[Hematologic chest pain]

HISTORY AND ADMISSION FINDINGS

We report the case of a 59-year-old male who was admitted to hospital with acute chest pain. Coronary heart disease was known from the medical history. The patient reported recurrent ostealgia and susceptibility for infection during the last months before admission.

INVESTIGATIONS

A 75% stenosis of the circumflex branch was treated with a drug eluting stent. Platelet aggregation was inhibited with acetylsalicylic acid and clopidogrel. Due to persisting ostealgia and inflammatory state, spondylodiscitis was excluded in MRI. However, platelets remained low after successful treatment of the infection.

DIAGNOSIS, TREATMENT AND COURSE

Bone marrow biopsy revealed an acute lymphoblastic leukemia with positive detection of the Philadelphia chromosome. After chemotherapy and allogenic hematopoietic cell transplantation the patient remains in remission of his acute lymphoblastic leukemia.

CONCLUSIONS

Especially in patients with documented history of coronary heart disease, the differential diagnosis of chest pain can be challenging. In this case, the chest pain was based on a subacute coronary ischemia as well as on proliferation of the acute lymphoblastic leukemia. The management of dual oral anticoagulation was performed with higher transfusion limits for thrombocytes and continuous application of thrombocyte aggregation inhibitors.

[Two autopsy cases with systemic amyloidosis--case 11/2010]

HISTORY AND ADMISSION FINDINGS

A 37-year old patient was admitted with upper abdominal pain, vomiting and diarrhea. A 38-year-old patient was admitted for liver failure.

INVESTIGATIONS

Case 1 was diagnosed with an AL amyloidosis due to deposition of the immunoglobulin light chain kappa in all tissues analyzed. In the bone marrow plasma cells were increased to 20-30%. Case 2 suffered from AA amlyoidosis secondary to familial mediterranean fever and underwent dialysis treatment for years. He was positive for hepatitis B and C.

DIAGNOSIS, TREATMENT AND COURSE

Patient 1 developed refractory nephrotic syndrome and low blood pressure. During hemodialysis circulatory failure occured and she died during resuscitation. In patient 2 a flare of chronic hepatitis B was found and treated with antiviral therapy. He was referred to ICU for rectal bleeding and developed pulmonary arrest. After resuscitation he died because of lactate acidosis and refractory circulatory failure. Both cases were subjected to autopsy.

CONCLUSIONS

The vast majority (90%) of amyloidoses are due to acquired AA or AL amyloidosis. Prognosis remains poor, in particular when cardiac and vascular involvement occurs.

Neonatal Marfan syndrome: unusually large deletion of exons 24-26 of FBN1 associated with poor prognosis

Neonatal Marfan syndrome is a very rare subset of the classical Marfan syndrome with pronounced phenotypic expression especially of the cardiovascular manifestations. It is associated with a very poor prognosis, with approximately 50% of affected infants dying from cardiac failure during the first year of life. We present a newborn with the classical phenotype of neonatal Marfan syndrome. Within few hours after birth, progressive and refractory heart failure developed. Postmortal molecular study revealed an unusually large deletion of exons 24-26 within the so-called neonatal region of the gene FBN1, which might explain the unfavourable course of the disease in our patient.

Acute twin-twin transfusion syndrome: a case report

BACKGROUND

Clinically relevant acute twin-twin transfusion syndrome (TTTS) is a rare and poorly defined placental pathology because the definitions of chronic TTTS do not apply. Antepartum cases of acute TTTS are infrequently described in the literature despite the presence of vascular anastomoses in most monochorionic placentas.

CASE

A case of otherwise-unexplained acute fetal distress in a monochorionic twin gestation led to an emnergeincy cesarean section and was found to be due to acute heiodynamiic inbalance secondary to activation of a large placental venovenous anastomosis.

CONCLUSION

Obstetricians should be aware of this potential cause of sudden fetal distress in monochorionic twin gestations.

