Arvi Kuusniemi - Academia.edu (original) (raw)

Papers by Arvi Kuusniemi

Research paper thumbnail of Ab Interno Trabeculotomy

Research paper thumbnail of Pathophysiology of Congenital Nephrotic Syndrome of the Finnish type

Congenital nephrotic syndrome of the Finnish type (NPHS1) is an autosomal recessive disease which... more Congenital nephrotic syndrome of the Finnish type (NPHS1) is an autosomal recessive disease which is highly enriched in the Finnish population. It is caused by mutations in the NPHS1 gene encoding for nephrin, which is a major component of the glomerular filtration barrier in the kidney. Patients with NPHS1 have heavy proteinuria and nephrotic syndrome (NS) from birth and develop renal fibrosis in early childhood. Renal transplantation (TX) is the only curative treatment for NPHS1. These patients form the largest group of pediatric kidney transplant children in our country. The NPHS1 kidneys are removed in infancy and they serve as an excellent human material for studies of the pathophysiology of proteinuric kidney diseases. Sustained proteinuria is a major factor leading to end-stage renal failure and understanding this process is crucial for nephrology. In this study we investigated the glomerular and tubulointerstitial changes that occur in the NPHS1 kidneys during infancy as wel...

Research paper thumbnail of Kidneys with heavy proteinuria show fibrosis, inflammation, and oxidative stress, but no tubular phenotypic change

Kidney international, 2005

Sustained proteinuria is a major factor leading to kidney fibrosis and end-stage renal failure. T... more Sustained proteinuria is a major factor leading to kidney fibrosis and end-stage renal failure. Tubular epithelial cells are believed to play a crucial role in this process by producing mediators leading to fibrosis and inflammation. Congenital nephrotic syndrome of the Finnish type (NPHS1) is a genetic disease caused by mutations in a podocyte protein nephrin, which leads to constant heavy proteinuria from birth. In this work we studied the tubulointerstitial changes that occur in NPHS1 kidneys during infancy. The pathologic lesions and expression of profibrotic and proinflammatory factors in nephrectomized NPHS1 kidneys were studied by immunohistochemistry, Western blotting, and cytokine antibody array. Oxidative stress in kidneys was assessed by measurement of gluthatione redox state. The results indicated that (1) severe tubulointerstitial lesions developed in NPHS1 kidneys during infancy; (2) tubular epithelial cells did not show transition into myofibroblasts as studied by the...

Research paper thumbnail of Plasma Exchange and Retransplantation in Recurrent Nephrosis of Patients With Congenital Nephrotic Syndrome of the Finnish Type (NPHS1)

Transplantation, 2007

Recurrent nephrotic syndrome (NS) is a severe problem after renal transplantation in patients wit... more Recurrent nephrotic syndrome (NS) is a severe problem after renal transplantation in patients with congenital nephrotic syndrome of the Finnish type (NPHS1). The NPHS1 kidneys do not express nephrin, and antibodies against this major glomerular filter protein have been observed in NPHS1 children with recurrent NS. We evaluated here the use of plasma exchange (PE) therapy and kidney retransplantation in NPHS1 patients with recurrent NS and extended our studies on the pathogenesis of the recurrence. Clinical data on 65 NPHS1 patients who received 77 kidney transplants between the years 1986 and 2006 was collected. Serum anti-nephrin antibodies were assayed with an enzyme-linked immunosorbent assay method, and the kidney biopsy samples were evaluated by light microscopy and immunohistochemistry. Twenty-three episodes of recurrent NS occurred in 19 grafts of 13 NPSH1 patients homozygous for Fin-major mutation. Six retransplantations were performed to four NPHS1 patients, who lost their graft because of recurrent NS, and heavy proteinuria developed immediately in all cases. Although 73% of the patients had detectable serum anti-nephrin antibodies, the kidney biopsy findings were minimal. Introduction of PE alongside cyclophosphamide proved effective in the treatment of the proteinuric episodes (one graft loss out of nine). If remission was achieved, recurrent NS did not significantly deteriorate the long term graft function. The clinical and pathological data suggest that anti-nephrin antibodies effectively impair the glomerular function in kidney grafts of NPHS1 patients homozygous for Fin-major mutation. Plasma exchange is a useful adjunct to the treatment of the recurrent NS.

