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Biomedical subjects

H Jalanko

Publications and source records attributed to H Jalanko.

At least 19 recordsLinked to original sources

Course of renal allograft histopathology after transplantation in early childhood.

BACKGROUND: We report a long-term prospective follow-up of renal allograft histology in children <5 years of age at transplantation (Tx). METHODS: Fifty-one kidney allograft recipients were prospectively followed for renal allograft histology and function up to 7 years after Tx. Twenty patients were recipients of kidneys from living related donors, and 31 were cadaveric kidney recipients. All patients received triple immunosuppression. Biopsies were analyzed according to the Banff classification and scored semiquantitatively. The "chronic allograft damage index" (CADI) was calculated. RESULTS: Five of seven grafts were lost because of nephrosis in patients with congenital nephrotic syndrome of the Finnish type. Most of the biopsies (52-69%) were considered normal (Banff classification), and the proportion with chronic allograft nephropathy did not increase with time. The median CADI score was 2.5 (scale: 0-36) at 1.5 years and 3.5 at 7 years. Recipients with an acute rejection episode had higher CADI scores than recipients without acute rejection episode. Patients with a high CADI score at 3 years had inferior graft function at 5 years. Recipients <2 years of age had CADI scores and numbers of acute rejection episode similar to recipients between 2 and 5 years of age. However, in contrast to the older recipients, the younger recipients did not improve their absolute glomerular filtration rate with time. CONCLUSIONS: The long-term histopathological findings were mostly mild and stable with time. Acute rejection episode had an impact on these changes and CADI predicted later graft function. Nonimmunological risk factors seem to be more important in the youngest recipients.

Acute Disease↗

Infections in pediatric kidney and liver transplant patients after perioperative hospitalization.

BACKGROUND: Infectious complications are a major cause of morbidity and mortality after organ transplantation. There are several reports on infections during the first months after transplantation, but there are very few data regarding infections in long-term survivors of pediatric organ transplantation. METHODS: The incidence and type of infections were retrospectively analyzed in 56 children who underwent 59 liver or renal transplantations. Follow-up was begun when the patient was sent home after a successful operation. All of the children received triple immunosuppression. RESULTS: During a mean follow-up of 4.8 years (total, 286 patient years), 1540 episodes of infection were recorded. The median incidence was 4.8 episodes/patient year. The greatest number was seen in the smallest children, 3 to 6 months after transplantation. Viral upper respiratory tract infections were the most common problem, accounting for half of the episodes (2.7 episodes/patient year). Gastroenteritis was the second most common viral infection. Only 45 episodes of infection with herpesviruses were recorded, and seven of those were caused by cytomegalovirus. Otitis media and sinusitis were the most common bacterial infections and complicated upper respiratory infection in 23% of episodes. Thirty-nine episodes of urinary tract infections were diagnosed, thirty-one in children with renal transplants. Other bacterial infections were rare, and only three episodes of verified bacterial sepsis were diagnosed. CONCLUSION: The frequency and type of infections in children with liver and renal transplants who are on triple immunosuppression are quite similar to those in age-matched healthy children.

Adolescent↗

Clinical outcome of pediatric patients on peritoneal dialysis under adequacy control.

Clinical outcome under adequacy control was studied in 10 pediatric patients under 5 years and 11 patients over 5 years of age on continuous peritoneal dialysis (PD). Outcome was compared between the age groups and with our previous results in patients under 5 years of age. Peritoneal equilibration test and 24-h dialysate collection were performed. Laboratory data, clinical status, and diet were recorded. PD prescription was adjusted for these parameters. The mean weekly urea Kt/V was similar and stable in the two age groups (3.1+/-0.6 vs. 3.2+/-0.4 at baseline). The mean weekly creatinine clearance (C(Cr)) was at baseline significantly lower in the younger age group (58.7+/-11.9 vs. 78.0+/-14.9 l/week per 1.73 m2, P=0.004), but later similar. Urea Kt/V and C(Cr) correlated significantly. Hematological and biochemical parameters were stable, and catch-up growth was observed in 62% of the patients during 9 months of follow-up. The outcome for children under and over 5 years of age did not differ significantly. The clinical outcome in patients under 5 years of age improved under adequacy control, when compared with our previous results in patients of the same age. This suggests a positive effect of adequacy control on clinical outcome.

Adolescent↗

Role of nephrin in cell junction formation in human nephrogenesis.

