Toshimasa Hishiki

Detection of Serum IL-6 in Patients with Diabetic Nephropathy

Yasuhiko Tomino. MD, Division of Nephrology, Department of Medicine, Juntentto University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113 (Japan) Dear Sir, A study on the detection of serum IL-6 in patients with non-insulin-dependent diabetes mellitus (NIDDM) with or without nephropathy is described. IL-6 is generally regarded as a multifunctional cytokine which has a variety of biological activities, including the ability to stimulate bone marrow stem cell proliferation, B cell differentiation, immuno-globulin secretion, T cell activation, and acute phase protein synthesis [1, 2], IL-6 is also produced by the renal glomerular mesan-gial cells. Cytokines are known to play an important role in autoimmunity and appear to be involved in the pathogenesis of insulin-dependent diabetes mellitus (IDDM). However, Cavallo et al. [3] reported that detectable levels of serum IL-6 were observed in only 10% of IDDM patients. Serum samples were obtained from 9 patients with NIDDM with nephropathy (diabetic nephropathy), 9 patients with NIDDM without nephropathy and 29 patients with chronic glomerulonephritis (CGN). NIDDM was diagnosed with a 75-gram glucose tolerance test. Patients with diabetic nephropathy continuously showed more than 200 mg/24 h. Serum IL-6 levels were measured with ELISA as described previously [4]. Mouse monoclonal anti-IL-6 antibody (HH61-10) and monoclonal horse radish peroxidase-conjugated anti-IL-6 antibody (HH61-2 Fab’) were used in a double-antibody sandwich ELISA [5]. Levels of serum IL-6 of healthy controls were less than 4.0 pg/ml [5]. The mean levels of serum IL-6 in all patients with NIDDM were significantly higher than those in patients with CGN (p < 0.05). The levels of serum IL-6 in patients with diabetic nephropathy were significantly higher than those in cases of CGN or NIDDM without nephropathy (p < O.Ol and p < 0.05, respectively; table 1). It appears that the presence of IL-6 in the patients’ sera may reflect increased localized production of this cytokine at the pancreatic and/or glomerular me-sangial levels. The measurement in serum IL-6 may add

Podocyte Injury Predicts Prognosis in Patients with IgA Nephropathy Using a Small Amount of Renal Biopsy Tissue

To predict the progression in patients with IgA nephropathy, we analyzed glomerular lesions except for sclerosis, adhesion and/or crescents in 34 patients with this disease by morphometric analysis. Levels of urinary protein excretion (UP), creatinine clearance (Ccr), serum creatinine (sCr) and mean blood pressure (MBP) at the time of renal biopsy were used as the clinical parameters. The slope of 1/sCr was also used as a prognostic parameter. Renal specimens were obtained by echo-guided biopsy. In PAS-stained light microscopic renal sections, three midsections of open glomeruli were selected and photographed. Stereologic estimation was performed as follows: absolute values of glomerular volume (V_G), glomerular surface area (S_G), podocyte and nonpodocyte cell number per glomerulus (N_G(pod) and N_G(Non-pod)), glomerular surface area covered by one podocyte S_G/N_G(pod)) and glomerular volume occupied by one nonpodocyte cell (V_G/N_G(Non-pod)). There was a significant correlation between the levels of UP and the change of podocyte injury parameters (N_G(pod) and S_G/N_G(pod)) or N_G(Non-pod). N_G(pod) was negatively but S_G/N_G(pod) and N_G(Non-pod) were positively correlated with UP. S_G/N_G(pod) or N_G(Non-pod) was correlated with MBP. N_G(pod), S_G/N_G(pod), N_G(Non-pod), UP or MBP was significantly correlated with the slope of 1/sCr. High specificity was observed for N_G(pod), S_G/N_G(pod) and MBP. High sensitivity was also observed for N_G(Non-pod) and UP. It appears that podocyte injury might provide additional prognostic information in patients with IgA nephropathy.

Follow-up study on urinary type IV collagen in patients with early stage diabetic nephropathy

