Characterization of urinary CD4⁺ and CD8⁺ T cells in kidney transplantation patients with polyomavirus BK infection and allograft rejection.

BACKGROUND AND OBJECTIVES: The objective of this study was to characterize CD4(+) and CD8(+) T-cell populations in blood and urine of renal transplant patients with BK virus (BKV) infection or allograft rejection. MATERIALS AND METHODS: Percentages and absolute numbers of CD4(+) and CD8(+) effector memory T-cell subtype (TEM ) and terminal differentiated T cells (TTD ) in renal transplant patients with BKV infection (n = 14), with an episode of allograft rejection (n = 9), and in uncomplicated renal transplant patients with a stable kidney function (n = 12) were measured and compared using 4-color fluorescence-activated cell sorting. Results were correlated with the number of CD4(+) and CD8(+) T cells in renal biopsies. RESULTS: In patients with allograft rejection, the number of urinary CD4(+) TEM and CD8(+) TEM cells was significantly increased compared to patients with BKV infection or patients without complications. Positive correlation was found between the number of CD4(+) and CD8(+) cells in the renal biopsies and the number of CD4(+) and CD8(+) cells in urine. In patients with rejection, after 2 months of immunosuppressive therapy, a reduction in urinary CD8(+) TEM cells was found. CONCLUSIONS: CD4(+) TEM and CD8(+) TEM cells in urine could be a marker to distinguish allograft rejection from BKV-associated nephropathy and to monitor therapy effectiveness in renal transplant patients with allograft rejection.

Helicobacter canis bacteremia in a renal transplant patient.

Here we present a case report of a 41-year-old woman suffering from high fever and bacteremia due to Helicobacter canis, 11 months after kidney transplantation. Identification of H. canis was achieved by 16s rDNA sequence analysis of a positive blood culture. The patient was restored fully to health after antibiotics therapy (cefuroxime and ciprofloxacin). Until now, only 4 human clinical cases have been described with H. canis bacteremia. This study describes for the first time, to our knowledge, an infection with H. canis in a kidney transplant patient.

Complement mediated renal inflammation induced by donor brain death: role of renal C5a-C5aR interaction.

Kidneys retrieved from brain-dead donors have impaired allograft function after transplantation compared to kidneys from living donors. Donor brain death (BD) triggers inflammatory responses, including both systemic and local complement activation. The mechanism by which systemic activated complement contributes to allograft injury remains to be elucidated. The aim of this study was to investigate systemic C5a release after BD in human donors and direct effects of C5a on human renal tissue. C5a levels were measured in plasma from living and brain-dead donors. Renal C5aR gene and protein expression in living and brain-dead donors was investigated in renal pretransplantation biopsies. The direct effect of C5a on human renal tissue was investigated by stimulating human kidney slices with C5a using a newly developed precision-cut method. Elevated C5a levels were found in plasma from brain-dead donors in concert with induced C5aR expression in donor kidney biopsies. Exposure of precision-cut human kidney slices to C5a induced gene expression of pro-inflammatory cytokines IL-1 beta, IL-6 and IL-8. In conclusion, these findings suggest that systemic generation of C5a mediates renal inflammation in brain-dead donor grafts via tubular C5a-C5aR interaction. This study also introduces a novel in vitro technique to analyze renal cells in their biological environment.

Treatment of steroid-resistant acute renal allograft rejection with alemtuzumab.

Steroid-resistant renal allograft rejections are commonly treated with rabbit antithymocyte globulin (RATG), but alemtuzumab could be an effective, safe and more convenient alternative. Adult patients with steroid-resistant renal allograft rejection treated with alemtuzumab (15-30 mg s.c. on 2 subsequent days) from 2008 to 2012 (n = 11) were compared to patients treated with RATG (2.5-4.0 mg/kg bodyweight i.v. for 10-14 days; n = 20). We assessed treatment-failure (graft loss, lack of improvement of graft function or need for additional anti-rejection treatment), infections during the first 3 months after treatment and infusion-related side effects. In both groups, the median time-interval between rejection and transplantation was 2 weeks, and approximately 75% of rejections were classified as Banff-IIA or higher. Three alemtuzumab-treated patients (27%) experienced treatment failure, compared to eight RATG treated patients (40%, p = 0.70). There was no difference in the incidence of infections. There were mild infusion-related side-effects in three alemtuzumab-treated patients (27%), and more severe infusion-related side effects in 17 RATG-treated patients (85%, p = 0.013). Drug related costs of alemtuzumab-treatment were lower than of RATG-treatment (€1050 vs. €2024; p < 0.01). Alemtuzumab might be an effective therapy for steroid-resistant renal allograft rejections. In contrast to RATG, alemtuzumab is nearly devoid of infusion-related side-effects. These data warrant a prospective trial.

