Dialysis patients experience high chronic oxidative stress levels. Oxidative stress enhances the inflammatory responses of dialysis patients, and it is also associated with the onset and deterioration of various complications. In this study, we examined the effects of hydrogen gas inhalation on oxidative stress in hemodialysis patients. We evaluated these effects of hydrogen gas inhalation by measuring oxidative stress, antioxidant capacity, and C‒reactive protein (CRP) levels in 6 hemodialysis patients. We evaluated oxidative stress and antioxidant capacity using the Diacron‒reactive oxygen metabolites (d‒ROMs) test and biological antioxidant potential (BAP) test, respectively. The hemodialysis patients started inhaling hydrogen gas 5 to 10 minutes before the start of dialysis and continued inhaling it until 5 to 10 minutes after the dialysis. In this study, hydrogen gas inhalation was employed in 6 consecutive dialysis sessions (over 2 weeks). After that, the patients underwent normal dialysis to evaluate the durability of the effects of hydrogen gas inhalation. Hydrogen gas inhalation during dialysis reduced the mean oxidative stress level of the subjects from 433 U.CARR to 395 U.CARR and reduced their mean CRP level from 1.05 mg/dL to 0.61 mg/dL. Furthermore, the effects of hydrogen gas inhalation during dialysis persisted even after the hydrogen gas inhalation was stopped; i.e., the mean oxidative stress level was reduced to 349 U.CARR, and the mean CRP level was reduced to 0.42 mg/dL. Hydrogen gas inhalation is simple and inexpensive, and is easy to carry out, even at small dialysis clinics or for home hemodialysis patients. Therefore, it is expected that hydrogen gas inhalation will prevent complications and bring about prognostic improvements in many dialysis treatment settings.

［Objective］Little is known about the clinical courses of hemodialysis patients with COVID‒19. We examined the characteristics of COVID‒19 in hemodialysis patients.［Materials and Methods］We enrolled 33 hemodialysis patients with COVID‒19 and 174 non‒hemodialysis patients with COVID‒19 who were admitted to our hospital in this study. We compared the clinical course of COVID‒19 between the hemodialysis and non‒hemodialysis patients. Among the hemodialysis patients with COVID‒19, we also compared the laboratory data of the severe and non‒severe groups.［Results］While 44.4％ of the hemodialysis patients were treated with steroids, only 13.2％ of the non‒hemodialysis patients received steroid treatment (p＜0.001). Among the patients who were not treated with steroids, it took 10.3±3.2 days for fevers to resolve in the hemodialysis patients, which was significantly longer than in the non‒hemodialysis patients (8.0±3.6 days, p＝0.034). In addition, it took 31.1±7.3 days for the hemodialysis patients to become PCR‒negative, which was significantly longer than it took in the non‒hemodialysis patients (21.7±4.4 days, p＝0.016). The mortality rate among the dialysis patients was 12.1％, whereas none of the non‒hemodialysis patients died. The hemodialysis patients had a significantly worse prognosis than the non‒hemodialysis patients (p＜0.001). Of the 4 deaths, thrombosis was suspected to be the cause of death in 2 cases. In a comparison between the severe and non‒severe cases, high C‒reactive protein (CRP) and D‒dimer levels and leukocyte counts and low lymphocyte ratios were seen in the severe group.［Conclusion］Among COVID‒19 patients, more hemodialysis patients than non‒hemodialysis patients required steroid therapy. In the hemodialysis patients, it took longer for fevers to resolve and for PCR tests to become negative, and they also had worse prognoses. In COVID‒19 patients, clinicians should pay attention not only to the deterioration of oxygen saturation, but also to the risk of sudden death due to thrombosis. It may be necessary to pay attention to disease severity in patients with high CRP levels, white blood cell counts, or D‒dimer levels, or low lymphocyte ratios.