Nephrin is a cell adhesion protein located at the slit diaphragm area of glomerular podocytes. Mutations in nephrin-coding gene (NPHS1) cause congenital nephrotic syndrome (NPHS1). We studied the developmental expression of nephrin, ZO-1 and P-cadherin in normal fetal kidneys and in NPHS1 kidneys. We used in situ hybridization and immunohistochemistry at light and electron microscopic levels. Nephrin and zonula occludens-1 (ZO-1) were first expressed in late S-shaped bodies. During capillary loop stage, nephrin and ZO-1 localized at the basal margin and in the cell-cell adhesion sites between developing podocytes, especially in junctions with ladder-like structures. In mature glomeruli, nephrin and ZO-1 concentrated at the slit diaphragm area. P-cadherin was first detected in ureteric buds, tubules, and vesicle stage glomeruli. Later, P-cadherin was seen at the basal margin of developing podocytes. Fetal NPHS1 kidneys with Fin-major/Fin-major genotype did not express nephrin, whereas the expression of ZO-1 and P-cadherin was comparable to that of control kidneys. Although early junctional complexes proved structurally normal, junctions with ladder-like structures and slit diaphragms were completely missing. The results indicate that nephrin is dispensable for early development of podocyte junctional complexes. However, nephrin appears to be essential for formation of junctions with ladder-like structures and slit diaphragms.

Cadherins↗

Congenital nephrotic syndrome (NPHS1): features resulting from different mutations in Finnish patients.

BACKGROUND: Congenital nephrotic syndrome (NPHS1) is a rare disease inherited as an autosomally recessive trait. The NPHS1 gene mutated in NPHS1 children has recently been identified. The gene codes for nephrin, a cell-surface protein of podocytes. Two mutations, named Fin-major and Fin-minor, have been found in over 90% of the Finnish patients. In this study, we correlated the NPHS1 gene mutations to the clinical features and renal findings in 46 Finnish NPHS1 children. METHODS: Clinical data were collected from patient files, and kidney histology and electron microscopy samples were re-evaluated. The expression of nephrin was studied using immunohistochemistry, Western blotting, and in situ hybridization. RESULTS: Nephrotic syndrome was detected in most patients within days after birth regardless of the genotype detected. No difference could be found in neonatal, renal, cardiac, or neurological features in patients with different mutations. Nephrin was not expressed in kidneys with Fin-major or Fin-minor mutations, while another slit diaphragm-associated protein, ZO-1, stained normally. In electron microscopy, podocyte fusion and podocyte filtration slits of various sizes were detected. The slit diaphragms, however, were missing. In contrast to this, a nephrotic infant with Fin-major/R743C genotype expressed nephrin in kidney had normal slit diaphragms and responded to therapy with an angiotensin-converting enzyme inhibitor and indomethacin. CONCLUSIONS: The most common NPHS1 gene mutations, Fin-major and Fin-minor, both lead to an absence of nephrin and podocyte slit diaphragms, as well as a clinically severe form of NPHS1, the Finnish type of congenital nephrotic syndrome.

Blotting, Western↗

Nephrin is specifically located at the slit diaphragm of glomerular podocytes.

We describe here the size and location of nephrin, the first protein to be identified at the glomerular podocyte slit diaphragm. In Western blots, nephrin antibodies generated against the two terminal extracellular Ig domains of recombinant human nephrin recognized a 180-kDa protein in lysates of human glomeruli and a 150-kDa protein in transfected COS-7 cell lysates. In immunofluorescence, antibodies to this transmembrane protein revealed reactivity in the glomerular basement membrane region, whereas the podocyte cell bodies remained negative. In immunogold-stained thin sections, nephrin label was found at the slit between podocyte foot processes. The congenital nephrotic syndrome of the Finnish type (NPHS1), a disease in which the nephrin gene is mutated, is characterized by massive proteinuria already in utero and lack of slit diaphragm and foot processes. These features, together with the now demonstrated localization of nephrin to the slit diaphragm area, suggests an essential role for this protein in the normal glomerular filtration barrier. A zipper-like model for nephrin assembly in the slit diaphragm is discussed, based on the present and previous data.

Cell Membrane↗

Successful liver transplantation after induction chemotherapy in children with inoperable, multifocal primary hepatic malignancy.