Renal transplantation in patients with atypical haemolytic uraemic syndrome: a tailor made approach is necessary.

A 33-year-old woman with a history of chronic transplant dysfunction because of repeated bouts of haemolytic uraemic syndrome (HUS) was considered for a second transplant. Extensive genetic investigation of the complement system was executed to rule out known mutations prone to development of HUS. This case illustrates the importance of genetic screening in patients with recurrent HUS.

Modulation of brain dead induced inflammation by vagus nerve stimulation.

Because the vagus nerve is implicated in control of inflammation, we investigated if brain death (BD) causes impairment of the parasympathetic nervous system, thereby contributing to inflammation. BD was induced in rats. Anaesthetised ventilated rats (NBD) served as control. Heart rate variability (HRV) was assessed by ECG. The vagus nerve was electrically stimulated (BD + STIM) during BD. Intestine, kidney, heart and liver were recovered after 6 hours. Affymetrix chip-analysis was performed on intestinal RNA. Quantitative PCR was performed on all organs. Serum was collected to assess TNFalpha concentrations. Renal transplantations were performed to address the influence of vagus nerve stimulation on graft outcome. HRV was significantly lower in BD animals. Vagus nerve stimulation inhibited the increase in serum TNFalpha concentrations and resulted in down-regulation of a multiplicity of pro-inflammatory genes in intestinal tissue. In renal tissue vagal stimulation significantly decreased the expression of E-selectin, IL1beta and ITGA6. Renal function was significantly better in recipients that received a graft from a BD + STIM donor. Our study demonstrates impairment of the parasympathetic nervous system during BD and inhibition of serum TNFalpha through vagal stimulation. Vagus nerve stimulation variably affected gene expression in donor organs and improved renal function in recipients.

Nephrectomy elicits impact of age and BMI on renal hemodynamics: lower postdonation reserve capacity in older or overweight kidney donors.

Renal functional reserve could be relevant for the maintenance of renal function after kidney donation. Low-dose dopamine induces renal vasodilation with a rise in glomerular filtration rate (GFR) in healthy subjects and is thought to be a reflection of reserve capacity (RC). Older age and higher body mass index (BMI) may be associated with reduced RC. We therefore investigated RC in 178 consecutive living kidney donors (39% males, age 48 +/- 11 years, BMI 25.5 +/- 4.1). RC was determined as the rise in GFR ((125)I-iothalamate), 4 months before and 2 months after donor nephrectomy. Before donor nephrectomy, GFR was 114 +/- 20 mL/min, with a reduction to 72 +/- 12 mL/min after donor nephrectomy. The dopamine-induced rise in GFR of 11 +/- 10% was reduced to 5 +/- 7% after donor nephrectomy (p < 0.001). Before donor nephrectomy, older age and higher BMI did not affect reserve capacity. After donor nephrectomy, the response of GFR to dopamine independently and negatively correlated with older age and higher BMI. Moreover, postdonation reserve capacity was absent in obese donors. The presence of overweight had more impact on loss of RC in younger donors. In conclusion, donor nephrectomy unmasked an age- and overweight-induced loss of reserve capacity. Younger donors with obesity should be carefully monitored.

[Lymphoma in patients who have undergone organ transplantation: severe and variable clinical presentation]. / Lymfoom bij patiënten na een orgaantransplantatie: ernstig en variabel ziektebeeld.

Two patients presented with post-transplant lymphoproliferative disorder (PTLD). PTLD encompasses a broad range ofoften malignant proliferations of lymphoid tissue arising in the immunocompromised host after transplantation. The first patient, a 62-year-old woman, received a bilateral lung transplant due to end-stage emphysema and was diagnosed with PTLD 27 days after transplantation. Treatment consisted of reduction in immunosuppression and administration of rituximab. The PTLD regressed. The second patient, a 57-year-old woman, presented with a massively disseminated PTLD 12 years after kidney transplantation. Immunosuppression was reduced and rituximab was administered, but no response was observed. Despite salvage chemotherapy, the patient died due to progressive disease. These two cases illustrate the heterogeneous presentation of PTLD. The condition is caused by the proliferation of B lymphocytes infected with Epstein-Barr virus (EBV) that are no longer controlled by EBV-specific cytotoxic T lymphocytes, due to the immunosuppressive medication given to prevent transplant rejection. Regression of the lymphoma may be achieved by reducing the immunosuppression or treating with rituximab, which attacks B lymphocytes.

