Urinary neutrophil gelatinase-associated lipocalin after kidney transplantation: is it a good biomarker to assess delayed graft function?

Delayed graft function (DGF) is a common complication after transplantation. Its incidence is increased among patients receiving a graft from an expanded-criteria donor. Urinary neutrophil gelatinase-associated lipocalin (uNGAL), an acute kidney injury marker, could in the first days after transplantation be an early marker of DGF. We collected urine samples from 38 renal transplant recipients on days 1, 3, 6, and 10 post-transplantation, and months 1 and 6 creatinine to determine uNGAL, serum creatinine, Cystatin C, and albumin/creatinine ratio. We divided the patients into 2 groups, based on whether they developed DGF. We observed that mean uNGAL concentrations, Cystatin C, serum creatinine, and albumin/creatinine ratio were significantly lower in the non-DGF cohort on all measured days. uNGAL at day 3 showed a positive correlation with serum creatinine at day 10 (R = 0.58; P < .00) and day 30 (R = 0.57; P = .016) as well as with the length of hospital stay (r = 0.47; P < .00). Receiver operating characteristic analyses performed to assess the potential of uNGAL to predict DGF showed an area under the curve for day 3 of uNGAL of 0.917 (confidence interval [CI], 0.79-1.00; P = .00), with an optimal cutoff level of 124 ng/mL, sensitivity of 80% (CI, 62%-97%), and specificity of 83% (62%-104%; P = .001). In the first days after transplantation, uNGAL could be an early marker of DGF, providing additional information to standard biomarkers and potentially helping clinicians to take early measures to mitigate DGF.

Diagnosis of acute cortical necrosis in renal transplantation by contrast-enhanced ultrasound: a preliminary experience.

PURPOSE: To evaluate the use of contrast-enhanced ultrasound (CEUS) for diagnosis of cortical necrosis in renal allografts. MATERIALS AND METHODS: We reviewed the medical records and imaging studies of five patients who underwent emergency transplantectomy and a histological diagnosis of cortical necrosis in the period between May 2009 and May 2011. US examinations included initially B-mode and color Doppler and then contrast-enhanced ultrasound with low mechanical index after injection of 2.4 ml of a second generation echo-signal enhancer. Renal transplant vascularization was evaluated during a period of 4 minutes including arterial, corticomedullary and nephrographic phases. Radiologic-pathologic correlation was obtained after transplantectomy in all cases. RESULTS: Five patients with an age range between 30 and 48 years. Post-transplant color Doppler ultrasound showed decreased renal parenchymal vascularization and difficulty to find the spectral waveforms with resistive indexes greater than 0.7 in 4 of 5 patients. CEUS showed enhancement of the main arteries, followed by the enhancement of medullary pyramids, but with an unenhanced peripheral cortical continuous band viewed in all phases, a similar finding to the peripheral rim sign, pathognomonic of cortical necrosis on CT or MRI. The pathologic assessment showed violet kidneys macroscopically with hemorrhagic foci in the outer cortical that drew a well-defined band, findings agreed with CEUS findings. CONCLUSION: CEUS can show the typical peripheral rim sign in cases of cortical necrosis allowing a reliable and fast diagnosis of this condition and it could obviate further imaging studies or biopsy, allowing an earlier decision of nephrectomy.

One-year follow-up of en bloc renal transplants from pediatric donors in adult recipients.

OBJECTIVES: The optimal use of kidneys from small pediatric cadaveric donors remains controversial. The aim of this study was to analyze short-term graft and patient survivals of en bloc kidney transplantations compared with single cadaveric adult donor kidney transplantations. PATIENTS AND METHODS: We compared the 1-year evolution of 14 adult recipients of en bloc pediatric kidney donors (EBKT) of median age 13.5±14.5 months (range=3 days to 48 months) with 182 recipients of ideal adult cadaveric donors (ADT) showing a median age of 30±21 years (range=14-45 years). RESULTS: Besides the different age and weight of the donors, EBKT recipients were more commonly women (P=.05) and received thymoglobulin induction treatment (P=.00). Delayed graft function was higher in EBKT (46.2% vs 22.2%, P=.05), with no differences in the incidences of acute rejection episodes. Mean serum creatinine values at 3, 6, and 12 months after transplantation were 1.1±0.3, 1.1±0.2, and 1.0±0.2 mg/dL in the EBKT group, compared with 1.3±0.5 (P=.16), 1.3±0.5 (P=.02), and 1.3±0.6 (P<.01) in the ADT group. Vascular allograft complications were more frequent among EBKT. Graft survival rate at 1 year was 92% in both groups, with no differences in patient survival (100% in EBKT vs 92% in ADT; P=.49). CONCLUSIONS: EBKT from small pediatric donors show excellent graft function and 1-year survival and should be considered for transplantation into adults.