Research paper thumbnail of Tissue Expression of Nephrin in Human and Pig

Research paper thumbnail of Changes in glomerular mesangium in kidneys with congenital nephrotic syndrome of the Finnish type

Pediatric Nephrology, 2010

Congenital nephrotic syndrome of the Finnish type (NPHS1, CNF) is an autosomal recessive disease ... more Congenital nephrotic syndrome of the Finnish type (NPHS1, CNF) is an autosomal recessive disease caused by mutations in a major podocyte protein, nephrin. NPHS1 is associated with heavy proteinuria and the development of glomerular scarring. We studied the cellular and molecular changes affecting the glomerular mesangium in NPHS1 kidneys. Marked hyperplasia of mesangial cells (MC) was mainly responsible for the early mesangial expansion in NPHS1 glomeruli. The levels of the proliferation marker, mindbomb homolog 1 and the major MC mitogen, platelet-derived growth factor, and its receptors, however, were quite normal. Only a small number of cells were positive for CD68 (marker for phagocytic cells) and CD34 (marker for mesenchymal precursor cells) in the NPHS1 mesangium. MCs strongly expressed α-smooth muscle actin, indicating myofibloblast transformation. The expression levels of the profibrotic mediators osteopontin and transforming growth factor β were up-regulated in NPHS1 glomeruli by 3.2 and 1.6-fold, respectively, compared to the controls. The synthesis by MCs of the typical fibroblast products collagen I, fibronectin, and tenascin, however, was low, and the extracellular matrix increase was caused by the accumulation of a normal MC product, collagen IV. The results indicate that severe glomerular sclerosis can develop without major qualitative cellular or molecular changes in the mesangium.

Research paper thumbnail of Glomerular endothelium in kidneys with congenital nephrotic syndrome of the Finnish type (NPHS1)

Nephrology Dialysis Transplantation, 2007

Background. The role of glomerular capillary endothelium in the pathophysiology of nephrotic kidn... more Background. The role of glomerular capillary endothelium in the pathophysiology of nephrotic kidney diseases is poorly known. We analysed the glomerular endothelial lesions in kidneys from patients with congenital nephrotic syndrome of the Finnish type (NPHS1). The disorder is caused by a genetic defect in a major podocyte slit diaphragm protein, nephrin. It manifests as nephrotic syndrome soon after birth and leads to glomerular sclerosis in early childhood. Methods. The glomerular capillary and endothelial cell lesions in NPHS1 kidneys nephrectomized at infancy were studied by electron and light microscopy, immunohistochemistry and cytokine antibody array. Results. Mesangial expansion and capillary obliteration were evident in practically all NPHS1 glomeruli. No thrombus formation was detected by fibrin staining. Electron microscopy revealed endothelial blebs (endotheliosis). The endothelial fenestration and the attachment of endothelial cells to the basement membrane were, however, quite normal. This fits to the abundant expression of a vascular endothelial growth factor (VEGF) and its transcription factor, hypoxia-inducible factor-1α (HIF-1α), in NPHS1 glomeruli. The proliferative activity of the intracapillary cells was modest and no apoptosis was detected. The expression of an endothelial adhesion molecule, intercellular adhesion molecule 1 (ICAM-1) and several chemokines was upregulated in NPHS1 glomeruli as compared to adult control kidneys. The recruitment of leukocytes carrying ligands for the major endothelial adhesion molecules, however, was modest in the mesangial area of NPHS1 glomeruli. Conclusions. The findings indicate that the glomerular endothelium is quite resistant to the nephrotic state in NPHS1 kidneys and underscores the importance of mesangial cells in the progression of glomerular sclerosis.

