Decoy cells

[1] Decoy cells are clinically relevant since they may be used as a prognostic marker for clinical conditions such as polyomavirus BK-induced nephropathy in renal transplant recipients, and haemorrhagic cystitis in haematopoietic stem cell transplant recipients.

By Papanicolaou stain, most decoy cells have an enlarged nucleus that bears a basophilic inclusion which is surrounded by chromatin that confers a ground-glass or gelatinous appearance.

The only exception is represented by cells infected by cytomegalovirus, which frequently show a ‘bird's eye’ appearance.

[3] Several publications have tried to use decoy cells as a prognostic marker for polyomavirus-associated diseases such as polyomavirus BK-associated nephropathy (BKVAN), a condition occurring only in immunocompromised individuals and especially in renal transplant recipients.

However, in the context of overt viral replication against the background of immunodeficiency, the viruses that cause the emergence of decoy cells must be treated.

For example, in severely immunocompromised HIV-patients, previously called AIDS-patients, immunologic function can be restored by treatment with highly active anti-retroviral therapy.

Other agents that have been proposed to target polyomavirus BK, such as cidofovir,[5] fluoroquinolones,[6] leflunomide,[7] and statins[8] are far from established and the published results on their effectivity are conflicting.