Browsing by Author "Pedroso, S."
Now showing 1 - 10 of 16
Results Per Page
Sort Options
- BK virus nephropathy in kidney transplantation - A literature review following a clinical casePublication . Barreto, P.; Almeida, M.; Dias, L.; Vieira, P.; Pedroso, S.; Martins, L.; Castro-Henriques, A.; Cabrita, A.Over the last 15 years, better immunosuppressive drugs have decreased acute rejection rates in kidney transplantation but have also led to an increase in the incidence and impact of BK virus nephropathy. The authors report the case of a 62 -year -old man submitted to a renal transplant of a deceased donor with an immunosuppression regimen free of rabbit anti -thymocyte globulin and tacrolimus, in whom BK nephropathy was diagnosed at seven weeks post -transplant. Intravenous human immunoglobulin (IVIG) was administered after immunosuppression reduction. Instituted treatment was successful. This clinical case highlights the importance of a high index of suspicion for an atypical presentation of BK nephropathy in renal transplant recipients and strengthens the need for other therapeutic interventions beyond the reduction of immunosuppression. It was the starting point for a review of BK virus nephropathy in kidney transplantation with a focus on risk factors, diagnosis and treatment.
- Bone Mineral Density After Simultaneous Kidney–PancreasPublication . Pereira, S.; Pedroso, S.; Martins, L.; Santos, P.; Almeida, M.; Freitas, C.; Dias, L.; Dores, J.; Almeida, R.; Henriques, A.C.; Teixeira, M.ABSTRACT Bone disease and an high risk of fractures are major problems in transplantation. Among diabetic patients undergoing simultaneous kidney–pancreas (SKP) transplantation, there are few studies assessing long-term effects on bone mass. The aim of this study was to evaluate bone mineral density (BMD) over 4 years follow-up after SKP transplantation. Fifty-seven patients had 22.8 5.3 years of prior diabetes, 65% were female, and the overall mean age was 24.3 5.93 years. At the time of transplantation, the lumbar spine and femoral neck T-scores were 1.75 1.05 and 1.95 0.73, respectively; 28% of subjects had evidence of osteoporosis. One year after transplantation, 77.6% of patients displayed improved lumbar T-scores to 1.33 0.94 (.044) with stable femoral neck T-scores. Bone densitometry enhanced gradually through the 4 years follow-up: lumbar T-score to 1.04 0.67 (.004) and femoral neck T-score to 1.69 0.49 (.12). At year 4, no osteoporosis cases were detected but 86.7% of patients did not receive steroids in the immunosuppressive regimen. The graft function remained stable (serum creatinine, 1.2 mg/dL; fasting glucose, 87.7 mg/dL). During the follow-up, BMD improved more significantly at cortical sites. Our study reports a reduced prevalence of fractures (8.7%) compared with the literature, which could be related to a steroid-sparing protocol and/or aggressively treatment of osteoporosis.
- Histiocytic sarcoma; case report of a rare disease in a kidney transplant recipientPublication . Ventura Aguiar, P.; Dias, C.; Azevedo, P.; Silva, H.; Almeida, M.; Pedroso, S.; Martins, L.; Dias, L.; Rodrigues, A.; Viscaíño, R.; Cabrita, A.; Henriques, A.BACKGROUND: Histiocytic sarcoma (HS) is a rare hematologic neoplasm with a few hundred cases having been described to date.
- Impact of hepatitis C virus on renal transplantation: association with poor survival.Publication . Pedroso, S.; Martins, La Salete; Fonseca, Isabel; Dias, L.; Henriques, A.C.; Sarmento, A.M.; Cabrita, A.Transplant Proc. 2006 Jul-Aug;38(6):1890-4. Impact of hepatitis C virus on renal transplantation: association with poor survival. Pedroso S, Martins L, Fonseca I, Dias L, Henriques AC, Sarmento AM, Cabrita A. Nephrology and Transplant Departments, Hospital Geral de Santo António, Largo Professor Abel Salazar, 4050-011 Porto, Portugal. sofiapedroso@sapo.pt Abstract Data concerning the effect of hepatitis C virus (HCV) infection on the long-term outcome of patient and allograft survival are conflicting. We performed a retrospective study including all renal transplant recipients who underwent the procedure at our center between July 1983 and December 2004. We compared HCV-positive (n = 155) versus HCV-negative (n = 1044) recipients for the prevalence of anti-HCV, patient/donor characteristics, and graft/patient survival. The prevalence of HCV-positive patients was 12%. The anti-HCV positive recipients displayed a longer time on dialysis (P < .001), more blood transfusions prior to transplant (P < .001), and a higher number of previous transplants (P < .001). There were no differences in the incidence of acute rejection between the two groups. Patient (P = .006) and graft survival (P = .012) were significantly lower in the HCV-positive than the HCV-negative group. Graft survival censored for patient death with a functioning kidney did not differ significantly between HCV-positive and HCV-negative recipients (P = .083). Death from infectious causes was significantly higher among the HCV-positive group (P = .014). We concluded that HCV infection had a significant detrimental impact on patient and renal allograft prognosis. Death from infectious causes was significantly more frequent among HCV-positive than the non-HCV population. PMID: 16908314 [PubMed - indexed for MEDLINE