Research paper thumbnail of Glomerular sclerosis in kidneys with congenital nephrotic syndrome (NPHS1)

Kidney International, 2006

Congenital nephrotic syndrome of the Finnish type (NPHS1) is a rare genetic disease caused by mut... more Congenital nephrotic syndrome of the Finnish type (NPHS1) is a rare genetic disease caused by mutations in the NPHS1 gene encoding a major podocyte slit-diaphragm protein, nephrin. Patients with NPHS1 have severe nephrotic syndrome from birth and develop renal fibrosis in early childhood. In this work, we studied the development of glomerular sclerosis in kidneys removed from 4- to 44-month-old NPHS1 patients. The pathological lesions and expression of glomerular cell markers were studied in nephrectomized NPHS1 and control kidneys using light and electron microscopy and immunohistochemistry. An analysis of 1528 glomeruli from 20 patients revealed progressive mesangial sclerosis and capillary obliteration. Although few inflammatory cells were detected in the mesangial area, paraglomerular inflammation and fibrosis was common. The podocytes showed severe ultrastructural changes and hypertrophy with the upregulation of cyclins A and D1. Podocyte proliferation, however, was rare. Apoptosis was hardly detected and the expression of antiapoptotic B-cell lymphoma-2 and proapoptotic p53 were comparable to controls. Moderate amounts of podocytes were secreted into the urine of NPHS1 patients. Shrinkage of the glomerular tuft was common, whereas occlusion of tubular opening or protrusion of the glomerular tuft into subepithelial space or through the Bowman's capsule were not detected. The results indicate that, in NPHS1 kidneys, the damaged podocytes induce progressive mesangial expansion and capillary obliteration. Podocyte depletion, glomerular tuft adhesion, and misdirected filtration, however, seem to play a minor role in the nephron destruction.

Research paper thumbnail of Kidneys with heavy proteinuria show fibrosis, inflammation, and oxidative stress, but no tubular phenotypic change

Kidney International, 2005

Kidneys with heavy proteinuria show fibrosis, inflammation, and oxidative stress, but no tubular ... more Kidneys with heavy proteinuria show fibrosis, inflammation, and oxidative stress, but no tubular phenotypic change. Background. Sustained proteinuria is a major factor leading to kidney fibrosis and end-stage renal failure. Tubular epithelial cells are believed to play a crucial role in this process by producing mediators leading to fibrosis and inflammation. Congenital nephrotic syndrome of the Finnish type (NPHS1) is a genetic disease caused by mutations in a podocyte protein nephrin, which leads to constant heavy proteinuria from birth. In this work we studied the tubulointerstitial changes that occur in NPHS1 kidneys during infancy. Methods. The pathologic lesions and expression of profibrotic and proinflammatory factors in nephrectomized NPHS1 kidneys were studied by immunohistochemistry, Western blotting, and cytokine antibody array. Oxidative stress in kidneys was assessed by measurement of gluthatione redox state. Results. The results indicated that (1) severe tubulointerstitial lesions developed in NPHS1 kidneys during infancy; (2) tubular epithelial cells did not show transition into myofibroblasts as studied by the expression of vimentin, a-smooth muscle actin (a-SMA), collagen, and matrix metalloproteinases 2 and 9 (MMP-2 and-9); (3) the most abundant chemokines in NPHS1 tissue were neutrophil activating protein-2 (NAP-2), macrophage inhibiting factor (MIF), and monocyte chemoattractant protein-1 (MCP-1); (4) monocyte/macrophage cells expressing CD14 antigen were the major inflammatory cells invading the interstitium; (5) the arteries and arterioles showed intimal hypertrophy, but the microvasculature in NPHS1 kidneys remained quite normal; and (6) excessive oxidative stress was evident in NPHS1 kidneys. Conclusion. Heavy proteinuria in NPHS1 kidneys was associated with interstitial fibrosis, inflammation, and oxidative stress. The tubular epithelial cells, however, were resistant to proteinuria and did not show epithelial-mesenchymal transition. Sustained heavy proteinuria is believed to lead to progressive kidney damage [1]. High urinary protein con