Multiple thromboembolic events in fetofetal transfusion syndrome in triplets contributing to the understanding of pathogenesis of hydranencephaly in combination with polymicrogyria

Over the last 180 years, several theories concerning the origin of hydranencephaly have been proposed with an emphasis on infectious, aplastic, and vascular etiologies. In this report, we present a case of triplets with fetofetal transfusion syndrome of which 2 fetuses (1 and 2) developed almost similar hydranencephaly, whereas the third exhibited the features of a fetus papyraceus (3). In the monochorial triamniotic placenta, multiple arteriovenous anastomoses were detected, representing a probable route for the transmission of thrombi originating from fetus 3 causing visceral lesions in fetus 2. Hydranencephaly was histologically characterized by necrosis, macrophage invasion, and endothelial proliferation. In addition, polymicrogyria was seen in fetuses 1 and 2. The combination of multiple visceral thromboembolic events and the death of fetus 3 approximately in the 11th week of gestation suggested a vascular thrombotic pathogenesis of hydranencephaly. Polymicrogyria can be considered as postmigratory laminar necrosis. Our findings contribute to the pathogenetic understanding of combined hydranencephaly and polymicrogyria.

Hemodynamic changes with phenotype reversal during pregnancy in twin-twin transfusion syndrome

OBJECTIVES

We report an atypical case of twin-twin transfusion syndrome (TTTS) in monochorionic-diamniotic twins with arterio-arterial anastomoses in which the former donor became the recipient during pregnancy.

METHODS

Serial sonographic monitoring was performed.

RESULTS

There was a phenotype reversal in TTTS concerning growth and amniotic fluid ending at 27 weeks, with the dominance of the former smaller donor. Doppler sonography changed from absent enddiastolic flow of the donor to normal values in both twins. The new recipient showed transient ascites, the now smaller actual donor (former recipient) developed progressive cardiomegaly, hypertrophy of the myocardium and mitral and tricuspid insufficiency at 29 weeks. Doppler sonography in the new donor deteriorated to highly pathologic flow in the venous system, leading to cesarean section. The donor fetus died 12 h after delivery because of myocardial decompensation. The recipient did very well and was discharged 8 weeks later from the neonatology unit.

CONCLUSION

This atypical course shows the importance of serial sonographic monitoring in pregnancies with TTTS.

Hydrops fetalis in three male fetuses of a female with incontinentia pigmenti

OBJECTIVES

Careful investigation of hydrops fetalis (HF) is important with regard to genetic counselling and prenatal diagnosis. HF is known to be associated with various genetic disorders. To date there has been only one report of a male fetus in whom incontinentia pigmenti (IP) was associated with generalised oedema. We describe a family who had a girl with clinical signs of IP after three consecutive miscarriages of three male fetuses due to HF.

RESULTS

Molecular genetic analysis showed a mutation in the NEMO/IKK(chi) gene in the girl and the mother, which confirmed the diagnosis of IP in both cases. In the two fetuses that could be investigated, inheritance of the affected maternal X chromosome could be demonstrated retrospectively by linkage analysis.

CONCLUSION

The present findings suggest that IP might be an X-linked dominant trait causing HF in male fetuses. In cases of recurrent HF in male fetuses, minimal signs of IP in the maternal line should therefore be carefully investigated in order to be able to perform mutational analysis and to offer appropriate genetic counselling.

Chorioamnionitis and inflammation of the fetal lung

OBJECTIVE

Fetal intrauterine exposure to proinflammatory cytokines present in amniotic fluid has been associated with an increased risk of chronic lung disease. However, the impact of histologically confirmed chorioamnionitis on the fetal lung has not yet been elucidated. We therefore investigated cellular immune response, cell proliferation, and messenger ribonucleic acid cytokine expression in fetal pulmonary tissue in the presence or absence of chorioamnionitis.

STUDY DESIGN

Serial tissue sections were obtained from 27 fetuses at the time of autopsy. Three mothers had received antibiotics for treatment of clinical chorioamnionitis before abortion. Immunohistochemical staining of lung tissue comprised lineage-specific markers (CD68(+), CD3(+), neutrophil elastase). Positively stained cells were evaluated with a graticule, and cells per 5 mm(2) were counted. We undertook in situ hybridization to assess the expression of interleukin 8 messenger ribonucleic acid in the fetal lung.

RESULTS

Seven of 27 fetuses had been exposed to chorioamnionitis. Fetal lungs showed a marked increase in the presence of histologically confirmed chorioamnionitis in densities of CD68(+) macrophages (68 vs 9.5 cells/5 mm(2), median group vs control group; P =.02) and lymphocytes (7 vs 2.5 cells/5 mm(2), median chorioamnionitis vs control group; P =.05) and a similar but lesser increase in neutrophil density (16 vs 4 cells/5 mm(2); difference not significant). Interleukin 8 messenger ribonucleic acid was expressed in 4 of 6 tissue specimens investigated in the chorioamnionitis group. Exposure to chorioamnionitis resulted in interleukin 8 messenger ribonucleic acid expression 7-fold higher than in the nonchorioamnionitis group; however, this difference did not achieve statistical significance.

