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Case Report of a Familial Oxalosis
Case Reports Institut fur Pathologie der UniversiHit Basel, Laboratorium fUr Elektronenmikroskopie der Universitat Basel und Medizinische Klinik des Kantonsspitals Luzern
Case Report of a Familial Oxalosis (Ultrastructural Study on the Pathogenesis of Kidney Changes) U. N. RIEDE, H. U. ZOLLINGER, M. and W. VILLINGER
J. MIHATSCH, A. COLOMBI,
With 3 Figures' Received December 5, 1972 . Accepted December 15, 1972
Summary A case of familial oxalosis is reported in which altogether seven family members suffer from chronic nephropathy. The histological and electron microscopic investigation showed a contracted kidney. In the highly thickened tubular basement membrane and the glomerular capsule (however, not intracytoplasmatically) deposits of calcium oxalates are found. The thickening of the basement membrane is discussed as the cause of the contracted kidney. Another factor playing a part could be the interstitial crystal deposits. although, in the case under discussion, they are missing in the renal cortex.
Introduction Oxalosis is based on an enzyme defect which, on the whole, is still obscure. However, it is known that the transformation of glycine into oxalic acid is strongly increased. The inborn error of metabolism leads to a contracted kidney which can render diagnosis very difficult for clinicians (Ref. BURl, 1962). At autopsy, deposits of calcium oxalate crystals whewellit (ZOLLINGER and ROSENMUND, 1952) can be found above all in the interstitium of the medullary cortical zone. If massive oxalate overload is produced in experiments, morphologically seen, the intratubular and in part intraepithelial crystal deposits are most striking. Besides, the strongly thickened basement membranes attract attention (LARGIADER, 1960; GALL, 1964; STAMPFEL, 1964; ZOLLINGER, 1966; DAVID and UERLINGS, 1968). The following findings at biopsy referring to a kidney not completely destroyed
Familial Oxalosis . Fig. I. Pedigree of a family with oxalosis. The 58-year-old woman (r) suffers from oxalosis. Her father (2), three of her brothers (3,4, 5), as well as one of her sisters (6) suffered from a chronic nephropathy. Because of the oxalosis the two kidneys of her son (7) had to be removed.
9I
__---:---0
I
2
+
7
by oxalosis show that intramembranous calcium oxalate deposits (rejected by GALL, 1964) playa part in the pathogenesis of the basement membrane changes.
Materials and Methods Fixation of the biopsy specimen in buffered formaline (4 %) for light microscopy and in phosphate-buffered glutardialdehyde (2.5 %) for electron microscopy. The ultrathin sections were mounted on formvar-coated grids and stained with uranyl acetate and lead citrate. To avoid the elution of the minerals from the tissue, neutralized water (r % of NaOH) was used for cutting, and the sections were removed immediately from the water surface. Part of the sections was examined unstained. The ultrastructural studies were carried out with a Zeiss electron microscope EM 9A and a Siemens Elmiskop r A.
Clinical data C. F. (Pkt 148/72; EN 8979/72) 58-year-old housewife, having suffered for 5 years from a chronic nephropathy which, in 1971, led to a terminal uremla. The case history of the family shows that the father died at the age of 46 due to nephropathy, one brother at the age 3I, one at the age of 34 and one of tender age. One sister receives treatment for nephropathy. * Because of chronic renal insufficiency, one of her 5 sons received a successful kidney transplantation at the age of 3I (Fig. I).
* Addendum: It was learnt after submission of the manuscript that another brother of our patient is undergoing hemodialysis for chronic uremia.
92 . U. N. RIED E et al.
Fig. 2. Kidney biopsy of the son (6316/68): Crystals of oxalosis acid (star) in the interstitium between atrophic tubules (T) of thickened basement membrane (~). H. E.-staining; X 650.
As far as the personal case history is concerned, only a proteinuria at the age 46 following recurrent angina is noteworthy. At the time of her admission to hospital in 1971 the 57-year-old patient suffered from chronic renal insufficiency, accompanied with a reduction of creatinine clearance to 6 ml/min. The uremia was characterized by an increase of the serum urea and creatinine to 270 and 9.9 mg% respectively, hypocalcemia 6.4mg%, hyperphasphatemia 8.6 mg% and acidosis (blood pH 7.31). At the same time there were an anemia (Hb 8.5 g%) and a hypertension (220/110 mm Hg) with hypertensive eye ground changes. Urine samples showed proteinuria (1.5 g/die), leucocyturia and bacteriuria. At the site of the kidneys neither the kidneys nor dense shadows could be delimited by X-ray. Due to mild perception deafness and the family history of the patient the clinical tentative diagnosis of an Alport syndrome was made. After temporary hemodialysis, in May 1972 the kidneys of the patient were removed, and transplantation was performed successfully.