Research paper thumbnail of Ab Interno Trabeculotomy

Research paper thumbnail of Pathophysiology of Congenital Nephrotic Syndrome of the Finnish type

Congenital nephrotic syndrome of the Finnish type (NPHS1) is an autosomal recessive disease which... more Congenital nephrotic syndrome of the Finnish type (NPHS1) is an autosomal recessive disease which is highly enriched in the Finnish population. It is caused by mutations in the NPHS1 gene encoding for nephrin, which is a major component of the glomerular filtration barrier in the kidney. Patients with NPHS1 have heavy proteinuria and nephrotic syndrome (NS) from birth and develop renal fibrosis in early childhood. Renal transplantation (TX) is the only curative treatment for NPHS1. These patients form the largest group of pediatric kidney transplant children in our country. The NPHS1 kidneys are removed in infancy and they serve as an excellent human material for studies of the pathophysiology of proteinuric kidney diseases. Sustained proteinuria is a major factor leading to end-stage renal failure and understanding this process is crucial for nephrology. In this study we investigated the glomerular and tubulointerstitial changes that occur in the NPHS1 kidneys during infancy as wel...

Research paper thumbnail of Kidneys with heavy proteinuria show fibrosis, inflammation, and oxidative stress, but no tubular phenotypic change

Kidney international, 2005

Sustained proteinuria is a major factor leading to kidney fibrosis and end-stage renal failure. T... more Sustained proteinuria is a major factor leading to kidney fibrosis and end-stage renal failure. Tubular epithelial cells are believed to play a crucial role in this process by producing mediators leading to fibrosis and inflammation. Congenital nephrotic syndrome of the Finnish type (NPHS1) is a genetic disease caused by mutations in a podocyte protein nephrin, which leads to constant heavy proteinuria from birth. In this work we studied the tubulointerstitial changes that occur in NPHS1 kidneys during infancy. The pathologic lesions and expression of profibrotic and proinflammatory factors in nephrectomized NPHS1 kidneys were studied by immunohistochemistry, Western blotting, and cytokine antibody array. Oxidative stress in kidneys was assessed by measurement of gluthatione redox state. The results indicated that (1) severe tubulointerstitial lesions developed in NPHS1 kidneys during infancy; (2) tubular epithelial cells did not show transition into myofibroblasts as studied by the...

Research paper thumbnail of Plasma Exchange and Retransplantation in Recurrent Nephrosis of Patients With Congenital Nephrotic Syndrome of the Finnish Type (NPHS1)

Transplantation, 2007

Recurrent nephrotic syndrome (NS) is a severe problem after renal transplantation in patients wit... more Recurrent nephrotic syndrome (NS) is a severe problem after renal transplantation in patients with congenital nephrotic syndrome of the Finnish type (NPHS1). The NPHS1 kidneys do not express nephrin, and antibodies against this major glomerular filter protein have been observed in NPHS1 children with recurrent NS. We evaluated here the use of plasma exchange (PE) therapy and kidney retransplantation in NPHS1 patients with recurrent NS and extended our studies on the pathogenesis of the recurrence. Clinical data on 65 NPHS1 patients who received 77 kidney transplants between the years 1986 and 2006 was collected. Serum anti-nephrin antibodies were assayed with an enzyme-linked immunosorbent assay method, and the kidney biopsy samples were evaluated by light microscopy and immunohistochemistry. Twenty-three episodes of recurrent NS occurred in 19 grafts of 13 NPSH1 patients homozygous for Fin-major mutation. Six retransplantations were performed to four NPHS1 patients, who lost their graft because of recurrent NS, and heavy proteinuria developed immediately in all cases. Although 73% of the patients had detectable serum anti-nephrin antibodies, the kidney biopsy findings were minimal. Introduction of PE alongside cyclophosphamide proved effective in the treatment of the proteinuric episodes (one graft loss out of nine). If remission was achieved, recurrent NS did not significantly deteriorate the long term graft function. The clinical and pathological data suggest that anti-nephrin antibodies effectively impair the glomerular function in kidney grafts of NPHS1 patients homozygous for Fin-major mutation. Plasma exchange is a useful adjunct to the treatment of the recurrent NS.