Ambulatory blood pressure monitoring in renal transplant patients: should it be routinely performed?

INTRODUCTION: Arterial hypertension is common among kidney transplant patients. It increases cardiovascular risk and is a factor for progression of renal failure. Our objective was to perform ambulatory blood pressure monitoring (ABPM) in renal transplant patients with office hypertension. METHODS: Patients were divided into 2 groups according to their mean ABPM blood pressures with treatment: well-controlled hypertension (blood pressure [BP] <130/85 mmHg), and poorly controlled hypertension (BP>130/85 mmHg). A "nondipper pattern" was defined as a decrease of <10% or an increase, and a "raiser pattern," in which mean blood pressure was greater during the nocturnal than the diurnal period. "White coat effect" was considered when the mean of 3 BP measurements in the clinic was >140/90 mmHg among well-controlled hypertensive patients as documented by ABPM. RESULTS: ABPM was performed in 53 patients: 25 (47%) "well-controlled hypertensives" and 28 (53%) "poorly controlled hypertensives." Of the latter, 24 (85%) showed a nondipper or raiser pattern with only 4 revealing dipper patterns. We compared well-controlled with poorly controlled hypertensives. The latter cohort were older (54.4±9.3 vs 45.5±13.8 years; P=.009), received grafts from older donors (56.7±15.0 vs 45.8±17 years; P=.02); had worse renal function measured by serum creatinine (1.7±0.5 vs 1.4±0.4 mg/dL, P=.03) or the Modification of Diet in Renal Disease (MDRD)=4 formula (41.8±14.0 vs 55.4±20.5 mL/min/1.73 m2; P=.009), and displayed more proteinuria (0.30±0.33 vs 0.18±0.10 g/d, P=.08). Nondipper or raiser patients showed a higher mean body mass index (27.1 vs 21.7 kg/m2; P=.04). Among 25 well-controlled patients, 11 presented "white coat phenomenon." CONCLUSION: We observed an important "white coat" effect, a large prevalence of uncontrolled nocturnal hypertension, and a small but important incident of "masked hypertension." Factors related to hypertension control were patient age, donor age, renal function, induction use, and proteinuria.

Beginning hemodialysis: do patients with a failed renal transplant start in worse condition?

OBJECTIVE: Predialysis management of patients with kidney transplant failure is a topic of growing interest. Herein we have reviewed a group of patients with a failed kidney transplant who returned to dialysis to compare them with patients with native kidney failure. PATIENTS AND METHODS: We analyzed 25 patients who returned to dialysis after a failed renal transplant (group A) and 38 patients initiating dialysis after native kidney failure (group B). RESULTS: We did not observe significant differences in the glomerular filtration rate (GFR), potassium, calcium, phosphorus, albumin, and hemoglobin levels between the 2 groups at the beginning of dialysis. Erythropoietin resistance index (ERI) was higher in group A. Progression of renal disease in the 2 years before dialysis was faster in group A, with a greater monthly decline in GFR and higher levels of systolic blood pressure. Renal transplant patients needed more evaluations in the 6 months before initiating dialysis: 1.75 +/- 0.97 vs 0.70 +/- 2.61 evaluations/month (P = .000). Also, the number of hospitalizations during the years before and after dialysis initiation was higher among group A. Patient survival after return to dialysis at 1 year was 75% in group A and 97% in group B (log-rank; P = .09). CONCLUSIONS: Patients with a failed kidney allograft initiated dialysis in similar condition to those with native kidney failure. The faster GFR decline may be related to immunosuppressive treatment. Transplant patients needed more frequent evaluations and more hospitalizations before and after dialysis initiation, indicating a higher morbidity rate.

