Eculizumab in Pediatric Dense Deposit Disease.

BACKGROUND AND OBJECTIVES: Dense deposit disease (DDD), a subtype of C3 glomerulopathy, is a rare disease affecting mostly children. Treatment options are limited. Debate exists whether eculizumab, a monoclonal antibody against complement factor C5, is effective in DDD. Reported data are scarce, especially in children. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The authors analyzed clinical and histologic data of five pediatric patients with a native kidney biopsy diagnosis of DDD. Patients received eculizumab as therapy of last resort for severe nephritic or nephrotic syndrome with alternative pathway complement activation; this therapy was given only when the patients had not or only marginally responded to immunosuppressive therapy. Outcome measures were kidney function, proteinuria, and urine analysis. RESULTS: In all, seven disease episodes were treated with eculizumab (six episodes of severe nephritic syndrome [two of which required dialysis] and one nephrotic syndrome episode). Median age at treatment start was 8.4 (range, 5.9-13) years. For three treatment episodes, eculizumab was the sole immunosuppressive treatment. In all patients, both proteinuria and renal function improved significantly within 12 weeks of treatment (median urinary protein-to-creatinine ratio of 8.5 [range, 2.2-17] versus 1.1 [range, 0.2-2.0] g/g, P<0.005, and eGFR of 58 [range, 17-114] versus 77 [range, 50-129] ml/min per 1.73 m(2), P<0.01). A striking finding was the disappearance of leukocyturia within 1 week after the first eculizumab dose in all five episodes with leukocyturia at treatment initiation. CONCLUSIONS: In this case series of pediatric patients with DDD, eculizumab treatment was associated with reduction in proteinuria and increase in eGFR. Leukocyturia resolved within 1 week of initiation of eculizumab treatment. These results underscore the need for a randomized trial of eculizumab in DDD.

The difficulty in considering modifiable pathology risk factors in children with IgA nephropathy: crescents and timing of renal biopsy.

The need for an early diagnosis of primary IgA nephropathy (IgAN) is particularly felt in children since they have a long life expectancy. However, IgAN has a slowly progressive course and renal function can even remain unchanged for decades. The long-term predictive value of modifiable risk factors, such as proteinuria and proliferative/inflammatory lesion at renal biopsy, remains unknown. Interest has focused on crescents, which represent a clear risk factor for renal vasculitides. A number of rare cases of extracapillary IgAN involving >40 % of glomeruli have been reported, but in most cases of IgAN crescents involve <10 % of glomeruli. The long-term effect of small non-circumferential crescents detected by chance or without a clinical picture of progressive IgAN is still unknown. The Oxford study failed to find a predictive value of crescents in either children or adults, and these results were confirmed by the recent VALIGA study on 1,147 patients with IgAN (174 children). A recent study reports a correlation between the time elapsed from the diagnosis of urinary abnormalities and renal biopsy which suggests that crescents are associated with disease onset and then likely undergo a healing process into sclerotic lesions, which are commonly detected in biopsies performed years after onset. The authors of this study propose that primary IgAN may have similarities with Henoch-Schoenlein purpura nephritis, which presents with acute glomerular damage, mesangial proliferation, endocapillary leucocyte infiltration and crescent formations, and that these lesions can undergo resolution with sclerotic healing. This hypothesis is highly suggestive of the silent progression of several cases of IgAN without clear clinical changes, stressing once more the need for a combined clinical and pathological evaluation of children with IgAN that considers both the underlying pathogenetic event and its possible evolution.

Maintenance of kidney function following treatment with eculizumab and discontinuation of plasma exchange after a third kidney transplant for atypical hemolytic uremic syndrome associated with a CFH mutation.

