Hironobu Nobata

Tertiary Hyperparathyroidism Resistant to Cinacalcet Treatment

Cinacalcet hydrochloride (cinacalcet) has been reported to be efficacious for patients with tertiary hyperparathyroidism (THPT). We experienced five patients with THPT requiring parathyroidectomy (PTx) because of resistance to cinacalcet treatment and investigated their clinical characteristics and clinical course. The maximum diameter of the parathyroid gland estimated by ultrasonography before renal transplantation was evaluated. Serum total calcium, phosphorus, intact parathyroid hormone (iPTH), alkaline phosphatase (ALP), and creatinine (Cr) levels were investigated every three months after the administration of cinacalcet and at PTx. After surgery, the Cr levels were followed. In all five patients, at least one parathyroid gland had a largest diameter of more than 1 cm, and the mean diameter was 18.7 mm (range 14.9–24.1 mm). Intact PTH and ALP levels gradually increased after the initiation of cinacalcet and the Cr levels transiently increased after PTx. These findings suggest that the existence of a severely enlarged nodular hyperplastic gland is a main factor involved in resistance to cinacalcet.

Systemic AA amyloidosis in a patient with lung metastasis from renal cell carcinoma

AA amyloidosis occurs in patients with high levels of serum amyloid A protein (SAA), which is produced by liver cells in response to signals from several pro-inflammatory cytokines. Chronic inflammatory disease is a major cause of AA amyloidosis; however, malignant neoplasms are rarely reported to be associated with AA amyloidosis. We report herein a case of a solitary lung metastasis of renal cell carcinoma associated with systemic AA amyloidosis. Pathological specimens of the resected lung tumor demonstrated renal cell carcinoma, and the presence of IL-1β, IL-6, and TNF-α in the lymphocytes and plasma cells surrounding the tumor cells, and AA amyloid in the vascular area, but not in metastatic clear cells. Four weeks after surgery, serum IL-6, SAA, and CRP levels normalized. Although this case is very rare, it is full of interesting suggestions about the pathogenesis of malignancy-related systemic amyloidosis.

Hypocalcemia immediately after renal transplantation

After renal transplantation (RTX), hypercalcemia, mainly due to persistent hyperparathyroidism, and hypophosphatemia, caused by the improved ability to excrete phosphorus in the renal tubules, are expected. However, immediately after RTX, a transient reduction in serum calcium (Ca) levels has been previously reported, the reason for which is not clear.

A comparative analysis of two interferon-γ releasing assays to detect past tuberculosis infections in Japanese rheumatoid arthritis patients

Abstract Objectives: To compare the utility of QuantiFERON-TB Gold in tube (QFT-GIT) and T-SPOT.TB assays to detect past tuberculosis infection in Japanese rheumatoid arthritis patients receiving methotrexate. Methods: We compared the sensitivities and specificities, the rates of indeterminate results, and the rates of positive results in patients with total and CD4-positive lymphocyte counts of both assays simultaneously performed on 68 rheumatoid arthritis patients receiving methotrexate, in whom 33 had evidence of past tuberculosis infection by chest computed tomography and the other had neither history of tuberculosis exposure nor abnormalities in chest computed tomography. Results: The sensitivities, specificities, and the rates of indeterminate results of QFT-GIT were 21.2%, 100%, and 4.4%, and those of T-SPOT.TB were 21.9%, 100%, and 1.5%, respectively. The overall agreement of both assays was good (κ = 0.68). In patients with past tuberculosis infection, there are significant positive linear trends in positive rates of both assays across ranges of larger numbers of total and CD4-positive lymphocyte counts. Conclusions: Both assays were equally useful with high specificities, but may falsely identify past tuberculosis infection owing to low sensitivities. In patients with low total and CD4-positive lymphocyte counts, both assays might give higher rates of false negative results.

Light Chain Deposition Disease Diagnosed with Laser Micro-dissection, Liquid Chromatography, and Tandem Mass Spectrometry of Nodular Glomerular Lesions

A 42-year-old man developed nephrotic syndrome and rapidly progressive renal failure. Kidney biopsy demonstrated nodular glomerulosclerosis, negative Congo red staining, and no deposition of light or heavy chains. Laser micro-dissection and liquid chromatography with tandem mass spectrometry of nodular lesions revealed the presence of a kappa chain constant region and kappa III variable region, which signified light chain deposition disease. Dexamethasone and thalidomide were effective in decreasing the serum levels of free kappa light chain from 147.0 to 38.0 mg/L, eliminating proteinuria, and halting the worsening of the kidney dysfunction, with serum creatinine levels stable around 4.0 mg/dL for 3 years.

Acid–base disturbances in nephrotic syndrome: analysis using the CO2/HCO3 method (traditional Boston model) and the physicochemical method (Stewart model)

BackgroundThe Stewart model for analyzing acid–base disturbances emphasizes serum albumin levels, which are ignored in the traditional Boston model. We compared data derived using the Stewart model to those using the Boston model in patients with nephrotic syndrome.MethodsTwenty-nine patients with nephrotic syndrome and six patients without urinary protein or acid–base disturbances provided blood and urine samples for analysis that included routine biochemical and arterial blood gas tests, plasma renin activity, and aldosterone. The total concentration of non-volatile weak acids (ATOT), apparent strong ion difference (SIDa), effective strong ion difference (SIDe), and strong ion gap (SIG) were calculated according to the formulas of Agrafiotis in the Stewart model.ResultsAccording to the Boston model, 25 of 29 patients (90%) had alkalemia. Eighteen patients had respiratory alkalosis, 11 had metabolic alkalosis, and 4 had both conditions. Only three patients had hyperreninemic hyperaldosteronism. The Stewart model demonstrated respiratory alkalosis based on decreased PaCO2, metabolic alkalosis based on decreased ATOT, and metabolic acidosis based on decreased SIDa. We could diagnose metabolic alkalosis or acidosis with a normal anion gap after comparing delta ATOT [(14.09 − measured ATOT) or (11.77 − 2.64 × Alb (g/dL))] and delta SIDa [(42.7 − measured SIDa) or (42.7 − (Na + K − Cl)]). We could also identify metabolic acidosis with an increased anion gap using SIG > 7.0 (SIG = 0.9463 × corrected anion gap—8.1956).ConclusionsPatients with nephrotic syndrome had primary respiratory alkalosis, decreased ATOT due to hypoalbuminemia (power to metabolic alkalosis), and decreased levels of SIDa (power to metabolic acidosis). We could detect metabolic acidosis with an increased anion gap by calculating SIG. The Stewart model in combination with the Boston model facilitates the analysis of complex acid–base disturbances in nephrotic syndrome.