Cytomegalovirus infection renal transplant recipients: risk factors and outcome.

OBJECTIVE: Cytomegalovirus (CMV) is the most common viral infection after allotransplantation; it can be a major cause of morbidity and mortality. Our aim was to analyze the main risk factors that lead to development of CMV infection and disease. PATIENTS AND METHODS: We retrospectively analyzed 207 patients who received a renal allograft from May 2003 to December 2007. Three patients (D-/R-) were excluded. CMV infection was defined by the detection of 2 or more positive tests for pp65 antigenemia and CMV disease by evidence of attributable symptoms in need of antiviral treatment. RESULTS: Thirty-two patients (15.7%) presented active CMV infections and another 35 (17.2%), CMV disease. The mean follow-up was 27.8 +/- 17 months. Prior to transplantation, 9.2% of patients were seronegative (D+/R-) and 77.9% seropositive (D+/R+). Compared with noninfected patients, those with CMV infection/disease were older and received an allograft from an older donor. Upon logistic regression analysis, recipient age older than 55 years, induction therapy with Thymoglobulin, and maintenance immunosuppression with cyclosporine were the major risk factors to develop CMV disease. An early acute rejection episode was more frequent and renal function measured by serum creatinine poorer until 18 months posttransplantation among CMV-infected versus noninfected patients. CONCLUSIONS: Our data showed that CMV infection is a common complication after kidney transplantation associated with older age, induction treatment with antilymphocyte globulin, worse renal function, and increased patient morbidity.

Renal allografts from donors older than 70 years are useful for single transplantation.

Kidney transplantation has been related in elderly recipients to a greater longevity compared with dialysis. Due to the scarcity of donors, transplantation of older patients depends on the acceptance of older donors. We compared the characteristics and evolution of transplants from donors >or=70 years (n = 53) with those from donors >55-<70 years (n = 201). Group D >or=70 included older recipients (65.37 +/- 4.9 vs 55.92 +/- 9.66 years; P = .000) and more women (62.3% vs 45.3%; P = .02), with more peripheral arterial disease (10.9% vs 2.4%; P = .011). No differences in donor characteristics were observed. Induction treatment with thymoglobulin or basiliximab was more common in D >or=70 (81.1% vs 57.3%; P = .006), with no differences in other immunosuppressive drugs. The incidence of delayed graft function (DGF) was similar (P = .82), with a trend to a lower incidence of acute rejection episodes among D>or=70 (11.8% vs 22.5%; P = 0.09). Serum creatinine and proteinuria levels did not differ during follow-up (P > .05). Patients in D >or=70 displayed more episodes of urinary sepsis (19.1% vs 6.4%; P = .008), but no differences were observed in cytomegalovirus (CMV) infection (P = .629), neoplasia (P = .118), ischemic cardiopathy (P = .642), or hospital readmission due to infections (P = .567). Graft survivals at 5 years were 70% and 75% (P = .279) among groups D >or=70 and D>55-<70, respectively, and patient survivals at 5 years were 88% and 88% (P = .63), respectively. In conclusion, our study showed that selected kidneys from donors older than 70 years were followed with excellent graft and patient survivals, permitting older patients on renal replacement therapy to benefit from renal transplantation.

Histological findings of early graft biopsies in old donor renal transplant patients receiving induction therapy.

Since recipients of transplants from elderly donors are exposed to an increased risk of delayed graft function (DGF) and acute rejection episodes, administration of induction treatment represents an alternative to preserve renal mass and improve graft survival. We compared the evolution and histological findings of early graft biopsies among 38 recipients treated with Thymoglobulim (33.6%) versus 75 (66.4%) with basiliximab. No differences were observes in the rate of DGF (P = .39). Forty kidneys were biopsed during the first 2 weeks after transplantation: 9 in the Thymoglobulin group (23.68%) and 31 in the basiliximab group (41.3%). Histological evaluation showed: acute tabular necrosis in 7 (78%) Thymoglobulin patients versus 14 (45%) basiliximab patients, with calcineurin nephrotoxicity in 2 (22%) and 1 (3.2%), respectively. An acute rejection episode was not diagnosed in the Thymoglobulin group, but 13 patients (17.3%) in the basiliximab group experienced this complication (P = .006). Banff classification showed: 6 grade IA (19.4%), 1 grade IB (3.2%), 3 grade IIA (9.7%), 1 grade IIB (3.2%), and 2 grade III (6.5%). Six of these patients required rescue treatment with Thymoglobulin. Serum creatinine and proteinuria levels between the 2 groups were not different (P > .05). There were no differences in cytomegalovirus (CMV) disease (P = .152), admission due to infection (P = .120), or neoplasia (P = .29). Graft and patient survivals at 3 years did not show a difference. The histological findings revealed that low doses of Thymoglobulin were much more effective to prevent renal inflammation and acute rejection episodes than basiliximab among renal transplant recipients, albiet without differences in survival at a mean of 3 years follow-up.