Research paper thumbnail of Tissue Expression of Nephrin in Human and Pig

Research paper thumbnail of Changes in glomerular mesangium in kidneys with congenital nephrotic syndrome of the Finnish type

Pediatric Nephrology, 2010

Congenital nephrotic syndrome of the Finnish type (NPHS1, CNF) is an autosomal recessive disease ... more Congenital nephrotic syndrome of the Finnish type (NPHS1, CNF) is an autosomal recessive disease caused by mutations in a major podocyte protein, nephrin. NPHS1 is associated with heavy proteinuria and the development of glomerular scarring. We studied the cellular and molecular changes affecting the glomerular mesangium in NPHS1 kidneys. Marked hyperplasia of mesangial cells (MC) was mainly responsible for the early mesangial expansion in NPHS1 glomeruli. The levels of the proliferation marker, mindbomb homolog 1 and the major MC mitogen, platelet-derived growth factor, and its receptors, however, were quite normal. Only a small number of cells were positive for CD68 (marker for phagocytic cells) and CD34 (marker for mesenchymal precursor cells) in the NPHS1 mesangium. MCs strongly expressed α-smooth muscle actin, indicating myofibloblast transformation. The expression levels of the profibrotic mediators osteopontin and transforming growth factor β were up-regulated in NPHS1 glomeruli by 3.2 and 1.6-fold, respectively, compared to the controls. The synthesis by MCs of the typical fibroblast products collagen I, fibronectin, and tenascin, however, was low, and the extracellular matrix increase was caused by the accumulation of a normal MC product, collagen IV. The results indicate that severe glomerular sclerosis can develop without major qualitative cellular or molecular changes in the mesangium.

Research paper thumbnail of Glomerular endothelium in kidneys with congenital nephrotic syndrome of the Finnish type (NPHS1)

Nephrology Dialysis Transplantation, 2007

Background. The role of glomerular capillary endothelium in the pathophysiology of nephrotic kidn... more Background. The role of glomerular capillary endothelium in the pathophysiology of nephrotic kidney diseases is poorly known. We analysed the glomerular endothelial lesions in kidneys from patients with congenital nephrotic syndrome of the Finnish type (NPHS1). The disorder is caused by a genetic defect in a major podocyte slit diaphragm protein, nephrin. It manifests as nephrotic syndrome soon after birth and leads to glomerular sclerosis in early childhood. Methods. The glomerular capillary and endothelial cell lesions in NPHS1 kidneys nephrectomized at infancy were studied by electron and light microscopy, immunohistochemistry and cytokine antibody array. Results. Mesangial expansion and capillary obliteration were evident in practically all NPHS1 glomeruli. No thrombus formation was detected by fibrin staining. Electron microscopy revealed endothelial blebs (endotheliosis). The endothelial fenestration and the attachment of endothelial cells to the basement membrane were, however, quite normal. This fits to the abundant expression of a vascular endothelial growth factor (VEGF) and its transcription factor, hypoxia-inducible factor-1α (HIF-1α), in NPHS1 glomeruli. The proliferative activity of the intracapillary cells was modest and no apoptosis was detected. The expression of an endothelial adhesion molecule, intercellular adhesion molecule 1 (ICAM-1) and several chemokines was upregulated in NPHS1 glomeruli as compared to adult control kidneys. The recruitment of leukocytes carrying ligands for the major endothelial adhesion molecules, however, was modest in the mesangial area of NPHS1 glomeruli. Conclusions. The findings indicate that the glomerular endothelium is quite resistant to the nephrotic state in NPHS1 kidneys and underscores the importance of mesangial cells in the progression of glomerular sclerosis.

