MARIA CRISTINA DOMINGUES DA SILVA FINK
Projetos de Pesquisa
Unidades Organizacionais
LIM/52 - Laboratório de Virologia, Hospital das Clínicas, Faculdade de Medicina
6 resultados
Resultados de Busca
Agora exibindo 1 - 6 de 6
- BK virus salivary shedding and viremia in renal transplant recipients(2019) SARMENTO, Dmitry Jose de Santana; PALMIERI, Michelle; GALVAO, Gustavo Souza; TOZETTO-MENDOZA, Tania Regina; CANTO, Cynthia Motta do; PIERROTTI, Ligia Camera; DAVID-NETO, Elias; AGENA, Fabiana; GALLOTTINI, Marina; PANNUTI, Claudio Sergio; FINK, Maria Cristina Domingues; BRAZ-SILVA, Paulo HenriqueObjectives: This study aimed to verify the presence of polyomavirus BK (BKPyV) in the saliva of kidney transplant recipients and to correlate it with blood viremia. Material and Methods: We have conducted a cross-sectional study with a sample involving 126 renal transplant recipients. 126 samples of saliva and 52 samples of blood were collected from these patients. Detection and quantification of BKPyV were performed using a real-time PCR. To compare the presence of BKPyV in blood and saliva, the binomial proportion test was used. To verify associations between salivary shedding BKPyV and post-transplant periods (in months), the Mann-Whitney test was used. Spearman's correlation was used to correlate the viral load in the saliva with blood of kidney transplant recipients. Results: The mean age of the study group was 51.11 +/- 12.45 years old, and 69 participants (54.8%) were female, with a mean post-transplantation time of 4.80 +/- 6.04 months. BKPyV was quantified in several samples of saliva and blood, with medians of 1,108 cp/mL and 1,255 cp/mL, respectively. Only 16/52 (30.8%) participants presented BKPyV in blood, and 59/126 (46.8%) excreted the virus in saliva (p=0.004). BKPyV shedding was found in patients at a shorter post-transplantation period (3.86 +/- 5.25, p=0.100). A weak correlation was observed between viral quantification in saliva and blood (Spearman's correlation coefficient=0.193). Conclusion: The results of this study suggested that, although saliva excretes more BKPyV than blood, there is no reliable correlation between salivary shedding and blood viremia, showing two independent compartments of viral replication.
- Variable sources of Bk virus in renal allograft recipients(2019) URBANO, Paulo Roberto P.; NALI, Luiz H. da Silva; OLIVEIRA, Renato dos R.; SUMITA, Laura M.; FINK, Maria Cristina D. da Silva; PIERROTTI, Ligia C.; BICALHO, Camila da Silva; DAVID-NETO, Elias; PANNUTI, Claudio S.; ROMANO, Camila M.BK virus is the causative agent of polyomavirus-associated nephropathy, a major cause of kidney transplant failure affecting 1%-10% of recipients. Previous studies that investigated the viral source on the kidney recipient pointed that the donor is implicated in the origin of human polyomavirus BK (BKPyV) infection in recipients, but giving the low genetic variability of BKPyV this subject is still controversial. The aim of this study was to determine if BKPyV replicating in kidney recipients after transplantation is always originated from the donor. Urine and blood samples from 68 pairs of living donors and kidney recipients who underwent renal transplantation from August 2010-September 2011 were screened for BKPyV by real time polymerase chain reaction. Only three recipients presented viremia. When both donors and recipients were BKPyV positive, a larger fragment of VP1 region was obtained and sequenced to determine the level of similarity between them. A phylogenetic tree was built for the 12 pairs of sequences obtained from urine and high level of similarity among all sequences was observed, indicating that homology inferences for donor and recipient viruses must be cautiously interpreted. However, a close inspection on the donor-recipient pairs sequences revealed that 3 of 12 pairs presented considerably different viruses and 4 of 12 presented mixed infection, indicating that the source of BKPyV infection is not exclusively derived from the donor. We report that about 60% of the renal recipients shed BKPyV genetically distinct from the donor, confronting the accepted concept that the donor is the main source of recipients' infection.
- Determination of viremia cut-off for risk to develop BKPyV-associated nephropathy among kidney transplant recipients(2018) BICALHO, Camila Silva; OLIVEIRA, Renato dos Reis; DAVID, Daisa Ribeiro; FINK, Maria Cristina Domingues Silva; AGENA, Fabiana; CASTRO, Maria Cristina; PANUTTI, Claudio; DAVID-NETO, Elias; PIERROTTI, Ligia CameraBackgroundBK polyomavirus (BKPyV)-associated nephropathy (BKPyVAN) is a consequence of BKPyV replication in the urinary tract in kidney transplant recipients (KTR). ObjectivesThe objectives were to determine the prevalence of BKPyV replication and BKPyVAN, risk factors associated to sustained viremia and BKPyVAN, and viremia cut-off that best predict the occurrence of sustained viremia and nephropathy in KTR of a single University Hospital Kidney Transplant Center. Patients and MethodsAll KTR undergoing transplantation from August 2010 to December 2011 were enrolled and monitored up to 2years posttransplantation for BKPyV viruria by decoy cells shedding or polymerase chain reaction (PCR) and viremia by PCR. Kidney biopsy was indicated if sustained viremia (two or more viremia above 10000copies/mL) to confirm BKPyVAN diagnosis. ResultsIn this study, 326 transplants were performed and 246 patients were included. Prevalence of viruria was 36.9%, viremia 22.3% and nephropathy 3.2%. Male gender was the only risk factor associated to sustained viremia or nephropathy. Cut-off value of viremia that best discriminates the progression to sustained viremia and to BKPyVAN was 37488 and 44956copies/mL, respectively. ConclusionsPrevalence of viruria, viremia, and nephropathy were similar to those reported in literature but the cut-off value of viremia that best discriminates the risk of progression to nephropathy was greater than the value usually reported, which is 10000copies/mL.