- Impact of pre-transplant anti-MICA sensitization in graft rejection and survivalPublication . Costa, R.; Malheiro, J.; Tafulo, S.; Santos, C.; Almeida, M.; Pedroso, S.; Martins, L.; Dias, L.; Castro-Henriques, A.Background: Evidence supporting deleterious effect of preformed major histocompatibility class I chain-related A (MICA) antibodies in rejection incidence and graft survival is still unclear. Methods: Retrospective analysis of 554 kidney transplanted patients. Comparison between positive or negative for MICA antibodies patients was performed to characterize sensitizing triggers. Further classification according to pre-transplant flow cytometry-recorded anti–MICA and/or anti-human leukocyte antigen (HLA) antibodies was made to determine first year rejection incidence and graft survival. Multivariate analysis was applied to determine predictors for acute rejection. Results: Pre-formed anti-MICA antibodies were detected in 41 patients (7.4%). HLA sensitization, blood transfusions and pregnancies were frequently found in anti-MICA+ patients but only pre-formed anti-HLA class I antibodies showed independent association (OR 2.67, p= 0.02). Comparing to MICA-/HLA–, MICA-/HLA+ group presented significantly lower first year rejection-free survival (78.6% vs. 89.3%, p< 0.01), mostly occurred in the first six months, while no difference was found in MICA+/HLA– (88.9% vs. 89.3%, p= ns). MICA-/HLA+ showed independent impact in rejection (OR 2.09, p= 0.03), while no evidence was found in MICA+/HLA- (OR 1.08, p= ns). At 4 years, MICA-/HLA+ group presented lower graft survival (85.8% vs. 95.3%, p= 0.03). Again, no difference was found in MICA+/HLA- group (95.1% vs. 95.3%, p= ns). Conclusion: Our results do not support HLA-independent deleterious pathogenic role of pre-formed MICA antibodies on first year rejection incidence and graft survival.
- Impact of preformed donor-specific antibodies against HLA class I on kidney graft outcomes: Comparative analysis of exclusively anti-Cw vs anti-A and/or -B antibodiesPublication . Santos, S.; Malheiro, J.; Tafulo, S.; Dias, L.; Carmo, R.; Sampaio, S.; Costa, M.; Campos, A.; Pedroso, S.; Almeida, M.; Martins, L.; Henriques, C.; Cabrita, A.AIM: To analyze the clinical impact of preformed antiHLA-Cw vs antiHLA-A and/or -B donor-specific antibodies (DSA) in kidney transplantation. METHODS: Retrospective study, comparing 12 patients transplanted with DSA exclusively antiHLA-Cw with 23 patients with preformed DSA antiHLA-A and/or B. RESULTS: One year after transplantation there were no differences in terms of acute rejection between the two groups (3 and 6 cases, respectively in the DSA-Cw and the DSA-A-B groups; P = 1). At one year, eGFR was not significantly different between groups (median 59 mL/min in DSA-Cw group, compared to median 51 mL/min in DSA-A-B group, P = 0.192). Moreover, kidney graft survival was similar between groups at 5-years (100% in DSA-Cw group vs 91% in DSA-A-B group, P = 0.528). The sole independent predictor of antibody mediated rejection (AMR) incidence was DSA strength (HR = 1.07 per 1000 increase in MFI, P = 0.034). AMR was associated with shortened graft survival at 5-years, with 75% and 100% grafts surviving in patients with or without AMR, respectively (Log-rank P = 0.005). CONCLUSION: Our data indicate that DSA-Cw are associated with an identical risk of AMR and impact on graft function in comparison with "classical" class I DSA.
- Implications for patients waiting for a kidney transplant of using the calculated panel reactive antibody (cPRA)Publication . Magriço, R.; Malheiro, J.; Tafulo, S.; Pedroso, S.; Almeida, M.; Martins, L.; Dias, L.; Castro-Henriques, A.; Cabrita, A.Introduction: Kidney transplant improves survival even in highly‑sensitized (HS) patients. To overcome their disadvantage in accessing transplantation, those with high Complement Dependent Cytotoxic PRA (CDC‑PRA) receive additional points during allocation. Whether this strategy reaches all HS patients and how long they wait for a transplant is largely undetermined. Methods: Patients on our unit’s active wait‑list for kidney transplantation in the year 2014 were analyzed. CDC‑PRA and calculated PRA (cPRA) were recorded. To obtain cPRA, antibodies in the last serum available specific for HLA‑A, ‑B or –DR with an intensity > 1000 MFI were considered. Results: The cPRA values in the population (N=551) were 0% (N=312), 1‑79% (N=118) and ≥ 80% (22%; N=121). Among these groups, the proportion of women (29.5, 55.9 and 61.2%, P<0.001), prior sensitizing events (43.3, 80.5 and 96.7%, P<0.001) and time on dialysis (median of 3.9, 4.1 and 6.0 years, P<0.001) increased with cPRA, respectively. In most of those with a cPRA ≥ 80%, the CDC‑PRA raised no suspicion of HS status (median 0%, P25‑75 0‑8%) and only 35 (28.9%) or 12 patients (9.9%) had a CDC‑PRA in the peak serum higher than 50 or 80%, respectively (cut‑offs needed to obtain additional points during allocation). HS patients by cPRA corresponded to 71% vs 15% of patients waiting for ≥ or <8 years, respectively (P<0.001). Even after exclusion of patients with a CDC‑PRA above 50%, this disproportionate representation remained (58% versus 13%, P<0.001). Conclusion: HS patients as measured by cPRA remained longer on the wait‑list, both in the primary analysis and when excluding those with a CDC‑PRA> 50%. Moreover, only 30% of HS by cPRA patients received the extra points designed to improve their transplantability. We consider that both CDC‑PRA and cPRA should be taken into account when defining HS status.
