Isoforms of alkaline phosphatase determined by isoelectric focusing in patients with chronic liver disorders

Toxic Effects of Docosahexaenoic Acid Treatment in the Rat Liver BRL-3A Cell

The cytotoxicity of docosahexaenoic acid (DHA) on normal cells is still unclear. This study investigated the effects of DHA on the cytotoxicity and possible mechanism in the BRL-3A cell. The cultured rat liver BRL-3A cell line was treated with 50, 100 and 200 μM DHA for 24 h. The cell viability was increased in the 50 and 100 μM DHA treatments, but decreased in the 200 μM DHA treatment. The 50, 100 and 200 μM DHA treatments increased the proportion of the apoptotic cells, the levels of lactate dehydrogenase (LDH), alkaline phosphatase (AKP) and IL-6 in the supernatant, and the ratio of the phosphonated p38MAPK to the p38MAPK (p-p38/p38) protein in the cells. The expression of TGF beta-activated kinase 1 (TAK1), nuclear transcription factor-κB p65 (NF-κB p65) and the inhibitor of NF-κB alpha (IκBα) mRNA, and the ratio of the phosphonated IκBα (p-IκBα) to IκBα protein were increased in the 200 μM DHA treatment, while the ratio of phosphonated extracellular regulated protein kinases (p-ERK) to ERK protein was decreased in the 200 μM DHA treatment. These results indicate that DHA-treated (50, 100 and 200 μM) BRL-3A cells for 24 h promotes cell apoptosis and inflammatory response, and the p38 MAPK, ERK and NF-κB signal pathways were involved in mediating the apoptosis and inflammatory response.

Alkaline Phosphatases Account for Low Plasma Levels of Inorganic Pyrophosphate in Chronic Kidney Disease

Introduction

Patients on dialysis and kidney transplant recipients (KTR) present the syndrome of mineral and bone disorders (MBD), which share common traits with monogenic calcifying diseases related to disturbances of the purinergic system. Low plasma levels of inorganic pyrophosphate (PP_i) and ectopic vascular calcifications belong to these two conditions. This suggests that the purinergic system may be altered in chronic kidney disease with MBD. Therefore, we perform a transversal pilot study in order to compare the determinants of PPi homeostasis and the plasma levels of PPi in patients on dialysis, in KTR and in healthy people.

Patients and Methods

We included 10 controls, 10 patients on maintenance dialysis, 10 early KTR 3 ± 1 months after transplantation and nine late KTR 24 ± 3 months after transplantation. We measured aortic calcifications, plasma and urine levels of PP_i, the renal fractional excretion of PP_i (FePP_i), nucleoside triphosphate hydrolase (NPP) and ALP activities in plasma. Correlations and comparisons were assessed with non-parametric tests.

Results

Low PP_i was found in patients on dialysis [1.11 (0.88–1.35), p = 0.004], in early KTR [0.91 (0.66–0.98), p = 0.0003] and in late KTR [1.16 (1.07–1.45), p = 0.02] compared to controls [1.66 (1.31–1.72) μmol/L]. Arterial calcifications were higher in patients on dialysis than in controls [9 (1–75) vs. 399 (25–526) calcium score/cm², p < 0.05]. ALP activity was augmented in patients on dialysis [113 (74–160), p = 0.01] and in early KTR [120 (84–142), p = 0.002] compared to controls [64 (56–70) UI/L]. The activity of NPP and FePP_i were not different between groups. ALP activity was negatively correlated with PP_i (r = −0.49, p = 0.001).

Discussion

Patients on dialysis and KTR have low plasma levels of PP_i, which are partly related to high ALP activity, but neither to low NPP activity, nor to increased renal excretion of PP_i. Further work is necessary to explore comprehensively the purinergic system in chronic kidney disease.

Prognostic impact of alkaline phosphatase for in-hospital mortality in patients with acute coronary syndrome: a prospective cohort study in China

OBJECTIVES

Alkaline phosphatase (ALP) can promote vascular calcification, but the association between ALP and in-hospital mortality in patients with acute coronary syndrome (ACS) is not well defined.

DESIGN

A prospective cohort study.

SETTING AND PARTICIPANTS

A total of 6368 patients with ACS undergoing percutaneous coronary intervention (PCI) from 1 January 2010 to 31 December 2017 were analysed.

MAIN OUTCOME MEASURES

In-hospital mortality was used in this study.

RESULTS

ALP was analysed both as a continuous variable and according to three categories. After multivariable adjustment, in-hospital mortality was significantly higher in Tertile 3 group (ALP＞85 U/L) (OR: 2.399, 95% CI 1.080 to 5.333, p=0.032), compared with other two groups (Tertile 1: ＜66 U/L; Tertile 2: 66-85 U/L). When ALP was evaluated as a continuous variable, after multivariable adjustment, the ALP level was associated with an increased risk of in-hospital mortality (OR: 1.011, 95% CI 1.002 to 1.020, p=0.014). C-statistic of ALP for predicting in-hospital mortality was 0.630 (95% CI 0.618 to 0.642, p=0.001). The cut-off value was 72 U/L with a sensitivity of 0.764 and a specificity of 0.468. However, ALP could not significantly improve the prognostic performance of Global Registry of Acute Coronary Events (GRACE) score (GRACE score+ALP vs GRACE score: C-statistic: z=0.485, p=0.628; integrated discrimination improvement: 0.014, p=0.056; net reclassification improvement: 0.020, p=0.630).

CONCLUSIONS

In patients with ACS undergoing PCI, ALP was an independent predictor of in-hospital mortality. But it could not improve the prognostic performance of GRACE score.