Efficacy of Magnesium Supplementation in Cancer Patients Developing Hypomagnesemia Due to Anti-EGFR Antibody: A Systematic Review.

Background/Aim: Hypomagnesemia is a common side effect of anti-epidermal growth factor receptor (EGFR) antibodies, which may lead to arrhythmia. However, there are no evidence-based guidelines for magnesium (Mg) supplementation in the management of hypomagnesemia in patients with anti-EGFR antibodies. Therefore, we performed a systematic review to address clinical questions regarding these cancer patients. Materials and Methods: Three electronic databases were searched for articles published until June 18, 2021. The main outcomes used were "anti-EGFR antibody" and "hypomagnesemia". Results: After screening 78 references in PubMed, Cochrane Library, and ICHUSHI-web databases, three studies were included in the review. One study revealed the effectiveness of Mg supplementation in the management of hypomagnesemia in patients receiving cetuximab. However, no studies have investigated whether correcting hypomagnesemia can lead to the suppression of arrhythmias as a clinical outcome. Conclusion: Weak evidence suggests that Mg supplementation, as a preventive measure when developing hypomagnesemia following the initiation of anti-EGFR antibody therapy, may prevent the worsening of hypomagnesemia, and subsequently prevent associated arrhythmia occurrence.

Effect of tonsillectomy combined with steroid pulse therapy upon IgA nephropathy depending on proteinuria status at diagnosis: a nationwide multicenter cohort study in Japan.

BACKGROUND: The effects of tonsillectomy combined with steroid pulse (TSP) therapy for IgA nephropathy (IgAN) are little known. Therefore, we examined the effects of TSP therapy on the kidney outcomes of IgAN in a large, nationwide cohort study in Japan. METHODS: Between 2002 and 2004, 632 IgAN patients with ≥ 0.5 g/day proteinuria at diagnosis were divided into three groups with mild (0.50-0.99 g/day; n = 264), moderate (1.00-1.99 g/day, n = 216), or severe (≥ 2.00 g/day; n = 153). Decline in kidney function and urinary remission were compared among the three groups after TSP therapy, corticosteroid (ST) therapy, or conservative therapy during a mean follow-up of 6.2 ± 3.3 years. 10.6% and 5.9% of patients in the ST and conservative therapy group underwent tonsillectomy. RESULTS: The rate of urinary remission at the final observation was significantly higher in the TSP therapy group than in the ST or conservative therapy groups (mild proteinuria: 64%, 43%, and 41%; moderate proteinuria: 51%, 45%, and 28%; severe proteinuria: 48%, 30%, and 22%, respectively). In contrast, the rate of a 50% increase in serum creatinine was lower in groups TSP therapy, than ST or conservative therapy (mild proteinuria: 2.1%, 10.1% and 16.7%; moderate proteinuria: 4.8%, 8.8% and 27.7%; severe proteinuria: 12.0%, 28.9% and 43.1%, respectively). In multivariate analysis, TSP therapy significantly prevented a 50% increase in serum creatinine levels compared with conservative therapy in groups with moderate and severe proteinuria (hazard ratio, 0.12 and 0.22, respectively). CONCLUSION: TSP significantly increased the rate of proteinuria disappearance and urinary remission in IgAN patients with mild-to-moderate urinary protein levels. It may also reduce the decline in kidney function in patients with moderate-to-severe urinary protein levels.

Analysis of the impact of obesity on the prognosis of IgA nephropathy according to renal function and sex.

BACKGROUND: Few studies have observed the direct effect of obesity on renal prognoses in immunoglobulin A nephropathy (IgAN) or separately evaluated its effects according to sex. We aimed to evaluate the direct and indirect effects of obesity on the renal outcomes of IgAN and observe these effects separately according to renal function and sex. METHODS: We extracted patients with body mass index (BMI) descriptions from a multicenter retrospective cohort analysis in Japan, and excluded those with < 30 days of follow-up, diabetes mellitus, and steroid treatment. Patients were divided into normal (n = 720; 18.5 ≤ BMI < 25) and obese (n = 212; BMI ≥ 25) groups, which were then compared. The endpoints were a 1.5-fold increase in serum creatinine levels and the initiation of renal replacement therapy. RESULTS: The obese group was older, included more males, and was more likely have hypertension, dyslipidemia, proteinuria, tubular atrophy, and lower renal function than the normal group. Patients with an eGFR < 60 mL/min/1.73 m2 had well-matched characteristics between the groups; however, hypertension, low high-density lipoprotein cholesterol, and hypertriglyceridemia were more common in the obese group. Obesity contributed to tubular atrophy, even when adjusted for renal function. In addition, it contributed to proteinuria only in females. However, obesity itself was not a significant prognostic factor. CONCLUSIONS: Although no independent effect on renal prognosis was observed during the study period, the obese group had more risk factors for IgAN progression and obesity contributed to tubular atrophy and female proteinuria. Our results suggest that separately analyzing the prognostic effect of obesity according to sex is important.

Serum IgA/C3 ratio: a useful marker of disease activity in patients with IgA nephropathy.