Type IV collagen is a major component released from the glomerular and tubular basement membranes. To investigate the alteration of renal type IV collagen turnover in early stage diabetic nephropathy, urinary type IV collagen was measured by a highly sensitive one‐step sandwich enzyme immunoassay (EIA). Urinary samples were obtained from 94 diabetic patients without overt proteinuria. Among those patients, 61 were normoalbuminuric and 33 patients were in the microalbuminuric group. Levels of urinary type IV collagen were serially examined at the start of this study and again one year later. The levels of urinary type IV collagen in patients in the microalbuminuric group were significantly higher than those in the normoalbuminuric group (P < 0.01). There was a significant correlation between the concentration of urinary albumin and urinary type IV collagen in both groups (P < 0.05). Twenty‐eight patients (45.3%) in the normoalbuminuric group who showed an abnormal elevation of urinary type IV collagen in comparison to the reference range of normal healthy adults (normal range; less than 3.5 μg/g · Cr). Seven (25%) out of these 28 normoalbuminuric patients with increased urinary type IV collagen progressed to the microalbuminuric group one year later. The levels of urinary type IV collagen in such patients were significantly increased. In the 21 patients who stayed within the normoalbuminuric group, the urinary type IV collagen levels were significantly decreased one year later. It appears that the levels of urinary type IV collagen might reflect ongoing alteration of the extracellular matrix (ECM) turnover and might define more specifically the early stage diabetic nephropathy than the detection of microalbuminuria. It is concluded that the serial measurement of urinary type IV collagen can be a useful marker for detecting renal injury in diabetes. J. Clin. Lab. Anal. 12:378–382, 1998.

Increase of Urinary Type IV Collagen in Normoalbuminuric Patients with Impaired Glucose Tolerance

Accessible online at: http://BioMedNet.com/karger Dear Sir, Microalbuminuria is the only early clinical sign of the subsequent diabetic nephropathy. However, it is also known that significant structural changes have already appeared even at the stage of microalbuminuria in non-insulin-dependent diabetes mellitus (NIDDM) patients. Thus, it is necessary to develop a more sensitive measurement for detecting the early stage of renal injury in patients with diabetic nephropathy. Since type IV collagen is the principal component of glomerular basement membrane and mesangial matrix, the levels of type IV collagen in sera and urinary samples may reflect the rate of its turnover, such as the balance of production by intrinsic renal cells and degradation by matrix proteinases in diseased kidneys. To investigate the alteration of renal turnover of type IV collagen in patients with impaired glucose tolerance (IGT), urinary type IV collagen (uIV) was measured by a highly sensitive one-step sandwich enzyme immunoassay (EIA) (Fuji Chemical Industries, Co. Ltd, Takaoka, Toyama, Japan) [1]. Diagnosis of NIDDM was made according to the criteria of the 75-gram oral glucose tol-

Retrospective analysis of effects of sodium-glucose co-transporter 2 inhibitor in Japanese type 2 diabetes mellitus patients with chronic kidney disease

Aim: The aim of this study was to assess the renal effects of the glucose-lowering SGLT2 inhibitors in Japanese type 2 diabetes mellitus patients with chronic kidney disease. Methods: The Kanagawa Physicians Association maintains a registry of patients who visit their 31 clinics. Clinical data of type 2 diabetes mellitus patients with chronic kidney disease, who were prescribed SGLT2 inhibitors in addition to other treatments, were collected and analysed. Results: SGLT2i was associated with a fall in HbA1c from 64.1 ± 16.7 mmol/mol (8.0 ± 1.5%) to 56.5 ± 12.9 mmol/mol (7.3 ± 1.2%) (p < 0.01) in 869 analysed cases, a decrease in urine albumin-creatinine ratio from a median of 47.1 to 41.1 mg/gCr, and decrease in estimated glomerular filtration rate from 77.7 ± 23.9 to 75.0 ± 23.9 mL/min/1.73 m2 (p < 0.01). The effect on albumin-creatinine ratio was independent of age or stage of estimated glomerular filtration; however, there was a significant negative correlation between albumin-creatinine ratio at the initiation of SGLT2 inhibitor and change in ACR. Multiple linear regression analysis identified use of empagliflozin, β-blockers, and sulphonylureas, Δsystolic blood pressure at office, serum Cr and albumin-creatinine ratio value at initiation of SGLT2 inhibitor as independent and significant determinants of change in ACR. Conclusions: This study confirmed that the beneficial renal effects of SGLT2 inhibitor in Japanese type 2 diabetes mellitus patients with chronic kidney disease, similar to those reported in large-scale clinical trials conducted in Western countries.

A case of immunoglobulin A nephropathy with a long history (32 years) in the relatively poor prognosis group

Abstract We report herein an immunoglobulin A nephropathy patient with a long history of 32 years in the relatively poor prognosis group according to pathological findings. In general, such cases in the relatively poor prognosis group develop end-stage renal failure, and undergo dialysis within 5 to 20 years. However, the period from the appearance of proteinuria to hemodialysis was very long in this patient. His mean blood pressure remained at approximately 100 mm Hg with the administration of some antihypertensive agent. The genotype of the angiotensin converting enzyme was II. Although normal renal function continued for the duration, he had severe acute tonsillitis at 45 and 49 years of age. After these infections, proteinuria and/or hematuria were exacerbated and he gradually progressed to end-stage renal failure. The good prognosis in this patient might be attributable to good control of blood pressure, whereas the decline in renal function might be attributable to severe recurrent upper respiratory tract infection. It seems that control of blood pressure and prevention of recurrent upper respiratory tract infection are important factors in the prognosis of patients with immunoglobulin A nephropathy. Although the association between angiotensin converting enzyme genotype and prognosis of immunoglobulin A nephropathy is controversial, it is postulated that angiotensin converting enzyme genotype II might be correlated with the good prognosis in this case.

