Focal Segmental Glomerular Sclerosis Ameliorated by Long-term Hemodialysis Therapy with Low-density Lipoprotein Apheresis

We report a case involving a 43-year-old Japanese woman with steroid-resistant focal segmental glomerular sclerosis (FSGS) and severe renal dysfunction, which was ameliorated by low-density lipoprotein apheresis (LDL-A). She had been treated with steroid therapy, but had experienced anuria for over 10 weeks and required hemodialysis. She was then treated with LDL-A, which resulted in improved urinary protein excretion and renal function. Her renal function recovered after 97 days of hemodialysis therapy. This case suggests that LDL-A may represent an effective rescue treatment in patients with FSGS and long-term anuria.

Arterial stiffness and renal impairment in non-proteinuric type 2 diabetic patients

Aims/Introduction:  Although increases in urinary protein excretion generally precede a decline in the glomerular filtration rate, non-proteinuric renal impairment is common in patients with diabetes. In the present study, we examined the relationship between indices of arterial stiffness and renal function in type 2 diabetic patients without proteinuria.

METHODS

  Blood sampling, 24-h urine collection, brachial-ankle pulse wave velocity, and 24-h ambulatory blood pressure monitoring were performed in type 2 diabetic patients without overt proteinuria. The ambulatory arterial stiffness index was calculated as (1 - the regression slope of diastolic/systolic ambulatory blood pressure). Estimated glomerular filtration rate (eGFR)was calculated using the simplified prediction equation proposed by the Japanese Society of Nephrology.

RESULTS

  Of 213 non-proteinuric patients with type 2 diabetes, 60 (28.2%) had a reduced eGFR (<60 mL/min per 1.73 m(2)). Although the urinary albumin excretion rate was significantly correlated with the eGFR, 34 of 152 patients with normoalbuminuria (22.4%) had a reduced eGFR. The eGFR was significantly and negatively correlated with the ambulatory arterial stiffness index and brachial-ankle pulse wave velocity, but not with 24-h pulse pressure. Multivariate analysis revealed that increased age and increased urinary albumin excretion were independently associated with decreased eGFR. In addition, the ambulatory arterial stiffness index, but not brachial-ankle pulse wave velocity, were found to be independently and significantly associated with eGFR.

CONCLUSIONS

  Ambulatory arterial stiffness index is a marker for increased risk of renal failure in non-proteinuric patients with type 2 diabetes. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2011.00146.x, 2012).

Role of angiotensin II-mediated AMPK inactivation on obesity-related salt-sensitive hypertension

Salt-sensitive hypertension is a characteristic of the metabolic syndrome. Given the links to cardiovascular events, the mechanisms underlying sodium metabolism may represent an important therapeutic target for this disorder. Angiotensin II (AII) is a key peptide underlying sodium retention. However, 5'AMP-activated protein kinase (AMPK) has also been reported to participate in the regulation of ion transport. In this study we examined the relationship between AII and AMPK on the development of hypertension in two salt-sensitive mouse models. In the first model, the mice were maintained on a high-fat diet (HFD) for 12 weeks, in order to develop features similar to the metabolic syndrome, including salt-sensitive hypertension. HFD-induced obese mice showed elevated systolic blood pressure and lower sodium excretion in response to salt loading, along with an increase in AII contents and inactivation of AMPK in the kidney, which were significantly improved by the treatment of an angiotensin II antagonist, losartan, for 2 weeks. To clarify the effects of AII, a second group of mice was infused with AII via an osmotic pump, which led to higher systolic blood pressure, and decreases in urinary sodium excretion and the expression of AMPK, in a manner similar to those observed in the HFD mice. However, treatment with an AMPK activator, metformin, improved the changes induced by the AII, suggesting that AII induced sodium retention works by acting on AMPK activity. Finally, we evaluated the changes in salt-sensitivity by performing 2-week salt loading experiments with or without metformin. AII infusion elevated blood pressure by salt loading but metformin prevented it. These findings indicate that AII suppresses AMPK activity in the kidney, leading to sodium retention and enhanced salt-sensitivity, and that AMPK activation may represent a new therapeutic target for obesity-related salt-sensitive hypertension.

Target for glycemic control in type 2 diabetic patients on hemodialysis: effects of anemia and erythropoietin injection on hemoglobin A(1c)

In hemodialysis (HD) patients the glycated hemoglobin (Hb(A1c)) level may underestimate glycemic control. The aim of this study is to estimate accurate glycemic control in type 2 diabetic patients on HD. Type 2 diabetes patients (N = 87) who had been receiving maintenance HD for at least one year were enrolled. Hb(A1c) and the percentage of glycated albumin relative to total the serum albumin (%GA) were measured in blood samples and the factors that affected the %GA/Hb(A1c) ratio were examined. There were significant and positive correlations between the plasma glucose and either the Hb(A1c) levels (r = 0.539, P < 0.01) or the %GA level (r = 0.520, P < 0.01). No relationship between the serum albumin levels and %GA levels was observed. A weekly dose of erythropoietin (EPO) was positively correlated with the ratio of %GA/Hb(A1c) and hematocrit (Ht) correlated negatively. There was no significant correlation between the %GA/Hb(A1c) level and the EPO dose in patients with Ht > or = 30%, although a significant correlation was found between those parameters in the Ht < 30% group. The mean of the %GA/Hb(A1c) ratios in patients with Ht > or = 30%, with Ht < 30% and treated with EPO < 100 IU/kg/week, and with Ht < 30% and treated with EPO > or = 100 IU/kg/week were 3.41, 3.56 and 4.13, respectively. In HD patients, accurate glycemic control may be estimated as: Hb(A1c) x 1.14 if Ht > or = 30%; Hb(A1c) x 1.19 if Ht < 30% and treated with low dosages of EPO; and Hb(A1c) x 1.38 if Ht < 30% and treated with high dosages of EPO.

