Presence of decoy cells for 6 months on urine cytology efficiently predicts BK virus nephropathy in renal transplant recipients

Sekito, Takanori; Araki, Motoo; Yoshinaga, Kasumi; Maruyama, Yuki; Sadahira, Takuya; Nishimura, Satoshi; Wada, Koichiro; Watanabe, Masami; Watanabe, Tetsuya; Tanabe, Katsuyuki; Takeuchi, Hidemi; Morinaga, Hiroshi; Kitagawa, Masashi; Kitamura, Shinji; Sugiyama, Hitoshi; Wada, Jun; Yanai, Hiroyuki; Nasu, Yasutomo

doi:10.1111/iju.14679

Cited by 7 publications

(6 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…6,22 The positive predictive value can be increased if other information is considered, such as dirty smear background, graft function, sustained DCs shedding (more than six weeks) and detection of DCs casts. 6,14,23,24 The identification of DCs using phase contrast microscopy has been highlighted as a more effective strategy than conventional cytopathology examination, in terms of cost and time, in the hands of trained professionals. 25 Phase-contrast microscopy of the samples with many DCs provided us with the opportunity to train and gain experience in DCs identification.…”

Section: Discussionmentioning

confidence: 99%

Is There Still a Role for Urine Cytology in Kidney Transplantation? Experience Report in a Teaching Hospital

Gouvêa,

Carvalho,

Nascimento

et al. 2023

BJT

View full text Add to dashboard Cite

Introduction: Urinary cytology has been used as a monitoring strategy for kidney transplant patients, live under chronic immunosuppression, as it is a non-invasive and low-cost method. The early detection of infections can prevent possible dysfunction and graft loss. However, its use has been decreased. Methods: We conducted a prospective study on voided urine samples from 29 consecutive patients undergoing kidney transplantation over a continuous period of 17 months, collected during their first-year post-transplantation. One technician prepared the samples by cytocentrifugation, Papanicolaou staining, and one pathologist analyzed them. Decoy cells (DCs) positive samples were prepared, by other two technicians, for contrast phase analysis, ultrastructural study, and immunofluorescence for SV40 T antigen. Results: We evaluated 252 urine samples from 26 patients. Two consecutive samples (0.8%) out of five, from the same patient (3.8%), referring to the fourth- and fifth-week post-transplant, showed low-grade squamous intraepithelial lesions; only rare epithelial cells with atypia of undetermined significance were detected (0.4%) in the sample corresponding to the sixth month post-transplant. The patient’s subsequent gynecological examination and Pap smear revealed no changes. Pseudohyphae and fungus yeasts were found in five samples (2.0%) from four patients (15.4%). Trichosporon sp. was identified in the urine of one of these patients. Decoy cells were detected in 25 samples (9.9 %) from six patients (23.1%). Two patients had sustained DCs shedding; one of them, presenting dirty background smears, developed Polyomavirus-associated nephropathy. Ultrastructural study of DCs showed icosahedral viral particles. Immunofluorescence (SV40 T antigen) was positive in DCs nuclei. Analysis by contrast phase was successful in samples with numerous DCs. Conclusion: Systematic urinary cytology after transplantation helps detect some infection signs. Patients with sustained DCs shedding and dirty background smears deserve special clinical attention. Electron microscopy and immunofluorescence (SV40 T antigen) are alternative techniques to detect polyomavirus reactivation. The findings suggest that urinary cytology still plays a role in kidney transplantation.

show abstract

Section: Discussionmentioning

confidence: 99%

Is There Still a Role for Urine Cytology in Kidney Transplantation? Experience Report in a Teaching Hospital

Gouvêa,

Carvalho,

Nascimento

et al. 2023

BJT

View full text Add to dashboard Cite

show abstract

“…6,22 O valor preditivo positivo pode ser aumentado se outras informações forem consideradas, como fundo de esfregaço sujo, função do enxerto, eliminação sustentada de DCs (mais de seis semanas) e detecção de cilindros de DCs. 6,14,23,24 A identificação de DCs usando microscopia de contraste de fase foi destacada como uma estratégia mais eficaz do que o exame citopatológico convencional, em termos de custo e tempo, nas mãos de profissionais treinados. 25 A microscopia de contraste de fase das amostras com muitas DCs nos deu a oportunidade de treinar e ganhar experiência na identificação de DCs.…”

Section: Discussionunclassified

Existe Ainda um Papel para a Citologia Urinária no Transplante Renal? Relato de Experiência em um Hospital Universitário