CONCLUSION

Chorioamnionitis was associated with an intrauterine inflammatory response of the fetal lung characterized by a severe infiltration of macrophages, neutrophils, and lymphocytes and also by an increased expression of interleukin 8 messenger ribonucleic acid.

Molecular and cytogenetic [correction of cytogenate] analysis of an X/autosomal translocation: 45,X,dic(X;17)(p22.2;p13)

We present an unusual case of monosomy 17p13-pter and monosomy Xp22.2-pter due to a dicentric translocation chromosome X/17 in a female newborn with severe anomalies. The karyotype was identified as 45,X,dic(X;17)(p22.2;p13) by high resolution GTG banding in lymphocytes. R banding showed the translocational X-chromosome to be late replicating, and there was no spreading of X-inactivation onto the autosomal segment. Furthermore, it could be demonstrated by C banding that the X-centromere in the translocation chromosome was inactive. The results of short tandem repeat (STR) typing confirmed the partial monosomy X and 17 as well as the paternal origin of the two chromosomes X and 17 which were involved in the translocation chromosome formation. The cell stage of the structural rearrangement was consistent with paternal meiosis as well as with postzygotic mitosis. The monosomy was confirmed in lymphocytes and fibroblasts, and mosaicism was not detected.

Fatal hepatic veno-occlusive disease in a newborn infant

We describe a newborn infant with veno-occlusive disease (VOD) of the liver. Prior to discharge from the hospital, the newborn, who had been treated for suspected neonatal infection, suddenly developed sepsis-like symptoms. The size of the liver as well as serum activity of hepatic enzymes increased progressively. Initial Doppler-flow studies demonstrated an absent flow in the vena portae, a finding that was compatible with vena portae thrombosis or occlusion of other hepatic veins. A therapy with recombinant tissue plasminogen activator (rt-PA) was initiated; due to extensive bleedings from various sides, the fibrinolytic therapy had to be withdrawn 12 hours later, when Doppler-flow examination revealed a reverse flow in hepatofugal direction. Despite supportive therapy, the general condition of the patient deteriorated continuously, finally resulting in liver and renal failure. Our patient died 19 days after birth. The autopsy demonstrated obliterative lesions of the centrilobular and sublobular hepatic veins, the classical signs of VOD of the liver. Despite extensive diagnostics and examinations, the etiology of VOD could not been elucidated in this newborn.

Significance of postglomerular capillaries in the pathogenesis of chronic renal failure

Correlations between the relative volume of the intertubular capillaries in the renal cortex and the serum creatinine concentration in primary glomerulopathies, renal vasculopathies, and chronic interstitial nephritides are reported. In the mesangioproliferative glomerulonephritides, there are significant negative correlations between the number and area of the intertubular capillaries in the cortex and the serum creatinine concentration. In diabetic glomerulosclerosis, renal glomerular amyloidosis, decompensated benign nephrosclerosis, secondary malignant nephrosclerosis, and chronic interstitial nephritis, there is a significant negative correlation between the relative area of the intertubular capillaries and the serum creatinine concentration. Thus, in these diseases, there is progressive narrowing/ obliteration of the postglomerular capillaries which leads to a progressive decrease in glomerular filtration rate and thus to a rise in serum creatinine concentration.

The long-term prognosis of AA and AL renal amyloidosis and the pathogenesis of chronic renal failure in renal amyloidosis

Investigation of the long-term prognosis and pathogenesis of chronic renal failure in 225 cases of AA and AL renal amyloidosis (perireticular and perireticular + pericollagenous amyloidosis) yielded the following results: 1) The prognosis of both AA and AL amyloidosis is poor, and is worse than all other types of glomerulopathy with the exception of rapidly progressive glomerulonephritis. 2) The probability of maintaining renal function in AL amyloidosis is no lower than that in AA amyloidosis. 3) The prognosis of both AA and AL amyloidosis is significantly worse in cases in which the renal cortical interstitium exhibits fibrosis at the time of the biopsy than in those in which it is normal. 4) In AA and AL amyloidosis, as in various types of inflammatory glomerulopathy, the relative area of the renal cortical interstitium shows a significant positive correlation with the serum creatinine concentration and a significant negative correlation with the creatinine clearance. However, the extent of interstitial amyloid deposition does not correlate with the serum creatinine concentration. Deposition of amyloid in the renal cortical interstitium has no effect on renal excretory function. 5) The long-term prognosis of renal amyloidosis is related to the severity of the glomerular amyloidosis in as much as it is generally worse in Grades III to V than in Grades I and II. However, it must be borne in mind that the incidence of interstitial fibrosis, which is decisive for the long-term prognosis, increases with the severity of glomerular changes. 6) The long-term prognosis of renal amyloidosis is worse if acute renal failure or interstitial fibrosis is present at the time of the biopsy. Patients with both acute renal failure and interstitial fibrosis have the worst prognosis. 7) Isolated glomerular amyloidosis, even if there is severe vascular amyloidosis (vas afferns), does not lead to renal insufficiency or even to a rise in serum creatinine concentration. 8) The number of T lymphocytes in the tubular epithelium in AA and AL amyloidosis is significantly greater than normal, and the number of T lymphocytes, macrophages/monocytes, and fibroblasts/fibrocytes per unit area of interstitium is also significantly increased. 9) As far as the pathogenesis of renal cortical interstitial fibrosis in renal amyloidosis is concerned, it is proposed that, in some cases, this develops from the interstitial edema that is seen in biopsy specimens of patients with renal amyloidosis and acute renal failure.(ABSTRACT TRUNCATED AT 400 WORDS)

The consequences for renal function of widening of the interstitium and changes in the tubular epithelium of the renal cortex and outer medulla in various renal diseases

The following parameters were measured in 63 renal biopsy specimens, most of which exhibited mesangioproliferative glomerulonephritis: the relative area of the interstitium and the area of the capillaries in the cortex and outer stripe of the outer medulla, and the area of the epithelium of the proximal tubules and of the ascending limbs of Henle's loop. The percentage of hyalinized glomeruli was also determined. Investigation of correlations between these values and parameters of renal function revealed the following: 1) The serum creatinine concentration increases and the endogenous creatinine clearance decreases significantly as the interstitium of both the cortex and the outer stripe of the outer medulla increases in width. 2) The urine osmolality decreases significantly as the epithelial areas of the proximal tubules and ascending limbs of Henle's loop decrease, and as the serum creatinine concentration rises and the areas of the interstitium increase. 3) No significant correlation exists between the percentage of hyalinized glomeruli and the urine osmolality. 4) The total area of the intertubular capillaries in the cortex decreases significantly as the interstitium in this area increases in width and as the serum creatinine concentration increases. 5) Compensatory hypertrophy of individual nephrons, as proposed by Bricker's hypothesis, was found only where more than 90% of the glomeruli were hyalinized.(ABSTRACT TRUNCATED AT 250 WORDS)

The consequences of tubulo-interstitial changes for renal function in glomerulopathies. A morphometric and cytological analysis

Morphometric investigation of the structures of the cortex in kidneys exhibiting various types of glomerulopathy revealed the following: 1. In various types of glomerulonephritis, diabetic glomerulosclerosis, and glomerular amyloidosis there are significant correlations between the severity of fibrosis of the renal cortical interstitium and tubular atrophy resulting from chronic interstitial inflammation, and the serum creatinine concentration, creatinine clearance, inulin clearance and PAH clearance. 2. As illustrated with the example of membranoproliferative glomerulonephritis type I, if glomerulopathy alone is present, there is no elevation of the serum creatinine concentration, even if the glomerular inflammatory changes are severe; neither are severe renal amyloidosis that is confined to the glomeruli and severe isolated diabetic glomerulosclerosis associated with elevation of the serum creatinine concentration. 3. There is a significant negative correlation between the severity of interstitial fibrosis resulting from chronic inflammation and the total number and cross-sectional area of the intertubular capillaries; i.e., the total cross-sectional area and number of capillaries per unit area decrease as the fibrosis of the cortical interstitium increases. 4. Cases of glomerulonephritis in which there is accompanying fibrosis of the renal cortical interstitium have a significantly worse long-term prognosis than those in which there is only severe glomerulitis. 5. Obliteration of the post-glomerular capillaries leads to an increase in the cross-sectional area of the glomerular capillary convolution, the morphological equivalent of an increase in intraglomerular pressure. 6. The cause of the disease of the renal cortical interstitium that may accompany the various types of glomerulonephritis is not known. It is considered possible, as a working hypothesis, that this inflammation represents a T-cell stimulated autoimmune process in which fibroblast proliferation occurs, leading to an increase in numbers of fibrocytes in the renal cortical interstitium and thus to increased production of collagen.