Research paper thumbnail of Glomerular sclerosis in kidneys with congenital nephrotic syndrome (NPHS1)

Kidney International, 2006

Congenital nephrotic syndrome of the Finnish type (NPHS1) is a rare genetic disease caused by mut... more Congenital nephrotic syndrome of the Finnish type (NPHS1) is a rare genetic disease caused by mutations in the NPHS1 gene encoding a major podocyte slit-diaphragm protein, nephrin. Patients with NPHS1 have severe nephrotic syndrome from birth and develop renal fibrosis in early childhood. In this work, we studied the development of glomerular sclerosis in kidneys removed from 4- to 44-month-old NPHS1 patients. The pathological lesions and expression of glomerular cell markers were studied in nephrectomized NPHS1 and control kidneys using light and electron microscopy and immunohistochemistry. An analysis of 1528 glomeruli from 20 patients revealed progressive mesangial sclerosis and capillary obliteration. Although few inflammatory cells were detected in the mesangial area, paraglomerular inflammation and fibrosis was common. The podocytes showed severe ultrastructural changes and hypertrophy with the upregulation of cyclins A and D1. Podocyte proliferation, however, was rare. Apoptosis was hardly detected and the expression of antiapoptotic B-cell lymphoma-2 and proapoptotic p53 were comparable to controls. Moderate amounts of podocytes were secreted into the urine of NPHS1 patients. Shrinkage of the glomerular tuft was common, whereas occlusion of tubular opening or protrusion of the glomerular tuft into subepithelial space or through the Bowman's capsule were not detected. The results indicate that, in NPHS1 kidneys, the damaged podocytes induce progressive mesangial expansion and capillary obliteration. Podocyte depletion, glomerular tuft adhesion, and misdirected filtration, however, seem to play a minor role in the nephron destruction.

Research paper thumbnail of Kidneys with heavy proteinuria show fibrosis, inflammation, and oxidative stress, but no tubular phenotypic change

Kidney International, 2005

Kidneys with heavy proteinuria show fibrosis, inflammation, and oxidative stress, but no tubular ... more Kidneys with heavy proteinuria show fibrosis, inflammation, and oxidative stress, but no tubular phenotypic change. Background. Sustained proteinuria is a major factor leading to kidney fibrosis and end-stage renal failure. Tubular epithelial cells are believed to play a crucial role in this process by producing mediators leading to fibrosis and inflammation. Congenital nephrotic syndrome of the Finnish type (NPHS1) is a genetic disease caused by mutations in a podocyte protein nephrin, which leads to constant heavy proteinuria from birth. In this work we studied the tubulointerstitial changes that occur in NPHS1 kidneys during infancy. Methods. The pathologic lesions and expression of profibrotic and proinflammatory factors in nephrectomized NPHS1 kidneys were studied by immunohistochemistry, Western blotting, and cytokine antibody array. Oxidative stress in kidneys was assessed by measurement of gluthatione redox state. Results. The results indicated that (1) severe tubulointerstitial lesions developed in NPHS1 kidneys during infancy; (2) tubular epithelial cells did not show transition into myofibroblasts as studied by the expression of vimentin, a-smooth muscle actin (a-SMA), collagen, and matrix metalloproteinases 2 and 9 (MMP-2 and-9); (3) the most abundant chemokines in NPHS1 tissue were neutrophil activating protein-2 (NAP-2), macrophage inhibiting factor (MIF), and monocyte chemoattractant protein-1 (MCP-1); (4) monocyte/macrophage cells expressing CD14 antigen were the major inflammatory cells invading the interstitium; (5) the arteries and arterioles showed intimal hypertrophy, but the microvasculature in NPHS1 kidneys remained quite normal; and (6) excessive oxidative stress was evident in NPHS1 kidneys. Conclusion. Heavy proteinuria in NPHS1 kidneys was associated with interstitial fibrosis, inflammation, and oxidative stress. The tubular epithelial cells, however, were resistant to proteinuria and did not show epithelial-mesenchymal transition. Sustained heavy proteinuria is believed to lead to progressive kidney damage [1]. High urinary protein con