Session Information
Session Type: ACR Poster Session B
Session Time: 9:00AM-11:00AM
Background/Purpose: ANCA-associated vasculitides are rare diseases and epidemiological data on them is scarce. Our objective was to estimate incidence and prevalence rates of Granulomatosis with Polyangiitis (GPA) and Microscopic Polyangiitis (MPA) using data from a university hospital-based health management organization (HMO) in Latin America
Methods: Multiple methods for case finding were used to ensure complete ascertainment: (a) patients with diagnosis of vasculitis inHMO electronic medical records, (b) patients with an ANCA, proteinase-3 or myeloperoxidase positive test in laboratory database, (c) patients who consumed azathioprine, cyclophosphamide, methotrexate, mycophenolate or rituximab, from the administrative HMO drugs database, (d) patients with a renal biopsy performed from pathology registry. GPA was diagnosed if fulfilling ACR 1990 criteria or a clinical diagnosis was made by an experienced rheumatologist; MPA if diagnosed by a rheumatologist in concordance with Chapel Hill 2012 consensus. Renal limited vasculitis (RLV) ANCA-P positive was considered along with MPA. Global, age-specific, and sex-specific incidence and prevalence rates were calculated for members of the HMO. Incidence study followed members with continuous affiliation ≥ 1 year from January 2000 to January 2015 until he/she voluntarily left the HMO, GPA or MPA were diagnosed, death, or study finalization. Prevalence was calculated on January 1, 2015 and only patients still on treatment at that time were considered for calculation
Results: 19 incident cases of GPA and 28 of MPA were identified from January 2000 to January 2015. Patients’ characteristics are shown in table 1. During this period, a total of 349,775 HMO persons contributed a total of 2,073,438 person-years. Incidence rates were measured as cases per 1,000,000 person-years. GPA and MPA overall incidence rate were9(CI 5–13) and 14 (CI 9-19) respectively. Incidence rates were greater in women [GPA 11 (CI 5-17) and MPA 17 (CI 10-24)] than in men [GPA 6 (CI 1-11) and MPA 8 (CI 2-14)]. Age-specific incidence rates in both female andmale patients peaked in the seventh decades of life in our population. On January 1, 2015, 10 GPA and 7 MPA prevalent cases were identified from a denominator population of 135,750 HMO members.Prevalence rates were 7.4 per 100,000 (CI 2.8-12) for GPA and 5.2 per 100,000 (CI 1.3-9) for MPA. Prevalence rates were higher in ages over 70 for both sexes and both diseases
Table 1. Incident cases of GPA and MPA characteristics
|
Granulomatosis with Polyangeiitis (n=19) |
Microscopic Polyangiitis (n=28) |
||
|
Female, n (%) |
14 (73.7) |
21 (75) |
|
|
Mean age at diagnosis, years (DS) |
69.8 (11.3) |
73.6 (13.2) |
|
|
Global Incidence per 1,000,000 patients-year (CI 95%) |
9 (5–13) |
14 (9-19) |
|
|
ANCA-C positive, % (CI 95%) |
78.9 (52.7-92.7) |
14.3 (5.1-33.9) |
|
|
ANCA- P positive, % (CI 95%) |
15.8 (4.6-42.2) |
82.1 (62.1-92.8) |
|
|
Clinicalfeatures, % (CI 95%) |
|||
|
Nasal /sino-nasal involvement |
42.1 (21.1-66.5) |
14.3 (5.1-34) |
|
|
Hearingloss/reduction |
52.6 (29.2-75) |
10.7 (3.2-30) |
|
|
Cartilagenousinvolvement |
10.5 (2.3-37.1) |
0 |
|
|
Red eye |
15.8 (4.6-42.2) |
0 |
|
|
Renal involvement |
84.2 (57.8-95.4) |
100 |
|
|
Nodules, mass or cavitation in chest CT |
36.8 (17.3-62) |
0 |
|
|
Interstitial Lung Disease |
5.3 (0.1-26) |
21.4(8.3-40.9) |
|
|
Alveolar hemorrhage |
15.8 (4.6-42.2) |
10.7(3.2-30.1) |
|
|
Skin vasculitis |
15.8 (4.6-42.2) |
10.7(3.2-30.1) |
|
|
Arthritis |
31.6 (13.7-57.3) |
7.1 (1.6-26.3) |
|
|
Peripheral neuropathy |
15.8 (4.6-42.2) |
3.6 (0.4-23.7) |
|
|
Renal limited vasculitis |
0 |
60.7 (40.6-78.5) |
|
|
Fulfillment of ACR 1990 GPA criteria |
42.1 (21.1-66.5) |
NA |
|
|
Fulfillment of GPA 2017 provisional criteria |
89.5 (62.9-97.7) |
NA |
|
|
Follow-up time after diagnosis, years, median (RIC) |
4.9 (2.4-7.8) |
2.6 (0.7-6.1) |
|
|
Mortality, n (%) – Infections – Cardiovascular – Cancer – Vasculitis – Others |
9 (47.4) – 3 – 3 – 2 – 0 – 1 |
12 (42.9) – 6 – 1 – 1 – 1 – 3 |
|
Conclusion: In this first study from Latin America,incidence and prevalence rates were in ranges of previous reports from other sites of the world. In our population GPA and MPA were more frequent in women and in older ages (over 70), and incidence of MPA was higher than GPA
To cite this abstract in AMA style:
Pierini F, Scolnik M, Scaglioni V, Mollerach FB, Soriano ER. Incidence and Prevalence of Granulomatosis with Polyangiitis and Microscopic Polyangiitis in a Health Management Organization: A 15-Year Study [abstract]. Arthritis Rheumatol. 2017; 69 (suppl 10). https://acrabstracts.org/abstract/incidence-and-prevalence-of-granulomatosis-with-polyangiitis-and-microscopic-polyangiitis-in-a-health-management-organization-a-15-year-study/. Accessed .« Back to 2017 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/incidence-and-prevalence-of-granulomatosis-with-polyangiitis-and-microscopic-polyangiitis-in-a-health-management-organization-a-15-year-study/