OBJECTIVE: High serum IgA and low serum C3 levels resulting from lectin and alternative pathway activation might be related to IgA nephropathy (IgAN) progression and exacerbation. This study examined whether the serum IgA/C3 ratio can serve as an IgAN progression marker. METHODS: (1) This nationwide multicenter retrospective study in Japan included 718 patients with biopsy-confirmed IgAN. The patients whose serum creatinine levels at the time of renal biopsy had doubled were defined as having disease progression. (2) Furthermore, to investigate the pathological significance of a reduction in serum IgA/C3 ratio, we reviewed 63 patients whose serum IgA and C3 data at the end of the observation period were obtained. RESULTS: (1) A Kaplan-Meier analysis of the patients with IgAN revealed that the group with a high serum IgA/C3 (≥ 3.3) had a significantly worse renal outcome. In a multivariate analysis of eGFR ≥ 60 mL/min per 1.73m2 at the time of biopsy, poor renal outcome was significantly predicted by a serum IgA/C3 ratio of ≥ 3.3. (2) A 15% reduction in the change of serum IgA/C3 ratio was associated with a significantly higher percentage of complete remission of proteinuria. Among the four groups divided by treatment, both the serum IgA/C3 ratio and proteinuria were reduced only in the tonsillectomy and steroid pulse group. CONCLUSION: The serum IgA/C3 level might reflect the disease activity and be a potent surrogate marker of therapeutic efficacy in patients with IgAN.

A case of non-traumatic rectus sheath hematoma in a post-kidney transplant patient undergoing catheter embolization during anticoagulation treatment for atrial fibrillation.

A 65-year-old man, a post living donor kidney transplant patient, was admitted to the intensive care unit (ICU) with a severe bacterial infection. He also tested positive for coronavirus disease and had a cough. On admission, heparin was administered for atrial fibrillation. On the third day of hospitalization, his general condition had recovered, and he was discharged from the ICU to the general ward. On the fourth day of hospitalization, he experienced abdominal pain, and a hard mass was palpated in the left lower abdomen. On the fifth day of hospitalization, contrast-enhanced computed tomography showed an extensive rectus sheath hematoma (RSH) extending from the left lower abdominal wall to the left side of the bladder, with extravasation from a small branch of the left inferior epigastric artery. Heparin was discontinued, and transcatheter arterial embolization was performed to control the bleeding. RSH is a rare disease, and cases of extensive hematoma in post-kidney transplant patients occur even less frequently. Patients taking anticoagulants and those with chronic kidney disease are at high risk for RSH, so physicians should be cognizant of this disease when these patients develop abdominal pain.

Efficacy and Safety of Anti-angiogenic Agents for Cancer Patients With Proteinuria or a History of Proteinuria: A Systematic Review.

BACKGROUND/AIM: The safety and efficacy of anti-angiogenic agents in patients with cancer with proteinuria and a history of proteinuria are not well established. This systematic review aimed to answer these questions. MATERIALS AND METHODS: We searched three electronic databases for articles published until June 18, 2021. The main outcomes used were "death", "renal impairment", and "proteinuria impairment". RESULTS: After screening 303 references in the PubMed, Cochrane Library, and ICHUSHI-web databases, this review included five studies on renal cell carcinoma (RCC). In patients with metastatic RCC, the hazard ratio of the presence of (or having) proteinuria (1+ or higher) at baseline was 0.82 (0.23-2.97); thus, proteinuria was not significantly associated with the outcome of death. No significant deterioration in kidney function was observed in patients with proteinuria. Although proteinuria at baseline was a significant risk factor for proteinuria progression during and after treatment, most patients maintained grade 1 or 2 proteinuria and continued treatment without dose reduction or discontinuation. CONCLUSION: While weak evidence suggests that proteinuria at the start of treatment with anti-angiogenic agents might be a risk factor for worsening proteinuria, it was not significantly associated with death or renal impairment.

Changes in antibody titer after four and five doses of the SARS-CoV-2 vaccine in Japanese post-kidney transplant patients.

INTRODUCTION: Immunosuppressed patients exhibit low antibody acquisition rates following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. Kidney transplant recipients previously exhibited low antibody acquisition rates after two vaccine doses, which increased after the third dose. We evaluated antibody titers of Japanese post-kidney transplant patients after the fourth and fifth vaccinations. METHODS: Antibody titers for SARS-CoV-2 spike protein were measured between 3 weeks and 3 months after the fourth or fifth vaccination. RESULTS: Increased antibody acquisition rates were observed after the fourth (75.0% antibody-positive) and fifth (81.5% antibody-positive) vaccinations. The antibody-acquired group after the fourth vaccination exhibited a higher body mass index and estimated glomerular filtration rate (eGFR) than the non-acquired group. A higher eGFR was associated with antibody acquisition after the fifth vaccination. CONCLUSION: In Japanese post-kidney transplant patients, the antibody acquisition rate increased with each vaccine additional dose. Additional vaccinations are recommended to protect against SARS-CoV-2 infection.