An intrarenal abscess as presenting symptom of an infection with Nocardia farcinica in a patient after renal transplantation.

A 52-year-old man presented 8 months after transplantation with an intrarenal mass, which proved to be caused by an infection with Nocardia farcinica. Because of the potential fatal course of nocardiosis, transplantectomy was performed and long-term antibiotic treatment was instituted. Three-and-a-half years later, this patient underwent successful re-transplantation under co-trimoxazole prophylaxis. At present, more than 1 year after his second transplant has been performed, there are no signs of recurrence of Nocardia infection. To our knowledge, this is the first report of a patient with nocardiosis with an intrarenal abscess as presenting symptom.

Successful treatment of respiratory dysfunction in cystinosis by nocturnal non-invasive positive pressure ventilation.

Cystinosis is a rare metabolic disorder characterized by lysosomal cystine accumulation leading to multi-organ damage, with kidneys being clinically first affected. Longer survival of cystinosis patients due to successful renal replacement therapy, revealed previously unknown extra-renal symptoms of cystinosis, generally appearing after the first decade. Respiratory insufficiency caused by overall respiratory muscle myopathy is a severely invalidating and sometimes a life-threatening complication of cystinosis. We report a successful treatment of hypoventilation, due to diaphragm myopathy in a cystinosis patient, by nocturnal non-invasive positive pressure ventilation (NIPPV). After initiation of NIPPV the clinical condition of the patient improved and blood-gasses normalized, indicating that this treatment modality should be considered in cystinosis patients with severe respiratory insufficiency.

[Intestinal perforation caused by tuberculosis in a kidney transplant patient who was extensively evaluated for tuberculosis prior to transplant]. / Darmperforatie door tuberculose bij een niertransplantatiepatiënt die hier vooraf uitgebreid op was onderzocht.

A 47-year-old man from Armenia presented at the emergency department with abdominal pain. He had had a kidney transplant 2 years earlier for renal failure caused by amyloidosis that was secondary to familial Mediterranean fever. He was also known to have chronic hepatitis B with persistent viraemia. He had not received any prophylactic anti-tuberculosis treatment due to impaired liver function, but an extensive work-up was performed prior to transplant, including chest radiography, a Mantoux tuberculin skin test and cultures from 3 consecutive fasting gastric lavage samples, which were all negative for active or latent tuberculosis infection. The patient had presented at the emergency department repeatedly with abdominal pain that was attributed to the familial Mediterranean fever. During his last visit his complaints were accompanied by vomiting, coughing, night sweats and weight loss. He was diagnosed with an intestinal perforation with faecal peritonitis and underwent several laparotomies to treat the faecal peritonitis. Histopathological examination of resected bowel tissue revealed granulomatous inflammation, and acid-fast bacilli were seen with appropriate staining. Later, cultures appeared to be positive for normally sensitive Mycobacterium tuberculosis. The patient died as a result of the disseminated tuberculosis. In immunocompromised patients, tuberculosis often has an atypical course and an increased chance of dissemination that may be difficult to recognize.

Predictive capacity of pre-donation GFR and renal reserve capacity for donor renal function after living kidney donation.