Kidney transplant in patients with atypical hemolytic uremic syndrome (aHUS) is associated with a poor outcome because of recurrent disease, especially in patients known to have a factor H mutation. Long-term prophylactic plasma exchange and combined liver-kidney transplant have prevented graft loss caused by recurrence. However, the mortality associated with liver transplant is not negligible, and prophylactic plasma exchange requires permanent vascular access and regular hospitalization and exposes the patient to potential allergic reactions to plasma. Eculizumab is a high-affinity humanized monoclonal antibody that binds to C5 and thus prevents generation of C5a and the membrane attack complex. We report the case of a 17-year-old girl with aHUS associated with a mutation in the gene for complement factor H (CFH; c.3572C>T, Ser1191Leu) who was highly dependent on plasma exchange. Because of severe allergic reactions to plasma after the third renal graft, eculizumab was introduced in place of plasma exchange without problems. This and other reports suggest that the promise of complement inhibitors in the management of aHUS is going to be fulfilled.

Pulmonary complaints and lung function after pediatric kidney transplantation.

Recently four of 38 children with a kidney transplant were diagnosed with bronchiectasis. The aim of the current study was to identify patients with increased risk for pulmonary damage. In this cross-sectional observational study, children with a functioning kidney graft in the Netherlands and Antwerp, Belgium, were screened with the use of a symptom checklist and spirometry. Maximum score for upper airway complaints was 21 (normal: <8), for lower airway complaints 28 (<10). Results of FVC, FEV(1) and MEF(25) were expressed as percentage predicted for height and sex. One hundred and thirty-five patients completed the interview (122) and/or spirometry (103); 91 did both. Lower airways symptoms were above acceptable levels in 18 (14%) patients. Forty-nine patients (48%) had an abnormal lung function test: in 12 concerning FVC%, in 11 FEV(1)%, in 24 MEF(25)% and in 36 FEV(1)/FVC. Of correlations between symptomatology or spirometry data, and clinical parameters, only that between GFR and MEF(25)% was statistically significant. Children with a kidney transplant are at increased risk for obstructive lung disease. We recommend to monitor lung function during the follow-up after renal transplantation.

Henoch Schonlein purpura in children: an epidemiological study among Dutch paediatricians on incidence and diagnostic criteria.

BACKGROUND: The aim of the present study on the occurrence of Henoch-Schönlein Purpura (HSP) in Dutch children is to give some insight into the epidemiology of HSP in the Netherlands, to record the diagnostic criteria used by Dutch paediatricians and to evaluate the accuracy of the latter using the presence of IgA in the skin when biopsies are available. METHODS: Each month in 2004, all Dutch paediatricians received an electronic card asking them to mention new diagnosed HSP. Paediatricians reporting one or more new patients with HSP were sent a list of questions concerning various parameters. RESULTS: 232 patients from 0 to 18 years of age (6.1/10(5)) were reported as having contracted HSP in 2004. 29% presented renal symptoms. In accordance with the classification criteria of the American College of Rheumatology, 80% of paediatricians consider that isolated purpura (without haematological abnormalities) is sufficient to allow the diagnosis of HSP in children. From the 17 skin biopsies performed, only 9 (53%) presented IgA deposits. The follow-up duration, considered as necessary, was longer in case of renal symptoms at presentation. However, 45% of patients without renal symptoms would be followed for more than 1 year. CONCLUSION: Considering the recent (2006) EULAR/PReS endorsed consensus criteria for the classification of childhood vasculitides, HSP should have been diagnosed in only 160 of the 179 patients of our study. The use of isolated non-thrombocytopenic purpura as the only criterion to diagnose HSP in children might therefore lead to over diagnosis and unnecessary follow-up.

IgG and complement receptor expression in children treated by peritoneal dialysis.

Children treated by peritoneal dialysis (PD) are at increased risk of infections. IgG receptors (FcgammaRs) and complement receptors (CRs) on white blood cells (WBCs) are important for the phagocytic process. We have investigated FcgammaR and CR expression on monocytes, macrophages and neutrophils in blood and in peritoneal dialysis effluent (PDE) of 39 PD children. WBCs were isolated from blood and PDE, labelled with FITC-conjugated CD16 (FcgammaRIII), CD32 (FcgammaRII), CD64 (FcgammaRI), CD11b (CR3) and CD35 (CR1) monoclonal antibodies, and analysed by flow cytometry. Peritoneal cells had lower percentages of FcgammaR-positive or CR-positive cells than blood. On the other hand, the receptor number per cell [mean fluorescence intensity (MFI)] was higher on peritoneal macrophages and neutrophils than blood, except for CD16. The FcgammaR and CR expression in blood and dialysate did not change significantly during the first year of PD treatment. During a peritonitis episode the MFI of all receptors in blood increased only on monocytes, with the exception of CD32. The percentages of FcgammaR-positive and CR-positive macrophages and neutrophils in the PDE increased, whereas the MFI did not increase consistently. Peritoneal cells of PD children showed a lower percentage of FcgammaR-positive and CR-positive neutrophils and macrophages, combined with an increased MFI, indicating a state of activation. Blood and peritoneal cells are capable of up-regulating the receptor expression during peritonitis but probably not to a maximum level.