Histologicial Findings At light microscopy, the severely changed renal parenchyma consists of a reduced cortex and a thin part of medullary tissue. About 25 % of all glomeruli are completely obliterated, the rest of them are collapsed. Tubules
Familial Oxalosis .
93
show atrophy and are often surrounded by a highly thickened basement membrane. Only single hypertrophic tubules show delicate basement membranes. 'The interstitium is focally widened by fibrotic tissue, which is dispersed by numerous lymphocytes and single macrophages. In the interstitium and the tubular lumina single big clusters of crystals are striking. Intraepithelial crystal deposits are missing. Besides, there is a slight arteriosclerosis as well as an adaptive fibrosis of arterial intima. 'The fibrous capsule is strongly thickened. 'The findings established with regard to the son of the patient in 1968 were similar. However, signs of destruction were much more marked. At electron microscopy, enormously thickened, layered basement membranes containing collagen fibres can be observed (Fig. 3). Without exception, the basement membranes are dispersed by hole-like defects of different size, in which electron-dense larger and smaller crystal aggregates occur quite often. 'The unstained section of the basement membrane is covered with very small electron-dense dots. 'The Bowman's capsule shows the same changes. 'The small crystal deposits are arranged in clusters; the larger ones show a multilayer concentric array with a translucent center, a so-called nidus. Despite very careful preparation and investigation there was nothing indicating intracytoplasmatic crystal deposits in the tubular epithelial cells, with the exception of those occurring in interstitial phagocytes. 'The glomeruli consist of collapsed loops whose lumina are partly obliterated. 'The glomerular basement membrane is ondulated and thickened. It shows the same ultrastructural changes as the tubular basement membrane.
Discussion 'The findings of experimental investigations leave no doubt about the fact that the first oxalate deposits can be observed in the lumina and the epithelial cells of the tubules respectively (ZOLLINGER and ROSENMUND, 1952). What has been unknown so far are deposits of calcium oxalate in the tubular basement membranes and the Bowman's capsule of the glomeruli, where light microscopic investigations have shown crystal deposits in very few cases. As is known in the case of mineralizing connective tissue, the nucleation of mineral crystals seems to be linked with mucopolysaccharid-containing structures (BONUCCI, 1971). In such a process, the very small electron-dense dots in the basement membranes possibly constitute amorphous calcium-containing precipitations which can aggregate into larger mineral deposits. However, for the most part, these deposits seem to be removed again from the tissue during preparation, so that hole-
Fig. 3. Kidney biopsy of the mother. The basement membrane of the tubules considerably thickened and perforated (arrow). Single phagocytes (P) in the interstitium, often recognizable only as cell debris, contain crystal deposits. The single crystal deposits are in clusters (D) or concentric arrays with a central nidus (C, E). C X 45,500) = section of A ( x 13,500), E ( x 40,000) = section of B (x 13,500), D ( x 75,000), all sections unstained.
Familial Oxalosis .
95
like defects remain in the basement membrane. The large crystal deposits of concentric array morphologically correspond to oxalate crystals (GALLE, 1964; MCCOMBS and GERSHOFF, 1972) and are not removed from the tissue due to the electron microscopic preparation. The question arises of why the tubular basement membrane is so considerably changed in the case of oxalosis. A possible reason might be a hypoxic lesion of the parenchyma, followed by a de-differentiation of the epithelial cells of the tubules, such as can be observed after chronic administration of sodium oxalate (DAVID and UERLINGS, 1968) and in the case of a contracted kidney due to chronic aterial obstruction (ZOLLINGER et aI., 1972). This thesis is advocated by the fact that renal vessels are also demaged by an oxalosis (ZOLLINGER and ROSENMAND, 1952). This leads to a collapse of the glomerular loops due to impeded blood supply and not, as was suggested formerly, to glomerulonephrosis or membranous glomerulonephritis (DAVID and UERLINGS, 1968). The de-differentiated epithelial cells of the tubules surround themselves with a thick basement membrane. Besides, one may assume that the hydroxyl groups of the oxalate crystals from hydrogen bonding with the lysosomal membranes and thus generate a lysosomal rupture, such as could been shown in the case of urate and silicate crystals (WEISSMANN, 1971). Accordingly, in the case of oxalosis the destruction process would also start from intratubular phagocytes loaded with oxalate which, by means of the release of proteases, damage the epithelial ceJls of the tubules and the basement membranes. In a late stage the debris could act as calciphilic agent in the way described in the case of chronic administration of oxalate (GALL, 1964; DAVID and UERLINGS, 1968). Correspondingly, the tubular basement membrane changes seem to play an important part in the pathogenesis of the renal oxalosis.
