Dataset Information

Protein Microarrays Discover Angiotensinogen and PRKRIP1 as Novel Targets for Autoantibodies in Chronic Renal Disease

ABSTRACT: Biomarkers for early detection of chronic kidney disease are needed, as millions of patients suffer from chronic diseases predisposing them to kidney failure. Protein microarrays may hold utility in the discovery of auto-antibodies in other conditions not commonly considered auto-immune diseases. We hypothesized that proteins are released as a consequence of damage at a cellular level during end-organ damage from renal injury, not otherwise recognized as self-antigens, and an adaptive humoral immune response to these proteins might be detected in the blood, as a non-invasive tracker of this injury. The resultant antibodies (Ab) detected in the blood would serve as effective biomarkers for occult renal injury, enabling earlier clinical detection of chronic kidney disease than currently possible, due to the redundancy of the serum creatinine as a biomarker for early kidney injury. To screen for novel autoantibodies in chronic kidney disease, 24 protein microarrays were used to compare serum Ab from patients with chronic kidney disease against matched controls. From a panel of 38 antigens with increased Ab binding, 4 were validated in 71 individuals, with (n=50) and without (n=21) renal insufficiency. Significant elevations in the titer of novel auto-Ab were noted against Angiotensinogen (AGT) and PRKRIP1 in renal insufficiency. Current validation is underway to evaluate if these auto-Ab can provide means to follow the evolution of chronic kidney disease in patients with early stages of renal insufficiency, and if these rising titers of these auto-Ab correlate with the rate of progression of chronic kidney disease.

ORGANISM(S): Homo sapiens

PROVIDER: GSE23609 | GEO | 2010/08/13

SECONDARY ACCESSION(S): PRJNA129949

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:Biomarkers for early detection of chronic kidney disease are needed, as millions of patients suffer from chronic diseases predisposing them to kidney failure. Protein microarrays may hold utility in the discovery of auto-antibodies in other conditions not commonly considered auto-immune diseases. We hypothesized that proteins are released as a consequence of damage at a cellular level during end-organ damage from renal injury, not otherwise recognized as self-antigens, and an adaptive humoral immune response to these proteins might be detected in the blood, as a non-invasive tracker of this injury. The resultant antibodies (Ab) detected in the blood would serve as effective biomarkers for occult renal injury, enabling earlier clinical detection of chronic kidney disease than currently possible, due to the redundancy of the serum creatinine as a biomarker for early kidney injury. To screen for novel autoantibodies in chronic kidney disease, 24 protein microarrays were used to compare serum Ab from patients with chronic kidney disease against matched controls. From a panel of 38 antigens with increased Ab binding, 4 were validated in 71 individuals, with (n=50) and without (n=21) renal insufficiency. Significant elevations in the titer of novel auto-Ab were noted against Angiotensinogen (AGT) and PRKRIP1 in renal insufficiency. Current validation is underway to evaluate if these auto-Ab can provide means to follow the evolution of chronic kidney disease in patients with early stages of renal insufficiency, and if these rising titers of these auto-Ab correlate with the rate of progression of chronic kidney disease. Serum antibodies were profiled for 7 healthy individuals and 17 patients with chronic kidney disease, using the Invitrogen ProtoArray® Human Protein Microarray v3.0 platform (Invitrogen, Carlsbad, CA). This platform contains 5,056 non-redundant human proteins expressed in a baculovirus system, purified from insect cells and printed in duplicate onto a nitrocellulose-coated glass slide. Each protein is spotted twice on each array, to measure the quality of the signal intensity. Details for experiment processing and analysis follow the previous publication from our group (Li et al Proc Natl Acad Sci U S A. 2009 Mar 17;106(11):4148-53). Prospector software was used to retrieve the expression based on immune response profiling of the .gal files.

Project description:Recurrence of focal segmental glomerulosclerosis (rFSGS) after kidney transplantation is a cause of early and accelerated graft loss. Immuneadsorption can alleviate renal dysfunction and suggests that circulating antibodies (Ab) are likely implicated in disease pathogenesis. To evaluate pathogenic Ab in rFSGS, we processed 141 unique serum samples from patients with and without primary rFSGS (n=64) and 34 non-FSGS control, transplanted at five (US and EU) hospitals. 9000 antigens were screened in pre-transplant sera by protein arrays and 10 Ab targeting glomerular antigens were selected for ELISA validation. A panel of 7 Ab (CD40, PTPRO, CGB-5, FAS, P2RY11, SNRPB2 and APOL2) could predict post-transplant FSGS recurrence with 92% accuracy. Pre-transplant elevation of anti-CD40 Ab levels alone had a substantial impact (78% accuracy) on the identification of rFSGS risk after transplantation. Epitope mapping of CD40 with customized peptide arrays and rFSGS sera demonstrated altered immunogenicity of the extracellular CD40 domain in rFSGS. Immunohistochemistry of CD40 demonstrated a differential expression of these antigens in FSGS compared to non-FSGS. Anti-CD40 Ab purified from rFSGS patients were uniquely pathogenic in human podocyte cultures; injection of these Ab resulted in heightened proteinuria, independently and in combination with suPAR in a rodent model, abrogated by injection of monoclonal Ab to CD40. In conclusion, a panel of 7 Ab can identify primary FSGS patients at high risk of recurrence prior to transplantation, allowing for customized therapies and improved patient selection for transplant. Intra-renal CD40 is an important axis of disease pathogenesis, and human trials of anti-CD40 therapies are warranted to evaluate their efficacy in preventing rFSGS and improving graft survival. The purpose of the study was to identify potential auto-Abs associated with rFSGS. We used a discovery set of pre-transplant sera from 20 unique patients with biopsy confirmed diagnosis of primary FSGS as their cause of ESRD, of which 10 had progressed to rFSGS within the first post-transplant year and 10 did not have recurrence of proteinuria or histological disease after transplantation (nrFSGS).

Dataset Information

Protein Microarrays Discover Angiotensinogen and PRKRIP1 as Novel Targets for Autoantibodies in Chronic Renal Disease

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure