A case of anti-neutrophil cytoplasmic antibody-associated vasculitis with anti-glomerular basement membrane antibodies that was successfully treated with mizoribine as a safe and effective remission maintenance therapy with prednisolone and plasma exchange.

We herein report the case of myeloperoxidase (MPO) anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis with anti-glomerular basement membrane (anti-GBM) antibody positivity that successfully treated with mizoribine (MZR) as an immunosuppressive drug for remission maintenance therapy after the initiation of dialysis in addition to plasma exchange (PE) and glucocorticoid treatment to control the disease condition. A 79-year-old woman developed serious renal dysfunction and pulmonary alveolar hemorrhaging due to MPO-ANCA and anti-GBM antibody double-positive vasculitis. She was started on hemodialysis and was treated with methylprednisolone (m-PSL) pulse therapy with PE, followed by oral prednisolone (PSL). The pulmonary alveolar hemorrhaging disappeared, and both antibody titers immediately decreased but then rose again. Thus, m-PSL pulse therapy performed again in combination with combined with MZR treatment. Her poor renal function was irreversible; however, this therapy decreased both antibody titers, and they did not increase again. The patient developed pancytopenia and hyperuricemia. It was considered likely that these conditions developed in association with MZR treatment. We, therefore, measured the patient's blood concentration of MZR, and the maintenance dose was finally set at 50 mg after each dialysis session. The patient's pancytopenia and hyperuricemia improved and PSL could be smoothly tapered. This is the first case report of the use of MZR for remission maintenance therapy in a patient on hemodialysis who was positive for both ANCA and anti-GBM antibodies. The findings suggest that MZR can be used safely and effectively in such cases.

Risks and Benefits of Sodium Polystyrene Sulfonate for Hyperkalemia in Patients on Maintenance Hemodialysis.

BACKGROUND: Concerns about sodium overload when using sodium polystyrene sulfonate (Na-resin) as an ion-exchange resin for the treatment of hyperkalemia led our institution to gradually shift to the use of calcium polystyrene sulfonate (Ca-resin). However, as serum potassium levels were insufficiently controlled and patients experienced constipation, we returned to using Na-resin and observed better results than previously. OBJECTIVE: As few papers have examined the potassium adsorption ability of Ca-resin compared with Na-resin, we investigated this issue within our institution. METHODS: We studied potassium adsorption in patients who switched from Ca-resin to an equivalent amount of Na-resin (change group). We also investigated the incidence of sodium loading with Na-resin, including in patients newly commencing Na-resin treatment (new start group). RESULTS: Mean (± standard deviation) serum potassium levels decreased significantly, from 5.5 ± 0.6 to 4.9 ± 0.6 mEq/l in the change group and from 5.9 ± 0.4 to 4.7 ± 0.6 mEq/l in the new start group. No changes were observed in blood pressure, weight gain or serum sodium levels in the change group, but serum sodium levels in the new start group increased significantly, from 137.4 ± 2.3 to 139.0 ± 2.5 mEq/l, although they remained within the normal range. CONCLUSIONS: Our results indicate that Na-resin exhibited an advantage in treating hyperkalemia when used in small amounts. However, when prescribing an ion-exchange resin at a higher dose, physicians should select the type and amount of resin according to the sodium and/or calcium load in each case.

Successful treatment of a patient with refractory nephrotic syndrome with PCSK9 inhibitors: a case report.

BACKGROUND: The proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor evolocumab is a low-density lipoprotein (LDL)-lowering drug with a new mechanism, which is currently available in Japan. Here, for the first time, we report the successful use of the PCSK9 inhibitor in a patient with refractory nephrotic syndrome. CASE PRESENTATION: A 61-year-old woman was diagnosed with minimal change-type nephrotic syndrome in October 2012. She received prednisolone (PSL) and cyclosporin A (CyA), but she experienced several cycles of relapse and remission and was hospitalized in May 2016 due to relapse. However, in spite of steroid pulse therapy and adrenocorticotropic hormone (ACTH) administration, her urinary protein level did not improve. We started her on evolocumab with the expectation of equivalent LDL-lowering effects as seen with LDL apheresis. After that, the LDL cholesterol level and UP/UC were concomitantly decreased, and the serum albumin was increased. This was maintained even when we reduced the PSL dose. This suggests that evolocumab clinically improves the nephrotic condition. CONCLUSION: No other report has described the use of evolocumab for nephrotic syndrome (NS) or its effect on similar nephrotic conditions. We believe that the findings presented here are unique and may be beneficial when treating similar cases.

A rare adult case of poststreptococcal acute glomerulonephritis with a retropharyngeal abscess.

Retropharyngeal abscess is an infection involving the retropharyngeal space which is posterior to the pharynx and oesophagus, and it results as a complication of a primary infection elsewhere in the head and neck including the nasopharynx, paranasal sinuses, or middle ear, which drain lymph to the retropharyngeal lymph nodes. Their lymph nodes are prominent in children and atrophy with age. Therefore, retropharyngeal abscess is most frequently encountered in children, with 75% of cases occurring before the age of 5 years, and often in the first year of life. We experienced a rare adult case of poststreptococcal acute glomerulonephritis with a retropharyngeal abscess, and conservative therapy ameliorated them. According to past reports, only one child with a retropharyngeal abscess and poststreptococcal acute glomerulonephritis has been presented at a conference to date; this is the first adult case of poststreptococcal acute glomerulonephritis with a retropharyngeal abscess. Retropharyngeal abscess can be fatal including airway compression, so it is important to remember retropharyngeal abscess in a case of poststreptococcal acute glomerulonephritis with severe symptoms of neck.