Gouvêa,

Carvalho,

Nascimento

et al. 2023

BJT

View full text Add to dashboard Cite

Introdução: A citologia urinária tem sido utilizada como estratégia de monitoramento dos pacientes transplantados renais, que vivem sob crônica imunossupressão, por ser um método não invasivo e de baixo custo. A detecção precoce de infecções pode prevenir possíveis disfunções e perda do enxerto. No entanto, a sua utilização tem decrescido. Métodos: Realizamos um estudo prospectivo em amostras de urina provenientes de 29 pacientes consecutivos, submetidos ao transplante renal ao longo de um período contínuo de 17 meses, coletadas durante seu primeiro ano pós-transplante. Um mesmo técnico preparou as amostras por citocentrifugação, coloração de Papanicolaou e um único patologista as analisou. Amostras positivas para “decoy cells” (DCs) foram preparadas por dois outros técnicos, para análise por microscopia de contraste de fase, estudo ultraestrutural e imunofluorescência (antígeno T SV40). Resultados: Foram avaliadas 252 amostras de urina de 26 pacientes. Duas amostras consecutivas (0,8%) dentre cinco, de uma mesma paciente (3,8%), referentes à quarta e quinta semana pós-transplante, apresentaram lesão intraepitelial escamosa de baixo grau; na amostra referente ao sexto mês pós-transplante foram detectadas apenas raras células epiteliais com atipias de significado indeterminado (0,4%); o posterior exame ginecológico da paciente e teste de Papanicolaou não revelaram alterações. Pseudohifas e esporos fúngicos foram encontrados em cinco amostras (2,0%) de quatro pacientes (15,4%). Trichosporon sp. foi identificado na urina de um desses pacientes. Decoy cells foram detectadas em 25 amostras (9,9%) de seis pacientes (23,1%). Dois pacientes tiveram eliminação sustentada de DCs; um deles, apresentando esfregaço de fundo sujo, desenvolveu Nefropatia associada ao poliomavírus. O estudo ultraestrutural das DCs mostrou partículas virais icosaédricas. A imunofluorescência (antígeno T SV40) foi positiva nos núcleos das DCs. A análise por microscopia de contraste de fase foi bem-sucedida em amostras com numerosas DCs. Conclusão: A citologia urinária sistemática após o transplante é útil na detecção de alguns sinais de infecção. Pacientes com eliminação sustentada de DCs e esfregaços de fundo sujo merecem atenção clínica especial. A microscopia eletrônica e a imunofluorescência (antígeno T SV40) são técnicas alternativas para detectar a reativação do poliomavírus. Os resultados sugerem que a citologia urinária ainda desempenha um papel no transplante renal.

show abstract

“…Testing urine sediment for decoy cells has, without debate, gained importance, and various methods, such as Sternberg-Malbin staining, have improved availability and show excellent discriminative potential from other cells of the urinary tract [41,42]. Combined confocal immunostaining for proteins specific to the early and late stages of infection will extend the specificity for counting polyomavirus-infected cells beyond simple decoy staining.…”

Section: Discussionmentioning

confidence: 99%

Lessons from Polyomavirus Immunofluorescence Staining of Urinary Decoy Cells

Pajenda

Hevesi

Eder

et al. 2023

Life

View full text Add to dashboard Cite

Decoy cells that can be detected in the urine sediment of immunosuppressed patients are often caused by the uncontrolled replication of polyomaviruses, such as BK-Virus (BKV) and John Cunningham (JC)-Virus (JCV), within the upper urinary tract. Due to the wide availability of highly sensitive BKV and JCV PCR, the diagnostic utility of screening for decoy cells in urine as an indicator of polyomavirus-associated nephropathy (PyVAN) has been questioned by some institutions. We hypothesize that specific staining of different infection time-dependent BKV-specific antigens in urine sediment could allow cell-specific mapping of antigen expression during decoy cell development. Urine sediment cells from six kidney transplant recipients (five males, one female) were stained for the presence of the early BKV gene transcript lTag and the major viral capsid protein VP1 using monospecific antibodies, monoclonal antibodies and confocal microscopy. For this purpose, cyto-preparations were prepared and the BK polyoma genotype was determined by sequencing the PCR-amplified coding region of the VP1 protein. lTag staining began at specific sites in the nucleus and spread across the nucleus in a cobweb-like pattern as the size of the nucleus increased. It spread into the cytosol as soon as the nuclear membrane was fragmented or dissolved, as in apoptosis or in the metaphase of the cell cycle. In comparison, we observed that VP1 staining started in the nuclear region and accumulated at the nuclear edge in 6–32% of VP1+ cells. The staining traveled through the cytosol of the proximal tubule cell and reached high intensities at the cytosol before spreading to the surrounding area in the form of exosome-like particles. The spreading virus-containing particles adhered to surrounding cells, including erythrocytes. VP1-positive proximal tubule cells contain apoptotic bodies, with 68–94% of them losing parts of their DNA and exhibiting membrane damage, appearing as “ghost cells” but still VP1+. Specific polyoma staining of urine sediment cells can help determine and enumerate exfoliation of BKV-positive cells based on VP1 staining, which exceeds single-face decoy staining in terms of accuracy. Furthermore, our staining approaches might serve as an early readout in primary diagnostics and for the evaluation of treatment responses in the setting of reduced immunosuppression.

show abstract

Presence of decoy cells for 6 months on urine cytology efficiently predicts BK virus nephropathy in renal transplant recipients

Cited by 7 publications

References 29 publications

Is There Still a Role for Urine Cytology in Kidney Transplantation? Experience Report in a Teaching Hospital

Is There Still a Role for Urine Cytology in Kidney Transplantation? Experience Report in a Teaching Hospital

Existe Ainda um Papel para a Citologia Urinária no Transplante Renal? Relato de Experiência em um Hospital Universitário

Lessons from Polyomavirus Immunofluorescence Staining of Urinary Decoy Cells

Contact Info

Product

Resources

About