Table 2.

Determinants in the development of polyomavirus-associated nephropathy

Determinants
Patient-related	Age > 50 yr
	Male gender
	Comorbidities (diabetes mellitus)
	Negative serostatus before transplantation
Organ-related	Degree of HLA mismatching
	Prior rejection episodes
	Renal injury
	Latent infection load
Viral-related	NCCR rearrangements
	Genotype
	Viral fitness
Immunity-related	Intense triple immunosuppression (calcineurin-inhibitor, antiproliferative agent, steroid)
	Rejection and anti-rejection treatment (anti-lymphocyte preparations, iv steroid boluses)
	Positive serostatus of donor
	Low number of BKV-specific T-cells

NCCR: Noncoding control region; BKV: BK virus.