BACKGROUND: The prognosis for primary epithelial liver tumor in children in whom radical surgery cannot be performed after chemotherapy is poor. Orthotopic liver transplantation has resulted in mortality up to 50%, largely as a result of problems in determining the criteria for transplantation. METHODS: We report results on liver transplantation for primary epithelial liver malignancy in five children (mean age at transplantation: 6.0 years). Only patients with inoperable residual tumor in the liver after four cycles of multidrug chemotherapy, but without extrahepatic infiltration or metastases, were considered eligible for transplantation. RESULTS: Mean follow-up was 4.6 years. Patient and graft survival was 100%, with no signs of residual or de novo malignancy. CONCLUSION: In children with inoperable primary liver malignancy with no extrahepatic tumor growth, orthotopic liver transplantation has an excellent outcome.

Adolescent↗

Graft function 5-7 years after renal transplantation in early childhood.

BACKGROUND: Low recipient age is still a risk factor for graft failure after kidney transplantation (Tx). Detailed prospective reports on long-term graft function in small children after renal Tx are still lacking. METHODS: Forty-nine kidney allograft recipients who received transplants before the age of 5 years were followed prospectively. The most common disease was congenital nephrotic syndrome of the Finnish type. Twenty patients were recipients of living related donors (LRD), and 29 were cadaveric kidney (CAD) recipients. All patients received triple immunosuppression. Glomerular filtration rate (GFR), effective renal plasma flow (ERPF), sodium, urate, and potassium handling, and concentrating capacity were studied for up to 7 years after Tx. RESULTS: Patient survival 7 years after Tx was 100% for LRD and 96% for CAD recipients. Graft survival was 94% for LRD and 79% for CAD recipients (P=NS) and 89% and 83% for children >2 years and <2 years of age at Tx, respectively (P=NS). Five years after Tx, GFR was 70 vs. 64 and ERPF was 380 vs. 310 ml/min/1.73 m2 for LRD and CAD recipients, respectively (P=NS). Mean absolute GFR remained stable. GFR was lower in children who received transplants at <2 years than in children who received transplants at >2 years of age, 54 vs. 75 ml/min/1.73 m2 (P=0.02). Sodium handling remained intact, but hyperuricemia was seen in 43-67%; 17-33% showed abnormal handling of potassium; and most patients had a subnormal concentrating capacity. CONCLUSIONS: Excellent long-term graft survival and good graft function can be achieved with triple immunosuppression, even in young CAD kidney recipients.

Cadaver↗

Long-term follow up of renal function and histology after renal allograft transplantation in early childhood.

Survival rates, renal function, and histopathology were evaluated in 49 prospectively followed patients transplanted under 5 years of age at our center. Most patients (84%) suffered from congenital nephrosis of the Finnish type. Triple immunosuppression with cyclosporine administered in three daily doses to pre-school children was used. Patient survival 7 years after transplantation was 98% and graft survival 88%. All graft losses were due to post-transplantation nephrosis. The proportion of pathological findings in the follow-up biopsies did not change substantially with time. Five years after transplantation, 47% showed a normal histology and after 7 years this rose to 67%. Mean glomerular filtration rate (GFR) was 68 and 55 ml min per 1.73 m2 5 years and 7 years, respectively, after transplantation. The decline in GFR with time was significant. We conclude that good long-term results can be achieved with individually tailored triple immunosuppression in the youngest age group, even with cadaveric donors.

Child, Preschool↗

Paediatric kidney transplantation.

Renal transplantation is the optimal form of renal replacement therapy leading to substantial improvement in the quality of life. It has rapidly become the standard treatment for end-stage renal disease in children. However, despite impressive short-term results significant long-term problems remain unsolved. Because of the lack of effective treatment for chronic rejection and common recipient noncompliance, allograft half-life has not improved significantly during the last decade. A paediatric recipient is likely to need several retransplantations in adulthood. Moreover, the immunosuppressive drugs used today have potentially serious side-effects including nephrotoxicity and de novo malignancy. These are especially relevant for paediatric recipients who will continue to receive therapy for several decades. Most therapeutic protocols used for children are derived from those used for adults. However, the metabolic differences between an adult and a growing and developing paediatric transplant recipient are not always adequately appreciated before these new therapies are initiated. In the near future, we are likely to see new and more efficient drugs become available. It is important that we try to understand their properties in children and use them and our current arsenal on an individual basis aiming at optimal graft survival but also at avoiding unnecessary adverse effects.

Adolescent↗

Kidney function after 1:1 conversion to the cyclosporine microemulsion formulation in children with liver allografts.