- Kidney transplantation in a patient with preformed and exclusively anti-HLA-Cw donor specific antibodyPublication . Santos, S.; Castro, A.; Campos, A.; Pedroso, S.; Dias, L.; Castro-Henriques, A.We report a patient who had received a first kidney transplant and had preformed DSA anti-HLA-Cw, developing AMR C4d+ soon after transplant. Classically anti-HLA-Cw are considered less immunogenic and are not considered in many organ allocation systems or immunologic risk stratification algorithms, including in Portugal. However, data from literature confirms that their presence is as deleterious as DSA anti-HLA A/B/DR/DQ. Thus we should take HLA-C typing and respective antibody identification into account in sensitized patients, in order to access risk stratification and establish the need for correct induction or desensitization therapies.
- Malignancy after renal transplantation: a single-centre experiencePublication . Vieira, P.; Bareto, P.; Pedroso, S.; Almeida, M.; Martins, L.; Dias, L.; Castro-Henriques, A.; Cabrita, A.Introduction: Malignancy management in renal transplant recipients is becoming a major factor affecting long‑term patient survival. Thus, we intended to evaluate both incidence and prognosis of malignant diseases following renal transplantation at a single centre in Portugal. Methods: We studied retrospectively the 2,358 patients who underwent kidney transplantation (KT) between 1983 and 2014. Apart from descriptive analysis, both demographic and clinical characteristics of cancer and non‑cancer cancer patients were compared. Results: During a median follow‑up of 118 (IQR 57‑179) months, 139 patients (5.8%) developed 158 de novo malignancies, with a median time from KT to diagnosis of 76..5 (IQR 21.0‑132.0) months. When compared to non‑cancer patients, they were older at KT date, had longer graft survival and a lower living donor recipients’ prevalence. As for post-transplant malignancies analysis, the most common were non‑cutaneous non‑lymphomatous cancers (49.4%, n=78), skin cancers (35.4%, n=56) and post‑transplant lymphoproliferative disorders (9.5%, n=15). Considering specific diagnosis, squamous cell carcinoma and basal cell carcinoma with 17.1% and 16.5% respectively, and non‑Hodgkin lymphomas with 7.6%, were the most frequent. Global mortality among cancer patients was 36.0%, with a median time of 9.7 (IQR 1.9‑17.5) months from time of diagnosis to death. As for survival analysis, cancer patient survival was significantly lower while censored graft survival was significantly higher in this group. Conclusion: Incidence and characteristics of malignancy following renal transplantation in our unit are similar to those globally described, despite some traits probably a result of specific ethnic and environmental characteristics.
- Neutrophil gelatinase-associated lipocalin in kidney transplantation is an early marker of graft dysfunction and is associated with one-year renal functionPublication . Fonseca, Isabel; Carlos Oliveira, José; Almeida, M.; Cruz, M.; Malho, A.; Martins, La Salete; Dias, L.; Pedroso, S.; Santos, J.; Lobato, L.; Castro-Henriques, A.; Mendonça, D.Urinary neutrophil gelatinase-associated lipocalin (uNGAL) has been suggested as potential early marker of delayed graft function (DGF) following kidney transplantation (KTx). We conducted a prospective study in 40 consecutive KTx recipients to evaluate serial changes of uNGAL within the first week after KTx and assess its performance in predicting DGF (dialysis requirement during initial posttransplant week) and graft function throughout first year. Urine samples were collected on post-KTx days 0, 1, 2, 4, and 7. Linear mixed and multivariable regression models, receiver-operating characteristic (ROC), and areas under ROC curves were used. At all-time points, mean uNGAL levels were significantly higher in patients developing DGF (n = 18). Shortly after KTx (3-6 h), uNGAL values were higher in DGF recipients (on average +242 ng/mL, considering mean dialysis time of 4.1 years) and rose further in following days, contrasting with prompt function recipients. Day-1 uNGAL levels accurately predicted DGF (AUC-ROC = 0.93), with a performance higher than serum creatinine (AUC-ROC = 0.76), and similar to cystatin C (AUC-ROC = 0.95). Multivariable analyses revealed that uNGAL levels at days 4 and 7 were strongly associated with one-year serum creatinine. Urinary NGAL is an early marker of graft injury and is independently associated with dialysis requirement within one week after KTx and one-year graft function.