[Diagnosing neoplasia in a kidney transplant unit]. / Diagnóstico de neoplasias en una consulta de trasplante renal.

BACKGROUND AND AIM: Cancer is one of the major causes of death with functioning allograft among renal transplant patients. The increasing age of patients in the waiting list has derived in a higher risk of cancer in this population. The aim of this study was to analyze the incidence of cancer in the waiting list and kidney transplant patients. METHODS: Between November/1996 and November/2007 we assisted 825 patients in the outpatient renal transplant clinic, 467 were transplanted, 120 remained in the waiting list and 238 have been removed from the waiting list or died. RESULTS: During this period, 97 malignancies were diagnosed, 33 of 32 kidney transplant candidates and 64 of 62 renal transplant patients. The comparative analysis between this two groups showed that candidates had higher frequency of solid organ tumours compared with a higher incidence of skin cancer in transplanted patients. Mean time between transplant and cancer diagnosis was 42.6 +/- 32.7 months, 48% of malignancies were diagnosed within the first three years postransplant. When comparing kidney transplant patients with and without cancer diagnosis, the formers were older and had worse patient survival at five years. Allograft survival was similar for both groups. CONCLUSIONS: we want to emphasize the extreme importance of a detailed screening in the renal transplant candidates and transplanted patients due to a higher incidence of malignancies in this population.

Diagnosis of neoplasia in a kidney transplant unit

Background and aim: Cancer is one of the major causes of death with functioning allograft among renal transplant patients. The increasing age of patients in the waiting list has derived in a higher risk of cancer in this population. The aim of this study was to analyze the incidence of cancer in the waiting list and kidney transplant patients. Methods: Between November/1996 and November/2007 we assisted 825 patients in the outpatient renal transplant clinic, 467 were transplanted, 120 remained in the waiting list and 238 have been removed from the waiting list or died. Results: During this period, 97 malignancies were diagnosed, 33 of 32 kidney transplant candidates and 64 of 62 renal transplant patients. The comparative analysis between this two groups showed that candidates had higher frequency of solid organ tumours compared with a higher incidence of skin cancer in transplanted patients. Mean time between transplant and cancer diagnosis was 42.6 ± 32.7 months, 48% of malignancies were diagnosed within the first three years postransplant. When comparing kidney transplant patients with and without cancer diagnosis, the formers were older and had worse patient survival at five years. Allograft survival was similar for both groups. Conclusions: we want to emphasize the extreme importance of a detailed screening in the renal transplant candidates and transplanted patients due to a higher incidence of malignancies in this population (AU)