Structural and functional changes in the kidneys of high-fat diet-induced obese mice

Metabolic syndrome has been reported to be associated with chronic kidney disease, but the mechanisms remain unclear. Although feeding of a high-fat diet (HFD) to C57BL/6 mice is reported to induce systemic metabolic abnormalities and subsequent renal injuries, such as albuminuria, similar to human metabolic syndrome, alterations in HFD-induced renal injuries have not been fully elucidated in detail. We therefore investigated the structural and functional changes in the kidneys of C57BL/6 mice on a HFD. Six-week-old mice were fed a low-fat diet (LFD; 10% of total calories from fat) or a HFD (60% fat) for 12 wk. Mice fed a HFD showed significant increases in body weight, systolic blood pressure, plasma insulin, glucose, and triglycerides compared with those on a LFD. Accompanying these systemic changes, mice on a HFD showed albuminuria, an increase in glomerular tuft area, and mesangial expansion. These systemic and renal alterations in mice on a HFD were prevented by body weight control with the dietary restriction of feeding a HFD. Furthermore, mice on a HFD showed renal pathophysiological alterations including renal lipid accumulation, an increased accumulation of type IV collagen in glomeruli, an increase in macrophage infiltration in the renal medulla, an increase in urinary 8-hydroxy-2'-deoxyguanosine excretion, and impaired sodium handling. In conclusion, this study suggests that local metabolic alterations in the kidney play important roles in the development of renal injury associated with metabolic syndrome in addition to systemic metabolic changes and an increase in body weight.

Emergence of panniculitis and haemophagocytic syndrome in a patient with chronic systemic lupus erythematosus

Panniculitis rarely occurs in the course of systemic lupus erythematosus (SLE). When it occurs, it is thought to be mainly lupus erythematosus panniculitis (LEP). Here we describe a 32-year old Japanese woman with chronic SLE, who simultaneously presented facial lymphocytic lobular panniculitis and pancytopenia due to haemophagocytic syndrome. She showed several auto-antibodies against trilineage haematopoetic cells, an anti-cardiolipin antibody, and no evidence of viral infection, indicating that her haemophagocytic syndrome might be autoimmune-associated haemophagocytic syndrome. The panniculitis and haemophagocytic syndrome presented simultaneously, and these manifestations were dramatically improved with corticosteroid therapy; therefore, the lymphocytic lobular panniculitis could be linked to autoimmune-associated haemophagocytic syndrome in this case.

Membranous nephropathy associated with the relatively selective cyclooxygenase-2 inhibitor, etodolac, in a patient with early rheumatoid arthritis

Renal dysfunction and urinary abnormalities, which are usually related to drug toxicity, secondary amyloidosis, or those which overlap with other autoimmune conditions, are frequently observed in patients with rheumatoid arthritis. This is the first case report of membranous nephropathy in a patient with early-stage rheumatoid arthritis treated with the relatively selective cyclooxygenase-2 inhibitor, etodolac. The present case suggests that any kind of non-steroidal anti-inflammatory drug can cause membranous nephropathy; thus, physicians should be aware of this renal toxicity when prescribing these drugs.

Pulmonary-renal syndrome, diffuse pulmonary hemorrhage and glomerulonephritis, associated with Wegener's granulomatosis effectively treated with early plasma exchange therapy

We present a case of a 38-year-old Japanese man with Wegener's granulomatosis complicated with pulmonary-renal syndrome, i.e., diffuse pulmonary hemorrhage and rapidly progressive renal glomerulonephritis. As this is a life-threatening condition, we promptly initiated plasma exchange with intravenous methylprednisolone therapy. Diffuse pulmonary hemorrhage and renal failure were markedly improved. This case merits presentation because there are few clinical studies of the treatment of Wegener's granulomatosis with pulmonary-renal syndrome, particularly with pulmonary hemorrhage.

Emerging minimal-change nephrotic syndrome in a patient with chronic mesangial proliferative lupus nephritis

A 41-year-old Japanese woman with a 25-year history of systemic lupus erythematosus was admitted because of abrupt onset of nephrotic syndrome and acute renal failure. Renal biopsy specimen showed only mild mesangial proliferative glomerulonephritis associated with mesangial deposition of immunoglobulins/complements. No significant immune deposits were found in the glomerular capillary walls, but mild foot process effacement was observed on electron microscopy. Further, two-month corticosteroid therapy improved her massive proteinuria and renal dysfunction, indicating that this patient showed minimal-change nephropathy superimposed on mesangial proliferative lupus nephritis.

Levofloxacin-induced Achilles tendon rupture in a patient with systemic microscopic polyangiitis

We report a case of spontaneous Achilles tendon rupture associated with myeloperoxidase-anti-neutrophil cytoplasmic antibody (MPO-ANCA)-related microscopic polyangiitis in a 77-year-old man who was treated with oral corticosteroids. Several days after 10 days of treatment with levoflaxacin (daily dose 200 mg) for bacterial pneumonia, he noted discomfort around both Achilles tendons. The discomfort developed into swelling around his left ankle, and he could not walk well. We diagnosed bilateral Achilles tendinitis with spontaneous rupture induced by levofloxacin. Epidemiological studies show that the risk of fluoroquinolone-related tendon rupture is highest among patients over the age of 60 years who are receiving a corticosteroid. Rupture of the Achilles tendon is a rare but serious side effect of fluoroquinolone usage. Thus, physicians should be aware of this adverse effect, especially when prescribing medication for aged patients being treated with corticosteroids.