Improved outcome of pediatric kidney transplantations in the Netherlands -- effect of the introduction of mycophenolate mofetil?

Collaboration of the Dutch centers for kidney transplantation in children started in 1997 with a shared immunosuppressive protocol, aimed at improving graft survival by diminishing the incidence of acute rejections. This study compares the results of transplantations in these patients to those in a historical reference group. Ninety-six consecutive patients receiving a first kidney transplant were treated with an immunosuppressive regimen consisting of mycophenolate mofetil, cyclosporine and corticosteroids. The results were compared with those of historic controls (first transplants between 1985 and 1995, n = 207), treated with different combinations of corticosteroids, cyclosporine A and/or azathioprine. Cytomegalovirus (CMV) prophylaxis was prescribed to high-risk patients in the study group, and only a small proportion of the reference group. The graft survival at 1 yr improved significantly: 92% in the study group, vs. 73% in the reference group (p < 0.001). In the study group 63% of patients remained rejection-free during the first year; in the reference group 28% (p < 0.001). After statistical adjustment of differences in baseline data, as cold ischemia time, the proportion of LRD, preemptive transplantation, and young donors, the difference between study and reference group in graft survival (RR 0.33, p = 0.003) and incidence of acute rejection (RR 0.37, p < 0.001), as the only factor, remained statistically significant, indicating the effect of the immunosuppressive therapy. In the first year one case of malignancy occurred in each group. CMV disease occurred less frequently in the study group (11%) than in the reference group (26%, p = 0.02). As a new complication in 4 patients bronchiectasis was diagnosed. A new consensus protocol, including the introduction of mycophenolate mofetil, considerably improved the outcome of pediatric kidney transplantation in the Netherlands, measured as reduction of the incidence of acute rejection and improved graft survival.

Cardiovascular disease as a late complication of end-stage renal disease in children.

As in older adults, cardiovascular disease is the most important cause of death in adolescents and young adult patients with end-stage renal disease (ESRD) since childhood. This concerns patients on dialysis as well as transplant patients, despite the fact that a long duration of dialysis during childhood is an extra mortality risk factor. Left ventricular hypertrophy (LVH), aortic valve calcification, and increased arterial stiffness, but not increased arterial intima media thickening, are the most frequently observed alterations in young adult survivors with childhood ESRD. In transplanted patients a concentric LVH as a result of chronic hypertension is mostly observed; in dialysis patients a more asymmetric septal LVH is found as a result of chronic volume overload. These results suggest that in children and young adults with ESRD chronic pressure and volume overload, a high calcium-phosphate product, and chronic inflammation, but not dyslipidemia, play a role in the development of cardiovascular disease.

Atypical relapse of hemolytic uremic syndrome after transplantation.

Atypical hemolytic uremic syndrome (HUS) frequently leads to end-stage renal failure and can relapse after transplantation. A 12-year-old girl presenting with familial atypical HUS with a factor H mutation was successfully transplanted 6 years after a first transplant that had failed because of immediate recurrent HUS. Prophylactic plasma exchange before and after transplantation was used. Two months after transplantation, concomitant with a reduction in plasma exchange frequency, the plasma creatinine increased from 70 micro mol/l to 194 micro mol/l in 2 weeks without thrombocytopenia or signs of hemolytic anemia. The patient had minimal clinical symptoms and a presumptive diagnosis of graft rejection was made. Despite treatment with six daily pulses of methylprednisolone, plasma creatinine continued to increase and a graft biopsy was therefore undertaken. This showed the typical appearance of a thrombotic microangiopathy without any evidence of rejection. Despite daily plasmapheresis and replacement of cyclosporine with tacrolimus, there was no improvement and transplant nephrectomy was undertaken. This patient demonstrates that HUS can recur in a kidney transplant without the diagnostic hematological features and emphasizes the need for early transplant biopsy in such patients showing a decline in transplant function.