Z usammenfassung Es wird tiber einen Fall einer familiaren Oxalose berichtet, bei dem insgesamt 7 Familienmitglieder an einer chronis chen Nephropathie leiden. Die histologische und elektronenmikroskopische Untersuchung ergab cine Oxalat-Schrumpfniere. In der hochgradig verdickten tubular en Basalmembran und der Glomeruluskapsel (jedoch nicht intrazytoplasmatisch) finden sich Einlagerungen von Calciumoxalaten. Die Basalmembranverdickung wird als Ursache der Schrumpfnierenbildung besprochen. Dabei kbnnen ursachlich auch die interstitiellen Kristallablagerungen mitwirken, obschon sie im besprochenen Fall im Bereiche der Nierenrinde vbllig fehlen.
References BONUCC1, E.: Clin. Orthop. 78, 108 (1971) BURl,]. F.: Helv. paediat. Acta Suppl. II, 3-126 (1962) DAVID, H. und UERLINGS, L.: Beitr. path. Anat. IJ6, 284 (1968)
96 . U.
N. RIEDE et al.
GALL, P.: Nephron I, I58 (I964) LARGIADER, F.: Virchows Arch. path. Anat. 333, 390 (1960) MCCOMBS, H. L. and GERSHOFF, S. N.: Lab. Invest. 26, 515 (1972) WEISSMANN, G.: Hospital Practice 6,43 (1971) ZOLLINGER, H. U. und ROSENMUND, H.: Schweiz. med. Wschr. 82, 1261 (1952) ZOLLINGER, H. Niere und ableitende Harnwege. In: Spezielle Pathologie, Hrsg. W. DOERR und E. UEHLINGER. Springer-Verlag, Berlin-Heidelberg-New York (1966) ZOLLINGER, H. U., TORHORST, J., VON TOENGES, V., GEE RING, M ., RIEDE, U. N. und ROHR, H. P.: Beitr. Path. 148, 15 (1973)
u.:
Dr. URS N. RIEDE, Institut fUr Pathologie der Universitat, SchonbeinstraBe 40, CH-4056 Basel
Case Report of a Familial Oxalosis (Ultrastructural Study on the Pathogenesis of Kidney Changes) U. N. RIEDE, H. U. ZOLLINGER, M. and W. VILLINGER
J. MIHATSCH, A. COLOMBI,
With 3 Figures' Received December 5, 1972 . Accepted December 15, 1972
Summary A case of familial oxalosis is reported in which altogether seven family members suffer from chronic nephropathy. The histological and electron microscopic investigation showed a contracted kidney. In the highly thickened tubular basement membrane and the glomerular capsule (however, not intracytoplasmatically) deposits of calcium oxalates are found. The thickening of the basement membrane is discussed as the cause of the contracted kidney. Another factor playing a part could be the interstitial crystal deposits. although, in the case under discussion, they are missing in the renal cortex.
Introduction Oxalosis is based on an enzyme defect which, on the whole, is still obscure. However, it is known that the transformation of glycine into oxalic acid is strongly increased. The inborn error of metabolism leads to a contracted kidney which can render diagnosis very difficult for clinicians (Ref. BURl, 1962). At autopsy, deposits of calcium oxalate crystals whewellit (ZOLLINGER and ROSENMUND, 1952) can be found above all in the interstitium of the medullary cortical zone. If massive oxalate overload is produced in experiments, morphologically seen, the intratubular and in part intraepithelial crystal deposits are most striking. Besides, the strongly thickened basement membranes attract attention (LARGIADER, 1960; GALL, 1964; STAMPFEL, 1964; ZOLLINGER, 1966; DAVID and UERLINGS, 1968). The following findings at biopsy referring to a kidney not completely destroyed
Familial Oxalosis . Fig. I. Pedigree of a family with oxalosis. The 58-year-old woman (r) suffers from oxalosis. Her father (2), three of her brothers (3,4, 5), as well as one of her sisters (6) suffered from a chronic nephropathy. Because of the oxalosis the two kidneys of her son (7) had to be removed.
9I
__---:---0
I
2
+
7
by oxalosis show that intramembranous calcium oxalate deposits (rejected by GALL, 1964) playa part in the pathogenesis of the basement membrane changes.