The usefulness of the toe‒brachial index (TBI) as a prognostic factor in patients undergoing maintenance hemodialysis (HD) is unknown. This study aimed to investigate patient survival 5 years after the measurement of the ankle‒brachial index (ABI), TBI, and skin perfusion pressure (SPP) in 157 patients undergoing HD, and to identify prognostic factors among the variables evaluated in this study. Analysis with the Cox proportional hazards model revealed that the TBI is an independent prognostic factor among patients undergoing HD (p＜0.001). Receiver operating characteristic (ROC) curves indicated that the optimal TBI cut‒off point for predicting mortality was 0.56, which resulted in an area under the ROC curve of 0.91, demonstrating that the TBI had greater predictive ability than the other examined parameters. When the calculated TBI cut‒off value was used to divide the patients into the TBI≥0.7 group, the 0.7＞TBI≥0.56 group, the TBI＜0.56 group, and zero TBI sign, no differences in survival were observed between the 0.7＞TBI≥0.56 group and the TBI≥0.7 group. Survival was significantly lower in the TBI＜0.56 group than in the 0.7＞TBI≥0.56 group (p＜0.001), and was also significantly lower in zero TBI sign than in the TBI＜0.56 group (p＝0.020). Cardiovascular events were not a cause of death in the TBI≥0.56 group, but accounted for 40％ of deaths in the TBI＜0.56 group and zero TBI sign. The TBI is more useful as a prognostic factor in patients undergoing HD than the ABI and SPP.

［Objective］We assessed whether ionized calcium (iCa), total Ca (tCa), or serum albumin level (Alb)‒corrected Ca is optimal for evaluating Ca levels in hemodialysis (HD) patients.［Method］We examined the relationships between pH‒corrected iCa (pH‒iCa) according to gas analysis and tCa, Alb‒corrected Ca based on the K/DOQI‒1 formula (KDOQI‒Ca), or Alb‒corrected Ca based on the Ca ionization rate (CaIR) obtained by dividing the pH‒corrected iCa by tCa; i.e., the CaIR‒Ca, before and after HD in 43 patients.［Results］Before and after HD, the relationship between the CaIR and Alb was y＝－0.011x＋0.558 (r＝0.199, p＞0.2) and y＝－0.031x＋0.655 (r＝0.720, p＜0.0001), respectively. Before HD, the relationships between pH‒iCa and tCa, KDOQI‒Ca, or CaIR‒Ca were y＝7.73x‒0.01 (r＝0.862), y＝7.46x＋0.30 (r＝0.846), and y＝7.61x＋0.21 (r＝0.859), respectively. After HD, these relationships were y＝3.50x＋5.08 (r＝0.482, p＜0.005), y＝3.81x＋4.66 (r＝0.460, p＜0.002), and y ＝1.55x＋7.36 (r＝0.282, p＜0.1), respectively. The attenuation of the relationship between pH‒iCa and tCa after HD seems to have occurred because the increase in the Ca‒bound Alb concentration caused by HD hindered the transfer of iCa from the dialysate to plasma.［Conclusion］For evaluating the Ca levels of HD patients, iCa, tCa, KDOQI‒Ca, and CaIR‒Ca can be used before HD, but iCa should not be used after HD.

A 65‒year‒old male patient with end‒stage renal disease resulting from type 2 diabetes was started on peritoneal dialysis. Six months later, he developed erythropoiesis stimulating agent‒hyporesponsive anemia because of bleeding caused by gastric angiodysplasia. He underwent endoscopic hemostasis, and the anemia improved. However, 8 months after the procedure, the gastric angiodysplasia‒induced anemia recurred. Although he underwent endoscopic hemostasis, gastric bleeding from additional angiodysplastic lesions was detected a few days later. Endoscopic hemostasis was then performed again. Four months later, he was switched from peritoneal dialysis to hemodialysis because he developed refractory peritonitis due to a suspected fungal infection. Subsequently, no gastrointestinal bleeding occurred. Among patients with end‒stage renal disease, hemodialysis patients are more likely than peritoneal dialysis patients to bleed from gastrointestinal angiodysplastic lesions. However, in this case, a patient who was on peritoneal dialysis experienced repeated bleeding due to gastric angiodysplasia, which ceased after he was switched to hemodialysis. We suggest that switching peritoneal dialysis patients to hemodialysis may prevent recurrent bleeding from gastrointestinal angiodysplastic lesions.

