Session Information
Session Type: ACR Poster Session C
Session Time: 9:00AM-11:00AM
Background/Purpose: Increased prevalence of IgA aCL and anti-PS/PT antibodies has been described in adult IgAV, making them potential markers of disease activity1. The aim of our prospective study was to evaluate the role of antiphospholipid antibodies (aPL-Abs) on the clinical presentation of adult IgA vasculitis (IgAV).
Methods: Adults with histologically proven IgAV, diagnosed for the first time between 1 January 2013 and 31 May 2016 at our at our secondary/tertiary rheumatology center were included. IgG, IgM and IgA isotypes of anticardiolipin antibodies (aCL), antibodies to β2-glycoprotein 1 (aβ2GP1) and antibodies to phosphatidylserine-prothrombin complex (aPS/PT) were determined at presentation. A cut-off level for positive result was set at 99th percentile for all aPL-Abs. Clinical characteristics of patients with and without aPL-Abs were compared. Additionally, characteristics of IgAV cases with positive IgA aPS/PT were analyzed as subgroup.
Results: During the 41-month observation period aPL-Abs were determined in 89 IgAV patients (53.9 % male; median (IQR) age 67.6 (50.3, 77.3) years). In total 32 patients (36.0%) had aPL-Abs. aCL, aβ2GP1 and aPS/PT were found in 9.0%, 13.5% and 23.6%, respectively. IgA aPS/PT subtype, found in 21.3% was the most common aPL-Ab present in our IgAV patients (Table 1). Characteristics of aPL-Abs negative vs. aPL-Abs positive patients vs. IgA PS/PT positive cases are presented in the Table 2. The presence of any aPL-Abs was associated neither with thrombotic events nor with distinct IgAV clinical manifestation. Yet, aPL-Abs positive IgAV patients had significantly higher erythrocyte sedimentation rate (p<0.001), C-reactive protein (p=0.007) and serum immunoglobulin A level (p=0.023) at presentation. However, IgA aPS/PT positive patients had more commonly had renal involvement than those without this antibody (p=0.031; RR 1.9 (95% CI 1.1–3.1)). This was unrelated to increased total serum IgA level. The latter was not a predictor of renal involvement in our cohort (p=0.177).
|
Table 1. |
|
|
aPL-Abs |
number of patients |
| aCL |
8 (9.0%) |
|
IgG |
7 |
|
IgM |
1 |
|
IgA |
1 |
| aβ2GP1 |
12 (13.5%) |
|
IgG |
6 |
|
IgM |
3 |
|
IgA |
7 |
| aPS/PT |
21 (23.6%) |
|
IgG |
6 |
|
IgM |
5 |
|
IgA |
19 |
|
Legend: aPL-Abs antiphospholipid antibodies; aCL – anticardiolipin antibodies, aβ2GP1 – antibodies to β2 glycoprotein 1; aPS/PT antibodies to phosphatidylserine-prothrombin complex |
|
| Table 2. |
aPL-Abs (number of patients) |
IgA aPS/PT (No of patients) |
|
|
Clinical characteristics |
Not present (57) |
Present# (32) |
Present (19) |
| M : F ratio |
1.0 |
1.2 |
1.1 |
| Age (years)* |
65.9 (43.6-77.3) |
68.6 (55.0-78.2) |
67.7 (54.6-79.9) |
| Disease duration (days)* |
8 (5-21) |
9 (5-14) |
7 (5-14) |
| Prior infection (%) |
40.4 |
28.1 |
26.3 |
| General symptoms (%) |
19.3 |
18.8 |
10.5 |
| Generalized purpura |
59.6 |
46.9 |
52.6 |
| Skin necroses (%) |
43.9 |
40.6 |
47.4 |
| Isolated skin involvement (%) |
29.8 |
18.8 |
21.1 |
| Joint involvement (%) |
36.8 |
40.6 |
26.3 |
| Arthritis (%) |
14.0 |
15.6 |
5.3 |
| GI tract involvement (%) |
38.6 |
21.9 |
26.3 |
| Severe GI tract involvement (%) |
8.8 |
9.4 |
10.5 |
| Renal involvement (%) |
33.3 |
50.0 |
63.2 |
| Severe renal involvement (%) |
12.3 |
18.8 |
21.1 |
| Thrombosis (%) |
1.8 |
3.1 |
0 |
| IgA level (g/l)* |
3.68 (2.80-4.99) |
4.56 (3.56-6.71) |
5.49 (4.49-7.22) |
| ESR (mm/h)* |
30 (14-46) |
53 (34-63) |
60 (44-70) |
| CRP (mg/l)* |
25 (7-45) |
48 (21-88) |
43 (18-92) |
| BVAS-3* |
8 (3-13) |
7 (3-13) |
8 (3-15) |
|
Legend: # at least one aPL antibody present (aCL, aβ2GP1 or aPS/PT), 24 cases were single positive, 8 double or triple positive); M – male; F – female; * median and IQR; severe GI tract involvement – bloody diarrhea or ileus or surgical intervention; severe renal involvement – acute kidney injury or nephrotic syndrome; BVAS-3 – Birmingham vasculitis activity score |
|||
Conclusion: IgA aPS/PT antibodies emerged as a potential marker of renal involvement in adult IgAV.
Reference: 1 Kawakami T,et al. Arthritis Rheum 2008; 59(4):561-7.
To cite this abstract in AMA style:
Hocevar A, Ostrovrsnik J, Žigon P, Čučnik S, Rotar Z, Tomšič M. Antiphospoholipid Antibodies in Adult IgA Vasculitis: Aps/PT Antibodies As a Potential Marker of Renal Involvement? [abstract]. Arthritis Rheumatol. 2016; 68 (suppl 10). https://acrabstracts.org/abstract/antiphospoholipid-antibodies-in-adult-iga-vasculitis-apspt-antibodies-as-a-potential-marker-of-renal-involvement/. Accessed .« Back to 2016 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/antiphospoholipid-antibodies-in-adult-iga-vasculitis-apspt-antibodies-as-a-potential-marker-of-renal-involvement/