Apoptotic cells in six patients with IgA nephropathy in repeat biopsies

SUMMARY: Programmed cell death is a selective process of physiological cell deletion and is known as apoptosis. The purpose of the present study was to determine the relationship between the existence of apoptotic cells in glomeruli and the clinical or histopathological findings obtained in repeat renal biopsies of patients with IgA nephropathy. Repeat renal biopsy specimens were obtained from six patients with IgA nephropathy. The nick end labelling method (TUNEL) was used for the detection of apoptotic cells. Clinical laboratory data, i.e. urinary protein excretion, creatinine clearance (Ccr), blood urea nitrogen (BUN) and serum creatinine, (s‐Cr) were obtained from these patients. At the first renal biopsy, apoptotic cells in the glomeruli were observed in three out of six patients using TUNEL. These patients were classified as the severe glomerular damage group. The other three patients without apoptotic cells were in the mild glomerular damage group. Mean levels of urinary protein excretion at the first renal biopsy in the patients with apoptotic cells were slightly higher than those in patients without apoptotic cells. Levels of Ccr in patients with apoptotic cells were lower than those in patients without apoptotic cells. There were no significant differences in the levels of BUN and s‐Cr in patients with or without apoptotic cells. Two patients with apoptotic cells in glomeruli at the first renal biopsy did not show apoptotic cells at the second renal biopsy. These two patients showed improvement not only in clinical laboratory findings but also in histological findings at the second biopsy. Only one patient with apoptotic cells at the first and second biopsies exhibited deterioration at the second biopsy. All three patients without apoptotic cells at the first renal biopsy also showed deterioration of the clinical laboratory and histopathological findings. It is postulated that various factors other than apoptosis might induce progression of renal injuries in such patients. It appears that the clinical laboratory data, i.e. proteinuria, renal function and histopathological findings, might be influenced by apoptosis in patients with IgA nephropathy. It is postulated that apoptosis may induce reduction of excess proliferative glomerular mesangial cells and/or infiltrating cells and tissue repair.

Effect of Acarbose on Blood Glucose and Proteinuria in Patients with Diabetic Nephropathy

Accessible online at: www.karger.com/journals/nef Dear Sir, A study of the effect of Acarbose on decreases in the levels of fasting blood glucose and urinary protein excretion in patients with diabetic nephropathy is described. The importance of strict control of hyperglycemia in diabetes mellitus is now well accepted. Acarbose (·-glucosidase inhibitor), a complex oligosaccharide, is a potent competitive inhibitor of sucrase and decreases postprandial hyperglycemia when administered with food [1, 2]. Lee [3] reported that glomerular mesangial thickening and mesangial immunoglobulin deposition were significantly reduced in ab/ab mice receiving highdose Acarbose (40 mg/100 g food). We recently determined the levels of fasting blood glucose, glycohemoglobin A1c (HbA1c) and urinary protein excretion after treatment with Acarbose (Glucobay®) for 24 months in diabetic patients with or without nephropathy. Non-insulin-dependent diabetes mellitus type 2 was diagnosed according to the criteria of the 75-gram oral glucose tolerance test of the Japanese Diabetic Research Council [4]. Blood and urine samples were obtained from 33 diabetic patients with or without nephropathy in our outpatient clinic. Thirteen patients who showed more than 300 mg of urinary albumin per gram creatinine (Cr) were included in this study. Levels of fasting glucose and HbA1c in the peripheral blood were measured by ordinary laboratory examination before and 24 months after initiation of the treatment. Oral doses of 150–300 mg/day of Acarbose (Glucobay) were administered for 24 months. Levels of fasting glucose 24 months after initiation of treatment with Acarbose (152 B 44 mg/dl; mean B SD) were significantly lower than those before treatment (212 B 96 mg/dl; p ! 0.001). The levels of HbA1c 24 months after initiation of treatment (7.7 B 0.9%) were also significantly lower than those before treatment (9.8 B 2.6%; p ! 0.001). The mean levels of urinary protein excretion 24 months after initiation (400 mg/g Cr) were lower than those before the treatment (540 mg/g Cr), but the difference was not statistically significant. It appears that mild glycemic control, rather than strict control, might not improve proteinuria in patients with diabetic nephropathy. It is necessary to decrease markedly the levels of blood glucose to improve proteinuria and vice versa. References