Long-term follow-up of renal transplantation in children: a Dutch cohort study.

BACKGROUND: Few data exist on long-term morbidity, overall survival, and graft survival of pediatric renal transplantation. METHODS: The authors performed a long-term cohort study in all Dutch patients, born before 1979, with onset of end-stage renal disease (ESRD) between 1972 and 1992 at age 0 to 15 years. Data on graft survival and determinants of outcome were obtained by reviewing all medical charts. The health status was assessed by cross-sectional examination of surviving patients. RESULTS: Three hundred ninety-seven transplantations were performed in 231 of all 249 patients, of whom 25 died with a functioning graft. Cardiovascular disease was the most prominent cause of death. Graft survival estimates for all transplantations were 59.2%, 45.3%, 35.4%, and 30.3% at 5, 10, 15, and 20 years, respectively. In comparison with azathioprine, cyclosporine as the immunosuppressant was associated with increased graft survival in retransplantations but not in first transplantations. Cross-sectional examination was performed on 110 patients. In 44 patients, the most recent graft survival exceeded 15 years. Co-morbidity was found in 40% of all patients; motor, hearing, or visual disabilities were found in 19%. Bone disease, headaches, itching, and tremors were the most reported disabling problems. Cyclosporine use was associated with hypertension and a history of epilepsy. Compared with all age-matched Dutch inhabitants, the educational attainment was low, and unemployment and parental dependency were high. CONCLUSIONS: The authors' results emphasize the need for reducing cardiovascular disease and metabolic bone disease in pediatric ESRD, a policy toward less toxic antirejection therapy, a more strict treatment of hypertension, and more attention for schooling and social development toward independence.

Spontaneous outgrowth of EBV-transformed B-cells reflects EBV-specific immunity in vivo; a useful tool in the follow-up of EBV-driven immunoproliferative disorders in allograft recipients.

During immunosuppressive medication, Epstein-Barr virus (EBV) infection is associated with a risk of developing posttransplant lymphoproliferative disease (PTLD). The appropriateness of a spontaneous EBV B-cell transformation (SET) assay as a monitor of EBV-specific immunity was evaluated to investigate if it safely allows reducing immunosuppressive medication, thereby decreasing the risk of developing PTLD. PBMC were isolated longitudinally from 20 pediatric renal allograft recipients treated with prednisone and cyclosporine combined with either azathioprine or mycophenolate mofetil. Most significantly, EBV-peptide-specific CD8+ T cells were detectable in the blood of patients with negative SET assays, coinciding with significantly lower EBV loads, whereas these cells were less frequent in the blood of patients with positive SET assays. Reducing the levels of immunosuppression resulted in normalization of the SET assays. Therefore, the SET assay is a reflection of the interaction between viral replication, transformation of B cells, and EBV-specific immunity in vivo and hence a valuable screening test for EBV-driven lymphoproliferative phenomena in allograft recipients.

Diagnosis of Henoch-Schönlein purpura: renal or skin biopsy?