Kidney transplantation from living donors is important to reduce organ shortage. Reliable pre-operative estimation of post-donation renal function is essential. We evaluated the predictive potential of pre-donation glomerular filtration rate (GFR) (iothalamate) and renal reserve capacity for post-donation GFR in kidney donors. GFR was measured in 125 consecutive donors (age 49 +/- 11 years; 36% male) 119 +/- 99 days before baseline GFR (GFRb) and 57 +/- 16 days after donation (GFRpost). Reserve capacity was assessed as GFR during stimulation by low-dose dopamine (GFRdopa), amino acids (GFRAA) and both (GFRmax). GFRb was 112 +/- 18, GFRdopa 124 +/- 22, GFRAA 127 +/- 19 and GFRmax 138 +/- 22 mL/min. After donation, GFR remained 64 +/- 7%. GFRpost was predicted by GFRb(R2 = 0.54), GFRdopa(R2 = 0.35), GFRAA(R2 = 0.56), GFRmax(R2 = 0.55)and age (R2 = -0.22; p < 0.001 for all). Linear regression provided the equation GFRpost = 20.01 + (0.46*GFRb). Multivariate analysis predicted GFRpost by GFRb, age and GFRmax(R2 = 0.61, p < 0.001). Post-donation renal function impairment (GFR < or = 60 mL/min/1.73 m2) occurred in 31 donors. On logistic regression, GFRb, body mass index (BMI) and age were independent predictors for renal function impairment, without added value of reserve capacity. GFR allows a relatively reliable prediction of post-donation GFR, improving by taking age and stimulated GFR into account. Long-term studies are needed to further assess the prognostic value of pre-donation characteristics and to prospectively identify subjects with higher risk for renal function loss.

The predictive value of renal vascular resistance for late renal allograft loss.

The renal artery resistance index (RI), assessed by Doppler ultrasonography, was recently identified as a new risk marker for late renal allograft loss. This finding requires confirmation since RI in that study was not measured at predetermined time points and ultrasonography is operator-dependent. We investigated the predictive value of renal vascular resistance (RVR), a less operator-dependent method as assessed by mean arterial pressure divided by renal blood flow, for the prediction of recipient mortality and death-censored graft loss. RVR was compared to commonly used risk markers such as creatinine clearance (CrCl), serum creatinine (SCreat) and proteinuria (UProt) in 793 first-time cadaveric renal transplant recipients at predetermined time points after transplantation using receiver operating characteristics (ROC) and Cox survival analyses. The present study showed that RVR is a prominent risk marker for recipient mortality and death-censored graft loss. However, the predictive value of RVR for recipient mortality owed mainly to the impact of mean arterial blood pressure. In contrast, RVR constituted more than the sum of its components for death-censored graft loss, but showed less predictive value than SCreat in univariate analysis. As the assessment of RVR is expensive and time-consuming, we believe that RVR holds no clinical merit for the follow-up of renal transplant recipients.

Initial cytomegalovirus prophylaxis with ganciclovir: no guarantee for prevention of late serious manifestations of CMV after solid organ transplantation.

A 37-year-old woman presented with malaise, upper abdominal pain and fever seven months after renal transplantation. She was seronegative for cytomegalovirus (CMV) and had received a kidney from a seropositive donor. She had received CMV prophylaxis (oral ganciclovir) for three months after transplantation. During this period all tests for CMV remained negative. On admission, she presented with symptoms compatible with an acute abdomen and with deterioration of renal function. On emergency laparotomy a perforation of the ileum was found. The resected specimen showed an ulcer with vasculitis at the site of perforation, with both microscopic (owl's eye inclusion bodies), as well as immunohistochemical evidence for a CMV infection. CMV can reactivate (usually in the first three months) after transplantation, sometimes resulting in serious morbidity. The use of antiviral prophylaxis during and after transplantation has certainly decreased the number and severity of CMV infections. This case illustrates that life-threatening infections such as CMV can still emerge a long time after transplantation. Unrelenting awareness of this condition is mandatory, even after apparently adequate anti-CMV prophylaxis.

Pulmonary involvement during cytomegalovirus infection in immunosuppressed patients.

Although cytomegalovirus (CMV) pulmonary involvement after solid organ transplantation is infrequently seen nowadays, CMV pneumonitis is still a potential lethal complication. Introduction of the pp65 antigenemia assay enabled early and rapid diagnosis of CMV viremia in transplant patients prior to symptoms. Also, in asymptomatic patients with CMV viremia, a decreased pulmonary diffusion capacity could be demonstrated. In this review, we discuss clinical and subclinical pulmonary involvement of CMV infection in the immunocompromised host with an emphasis on transplant recipients. The clinical course, diagnosis, therapy, prophylaxis, and pathophysiology of CMV pneumonitis are discussed.

Effects of changing immunosuppressive regimen on the incidence, duration, and viral load of cytomegalovirus infection in renal transplantation: a single center report.

