Comparing Presenting Clinical Features in 48 Children With Microscopic Polyangiitis to 183 Children Who Have Granulomatosis With Polyangiitis (Wegener's): An ARChiVe Cohort Study.
To uniquely classify children with microscopic polyangiitis (MPA), to describe their demographic characteristics, presenting clinical features, and initial treatments in comparison to patients with granulomatosis with polyangiitis (Wegener's) (GPA).



The European Medicines Agency (EMA) classification algorithm was applied by computation to categorical data from patients recruited to the ARChiVe (A Registry for Childhood Vasculitis: e-entry) cohort, with the data censored to November 2015. The EMA algorithm was used to uniquely distinguish children with MPA from children with GPA, whose diagnoses had been classified according to both adult- and pediatric-specific criteria. Descriptive statistics were used for comparisons.



In total, 231 of 440 patients (64% female) fulfilled the classification criteria for either MPA (n = 48) or GPA (n = 183). The median time to diagnosis was 1.6 months in the MPA group and 2.1 months in the GPA group (ranging to 39 and 73 months, respectively). Patients with MPA were significantly younger than those with GPA (median age 11 years versus 14 years). Constitutional features were equally common between the groups. In patients with MPA compared to those with GPA, pulmonary manifestations were less frequent (44% versus 74%) and less severe (primarily, hemorrhage, requirement for supplemental oxygen, and pulmonary failure). Renal pathologic features were frequently found in both groups (75% of patients with MPA versus 83% of patients with GPA) but tended toward greater severity in those with MPA (primarily, nephrotic-range proteinuria, requirement for dialysis, and end-stage renal disease). Airway/eye involvement was absent among patients with MPA, because these GPA-defining features preclude a diagnosis of MPA within the EMA algorithm. Similar proportions of patients with MPA and those with GPA received combination therapy with corticosteroids plus cyclophosphamide (69% and 78%, respectively) or both drugs in combination with plasmapheresis (19% and 22%, respectively). Other treatments administered, ranging in decreasing frequency from 13% to 3%, were rituximab, methotrexate, azathioprine, and mycophenolate mofetil.



Younger age at disease onset and, perhaps, both gastrointestinal manifestations and more severe kidney disease seem to characterize the clinical profile in children with MPA compared to those with GPA. Delay in diagnosis suggests that recognition of these systemic vasculitides is suboptimal. Compared with adults, initial treatment regimens in children were comparable, but the complete reversal of female-to-male disease prevalence ratios is a provocative finding.
British Columbia Children's Hospital, Vancouver, British Columbia, Canada. dcabral@cw.bc.ca.
David A
DA
Cabral
Texas Children's Hospital, Houston.
Debra L
DL
Canter
Texas Children's Hospital, Houston.
Eyal
E
Muscal
Seattle Children's Hospital, Seattle, Washington.
Kabita
K
Nanda
Children's Hospital at Montefiore, Bronx, New York.
Dawn M
DM
Wahezi
Cleveland Clinic, Cleveland, Ohio.
Steven J
SJ
Spalding
Alberta Children's Hospital and University of Calgary, Calgary, Alberta, Canada.
Marinka
M
Twilt
Alberta Children's Hospital and University of Calgary, Calgary, Alberta, Canada.
Susanne M
SM
Benseler
Montreal Children's Hospital and McGill University Health Centre, Montreal, Quebec, Canada.
Sarah
S
Campillo
Siriraj Hospital and Mahidol University, Bangkok, Thailand.
Sirirat
S
Charuvanij
Janeway Children's Health and Rehabilitation Centre, St. John's, Newfoundland, Canada.
Paul
P
Dancey
Cohen Children's Medical Center of New York, New Hyde Park.
Barbara A
BA
Eberhard
University of Florida, Gainesville.
Melissa E
ME
Elder
University of Utah, Salt Lake City.
Aimee
A
Hersh
Nationwide Children's Hospital, Columbus, Ohio.
Gloria C
GC
Higgins
IWK Health Centre and Dalhousie University, Halifax, Nova Scotia.
Adam M
AM
Huber
Breach Candy Hospital, Mumbai, India.
Raju
R
Khubchandani
Children's Hospital of Boston, Boston, Massachusetts.
Susan
S
Kim
Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois.
Marisa
M
Klein-Gitelman
St. Petersburg State Pediatric Medical University, St. Petersburg, Russia.
Mikhail M
MM
Kostik
University of California, San Francisco.
Erica F
EF
Lawson
Stanford Children's Health and Stanford University School of Medicine, Stanford, California.
Tzielan
T
Lee
Simon Fraser University, Burnaby, British Columbia, Canada.
Joanna M
JM
Lubieniecka
University of California, Los Angeles.
Deborah
D
McCurdy
Rutgers Robert Wood Johnson Medical School, New Brunswick, New Jersey.
Lakshmi N
LN
Moorthy
British Columbia Children's Hospital, Vancouver, British Columbia, Canada.
Kimberly A
KA
Morishita
Rigshospitalet, Copenhagen, Denmark.
Susan M
SM
Nielsen
Riley Children's Hospital, Indianapolis, Indiana.
Kathleen M
KM
O'Neil
Children's Hospital Los Angeles, Los Angeles, California.
Andreas
A
Reiff
Mother and Child Health Care Institute of Serbia, Belgrade, Serbia.
Goran
G
Ristic
University Hospitals Case Medical Center and Rainbow Babies and Children's Hospital, Cleveland, Ohio.
Angela B
AB
Robinson
British Columbia Children's Hospital, Vancouver, British Columbia, Canada.
Angelyne
A
Sarmiento
Seattle Children's Hospital, Seattle, Washington.
Susan
S
Shenoi
Akron Children's Hospital, Akron, Ohio.
Mary B
MB
Toth
Duke Children's Hospital and Health Center and Duke University Medical Center, Durham, North Carolina.
Heather A
HA
Van Mater
University of Chicago Medicine Comer Children's Hospital, Chicago, Illinois.
Linda
L
Wagner-Weiner
Joseph M. Sanzari Children's Hospital and Hackensack University Medical Center, Hackensack, New Jersey.
Jennifer E
JE
Weiss
St. Louis Children's Hospital and Washington University School of Medicine, St. Louis, Missouri.
Andrew J
AJ
White
Hospital for Sick Children, Toronto, Ontario, Canada.
Rae S M
RS
Yeung
D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D017677:Age Distribution; D019268:Antibodies, Antineutrophil Cytoplasmic; D001208:Asia / Q000453:epidemiology; D001379:Azathioprine / Q000627:therapeutic use; D002170:Canada / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003520:Cyclophosphamide / Q000627:therapeutic use; D004359:Drug Therapy, Combination; D005060:Europe / Q000453:epidemiology; D005260:Female; D014890:Granulomatosis with Polyangiitis / Q000150:complications / Q000453:epidemiology / Q000503:physiopathology* / Q000628:therapy; D006470:Hemorrhage / Q000209:etiology / Q000503:physiopathology*; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007223:Infant; D007676:Kidney Failure, Chronic / Q000209:etiology / Q000503:physiopathology* / Q000628:therapy; D008171:Lung Diseases / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D008727:Methotrexate / Q000627:therapeutic use; D055953:Microscopic Polyangiitis / Q000150:complications / Q000453:epidemiology / Q000503:physiopathology* / Q000628:therapy; D009173:Mycophenolic Acid / Q000627:therapeutic use; D009404:Nephrotic Syndrome / Q000209:etiology / Q000503:physiopathology*; D010102:Oxygen Inhalation Therapy; D010956:Plasmapheresis; D011507:Proteinuria / Q000209:etiology; D006435:Renal Dialysis; D012131:Respiratory Insufficiency / Q000209:etiology / Q000503:physiopathology* / Q000628:therapy; D000069283:Rituximab / Q000627:therapeutic use; D014481:United States / Q000453:epidemiology
D000305:Adrenal Cortex Hormones; D019268:Antibodies, Antineutrophil Cytoplasmic; D007166:Immunosuppressive Agents; D000069283:Rituximab; D003520:Cyclophosphamide; D009173:Mycophenolic Acid; D001379:Azathioprine; D008727:Methotrexate