Introducción y objetivo: El cáncer es una de las principales causas de muerte con injerto funcionante en los pacientes trasplantados renales. La creciente edad de los pacientes remitidos para su inclusión en lista de espera ha elevado el riesgo de neoplasias en esta población. El objetivo de este estudio fue analizarla incidencia de neoplasias en los pacientes evaluados para su inclusión en lista de espera para trasplante y en los trasplantados renales. Métodos: Entre noviembre de 1996 y noviembre de2007 fueron evaluados 825 pacientes en la consulta de trasplante renal; 467 habían recibido un injerto renal, 120 permanecían en lista de espera y 238 habían sido desestimados o fallecieron estando en lista de espera. Resultados: Se diagnosticaron 97 tumores, 33 de ellos en 32 pacientes candidatos a trasplante y 64tumores en 62 pacientes trasplantados. El análisis comparativo entre los pacientes candidatos (incluidos o no en lista de espera) y aquellos trasplantados mostró que los primeros presentaron con mayor frecuencia tumores sólidos, mientras que los segundos presentaron mayor porcentaje de neoplasias cutáneas. La incidencia de tumores sólidos en la población trasplantada fue del 5,6%. El tiempo entre la fecha de trasplante y el diagnóstico del tumor fue de 42,6 ± 32,7 meses, siendo el 48% de las neoplasias diagnosticadas en los primeros tres años postrasplante. Al analizar pacientes trasplantados con y sin diagnóstico de neoplasias, observamos que los primeros tenían mayor edad y un mayor seguimiento postrasplante. La supervivencia del injerto fue similar entre ambos grupos, siendo la supervivencia del paciente a los cinco años significativamente menor en el grupo de pacientes trasplantados con tumor. Conclusiones: La notable incidencia de tumores pre y postrasplante enfatiza la necesidad de una búsqueda y un seguimiento exhaustivos detumores en los pacientes trasplantados y una alta sospecha en la valoración pretrasplante (AU)

Treatment of renal transplant failure.

INTRODUCTION: Among graft failures beyond months, we performed progressive reduction and complete withdrawal of immunosuppressive drugs and steroids over a period of 6 months. PATIENTS AND METHODS: We analyzed the treatment and complications associated with all late allograft failures in 34 patients (8.19%) out of 415 patients transplanted from November 1996 to November 2006. RESULTS: In 21 patients (61.8%), the progressive reduction of immunosuppressive treatment was effective and well tolerated; however, in 13 patients (38.2%) there was rejection of the allograft at 10.74 +/- 8.95 months (0.77-34.80) after the failure. With the reintroduction of these drugs, the rejection was controlled in seven patients, but in the other six we had to embolize the allograft, which had to be repeated in one case. Embolization was well tolerated, but in one case there was migration of one coil to the femoral artery. One patient treated with drug withdrawal experienced emphysematous pyelonephritis after repeated urinary infections, requiring a nephrectomy. Thirteen (38.2%) of the patients with late failures have been admitted for a second transplant; five of them showed HLA sensitization. CONCLUSIONS: Conservative treatment with progressive withdrawal of immunosuppression was effective and well tolerated in two-thirds of the patients with late renal allograft failure, but one-third of the patients rejected the graft and needed allograft embolization. Infection of the graft and HLA sensitization can complicate the course of these patients.

Risk factors and prognosis for proteinuria in renal transplant recipients.

INTRODUCTION: Proteinuria in renal transplant recipients has been recognized as a risk factor of progression of chronic allograft nephropathy and for cardiovascular disease, the main causes of transplant failure. PATIENTS AND METHODS: We analyzed the risk factors for persistent proteinuria (>0.5 g/day) among 337 kidney allograft recipients with a minimum follow-up of 6 months, among a series of 375 transplants performed during a decade, as well as their association with allograft and patient survivals. Patients with proteinuria greater than 0.5 g/d were treated with angiotensin-converting enzyme inhibitors (ACEI) and/or angiotensin-receptor blockers. RESULTS: After a mean follow-up of 53.35 +/- 52.63 months, 68 patients (20.17%) had persistent proteinuria greater than 0.5 g/d. Female patients (P = .012), body mass index (BMI) >25 (P = .008), pretransplant HLA sensitization (P = .039), and delayed graft function (DGF; P = .001) were associated with proteinuria. Induction treatment with antithymocyte globulin (P = .030) and treatment with tacrolimus instead of cyclosporine (P = .046) were associated with an increased risk of proteinuria. Multivariate analysis confirmed the independent value of DGF (RR = 2.23; 95% confidence interval [CI] 1.22 to 4.07; P = .009) and BMI >25 (RR = 1.968; 95% CI 1.05 to 3.68; P = .035) to predict postransplant proteinuria. The mean values of serum creatinine (P = .000) and systolic blood pressure (P < .05) were persistently higher from the early stages after transplantation in the proteinuric group. Graft survival at 5 years was 69% among patients who developed proteinuria and 93% in those without proteinuria (P = .000), with no differences in patient survival (P = .062). CONCLUSION: Proteinuria in renal transplant recipients was related to immunological and nonimmunological factors, some of which, such as hypertension and obesity could be modifiable. Proteinuria in renal transplant recipients predicted a worse allograft survival despite of intensive treatment of hypertension including ACEI/angiotensin-receptor blockers.