Materials and Methods Fixation of the biopsy specimen in buffered formaline (4 %) for light microscopy and in phosphate-buffered glutardialdehyde (2.5 %) for electron microscopy. The ultrathin sections were mounted on formvar-coated grids and stained with uranyl acetate and lead citrate. To avoid the elution of the minerals from the tissue, neutralized water (r % of NaOH) was used for cutting, and the sections were removed immediately from the water surface. Part of the sections was examined unstained. The ultrastructural studies were carried out with a Zeiss electron microscope EM 9A and a Siemens Elmiskop r A.
Clinical data C. F. (Pkt 148/72; EN 8979/72) 58-year-old housewife, having suffered for 5 years from a chronic nephropathy which, in 1971, led to a terminal uremla. The case history of the family shows that the father died at the age of 46 due to nephropathy, one brother at the age 3I, one at the age of 34 and one of tender age. One sister receives treatment for nephropathy. * Because of chronic renal insufficiency, one of her 5 sons received a successful kidney transplantation at the age of 3I (Fig. I).
* Addendum: It was learnt after submission of the manuscript that another brother of our patient is undergoing hemodialysis for chronic uremia.
92 . U. N. RIED E et al.
Fig. 2. Kidney biopsy of the son (6316/68): Crystals of oxalosis acid (star) in the interstitium between atrophic tubules (T) of thickened basement membrane (~). H. E.-staining; X 650.
As far as the personal case history is concerned, only a proteinuria at the age 46 following recurrent angina is noteworthy. At the time of her admission to hospital in 1971 the 57-year-old patient suffered from chronic renal insufficiency, accompanied with a reduction of creatinine clearance to 6 ml/min. The uremia was characterized by an increase of the serum urea and creatinine to 270 and 9.9 mg% respectively, hypocalcemia 6.4mg%, hyperphasphatemia 8.6 mg% and acidosis (blood pH 7.31). At the same time there were an anemia (Hb 8.5 g%) and a hypertension (220/110 mm Hg) with hypertensive eye ground changes. Urine samples showed proteinuria (1.5 g/die), leucocyturia and bacteriuria. At the site of the kidneys neither the kidneys nor dense shadows could be delimited by X-ray. Due to mild perception deafness and the family history of the patient the clinical tentative diagnosis of an Alport syndrome was made. After temporary hemodialysis, in May 1972 the kidneys of the patient were removed, and transplantation was performed successfully.
Histologicial Findings At light microscopy, the severely changed renal parenchyma consists of a reduced cortex and a thin part of medullary tissue. About 25 % of all glomeruli are completely obliterated, the rest of them are collapsed. Tubules
Familial Oxalosis .
93
show atrophy and are often surrounded by a highly thickened basement membrane. Only single hypertrophic tubules show delicate basement membranes. 'The interstitium is focally widened by fibrotic tissue, which is dispersed by numerous lymphocytes and single macrophages. In the interstitium and the tubular lumina single big clusters of crystals are striking. Intraepithelial crystal deposits are missing. Besides, there is a slight arteriosclerosis as well as an adaptive fibrosis of arterial intima. 'The fibrous capsule is strongly thickened. 'The findings established with regard to the son of the patient in 1968 were similar. However, signs of destruction were much more marked. At electron microscopy, enormously thickened, layered basement membranes containing collagen fibres can be observed (Fig. 3). Without exception, the basement membranes are dispersed by hole-like defects of different size, in which electron-dense larger and smaller crystal aggregates occur quite often. 'The unstained section of the basement membrane is covered with very small electron-dense dots. 'The Bowman's capsule shows the same changes. 'The small crystal deposits are arranged in clusters; the larger ones show a multilayer concentric array with a translucent center, a so-called nidus. Despite very careful preparation and investigation there was nothing indicating intracytoplasmatic crystal deposits in the tubular epithelial cells, with the exception of those occurring in interstitial phagocytes. 'The glomeruli consist of collapsed loops whose lumina are partly obliterated. 'The glomerular basement membrane is ondulated and thickened. It shows the same ultrastructural changes as the tubular basement membrane.