Background. In this retrospective single center study we have evaluated the relation between the immunosuppressive regimen and the incidence and characteristics of cytomegalovirus (CMV) infection in the setting without CMV prophylaxis from 1989 through 1998. Methods. All (470) first cadaveric renal transplantations in nonsensitized (PRA < 60%) patients were analyzed. Immunosuppression consisted of cyclosporine A (Sandimmune) and prednisolone from 1989 through 2-1993 (S; 189 patients), of cyclosporine microemulsion (Neoral) and prednisolone from 3-1993 through 5-1997 (N; 200 patients) and of mycophenolate mofetil, Neoral and prednisolone from 5-1997 until 1998 (M; 81 patients). The CMV pp65-antigenemia was measured routinely at least once weekly from day 10 till 12 weeks after transplantation or until pp65-antigenemia became negative. No CMV-prophylaxis was given. Results. By changing from Sandimmune to Neoral and by adding mycophenolate mofetil, respectively, we observed a higher frequency of especially secondary CMV infections (S vs. N vs. M, respectively, 28 vs. 50 vs. 63%, P = 0.026; S vs. N, P = 0.027; S vs. M, P = 0.015; and N vs. M, n.s). The CMV infections lasted longer (median duration antigenemia S vs. N vs. M, respectively, 3 vs. 5 vs. 7 weeks, P = 0.0003; S vs. N, P < 0.002; S vs. M, P < 0.001; and N vs. M, P < 0.05). Viral load was higher in M (median maximal pp65-antigenemia S vs. N vs. M, respectively, 19 vs. 14.5 vs. 73, P < 0.01; S vs. N, n.s.; S vs. M, P < 0.001 and N vs. M, P < 0.01). Conclusions. The use of Neoral and the addition of mycophenolate mofetil caused significant changes in the incidence, duration and viral load of CMV infections.

Comparison of contrast enhanced MR-angiography-MRI and digital subtraction angiography in the evaluation of pancreas and/or kidney transplantation patients: initial experience.

To evaluate whether combined contrast enhanced MRA and MRI (ce-MRA-MRI) has the potential to replace intra-arterial DSA (i.a.DSA) in patients with impaired graft function or suspected of vascular complications after pancreas and/or kidney transplantation. 7 patients after combined pancreas-kidney and 22 patients after kidney transplantation underwent ce-MRA-MRI and i.a.DSA within a 3 days interval. Qualitative and quantitative comparison of the arterial and venous supply, the parenchyma and urinary collecting system was made. Both ce-MRA and i.a.DSA showed good results in the detection of arterial stenoses. However, ce-MRA falsely suggested stenoses if vascular clips were used; on the other hand, i.a.DSA was less informative if the graft arteries were very tortuous. Ce-MRA was superior in depicting the venous anatomy (p < 0.001) and the parenchymal enhancement of the pancreatic grafts. For the assessment of the contrast excretion, the pyelocalyceal system and the ureter of the renal graft ce-MRA-MRI was superior (p < 0.001), for small caliber arteries in the renal grafts i.a.DSA was of greater value (p < 0.001). The combination of ce-MRA and MRI is reliable for evaluating the vascular anatomy and has several advantages over i.a.DSA after pancreas and/or kidney transplantation. It can replace i.a.DSA in patients with impaired graft function or suspected of vascular complications after pancreas and/or kidney transplantation.

Pulmonary diffusion abnormalities in relation to cytomegalovirus antigenemia and cytomegalic endothelial cells in blood.

The pathophysiology of HCMV infection may involve many different organs including the lungs. In this study we investigated HCMV antigenemia levels and cytomegalic endothelial cells (CEC) in blood in relation to the pulmonary diffusion capacity. Patients with high HCMV antigenemia (> or = 100 pp65+ PMNs/50.000) (n = 8) showed a more extensive decrease in the membrane factor (Dm) than patients with lower levels of HCMV antigenemia (n = 7). The decline of the diffusion capacity of the alveolar capillary membrane (KCOc) and of the pulmonary capillary volume (Vcap) was the same in both groups. Four out of nine patients had CEC in the range of 0.22 CEC/ml to 30.26 CEC/ml. All the HCMV patients showed a decreased KCOc together with a decrease of Dm and Vcap but no difference was observed between patients with and without CEC. We conclude that a higher viral load is associated with a more extensive decrease in the membrane factor and therefore with more subclinical pneumonitis. No relation was observed between CEC and pulmonary dysfunction. Therefore, we postulate that CEC levels are related indirectly to subclinical pneumonitis mediated via the viral load.