Benefits derivated from late steroid withdrawal in renal transplant recipients.

Because corticosteroids have adverse metabolic effects, inducing bone-mineral imbalance and contributing to infections among renal transplant recipients, many withdrawal trials have been attempted to reduce adverse events and improve quality of life. We retrospectively analyzed the safety and efficacy of late steroid withdrawal, after the first posttransplant year, among a selected group of kidney allograft recipients. In 42 low immunological risk allograft recipients, among 382 patients transplanted during a decade, corticosteroids were progressively reduced and completely withdrawn. The evolution of clinical and biochemical parameters after the withdrawal were analyzed. Corticosteroid withdrawal was performed as a mean of 52.16 +/- 28.41 months posttransplant, with subsequent follow-up without steroid treatment of 18.13 +/- 16.11 months. Comparing the most recent evaluation with the data previous to steroid withdrawal, patients showed a significant decreases in diastolic pressure (P = .039), total cholesterol (P = .000), and low-density lipoprotein cholesterol levels (P = .039), but not in triglyceride levels (P = .33). Body weight did not change (P = .77), but increased fasting glucose levels were noted (P = .03), in absence of new diagnosed diabetes mellitus. A significant reduction in cyclosporine Neoral (P = .01) or tacrolimus doses were detected (P = .01). At the last visit, serum creatinine in the whole group remained stable (P = .06). Only five patients showed an increase in serum creatinine more than 20% (from 1.44 +/- 0.41 to 1.94 +/- 0.45 mg/dL P = .04) and proteinuria did not increase (P = .94). No patient was diagnosed with a rejection episodes or required corticosteroid resumption. Graft and patient survivals were 100% at the end of follow-up. In conclusion, our data showed that late corticosteroid withdrawal in renal transplant recipients of low immunological risk is safe and is followed by an improvement in their metabolic profile and in blood pressure.

Effect of overweight on kidney transplantation outcome.

INTRODUCTION: Obesity is a prevalent problem in renal transplant recipients that is followed by reduced graft and patient survivals. Because the prevalence of overweight (OW) is increasing in the renal transplant population, we studied the influence of OW on graft and recipient evolution. PATIENTS AND METHODS: We analyzed a series of 337 patients with renal allografts having a mean follow-up of 53.4 +/- 30.6 months. We excluded 39 patients obese at transplantation. We compared the evolution of 134 OW patients (45.5%), and 160 patients (54.4%) with a body mass index <25 (NW group). RESULTS: OW patients were older (P = .000) with a higher prevalence of hypertension (P = .028), left ventricular hypertrophy (P = .014), and dyslipidemia (P = .001). They had received kidneys from older donors (P = .019). OW patients showed a higher incidence of acute tubular necrosis (ATN) (P = .006), without a higher incidence of acute rejection episodes (P = .756). Postransplant diabetes mellitus was more frequent (P = .000), and systolic blood pressure (P < .05), total cholesterol (P < .05), and tryglicerides were higher (P < .05) in the OW group. Serum creatinine at 6 months (P = .007) and proteinuria >0.5 g/24 hours, (P = .023) were higher among the OW group. Graft survival was not different between groups, but patient survival was lower in the OW group (P = .002). A logistic regression analysis showed that the recipient age (RR: 5.243) and the presence of OW (RR: 1.100) were independent prognostic factors for patient death. CONCLUSIONS: OW was a common situation among renal transplant candidates. It was associated with worse cardiovascular and metabolic profiles. OW patients showed worse allograft function and lower patient survival. A major effort must be exerted to avoid excessive weight gain, particularly among those OW at transplantation.

[Seasonal perodicity in vascular access thrombosis for haemodialysis]. / Ritmo estacional en la trombosis del acceso vascular para hemodiálisis.

