A case of pulmonary hyalinizing granuloma characterized by pseudohyponatremia due to hyperproteinemia.

A 57-year-old man presented with multiple pulmonary nodules. Thoracoscopic lung biopsy led to a pathological diagnosis of pulmonary hyalinizing granuloma (PHG) at the age of 39 years. The disease was progressive, refractory to therapy, and necessitated home oxygen therapy 10 years after the diagnosis. Hyponatremia progressed gradually along with lung disease. His serum sodium level was 129 mEq/L but serum osmolality was normal (287 mOsm/kg). Concomitant hyperproteinemia (12.1 g/dL) was attributable to hyperglobulinemia. Direct ion-selective electrode measurement revealed a normal sodium level (137 mmol/L). We herein report a case of PHG characterized by pseudohyponatremia due to hyperproteinemia, an uncommon finding in this rare entity. A left lung transplant was successfully performed, and no pseudohyponatremia was observed. Pseudohyponatremia should be suspected and diagnosed to prevent a misdiagnosis that could lead to complications from inappropriate treatment with sodium supplementation or restriction of drinking water. The direct ion-selective electrode measurement was useful for diagnosing pseudohyponatremia.

Marked Metabolic Acidosis Due to a Transverse Stoma after Urethroplasty for Congenital Epispadias.

A 58-year-old woman was admitted to our hospital. At 10 years old, she had undergone bilateral uretero-sigmoid anastomosis for congenital epispadias, and at 57 years old, she had received transverse colostomy. Biochemical tests showed marked metabolic acidosis. Computed tomography showed urine stagnation in the sigmoid colon, leading to a diagnosis of metabolic acidosis associated with transverse stoma after bilateral uretero-sigmoid anastomosis. Her bone mineral density was below normal, and the bone metabolic marker levels were high, indicating high-turnover osteoporosis. Both metabolic acidosis and bone metabolism were stabilized by treatment with a transanal urinary catheter, sodium bicarbonate, and vitamin D.

Long-term Clinical Course after Living Kidney Donation by a Patient with Gitelman Syndrome Harboring a Compound Heterozygous Mutation of the SLC12A3 Gene.

The eligibility for kidney donation and long-term post-donation renal prognosis of patients with Gitelman syndrome (GS) are unknown. We herein report a 44-year-old woman with GS who donated her kidney for transplant. A gene sequence analysis revealed compound heterozygous mutations of T180K and L858H in the SLC12A3 gene. Since transplantation, the renal function and serum potassium and magnesium levels of the donor and recipient have remained stable for seven years with careful monitoring and supplementation. Patients with asymptomatic GS who have no complications can be considered eligible to donate their kidney for transplant with proper monitoring after transplantation.

Hypercalcemia caused by comorbid parathyroid adenoma and pulmonary tuberculosis.

Hypercalcemia is usually secondary to one etiology, although two coexisting etiologies can rarely cause hypercalcemia. Here, we report a 47-year-old woman with hypercalcemia caused by comorbid parathyroid adenoma and pulmonary tuberculosis. Primary hyperparathyroidism is the most common cause of hypercalcemia. Tuberculosis is a rare cause of hypercalcemia, but Japan continues to have an intermediate tuberculosis burden. Therefore, tuberculosis should be considered as a cause of hypercalcemia in Japan. Patients with tuberculosis are often asymptomatic, making the diagnosis difficult. In the previous cases in which these diseases coexisted, one disease was diagnosed after treatment of the other. In our case, the very high 1,25-dihydroxyvitamin D level (162 pg/mL) helped us to diagnose asymptomatic tuberculosis and both diseases were diagnosed promptly. It is necessary to consider comorbidities, including tuberculosis in a case with a very high 1,25-dihydroxyvitamin D level. We report a valuable case in which the early diagnosis and treatment of tuberculosis and primary hyperparathyroidism prevented the spread of tuberculosis.

Gcm1 is involved in cell proliferation and fibrosis during kidney regeneration after ischemia-reperfusion injury.

In acute kidney injury (AKI), the S3 segment of the proximal tubule is particularly damaged, as it is most vulnerable to ischemia. However, this region is also involved in renal tubular regeneration. To deeply understand the mechanism of the repair process after ischemic injury in AKI, we focused on glial cells missing 1 (Gcm1), which is one of the genes expressed in the S3 segment. Gcm1 is essential for the development of the placenta, and Gcm1 knockout (KO) is embryonically lethal. Thus, the function of Gcm1 in the kidney has not been analyzed yet. We analyzed the function of Gcm1 in the kidney by specifically knocking out Gcm1 in the kidney. We created an ischemia-reperfusion injury (IRI) model to observe the repair process after AKI. We found that Gcm1 expression was transiently increased during the recovery phase of IRI. In Gcm1 conditional KO mice, during the recovery phase of IRI, tubular cell proliferation reduced and transforming growth factor-ß1 expression was downregulated resulting in a reduction in fibrosis. In vitro, Gcm1 overexpression promoted cell proliferation and upregulated TGF-ß1 expression. These findings indicate that Gcm1 is involved in the mechanisms of fibrosis and cell proliferation after ischemic injury of the kidney.

Gcm2 regulates the maintenance of parathyroid cells in adult mice.