Discussion 'The findings of experimental investigations leave no doubt about the fact that the first oxalate deposits can be observed in the lumina and the epithelial cells of the tubules respectively (ZOLLINGER and ROSENMUND, 1952). What has been unknown so far are deposits of calcium oxalate in the tubular basement membranes and the Bowman's capsule of the glomeruli, where light microscopic investigations have shown crystal deposits in very few cases. As is known in the case of mineralizing connective tissue, the nucleation of mineral crystals seems to be linked with mucopolysaccharid-containing structures (BONUCCI, 1971). In such a process, the very small electron-dense dots in the basement membranes possibly constitute amorphous calcium-containing precipitations which can aggregate into larger mineral deposits. However, for the most part, these deposits seem to be removed again from the tissue during preparation, so that hole-
Fig. 3. Kidney biopsy of the mother. The basement membrane of the tubules considerably thickened and perforated (arrow). Single phagocytes (P) in the interstitium, often recognizable only as cell debris, contain crystal deposits. The single crystal deposits are in clusters (D) or concentric arrays with a central nidus (C, E). C X 45,500) = section of A ( x 13,500), E ( x 40,000) = section of B (x 13,500), D ( x 75,000), all sections unstained.
Familial Oxalosis .
95
like defects remain in the basement membrane. The large crystal deposits of concentric array morphologically correspond to oxalate crystals (GALLE, 1964; MCCOMBS and GERSHOFF, 1972) and are not removed from the tissue due to the electron microscopic preparation. The question arises of why the tubular basement membrane is so considerably changed in the case of oxalosis. A possible reason might be a hypoxic lesion of the parenchyma, followed by a de-differentiation of the epithelial cells of the tubules, such as can be observed after chronic administration of sodium oxalate (DAVID and UERLINGS, 1968) and in the case of a contracted kidney due to chronic aterial obstruction (ZOLLINGER et aI., 1972). This thesis is advocated by the fact that renal vessels are also demaged by an oxalosis (ZOLLINGER and ROSENMAND, 1952). This leads to a collapse of the glomerular loops due to impeded blood supply and not, as was suggested formerly, to glomerulonephrosis or membranous glomerulonephritis (DAVID and UERLINGS, 1968). The de-differentiated epithelial cells of the tubules surround themselves with a thick basement membrane. Besides, one may assume that the hydroxyl groups of the oxalate crystals from hydrogen bonding with the lysosomal membranes and thus generate a lysosomal rupture, such as could been shown in the case of urate and silicate crystals (WEISSMANN, 1971). Accordingly, in the case of oxalosis the destruction process would also start from intratubular phagocytes loaded with oxalate which, by means of the release of proteases, damage the epithelial ceJls of the tubules and the basement membranes. In a late stage the debris could act as calciphilic agent in the way described in the case of chronic administration of oxalate (GALL, 1964; DAVID and UERLINGS, 1968). Correspondingly, the tubular basement membrane changes seem to play an important part in the pathogenesis of the renal oxalosis.
Z usammenfassung Es wird tiber einen Fall einer familiaren Oxalose berichtet, bei dem insgesamt 7 Familienmitglieder an einer chronis chen Nephropathie leiden. Die histologische und elektronenmikroskopische Untersuchung ergab cine Oxalat-Schrumpfniere. In der hochgradig verdickten tubular en Basalmembran und der Glomeruluskapsel (jedoch nicht intrazytoplasmatisch) finden sich Einlagerungen von Calciumoxalaten. Die Basalmembranverdickung wird als Ursache der Schrumpfnierenbildung besprochen. Dabei kbnnen ursachlich auch die interstitiellen Kristallablagerungen mitwirken, obschon sie im besprochenen Fall im Bereiche der Nierenrinde vbllig fehlen.
References BONUCC1, E.: Clin. Orthop. 78, 108 (1971) BURl,]. F.: Helv. paediat. Acta Suppl. II, 3-126 (1962) DAVID, H. und UERLINGS, L.: Beitr. path. Anat. IJ6, 284 (1968)
96 . U.
N. RIEDE et al.
GALL, P.: Nephron I, I58 (I964) LARGIADER, F.: Virchows Arch. path. Anat. 333, 390 (1960) MCCOMBS, H. L. and GERSHOFF, S. N.: Lab. Invest. 26, 515 (1972) WEISSMANN, G.: Hospital Practice 6,43 (1971) ZOLLINGER, H. U. und ROSENMUND, H.: Schweiz. med. Wschr. 82, 1261 (1952) ZOLLINGER, H. Niere und ableitende Harnwege. In: Spezielle Pathologie, Hrsg. W. DOERR und E. UEHLINGER. Springer-Verlag, Berlin-Heidelberg-New York (1966) ZOLLINGER, H. U., TORHORST, J., VON TOENGES, V., GEE RING, M ., RIEDE, U. N. und ROHR, H. P.: Beitr. Path. 148, 15 (1973)
u.:
Dr. URS N. RIEDE, Institut fUr Pathologie der Universitat, SchonbeinstraBe 40, CH-4056 Basel