Different studies have shown that some clinical events, particularly cardiovascular and thrombotic events, show a regularity in its appearance. The aim of our study was to analyse the possible existence of seasonal periodicity in the incidence of the vascular access thrombosis in patients on chronic haemodialysis. Prospectively, we collected information of 164 patients with 250 episodes of vascular access thrombosis referred to our hospital from january 1995 to december 1999. An ANOVA test for comparison of the means, and a time series analysis were performed. During the five year study the consecutive number of thrombosis were 43, 57, 55, 59 and 36. When the different seasons were analysed, the cumulative number of events in summer during the study period were 91, a significant increase compared to spring, autumn, and winter (54, 54, and 51, respectively; p<0.001). Time series analysis confirmed that thrombolic events during summer showed an increased incidence over the mean (p<0.001), and it occurred every year. The same results were obtained when the PTFE grafts were analyzed separetely (july RR 2.62, p=0.002; august, RR 2.37, p=0.04), but not with the arteriovenous fistulae. In conclusion, this study showed a seasonal periodicity of vascular access thrombosis, with a PTFE graft. Although the causes were unknown, these data alert us on the convenience of an increased attention to the vascular access during the summer months in order to prevent its thrombosis.

Ritmo estacional en la trombosis del acceso vascular para hemodiálisis / seasonal perodicity in vascular access thrombosis for haemodialysis

Algunos estudios han detectado periodicidad en la aparición de eventos trombóticos y cardiovasculares. No obstante, este tema es motivo de controversia. El objetivo de nuestro estudio fue analizar la posible existencia de un ritmo estacional en la aparición de trombosis de los accesos vasculares en pacientes en hemodiálisis. Para ello hemos recogimos de forma prospectiva los episodios de trombosis del acceso vascular remitidos a nuestro hospital desde el 1 de enero 1995 hasta el 31 de diciembre de 1999, contabilizando un total de 250 casos correspondientes a 164 pacientes. Para determinar si existía periodicidad en las trombosis se realizó comparación de medias (test ANOVA) y análisis de series temporales mediante un modelo de regresión de Poison mostrando riesgo relativo (RR) de trombosis. Durante el periodo de estudio, el numero de casos por año fue de 43, 57, 55, 59 y 36 correspondientes a los años 1995, 1996, 1997, 1998 y 1999 respectivamente. Cuando se realizó el análisis por estaciones se vio que el número de episodios acumulados en verano durante los años analizados fue de 91, prácticamente el doble que en primavera, otoño e invierno (54, 54 y 51 respectivamente) (p < 0,001). El análisis de series temporales mostró que los episodios de trombosis durante el verano presentaban picos de incidencia por encima de la media (p < 0,001) y que este hecho se repetía en todos los años. Estos hallazgos fueron evidentes en el caso de los pacientes portadores de prótesis de PTFE (julio, RR 2,62, p = 0,002; agosto RR 2,37, p = 0,04) sin existir diferencias en el caso de las fístulas autógenas (p = ns). En nuestra experiencia, la trombosis del acceso vascular en pacientes en hemodiálisis presenta una periodicidad relacionada con las estaciones del año existiendo un mayor riesgo relativo de presentar estos eventos durante los meses de verano especialmente en los pacientes con prótesis de PTFE. Aunque las causas están por determinar, estos hallazgos nos advierten sobre especiales medidas a tomar en los meses de verano para la prevención de posibles trombosis del acceso vascular durante esta época

Different studies have shown that some clinical events, particularly cardiovascular and thrombotic events, show a regularity in its appearance. The aim of our study was to analyse the possible existence of seasonal periodicity in the incidence of the vascular access thrombosis in patients on chronic haemodialysis. Prospectively, we collected information of 164 patients with 250 episodes of vascular access thrombosis referred to our hospital from january 1995 to december 1999. An ANOVA test for comparison of the means, and a time series analysis were performed. During the five year study the consecutive number of thrombosis were 43, 57, 55, 59 and 36. When the different seasons were analysed, the cumulative number of events in summer during the study period were 91, a significant increase compared to spring, autumn, and winter (54, 54, and 51, respectively; p < 0.001). Time series analysis confirmed that thrombotic events during summer showed an increased incidence over the mean (p < 0.001), and it accurred every year. The same results were obtained when the PTFE grafts were analyzed separately (july RR 2.62, p = 0.002; august, RR 2.37, p = 0.04), but not with the arteriovenous fistulae. In conclusion, this study showed a seasonal periodicity of vascular access thrombosis, with an increased risk during the summer months, particularly in patients with a PTFE graft. Although the causes were unknown, these data alert us on the convenience of an increased attention to the vascular access during the summer months in order to prevent its thrombosis

Transplant renal artery stenosis: association with acute vascular rejection.