Glial cells missing homolog 2 (GCM2), a zinc finger-type transcription factor, is essential for the development of parathyroid glands. It is considered to be a master regulator because the glands do not form when Gcm2 is deficient. Remarkably, Gcm2 expression is maintained throughout the fetal stage and after birth. Considering the Gcm2 function in embryonic stages, it is predicted that Gcm2 maintains parathyroid cell differentiation and survival in adults. However, there is a lack of research regarding the function of Gcm2 in adulthood. Therefore, we analyzed Gcm2 function in adult tamoxifen-inducible Gcm2 conditional knockout mice. One month after tamoxifen injection, Gcm2-knockout mice showed no significant difference in serum calcium, phosphate, and PTH levels and in the expressions of calcium-sensing receptor (Casr) and parathyroid hormone (Pth), whereas Ki-67 positive cells were decreased and terminal deoxynucleotidyl transferase (TdT) dUTP Nick-End Labeling (TUNEL) positive cell number did not change, as compared with those of controls. Seven months after tamoxifen injection, Gcm2-knockout mice showed shrinkage of the parathyroid glands and fewer parathyroid cells. A significant decrease was noted in Casr- and Pth-expressing cells and serum PTH and Ca levels, whereas serum phosphate levels increased, as compared with those of controls. All our results concluded that a reduction of Gcm2 expression leads to a reduction of parathyroid cell proliferation, an increase in cell death, and an attenuation of parathyroid function. Therefore, we indicate that Gcm2 plays a prominent role in adult parathyroid cell proliferation and maintenance.

Hypermethylation of the CaSR and VDR genes in the parathyroid glands in chronic kidney disease rats with high-phosphate diet.

Chronic kidney disease (CKD) disrupts mineral homeostasis and its representative pathosis is defined as secondary hyperparathyroidism (SHPT). SHPT occurs during the early course of progressive renal insufficiency, and is associated with mortality and cardiovascular events. SHPT results in reduction of calcium-sensing receptor (CaSR) and vitamin D receptor (VDR) in the parathyroid glands during CKD. However, the precise mechanism of CaSR and VDR reduction is largely unknown. CKD was induced through two-step 5/6 nephrectomy, and then CKD rats and sham-operated rats were maintained for 8 weeks on diets containing 0.7 % phosphorus (normal phosphate) or 1.2 % phosphorus (high phosphate). In gene expression analysis, TaqMan probes were used for quantitative real-time polymerase chain reaction. Finally, CaSR and VDR protein expressions were analyzed using immunohistochemistry. DNA methylation analysis was performed using a restriction digestion and quantitative PCR. CaSR and VDR mRNA were reduced only in CKD rats fed the high-phosphorus diets (CKD HP), then CaSR and VDR immunohistochemical expressions were compatible with gene expression assay. SHPT was then confirmed only in CKD HP rats. Furthermore, sole CKD HP rats showed the hypermethylation in CaSR and VDR genes; however, the percentage methylation of both genes was low. Although CaSR and VDR hypermethylation was demonstrated in PTGs of CKD HP rats, the extent of hypermethylation was insufficient to support the relevance between hypermethylation and down-regulation of gene expression because of the low percentage of methylation. Consequently, our data suggest that mechanisms, other than DNA hypermethylation, were responsible for the reduction in mRNA and protein levels of CaSR and VDR in PTGs of CKD HP rats.

Probable C4d-negative accelerated acute antibody-mediated rejection due to non-HLA antibodies.

We report a case of probable C4d-negative accelerated acute antibody-mediated rejection due to non-HLA antibodies. A 44 year-old male was admitted to our hospital for a kidney transplant. The donor, his wife, was an ABO minor mismatch (blood type O to A) and had Gitelman syndrome. Graft function was delayed; his serum creatinine level was 10.1 mg/dL at 3 days after transplantation. Open biopsy was performed immediately; no venous thrombosis was observed during surgery. Histology revealed moderate peritubular capillaritis and mild glomerulitis without C4d immunoreactivity. Flow cytometric crossmatching was positive, but no panel-reactive antibodies against HLA or donor-specific antibodies (DSAbs) to major histocompatibility complex class I-related chain A (MICA) were detected. Taken together, we diagnosed him with probable C4d-negative accelerated antibody-mediated rejection due to non-HLA, non-MICA antibodies, the patient was treated with steroid pulse therapy (methylprednisolone 500 mg/day for 3 days), plasma exchange, intravenous immunoglobulin (40 g/body), and rituximab (200 mg/body) were performed. Biopsy at 58 days after transplantation, at which time S-Cr levels were 1.56 mg/dL, found no evidence of rejection. This case, presented with a review of relevant literature, demonstrates that probable C4d-negative accelerated acute AMR can result from non-HLA antibodies.

Is granular formulation of lanthanum carbonate more effective than chewable tablets?

Maintenance dialysis patients at our hospital who had been receiving lanthanum carbonate (LC) chewable tablets were switched to the same dosage of the granules, and the differences in serum phosphorus (P) levels were compared, together with stratifying patients at the baseline characteristics. Compared to average serum P level of 5.48 mg/dL for 2 months prior to switching, the average level for 2 months after switching was 4.99 mg/dL (P = 0.049). For patients who were under 60, serum P levels were significantly improved after switching (P = 0.016), and for patients who were concomitantly taking many kinds of medications, a correlation to high reductions of serum P level after switching was shown (R = -0.635, P = 0.015). In order to maximize pharmaceutical potential of LC, we think that it is not only necessary to provide patients with how to take the medication, but it is also important to take into consideration the patients' baseline characteristics.