No relationship between lipoprotein-associated phospholipase A2, proinflammatory cytokines, and neopterin in Alzheimer's disease.

OBJECTIVE: Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a reported risk factor for dementia. However, the relationship between Alzheimer's disease (AD) and Lp-PLA2 is still debatable and, to the best of our knowledge, no study has evaluated the associations between levels of Lp-PLA2, proinflammatory cytokines, and neopterin in AD. METHODS: In total, 59 patients with AD and 38 non-demented individuals were included in the case-control study. Fasting serum concentrations of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), neopterin, and Lp-PLA2 were determined using ELISA. The associations between AD and each of the variables were analyzed by logistic regression. RESULTS: The median Lp-PLA2 levels in AD and controls were similar (P=0.29, not significant). Median serum neopterin and IL-6 levels were significantly higher in patients with AD than in controls (P=0.0001 and P=0.03, respectively). In regression analyses, median neopterin levels, a lower level of education, and female gender were significantly associated with AD when compared with controls (OR, 31.44, 95% CI 3.59-275.28, P=0.002; OR, 4.35, 95% CI 1.13-16.61, P=0.032; OR, 7.25, 95% CI 1.88-28.00, P=0.004, respectively). CONCLUSION: In contrast to previous evidence suggesting its role in dementia and AD, Lp-PLA2 enzyme levels were higher in the controls, and no relationship between Lp-PLA2 and either proinflammatory cytokines or neopterin was identified in AD. Elevated neopterin levels may be considered inflammatory markers of AD.

Effect of different levels of cigarette smoking on lipid peroxidation, glutathione enzymes and paraoxonase 1 activity in healthy people.

The purpose of this study was to examine the effect of different levels of cigarette smoking on lipid peroxidation, glutathione enzymes and paraoxonase 1 (PON1) activity in a healthy population. The study included 130 subjects who were classified as mild (20 cigarettes daily, Group III, n=33) and never smokers (controls, Group IV, n=32). Malondialdehyde (MDA) levels, PON1 and erythrocyte glutathione enzyme activities were measured. MDA levels were significantly higher in smokers than never smokers (P<0.05 for Group I, P<0.001 for Group II and III). PON1 activity was significantly lower in heavy smokers (P<0.001). Glutathione peroxidase (GSH-Px) activity was significantly lower in the smokers (P<0.0001). Glutathione reductase (GR) activity was significantly higher in smokers (P<0.0001). MDA levels negatively correlated with PON1 and GSH-PX activities (P<0.01), whereas they positively correlated with GR activities (P<0.001). At every level, cigarette smoking is associated with increased lipid peroxidation and causes an impairment in antioxidant systems.

Beta2-microglobulin and cystatin C in type 2 diabetes: assessment of diabetic nephropathy.

BACKGROUND: Changes in glomerular filtration rate (GFR) provide a valuable indicator of the progression of diabetic nephropathy (DN). This study was designed to demonstrate the clinical values of serum cystatin C (Cys C) and beta2-microglobulin in the assessment of renal function in type 2 diabetics by comparing them with the GFR, estimated from the uptake phase of 99 m technetium dimetiltriamino pentaacetic acid renogram (GFR-DTPA) and creatinine clearances. MATERIALS AND METHODS: 68 type 2 diabetic patients with (urinary albumin excretions (UAE) 30 - 300 mg/24 h) (n = 39) and without (UAE < 30 mg/24 h) (n = 29) microalbuminuria and 32 controls were enrolled in the study. Serum Cys C, beta2-microglobulin, creatinine, urinary microalbumin levels, creatinine clearances and GFR-DTPA values were determined in all groups. Non-parametric ROC curves, using a cut-off GFR-DTPA of 60 mL/min/1.73 m (2), were obtained for these markers. RESULTS: Serum Cys C, beta2-microglobulin, glucose and HbA1c concentrations were significantly higher in the group with diabetes compared to controls. In the patients with microalbuminuria, serum Cys C and glucose concentrations increased significantly in comparison to patients with normoalbuminuria, while no differences were observed for beta2-microglobulin levels. Serum creatinine concentrations, GFR-DTPA values and creatinine clearances were not different between both diabetic groups and controls. Cys C was positively correlated with beta2-microglobulin and creatinine and negatively with GFR values; beta2-microglobulin was also positively correlated with serum creatinine in microalbuminurics. A significant inverse correlation was found between beta2-microglobulin and GFR values in both microalbuminurics and normoalbuminurics. CONCLUSIONS: Increased Cys C and beta2-microglobulin in diabetics may be early indicators of incipient DN. The diagnostic accuracies of Cys C and beta2-microglobulin are superior to that of serum creatinine in distinguishing between mild and moderately reduced GFR.

Spuriously elevated inorganic phosphate level in a multiple myeloma patient.

We report the case of a patient with IgG multiple myeloma and pseudohyperphosphatemia. The patient had no clinical features of hyperphosphatemia. Subsequent investigations demonstrated that this hyperphosphatemia was spurious and was caused by a high concentration of the paraprotein. Deproteinization of the serum samples by sulfosalicylic acid resulted in normalization of the elevated phosphate values. This pseudohyperphosphatemia resulted from an increase in optic density because of interference between monoclonal immunoglobulin and the molybdic reagent used to determine phosphate in serum. These data indicate that the finding of marked hyperphosphatemia in multiple myeloma patients should always prompt an assay carried out on a deproteinized sample. In addition, knowledge of this phenomenon may avoid confusion, unnecessary testing and obviate confusion in the clinical evaluation of patients with multiple myeloma.

The urinary excretion of glycosaminoglycans and heparan sulphate in lupus nephritis.

Renal involvement in systemic lupus erythematosus (SLE) affects the disease outcome. In order to advance the diagnosis and the initiation of therapy, non-invasive diagnostic techniques are required. In this study, urinary glycosaminoglycans (GAG) and heparan sulphate (HS) were measured in 26 patients with biopsy-proven lupus nephritis and compared to 16 healthy controls. Uronic acid as a representative of GAGs in urine was determined spectrophotometrically with the meta-hydroxydiphenyl, following acid treatment. HS was determined as hexosamine by the method of Smith and Gilkerson. The median values of GAG (3.99 mg/g crea./day) and HS (2.41 mg/g crea./day) in patients were significantly ( P = 0.001) higher than in the control group (1.98 and 0.87, respectively). There was a positive correlation between GAG and HS values ( P = 0.000, r = 0.924) in SLE patients. There were no differences in HS excretion, microalbuminuria and SLE-DAI scores between different classes of lupus nephritis. However, GAG values in class 3 nephritis were significantly ( P = 0.033) higher than from both class 2 and class 4 lupus nephritis. There were no differences in all the measured parameters between normoalbuminuric, microalbuminuric and macroproteinuric patients. Furthermore, there were no correlations between GAG, HS excretions and SLE-DAI scores or microalbuminuria. These results suggest that urinary GAG and HS may serve as useful, independent and non-invasive markers of lupus nephritis.