Contribution on the correlation between morphometric parameters gained from the renal cortex and renal function in IgA nephritis

The following findings were obtained in a comparative morphometric and clinical study of 130 adult men and women with immunologically confirmed IgA nephritis: (a) IgA nephritis develops in varying frequency as minimal proliferating intercapillary glomerulonephritis, low-grade mesangioproliferative glomerulonephritis, moderate to severe mesangioproliferative glomerulonephritis, or variously severe mesangioproliferative glomerulonephritis with signs of focal accentuation. (b) Tubular epithelial surface area and interstitial width in 62 of 130 cases of IgA nephritis was the same as in normal kidneys. IgA nephritis was complicated in 33 cases by interstitial cortical fibrosis, in 23 cases by acute renal failure, and in 12 cases by acute renal failure and interstitial fibrosis. (c) In IgA nephritis with acute renal failure, the tubular epithelium (only proximal tubular epithelium was measured) was significantly swollen. In IgA nephritis with interstitial fibrosis, the epithelial surface area of the proximal tubules was significantly smaller than the normal surface area. In IgA nephritis with acute renal failure (ARF) and interstitial fibrosis, tubular swelling was less severe than in ARF. Proximal tubular epithelial surface area, however, was significantly larger than the normal surface area. (d) In IgA nephritis, like in other inflammatory and noninflammatory glomerular diseases, a significant positive correlation existed between width of the cortical interstitium and height of serum creatinine level. Moreover, in IgA nephritis, significantly negative correlation existed between width of the cortical interstitium and C creatinine. (e) In IgA nephritis, significant negative correlations existed between C creatinine and age. (f) In IgA nephritis, a significant correlation existed between proximal tubular epithelial surface area and serum creatinine level and a significant negative correlation, between C creatinine and proximal tubular epithelial surface area, when ARF cases were excluded from the total group of IgA nephritis. (All correlations are closer when the cases with accompanying ARF are eliminated.) The discrepancy between the findings of Bennett et al. (Bennett WM, Walker RG, Kincaid-Smith P: Lab Invest 47:330, 1982) and ours is clarified when it is presumed that the group of patients investigated by Bennett et al. (N = 85) included just as many ARF cases as our material. Consequently, there is no reason to correct our interpretation of the influence of tubulointerstitial changes on glomerular function.

Significance of tubulointerstitial changes in the renal cortex for the excretory function and concentration ability of the kidney: a morphometric contribution

This is an editorial review of investigations into the correlation of structure and function of the kidney in various inflammatory and noninflammatory glomerular diseases and in focal and diffuse interstitial nephritis. In detail these investigations produced the following results: (1) The excretory function of the glomeruli for substances usually eliminated with the urine is, in the case of inflammatory and noninflammatory glomerular diseases, detrimentally affected by tubulointerstitial changes, i.e. by processes accompanied by interstitial fibrosis and tubular atrophy. Likewise primary interstitial renal diseases when accompanied by interstitial fibrosis and tubular atrophy may lead to reduction in GFR. (2) Inflammatory and noninflammatory glomerular diseases, even when very severe, are not accompanied by a measurable reduction in GFR when the renal cortex interstitium shows no changes and the tubules exhibit no pathological findings. (3) The concentration ability of the kidney, too, depends primarily on tubulointerstitial changes and not primarily on a reduction of the glomerular filtration surface area. As interstitial fibrosis and tubular atrophy increase, the maximum concentration ability of the kidney decreases, even when the glomerular structure is preserved. (4) The decrease in GFR in the case of processes in the renal cortex accompanied by severe interstitial fibrosis is the result of the reduction of the number and of the area of the postglomerular vessels, i.e. the result of an impeded outflow from the glomeruli and of a concomitant slower circulation through the glomeruli. (5) In the case of inflammatory and noninflammatory glomerular and extraglomerular renal diseases accompanied by slight interstitial fibrosis and tubular atrophy, the GFR is detrimentally affected via a hormonally controlled self-regulating mechanism (Thurau-mechanism) in the form as modified by Baumbach and Skott and Leyssac. The glomerular function thereby adapts to an insufficient tubular function, without there necessarily being any structural changes in the glomeruli.