BACKGROUND: One-to-one (mg:mg) conversion from the conventional to the microemulsion formulation of cyclosporine (CsA) is advocated as a simple way to use the new therapeutic regimen. However, the potentially harmful effects of the conversion on kidney function in nonrenal transplant recipients are poorly known. METHODS: Renal effects of the conversion were prospectively investigated in 22 pediatric liver transplant recipients (mean age, 8.4 years; mean time from transplantation, 3.2 years). Patients were followed for 12 months. Pharmacokinetic studies were performed at baseline and 5 days and 6 and 12 months after conversion. RESULTS: Peak concentration, minimum concentration, average steady state concentration, and area under the concentration-versus-time curve increased by 60-130% after conversion. Graft losses, progressive deterioration of graft function, and acute rejection episodes did not occur. The mean glomerular filtration rate (GFR) was 103 ml/min/1.73 m2 at baseline and 100 ml/min/1.73 m2 after 12 months. However, 6 of the 22 patients showed at least a 15% (range, 16-38%) decrease in GFR between baseline and 6 months (P<0.01). They had a significantly higher increase in average steady state concentration between baseline and 6 months than the six patients with the best outcome in GFR during the same time period (164 ng/ml vs. 53 ng/ml, P<0.05). At this point (6 months), target CsA trough levels were reduced by 20-30%, while the mean area under the concentration-versus-time curve remained above that obtained at baseline. The GFR of three of the six patients subsequently improved. CONCLUSIONS: One-to-one conversion can be performed safely in liver transplant recipients if strict follow-up is feasible.

Adolescent↗

Infections in infants with congenital nephrosis of the Finnish type.

The incidence and type of infections were retrospectively analyzed in 21 infants with congenital nephrosis of the Finnish type (CNF). During the median follow-up time of 1.1 years the infants suffered from 63 verified and 62 suspected episodes of sepsis. These accounted for half of all infections recorded. Forty percent of bacteremias were caused by coagulase-negative staphylococci, 16% were caused by Staphylococcus aureus, 17% were streptococcal, and 24% were caused by Gram-negative bacteria. One infant died of pleural empyema, but otherwise the outcome of infections was good. The use of central venous lines tended to increase the rate of staphylococcal bacteremias but had no significant effect on the overall incidence of infections. Prophylactic use of antibiotics did not reduce the incidence of septic or other infections. Infants with CNF had low levels of serum IgG, but prophylactic immunoglobulin infusions (0.5-1.0 g once or twice a week) did not reduce the frequency of infections, probably because the infused IgG was quickly lost into the urine. The results indicate that infants with CNF often suffer from septic infections associated with the invasive treatment modalities. Parenteral antibiotics covering the hospital strains of bacteria (especially staphylococci) should be started without delay when a nephrotic patient is not doing well.

Anti-Bacterial Agents↗

Persistent cytomegalovirus in liver allografts with chronic rejection.

Cytomegalovirus (CMV) infection is one of the suggested risk factors for chronic allograft rejection. Clinical and experimental studies have shown that CMV is somehow implicated in rejection mechanisms and in the generation of graft arteriosclerosis, characteristic of chronic rejection. In liver transplantation, there is also evidence of an association between CMV and vanishing bile duct-syndrome (VBDS), which is characteristic of chronic liver allograft rejection. In this study, the role of posttransplant CMV infection and of acute rejection in the patients with irreversible, histologically confirmed chronic liver rejection with VBDS and vasculopathy was analyzed. Ten of 200 (5%) consecutive liver transplants were lost due to chronic rejection, from between 5 and 28 months from transplantation. In these 10 patients, acute rejections were frequent, and nine of ten patients had at least one episode of rejection early after transplantation. All patients (10 of 10) had a history of CMV infection usually following acute rejection. To investigate the role of CMV in chronic rejection, nine available removed grafts were examined for the presence of the CMV genome by DNA-hybridization in situ using a biotinylated CMV-DNA probe. Persistent CMV-DNA was found in all of those available grafts with chronic rejection. CMV-DNA was strongly expressed in the remaining bile ducts and moderately expressed in the endothelial cells of the vascular structures, the CMV positivity of hepatocytes varied from graft to graft. Thus, persistent CMV genome was found in those structures that are the major targets of the chronic rejection process in the liver. These findings support the previous suggestion of an association between CMV and chronic allograft rejection.

Bile Ducts↗