BACKGROUND: Transplant renal artery stenosis, the prevalence of which varies from 2% to 12%, is an important cause of hypertension and allograft dysfunction. We sought to determine the clinical characteristics of this disorder, assessing, predisposing factors, establishing treatment options, and examining patient outcomes. PATIENTS AND METHODS: Among 321 renal allograft recipients between November 1996 and December 2004, six patients were identified with this finding. We analyzed their clinical data before and after treatment compared with the 315 recipients face of the disorder. RESULTS: The six patients with the disorder were diagnosed within the first year (2 to 8 months; median 5.5 months). All patients displayed renal dysfunction, peripheral edema, and new-onset or uncontrolled hypertension at presentation. Abnormal Doppler findings were observed in 5 (83.3%) patients. The hemodynamically significant stenosis was successfully treated with percutaneous transluminal angioplasty (PTA) in all six. However, 3 (50%) patients displayed recurrent stenosis requiring a second PTA. The mean serum creatinine level decreased from a pre-PTA value of 4.4 +/- 1.8 mg/dL to a 1-month post-PTA value of 2.2 +/- 0.5 mg/dL (P = .027). Patients had no significant improvement in mean systolic and diastolic pressure. Vascular acute rejection episodes were more frequent among the affected than the control group (3/6; 50% vs 18/315; 5.7%; P < .001). No differences were found in age, sex, donor type, etiology of renal disease, immunosuppression, acute tubular necrosis, acute cellular rejection, cold ischemia time, or HLA matching. CONCLUSION: Transplant renal artery stenosis is a common cause of hypertension and renal allograft dysfunction. Acute vascular rejection is associated with this disorder.

Erythropoietin treatment in the sixth posttransplant month as a prognostic factor for renal allograft survival.

The purpose of this work was to assess the prognostic value of the need for erythropoietin (EPO) treatment at 6 months after transplantation. We retrospectively reviewed the outcomes of 143 consecutive cadaveric kidney transplants performed between January 2000 and April 2004, functioning at 6 months postransplantation. Patients were divided into two groups: group EPO6m (n = 24) received EPO treatment in the sixth month, and a control group (n = 119) did not receive EPO. Renal function deterioration (RFD) was considered to be a sustained decrease in creatinine clearance (CrCl) greater than 20% between the sixth month postransplant and the last visit. Mean follow-up was 38 +/- 16 months. The mean ages of the donor (57 +/- 9 vs 49 +/- 12 years; P = .001) and the recipient (59 +/- 12 vs 47 +/- 17 years; P = .000) were greater in the EPO6m group. Delayed graft function (83% vs 48%; P = .001) was more frequent in the EPO6m group. At 6 months after transplantation the EPO6m group showed lower hemoglobin (11.52 +/- 1.71 vs 13.32 +/- 1.69 g/dL; P = .000), higher serum creatinine (2.31 +/- 0.72 vs 1.65 +/- 0.53 mg/dL; P = .000), lower CrCl (33.53 +/- 10.83 vs 53.6 +/- 17.58 mL/min; P = .000), and similar proteinuria. RFD was more common in the EPO6m group (38% vs 10%; P = .026), with a different pattern of evolution of CrCl (-0.098 +/- 0.176 vs +0.093 +/- 0.396 mL/min/mo, P = .000). Multivariate analysis demonstrated that treatment with EPO at 6 months was the only predictor of RFD (RR 4.46; 1.58 to 12.58; P = .005). The need for EPO at 6 months postransplant was a good predictor of later renal allograft deterioration, more sensitive than serum creatinine or proteinuria.

[Chronological aggregation of subcutaneous mycosis in renal transplant recipients]. / Agregación cronológica de cuatro casos de micosis subcutánea invasiva en receptores de trasplante renal.

We present four cases of subcutaneous invasive mycosis in renal transplant recipients that happened in our Unit during a period of eight months. The Microbiology Department did not find any fungi when they studied possible reservoirs and vectors for transmission. We speculate about the reasons of this chronological aggregation. We discuss the treatment that we used for these infections.