Generation and Characterization of a Polyclonal Human Reference Antibody to Measure Anti-Drug Antibody Titers in Patients with Fabry Disease.

Malte Lenders,Eva Brand,Seraphine Valeska Wegner,David Scharnetzki,Ali Heidari,Daniele Di Iorio

doi:10.3390/ijms22052680

Malte Lenders, Eva Brand + Show 4 more

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https://doi.org/10.3390/ijms22052680

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Abstract

Male patients with Fabry disease (FD) are at high risk for the formation of antibodies to recombinant α-galactosidase A (AGAL), used for enzyme replacement therapy. Due to the rapid disease progression, the identification of patients at risk is highly warranted. However, currently suitable references and standardized protocols for anti-drug antibodies (ADA) determination do not exist. Here we generate a comprehensive patient-derived antibody mixture as a reference, allowing ELISA-based quantification of antibody titers from individual blood samples. Serum samples of 22 male patients with FD and ADAs against AGAL were pooled and purified by immune adsorption. ADA-affinities against agalsidase-α, agalsidase-β and Moss-AGAL were measured by quartz crystal microbalance with dissipation monitoring (QCM-D). AGAL-specific immune adsorption generated a polyclonal ADA mixture showing a concentration-dependent binding and inhibition of AGAL. Titers in raw sera and from purified total IgGs (r2 = 0.9063 and r2 = 0.8952, both p < 0.0001) correlated with the individual inhibitory capacities of ADAs. QCM-D measurements demonstrated comparable affinities of the reference antibody for agalsidase-α, agalsidase-β and Moss-AGAL (KD: 1.94 ± 0.11 µM, 2.46 ± 0.21 µM, and 1.33 ± 0.09 µM, respectively). The reference antibody allows the ELISA-based ADA titer determination and quantification of absolute concentrations. Furthermore, ADAs from patients with FD have comparable affinities to agalsidase-α, agalsidase-β and Moss-AGAL.

Highlights

Introduction published maps and institutional affilFabry disease (FD, online Mendelian Inheritance in Man (OMIM) no. 301500) is a rare X-chromosomal-linked lysosomal storage disorder, caused by a deficiency of the α-galactosidase A (AGAL; EC 3.2.1.22) enzyme
[1] Currently, in addition to chaperone therapy, FD is treatable by enzyme replacement therapy (ERT) using either agalsidase-α (0.2 mg/kg body weight every other week; Shire/Takeda, Lexington, MA, USA) or agalsidase-β (1.0 mg/kg body weight every other week; Sanofi-Genzyme, Cambridge, MA, USA). [2,3] Treatment with either agalsidaseα or agalsidase-β demonstrated beneficial effects on disease progression and manifestations in affected patients
[4] Comparable to other lysosomal storage disorders such as Pompe or Gaucher diseases, which are treated by ERT, classical male FD patients are at high iations

Summary

Introduction

Introduction published maps and institutional affilFabry disease (FD, online Mendelian Inheritance in Man (OMIM) no. 301500) is a rare X-chromosomal-linked lysosomal storage disorder, caused by a deficiency of the α-galactosidase A (AGAL; EC 3.2.1.22) enzyme. 301500) is a rare X-chromosomal-linked lysosomal storage disorder, caused by a deficiency of the α-galactosidase A (AGAL; EC 3.2.1.22) enzyme. [2,3] Treatment with either agalsidaseα or agalsidase-β demonstrated beneficial effects on disease progression and manifestations in affected patients. [4] Comparable to other lysosomal storage disorders such as Pompe or Gaucher diseases, which are treated by ERT, classical male FD patients are at high iations. Due to the rapid disease progression the measurement of ADA titers is important for an individually tailored treatment management in affected patients. Several different approaches to measure ADAs are used, including ELISA-based measures ( including IgG subclass analyses) [5,9], inhibitory-based measures [5,7,10,11], cell-based measures (to identify effects on cellular ERT uptake) [12] and bed-side tests [13]

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