.
Bansal
Priya J
PJ
Department of Immunology and Microbiology, Rush University Medical Center, Chicago, Illinois 60612, USA.
Tobin
Mary C
MC
D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000328:Adult; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood* / Q000276:immunology; D001803:Blood Transfusion; D005260:Female; D006470:Hemorrhage / Q000188:drug therapy / Q000209:etiology* / Q000628:therapy; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000188:drug therapy / Q000209:etiology* / Q000628:therapy; D007674:Kidney Diseases / Q000188:drug therapy / Q000209:etiology* / Q000628:therapy; D008171:Lung Diseases / Q000188:drug therapy / Q000209:etiology* / Q000628:therapy; D008431:Maternal-Fetal Exchange; D009195:Peroxidase / Q000276:immunology*; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000209:etiology; D014657:Vasculitis / Q000150:complications*
D000305:Adrenal Cortex Hormones; D019268:Antibodies, Antineutrophil Cytoplasmic; D009195:Peroxidase