- Effect of polyoma viremia on 3-year allograft kidney function(2019) DAVID-NETO, Elias; AGENA, Fabiana; DAVID, Daisa Silva Ribeiro; PAULA, Flavio Jota de; PIERROTTI, Ligia Camera; FINK, Maria Cristina Domingues; AZEVEDO, Luiz Sergio Fonseca deBackground Polyoma viremia is associated with damage to renal tubular and urothelial cells. This may imply that a certain level of viremia, even cleared thereafter, could be associated with long-term renal dysfunction. Methods We, retrospectively, analyzed 390 first renal transplants adult recipients (>= 18 years) who were monitored for BK viremia in the first 12 months and evaluated estimated GFR (MDRD-4 equation) at 1 month and at the last follow-up (959 +/- 392 days). Results One hundred and ninety-nine patients (51%) developed at least one positive viremia: 105 (53%) low viremia (<10(4) copies/mL), 36 (18%) high viremia (4 x 10(4) > viremia >= 10(4) copies/mL) and 58 (15%) viremia (>= 4 x 10(4) copies/mL) consistent with polyoma virus associated nephropathy (PyVAN). Out of these 58 patients, 24 (6%) developed bx-proven (SV40+) PyVAN and 34(8.7%) presumptive PyVAN (SV40-). Baseline characteristics, immunosuppression, KDRI, rejection episodes, etc., did not differ among groups but there were more deceased donors and ATG induction therapy in the high viremia group. At last follow-up, all patients in the low, high viremia and presumptive PyVAN (except 2) had cleared BK viremia. Bx-proven PyVAN led to 14 graft losses, 10 due to PyVAN. In the presumptive PyVAN there was only one graft loss registered as due to PyVAN. eGFR, at 1 month after KTx, did not differ among groups (51 +/- 22 vs 48 +/- 24 vs 45 +/- 27 vs 43 +/- 18 vs 46 +/- 22 mL/min/1.73 m(2)), for no, low and high viremia as well for presumptive PyVAN and bx-proven PyVAN groups, respectively. At the last follow-up, eGFR did not differ between the no, low, and high viremia compared to baseline and to each other but was statistically lower in the presumptive and bx-proven PyVAN (38 +/- 15 and 17 +/- 7 mL/min/1.73 m(2)) either compared to baseline or to the other groups. Conclusions This study shows that low and high levels of BK viremia do not lead to GFR changes although very high viremia levels, compatible with presumptive or bx-proven PyVAN, even if cleared thereafter, lead to allograft damage and decreased GFR.
conferenceObject Defining a BKV Cutt-Off and Profile for Early Detection of BKV Associated Nephropathy(2017) NIHEI, C.; AGENA, F.; PAULA, F.; DAVID, D.; FINK, M.; PIERROTTI, L.; DAVID-NETO, E.- Pre-transplant shedding of BK virus in urine is unrelated to post-transplant viruria and viremia in kidney transplant recipients(2016) BICALHO, C. S.; OLIVEIRA, R. R.; PIERROTTI, L. C.; FINK, M. C. D. S.; URBANO, P. R. P.; NALI, L. H. S.; LUNA, E. J. A.; ROMANO, C. M.; DAVID, D. R.; DAVID-NETO, E.; PANNUTI, C. S.BK virus-(BKV) associated nephropathy (BKVN) is a major cause of allograft injury in kidney transplant recipients. In such patients, subclinical reactivation of latent BKV infection can occur in the pre-transplant period. The purpose of this study was to determine whether urinary BKV shedding in the immediate pre-transplant period is associated with a higher incidence of viruria and viremia during the first year after kidney transplantation. We examined urine samples from 34 kidney transplant recipients, using real-time quantitative polymerase chain reaction to detect BKV. Urine samples were obtained in the immediate pre-transplant period and during the first year after transplant on a monthly basis. If BKV viruria was detected, blood samples were collected and screened for BKV viremia. In the immediate pre-transplant period, we detected BKV viruria in 11 (32.3%) of the 34 recipients. During the first year after transplantation, we detected BKV viruria in all 34 patients and viremia in eight (23.5%). We found no correlation between pre-transplant viruria and post-transplant viruria or viremia (p = 0.2). Although reactivation of latent BKV infection in the pre-transplant period is fairly common among kidney transplant recipients, it is not a risk factor for post-transplant BKV viruria or viremia.