Publications and intellectual property

SPyDiag grew out of twenty-five years of academic research on polyomaviruses, carried out at the University of Tours and the University of Picardie Jules Verne. This page lists the published work underpinning our programmes.

Evaluation of the urinary antigen test

Two papers describe the development and evaluation of the urinary antigen test behind UriFastBK.

1. Brochot E, Fourdinier O, Demey B, Aubry A, Collet L, Descamps V, Morel V, Gaboriaud P, Castelain S, Helle F, Touzé A. Development of a urinary antigen test for BK Polyomavirus to help clinicians in patients’ follow-up. Journal of Virological Methods, 2025.
   The authors note that BKPyV follow-up currently relies on quantitative molecular measurement of viral DNA in urine and blood, that critical issues have been raised about these methods, and that detection of viral genomes by a positive PCR is not always associated with true viral replication. The work covers the development of an antigen test intended to complement patient follow-up.
2. Brochot E, Paubelle E, Fourdinier O, Demey B, Aubry A, Morel V, Touzé A, Castelain S, Helle F. A Rapid Immunochromatographic Assay for the Detection of BK Polyomavirus in Urine Samples from Hematopoietic Stem Cell Transplant Recipients. Preprint, 2025.
   Retrospective evaluation of the rapid test against urine PCR in allogeneic haematopoietic stem cell transplant recipients with suspected haemorrhagic cystitis. Across 49 samples from 49 patients, 20 of whom presented with haemorrhagic cystitis, 19 of those 20 samples (95 %) were positive by the rapid antigen test. Of the 37 BKPyV PCR-positive samples, 31 were above 7 log₁₀ copies/mL, including all 20 patients with haemorrhagic cystitis. Study approved by the local institutional review board (reference PI2022_843_0079).

Foundational work on BK polyomavirus and the VP1 protein

1. Dakroub F, Touzé A, Akl H, Brochot E. Pre-Transplantation Assessment of BK Virus Serostatus: Significance, Current Methods, and Obstacles. 2019. PMID 31615131.
2. Touzé A et al. Characterization of self-assembled virus-like particles of human polyomavirus BK generated by recombinant baculoviruses. 2003. PMID 12832209.
3. Touzé A, Bousarghin L, Ster C, Combita AL, Roingeard P, Coursaget P. Gene transfer using human polyomavirus BK virus-like particles expressed in insect cells. Journal of General Virology. 2001;82(12):3005-9. PMID 11714977.
4. Bentz M, Collet L, Morel V et al., with Helle F. The Conserved YPX3L Motif in the BK Polyomavirus VP1 Protein Is Important for Viral Particle Assembly but Not for Its Secretion into Extracellular Vesicles. Viruses. 2024.
5. Sikorski M et al., with Gaboriaud P and Touzé A. Non-permissive human conventional CD1c+ dendritic cells enable trans-infection of human primary renal tubular epithelial cells and protect BK polyomavirus from neutralization.
6. Pretransplantation Donor-Recipient Pair Seroreactivity Against BK Polyomavirus Predicts Viremia and Nephropathy After Kidney Transplantation, with Touzé A.

Intellectual property

Patent	Subject	Status
Diagnostic	F6 anti-VP1 monoclonal antibody and its use in lateral flow assays	Granted in France and Europe (October 2024) and in the United States (April 2025)
Therapeutic	Neutralising antibodies directed against BK virus genotypes I and IV	Filed (FR no. 25/10627), PCT extension planned

Inventors: Aubrey N., Boursin F., Brochot E., Dupeyrol G., Gaboriaud P., Touzé A. Worldwide exclusive licence held by SPyDiag.

Two indications, one target

The published work covers two distinct immunocompromised populations in which BKPyV reactivation poses a clinical problem: nephropathy in kidney transplant recipients, and haemorrhagic cystitis in allogeneic haematopoietic stem cell transplant recipients. The VP1 capsid protein is the common target across both settings.

This page lists published papers and preprints, and is updated as new work appears. For reprint requests or scientific collaboration, please use our Contact page.