Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


Characterization at Diagnosis of Children with Microscopic Polyangiitis (MPA) Defined Uniquely among Patients with ANCA-Associated Vasculitis (AAV) in a Registry for Children with Vasculitis (ARChiVe).

Cabral2,  David A., Uribe2,  America G., Abramson37,  Leslie S., Adams5,  Matthew D., Benseler31,  Susanne M., Campillo20,  Sarah S. C., Chira30,  Peter

Baylor College of Medicine, Houston, TX
Childrens Hospital of NY, New York, NY
Childrens Med Ctr Med Schl GA, Augusta, GA
Childrens Mem Hosp/NW Univ, Chicago, IL
Corner Children's Hospital, Chicago, IL
Duke University Medical Center, Durham, NC
IWK Health Centre, Halifax, NS, Canada
Joseph M Sanzari Children's Hospital, Short Hills, NJ
Legacy Emanuel Children's Hosp, Portland, OR
Mattel Children's UCLA, Los Angeles, CA
Mayo Clinic Rochester, Rochester, MN
BC Children's Hospital, Vancouver, BC, Canada
Montreal Children's Hospital, Montreal, QC, Canada
Nationwide Childrens Hosp, Columbus, OH
OU Health Science Center, Oklahoma City, OK
Pediatrics, U. of Washington, Seattle, WA
Phoenix Children's Hospital, Phoenix, AZ
Rainbow Babies and Children's Hospital, Beachwood, OH
Riley Children's Hospital, Nashville, TN
Robert Wood Johnson Medical School, Metuchen, NJ
Schneider Children's Hospital, New Hyde Park, NY
St Louis Childrens Hosp, St Louis, MO
Children's Hospital at Montefiore, Bronx, NY
Stanford Univ Schl of Med, Stanford, CA
The Hospital for Sick Children, Toronto, ON, Canada
TX Scottish Rite Hosp, Dallas, TX
UCSF, San Francisco, CA
University of Florida, Orlando, FL
University of Louisville SOM, Louisville, KY
University of Utah, Salt Lake City, UT
University of Vermont, Morrisville, VT
Children's Hospital Med Ctr, Akron, OH
Children's Hospital of Michigan, Huntington Woods, MI
Children's Hospital of Pittsburgh, Pittsburgh, PA
Childrens Hosp LA MS60, Los Angeles, CA
Childrens Hospital Boston, Boston, MA
Childrens Hospital Medical Center, Cincinnati, OH

Background:

Descriptions of MPA are limited by the inability of definitions (e.g. Chapel Hill Consensus Conference) to uniquely define patients and exclude another related vasculitis. Classification algorithms have been used to distinguish patients with related vasculitides by applying in a hierarchical sequence, from the most specific to the least specific, diagnostic criteria for each patient in a population.

Aims:

To describe interval to diagnosis, presenting features and initial treatment for children uniquely classified as having MPA in ARChiVe.

Methods:

Time-of-diagnosis data on children with AAV diagnosed since 2004 by expert rheumatologists (MD-diagnosis) has been contributed to ARChiVe from 37 US/ Canadian sites. A pediatric modification of the European Medicines Agency (EMEA) for AAV and polyarteritis nodosa (PAN) classification algorithm was applied by computation to this cohort to uniquely classify patients with MPA. Descriptive data on these MPA patients were then extracted. Sensitivity and specificity of the algorithm classification of MPA were tested (MD-diagnosis reference standard). The recently validated EULAR/PRINTO/PRES pediatric Wegener's granulomatosis (WG) criteria were applied to children with MPA to determine if there was diagnostic overlap.

Results:

Of the 155 patients, 18 (12%) had MPA, 113 WG, 2 Churg-Strauss syndrome, 1 PAN, and 21 were unclassifiable. For the 18 children with MPA (67% female, 56% Caucasian) the median age at diagnosis was 13 (range 3–16) y, and the median interval from disease onset to diagnosis was 23 (range 2–50) mo. Presenting features are shown in Table and included: renal 95%, constitutional 89%, pulmonary 28% and sinus-upper respiratory 17%. Anti-MPO and anti-PR3 were present in 61% and 28% of patients respectively. Necrotizing pauci-immune glomerulonephritis was reported in 20% of 15 kidney biopsies. In 14 (78%) patients corticosteroids (CS) and cyclophosphamide (6 PO, 7 IV, 1 PO+IV) were the initial treatment; plasmapheresis (n=3), rituximab (n=2), and methotrexate (n=1) were also used in these 14. The remainder (n=4) received CS alone. Sensitivity and specificity of the EMEA algorithm for MPA were 22% and 92%. No MPA patients were concurrently classified by EULAR/PRINTO/PRES as WG.

Table. Frequency of presenting clinical features in pediatric patients with microscopic polyangiitis in the ARChiVe cohort (n = 155)

Clinical featureAffected patients, n (%)
CONSTITUTIONAL/GENERAL58 (89)
        Malaise, fatigue14 (78)
        Weight loss9 (50)
        Fever7 (39)
RENAL17 (95)
        Elevated serum creatinine13 (72)
        Hematuria with proteinuria11 (61)
        Hematuria with red blood cell casts6 (33)
PULMONARY5 (28)
        Shortness of breath3 (17)
        Chronic cough3 (17)
        Hemoptysis/alveolar hemorrhage2 (11)
        Respiratory failure requiring ventilation1 (6)
EAR, NOSE, THROAT3 (17)
        Sore throat2 (11)
        Nasal stuffiness1 (6)
ANCA SEROLOGY 
        Immunofluorescence for cANCA/pANCA, positive14 (78)
        Anti-MPO positive ELISA11 (61)
        Anti-PR3 positive ELISA5 (28)
        Negative ELISA1 (6)
        ELISA not done/not available1 (6)

Conclusion:

Pediatric patients uniquely classified with MPA had predominantly renal and constitutional manifestations and a positive ANCA. A minority had upper or lower respiratory tract disease. Initial therapy varied considerably. The protracted interval from symptom onset to diagnosis suggests MPA is a poorly recognized entity in children.

To cite this abstract, please use the following information:
Cabral, David A., Uribe, America G., Abramson, Leslie S., Adams, Matthew D., Benseler, Susanne M., Campillo, Sarah S. C., et al; Characterization at Diagnosis of Children with Microscopic Polyangiitis (MPA) Defined Uniquely among Patients with ANCA-Associated Vasculitis (AAV) in a Registry for Children with Vasculitis (ARChiVe). [abstract]. Arthritis Rheum 2010;62 Suppl 10 :1673
DOI: 10.1002/art.29438

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