Antibodies Directed Against HLA-DQ Are Significantly Associated to Complement Activation In Vitro
1Transplantation, 1aNephrology-Mineral Metabolism, Inst Nal de Ciencias Medicas y Nutricion SZ, Mexico City, Distrito Federal, Mexico.
Meeting: 2015 American Transplant Congress
Abstract number: A106
Keywords: Highly-sensitized, Histocompatibility antigens, HLA antibodies, HLA antigens
Session Information
Session Name: Poster Session A: Kidney Antibody Mediated Rejection
Session Type: Poster Session
Date: Saturday, May 2, 2015
Session Time: 5:30pm-7:30pm
Presentation Time: 5:30pm-7:30pm
Location: Exhibit Hall E
Background: C1q-binding HLA antibodies (HLAabs) have been related to acute rejection and long-term graft loss. The characteristics of these antibodies and factors associated to complement activation have not been well studied. Aim: To describe the class I and class II HLAabs (specificities and MFI) present in the serum of sensitized patients and their correlation with C1q activation. Methods: This is a cross-sectional, observational and descriptive study of patients with high immunological risk in the pre-transplant period and evaluated between 01/2012 and 02/2014. HLAabs and C1q activation (C1qScreenTM One Lamda) were determined by Luminex. Results: The sera of 58 sensitized patients were analyzed; 877 HLAabs directed against different HLA antigenic specificities were detected. Fifteen point five percent (15.5%) (136/877) of the HLAabs activated C1q. The median MFI of the C1q+ Abs was 12,786 (9,071-18,562) and that of the C1q- Abs was 2128 (1402 – 4957) (p<0.001). Fifty eight (10.39%) HLAabs against class I were C1q+ while 79 (24.76%) of the class II HLAabs were C1q+ (p<0.001). By logistic regression, factors positively associated to C1q activation included HLAabs vs. HLA-DQ and the Abs MFI, while Abs vs. HLA-A and HLA-C appeared to be protective. (Table1). When dividing the Abs by MFI (<1000, 1001-2500, 2501-5000, 5001-7500, 7501-10 K and > 10 K), those >7500 were significantly associated to C1q+. On multivariate analysis, a MFI >7500 (OR 21.73 CI95% 12.5 – 37.5) and the HLA-DQ specificity (OR 21.73 IC95% 3.74 – 12.76) were significantly and independently related to C1q+.
| C1q + (n=137) | C1q – (n=741) | OR CI95% | ||
| HLAabs vs Class I, n(%) | 58 (42.3) | 500 (67.4) | Ref | Ref |
| HLA-A | 16 (11.76) | 105 (14.17) | 0.79 (0.45 to 1.401) | 0.435 |
| HLA-B | 34 (25.0) | 287 (38.7) | 0.52 (0.34 to 0.788) | 0.002 |
| HLA-C | 8 (5.88) | 108 (14.57) | 0.36 (0.17 to 0.76) | 0.007 |
| HLAabs vs Class II, n(% | 79 (57.35) | 241 (32.52) | 2.85 (1.95 to 4.11) | <0.001 |
| HLA-DP | 8 (5.88) | 65 (8.77) | 0.64 (0.301 to 1.37) | 0.255 |
| HLA-DQ | 49 (36.03) | 55 (7.42) | 6.93 (4.44 to 10.81) | <0.001 |
| HLA-DR | 21 (15.44) | 121 (16.33) | 0.98 (0.601 to 1.62) | 0.963 |
| MFI | 12786 (9,071 to 18,562) | 2128 (1,402 to 4,957) | 1.0002 (1.002 to 1.0003) | <0.0001 |
Conclusions: C1q+ HLAabs were significantly and independently associated to a MFI >7500 and to antigenic specificities vs. HLA-DQ.
To cite this abstract in AMA style:
Arreola-Guerra J, Santiago Ade, Arvizu A, Gonzalez-Tableros N, Lopez M, Vilatoba M, Morales-Buenrostro L, Alberu J, Castelan N. Antibodies Directed Against HLA-DQ Are Significantly Associated to Complement Activation In Vitro [abstract]. Am J Transplant. 2015; 15 (suppl 3). https://atcmeetingabstracts.com/abstract/antibodies-directed-against-hla-dq-are-significantly-associated-to-complement-activation-in-vitro/. Accessed May 8, 2025.« Back to 2015 American Transplant Congress