Creatinine clearance and renal interstitium in diffuse endocapillary proliferative glomerulonephritis

Morphometric investigations of the renal cortex on biopsies obtained from patients with diffuse proliferative endocapillary glomerulonephritis (EPGN) were compared to biopsies without pathological changes, both groups having a normal serum creatinine concentration at the time of biopsy. Our findings are as follows: In both groups a statistically significant correlation exists between the decrease of the endogenous creatinine clearance and the broadening of the interstitium. The mean endogenous creatinine clearance value in EPGN is 107.6 +/- 40.6 ml/min/1.73 qm, the mean endogenous creatinine clearance in normal kidneys is 108.2 +/- 28.5 ml/min/1.73 qm; the mean interstitial volume in EPGN is 14.5 +/- 2.9 vol.%, that in normal kidneys 9.5 +/- 2.9 vol.%, the difference is statistically significant. Comparing the run of the two curves (relationship between endogenous creatinine clearance and interstitial volume) of the investigated groups, one finds that they run a nearly parallel course, the curve of the EPGN being shifted statistically significant to the right. The mean values of number, single- and total area of the peri- and intertubular capillaries are identical in the cases of EPGN and in those biopsies without pathological findings. Furthermore no correlations could be established between the above mentioned measuring values and the endogenous creatinine clearance in the both investigated groups. Consequently in these cases with normal serum creatinine concentration the reduction of the glomerular filtration rate (gfr) accompanied by interstitial broadening cannot be explained by an impairment of the postglomerular blood flow. Perhaps a tubular functional disturbance, the cause or the consequence of the interstitial broadening impairs glomerular function by the tubular-glomerular feedback-mechanism and/or by an elevation of the intratubular hydrostatic pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Correlations between renal cortical interstitial fibrosis, atrophy of the proximal tubules and impairment of the glomerular filtration rate

This study has confirmed impairment of the glomerular filtration rate (GFR) (increase of the serum creatinine concentration) by fibrosing processes in the renal cortical interstitium. In addition statistically significant correlations were found between the decrease of the total area of the proximal tubules and of the area of the epithelial cells and both the extent of the renal cortical interstitial fibrosis and the serum creatinine concentration. Further statistically significant positive correlations were observed between the age of the patients and both the grade of interstitial fibrosis and the serum creatinine concentration. No correlation could be established between the age of the patients and the total area of the epithelial cells of the proximal tubules. Pathogenetically it is conceivable that with progressive interstitial fibrosis the tubules become atrophic as a result of malnutrition. The function of these atrophied tubules may be disturbed, the reabsorptive capacity for NaCl impaired and consequently the GFR reduced not only by slowing of the glomerular blood flow secondary to interstitial fibrosis, but also by the tubular-glomerular feedback-mechanism.

Structure and function of the kidney in diabetic glomerulosclerosis. Correlations between morphological and functional parameters

Histological and clinical findings in 103 middle-aged patients suffering from diabetic glomerulosclerosis (gs) (biopsy material) are reported. In diabetic gs (as in other inflammatory and non-inflammatory glomerular disease) a statistically highly significant positive correlation exists between the grade of fibrosis of the renal cortical interstitium and the serum creatinine concentration at the time of biopsy. Rank correlations exist between vessel index and relative cortical interstitial volume on the one hand as well as serum creatinine concentration on the other. Significant differences are also shown to exist between the mean values of the cortical interstitium as well as the serum creatinine concentration and the vessel index in the four grades of diabetic gs. Severe glomerular lesions may be accompanied by a normal serum creatinine concentration, only if the interstitium shows no fibrotic changes. Mild glomerular lesions, when accompanied by an interstitial fibrosis, always have elevated serum creatinine concentrations. The incidence of hypertension, proteinuria, the nephrotic syndrome and hematuria in diabetic gs appears to vary greatly. From the highly significant correlation between the cortical interstitium and the serum creatinine concentration we presume the following: Alterations of the postglomerular vessels by interstitial fibrotic changes result in an increased resistance to renal cortical blood flow with a subsequent reduction of glomerular perfusion. This reduction of the glomerular perfusion may result in a rise of the serum creatinine concentration, independently of the severity of the glomerulosclerosis. It is also conceivable that glomerular function is affected by the malfunctioning atrophic tubules in areas of interstitial fibrosis.