Henoch-Schönlein purpura (HSP) is a form of systemic vasculitis characterized by vascular wall deposits of predominantly IgA, typically involving small vessels in skin, gut, and glomeruli and associated with purpura, intestinal colic, hematuria, and arthralgia or arthritis. HSP nephritis leads to chronic renal failure in up to 20% of pediatric patients after 20 years of follow-up in selected series. The risk is related to the initial clinical presentation and is maximal (more than 50%) when initial signs are a combination of nephrotic and nephritic syndromes. Although less important, the risk persists for mild renal symptoms or when the patient has apparently completely recovered from the renal disease. Other types of non-IgA-related leukocytoclastic vasculitis may be difficult to discriminate from HSP, thus confounding the diagnosis. The clinical picture of HSP is often incomplete and renal signs can become manifest years after initial signs. When based on clinical signs only, the diagnosis of HSP can therefore be missed, and some patients risk developing silent chronic renal failure after decades without appropriate treatment. Patients can also be overdiagnosed as HSP and thus submitted to unnecessary follow-up. It is therefore important that HSP should be correctly diagnosed from the initial signs. As the finding of IgA deposits in vessel walls associated with the characteristic signs of small-vessel vasculitis is a sine qua non in the diagnosis, a skin biopsy should be performed for histological and immunofluorescence studies in cases of clinical suspicion of HSP. The systematic diagnostic use of a cutaneous biopsy should not only improve the follow-up of patients with HSP but will also allow a reliable epidemiological study of vasculitis in children and a better knowledge of the disease.

Frequencies of circulating cytolytic, CD45RA+CD27-, CD8+ T lymphocytes depend on infection with CMV.

Viral infections may cause serious disease unless the adaptive immune system is able to clear the viral agents through its effector arms. Recent identification and functional characterization of subpopulations of human CD8(+) T cells has set the stage to study the correlation between the appearance of particular subsets and common viral infections during childhood, i.e., EBV, CMV, varicella-zoster virus (VZV), and the attenuated measles-mumps-rubella (MMR) vaccine strains. In a cohort of 220 healthy children we analyzed lymphocytes and subpopulations of CD4(+) and CD8(+) T cells. The presence of the cytolytic CD45RA(+)CD27(-) subset of CD8(+) T cells correlated with prior CMV infection as defined by seroconversion (p < 0.0001). The number of this CD8(+) T cell subset remained stable during follow-up over 3 years in 40 children. The CD45RA(+)CD27(-) subset of CD8(+) T cells first appeared during acute CMV infection and subsequently stabilized at an individual set-point defined by age and immunocompetence. The functional importance of these cells in CMV surveillance was reflected by their increased numbers in immunosuppressed pediatric kidney transplant patients. Preferential expansion of CD8(+)CD45RA(+)CD27(-) cytolytic T cells seems unique for CMV.

Cardiac disease in young adult patients with end-stage renal disease since childhood: a Dutch cohort study.

BACKGROUND: Cardiovascular disease is the most important cause of death in patients with pediatric end-stage renal disease (ESRD). Yet, few data exist on cardiac function in these patients. We assessed the extent of cardiac abnormality and analyzed its association with potential determinants in young adult patients with pediatric ESRD in a long-term follow-up study. METHODS: All Dutch living adult patients with ESRD onset at age of 0 to 14 years between 1972 and 1992 were invited for echocardiography and blood pressure assessment. Special attention was paid to evidence of left ventricular hypertrophy (LVH), diastolic dysfunction, and aortic valve calcification. We collected data on determinants by review of all medical charts. RESULTS: Of all the 187 living patients, 140 participated in the study. Of those, 110 patients had received a transplant and 30 patients were on dialysis. Mean age was 29.2 (20.7 to 41.8) years. Left ventricular mass index (LVMI) exceeded 150 g/m2 in 47% of all male patients and 120 g/m2 in 39% of all female patients, both consistent with LVH. Diastolic dysfunction, defined as an early over atrial transmitral blood flow velocity (E/A ratio) <1, was found in 18 (13%) patients; 27 (19%) had aortic valve calcification. Multiple regression analysis revealed the following: a high LVMI was associated with a current high blood pressure (beta=0.46, P < 0.001) and male gender (beta=0.21, P=0.009), a low E/A ratio with aging (beta=-0.28, P < 0.001) and a glomerular filtration rate (GFR) <25 mL/min/1.73 m2 (beta=-0.29, P < 0.001), and aortic valve calcification with prolonged peritoneal dialysis (beta=0.36, P < 0.001). CONCLUSION: Young adult patients with pediatric ESRD are at risk for LVH caused by hypertension and for aortic valve calcification. Diastolic function decreases with age and is enhanced by a current low GFR. Prolonged peritoneal dialysis may enhance aortic valve calcification.