This case involved a 70‒year‒old male. He had a history of abdominal aortic aneurysm replacement and coronary angioplasty 6 years ago and cerebral aneurysm coil embolization 5 years ago. He complained of weight loss, and a blood test revealed an acute reduction in his renal function. Many purpura were found on both of his soles and feet, and a cholesterol crystal embolism (CCE) was suspected. Statin and steroid therapy were started on the second day after admission, but his renal function did not show any improvement. Hemodiafiltration was started on day 4. He was diagnosed with a CCE because compatible pathological findings were obtained in skin and kidney biopsy examinations. Low‒density lipoprotein (LDL) apheresis was started on day 10. As a result, the patient’s renal function gradually recovered, and he was withdrawn from hemodiafiltration on day 30. He subsequently developed intestinal perforations three times and required surgery twice. However, he survived for ＞3 months after the onset of the CCE. We report a rare case in which a combination of steroid and intensive lipid‒lowering therapy (LDL apheresis) helped the patient to survive for ＞3 months after a CCE, the acute worsening of his renal function, and repeated small bowel perforations.

A 69‒year‒old male underwent surgery and chemotherapy for a bladder tumor, a left renal pelvic tumor, and paraaortic lymph node metastasis (Stage IV) in July X‒1. A recurrent left renal pelvic tumor and paraaortic lymph node swelling were discovered in May X. He received two intravenous cycles of pembrolizumab, an immune checkpoint inhibitor, on June 7th and July 12th. He presented with an acute kidney injury (AKI) after two cycles of pembrolizumab. His baseline serum creatinine level was around 1.4 mg/dL. However, on August 3rd his serum creatinine level increased to 10.4 mg/dL. On August 4th, his serum creatinine level increased, and worsening metabolic acidosis was seen. Therefore, hemodialysis was performed. Based on a suspicion that pembrolizumab may have caused the AKI, oral prednisolone (50 mg daily) was started on August 10th. The patient’s serum creatinine level progressively improved to around 1.4 mg/dL. He received prednisolone for 60 days. After the prednisolone was discontinued, his serum creatinine level did not increase. In this rare case, a severe pembrolizumab‒induced AKI was resolved with steroid therapy.

A 62‒year‒old male, who had been undergoing hemodialysis for 19 years and 3 months, experienced a loss of appetite and diarrhea for one month. He developed a fever and low blood pressure during dialysis and was admitted to our hospital, Saitama Sekishinkai Hospital. Hypercalcemia (corrected calcium＝11.8 mg/dL), hypoglycemia, and eosinophilia were observed. He stopped taking precipitated calcium carbonate and maxacalcitol (a vitamin D derivative) and was administered antibiotics due to a suspected infection. The antibiotics did not alleviate his symptoms, and there was no improvement in his laboratory test results. A subsequent examination revealed that his serum basal cortisol (0.4 µg/dL) and adrenocorticotropic hormone ( ＜1.5 pg/mL) levels were low, which resulted in him being diagnosed with secondary adrenal insufficiency. He was treated with hydrocortisone, after which his symptoms, hypercalcemia, hypoglycemia, and eosinophilia were ameliorated. Calcium‒containing phosphate binders and vitamin D analogues are often used for the management of chronic kidney disease‒mineral bone disorder in patients undergoing long‒term hemodialysis. We eventually diagnosed our patient with adrenal insufficiency, after excluding iatrogenic hypercalcemia.