Cystatin C predicts the risk of incident cerebrovascular disease in the elderly: A meta-analysis on survival date studies.

BACKGROUND: Stroke is the third leading cause of global year of life lost in all-age and second-ranked cause of disability adjusted life years in middle-aged and elder population. Therefore, it is critical to study the relationship between vascular-related risk factors and cerebrovascular diseases. Several cross-sectional studies have shown that Cystatin C (Cys C) is an independent risk factor for cerebrovascular diseases and levels of Cys C are significantly higher in stroke patients than in healthy individuals. In this meta-analysis, we introduce a Cox proportional hazards model to evaluate the causality between Cys C and the risk of cerebrovascular accident in the elderly. METHODS: We searched PubMed, EMBASE, the Web of Science, and the Cochrane Library from 1985 to 2019 for studies on the relationship between serum Cys C and incidence stroke with Cox proportional hazards models. We conducted a subgroup analysis of the selected studies to determine a connection between atherosclerosis and stroke. Finally, 7 research studies, including 26,768 patients without a history of cerebrovascular, were studied. RESULTS: After comparing the maximum and minimum Cys C levels, the hazard ratio for all types of stroke, including ischemic and hemorrhagic stroke, was 1.18 (95% confidence interval 1.04-1.31) with moderate heterogeneity (I2 = 43.0%; P = .119) in a fixed-effect model after pooled adjustment for other potential risk factors. In the subgroup analysis, the hazard ratio and 95% confidence interval for Cys C stratified by atherosclerosis was 1.85 (0.97-2.72). As shown in Egger linear regression test, there was no distinct publication bias (P = .153). CONCLUSION: Increased serum Cys C is significantly associated with future stroke events in the elderly, especially in patients with carotid atherosclerosis. Thus, serum levels of Cys C could serve as a predicted biomarker for stroke attack.

What makes D-dimer assays suspicious-heterophilic antibodies?

BACKGROUND: Heterophilic antibodies are still an important source of interference in immunoassays, but reports of interference with D-dimers are rare. Are D-dimer level abnormalities, found in the clinic, caused by heterophilic antibodies as well, or are other mechanisms involved? We will elaborate on this issue through two different examples in this article. METHODS: Serum from two patients with significantly elevated levels of D-dimers were measured and compared by different methods, diluted, and dealt with heterophilic antibody blockers. At the same time, to retrieve the interference, we focused on the cause of D-dimer false positives and made a systematic review of the literature. RESULTS: The D-dimer values were normal (0.49 and 0.15 µg/mL) detected with different testing method and decreased after addition of heterophilic antibody blocking reagent. According to literature data, there were 66.7% (4/6) references showed the interference were heterophilic antibody. CONCLUSIONS: The influence of heterophilic antibodies on the measurement of D-dimers remains a big challenge. Different measuring instruments and methods may have significant differences in the measurement of D-dimers. By using a combination of instrumental methods for measuring, incorporating heterophilic antibody blockers, and combining with clinical performance and imaging data, most of the interference can be eliminated.

Association of vitamin D level with asthma control and pulmonary function in asthmatic children aged 4-12 years / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the association of vitamin D level with asthma control and pulmonary function in children with asthma.</p><p><b>METHODS</b>A total of 150 children with asthma were enrolled as observation group, and 55 healthy children were enrolled as control group. According to the level of asthma control, the children were divided into good control group, partial control group, and non-control group. Chemiluminescence microparticle immunoassay was used to measure the serum level of 25-hydroxyvitamin D [25(OH)D] for all groups. According to the level of 25(OH)D, the asthmatic children were divided into normal vitamin D group, vitamin D insufficiency group, and vitamin D deficiency group. Pulmonary function was measured for all asthmatic children.</p><p><b>RESULTS</b>The observation group had a significantly lower serum level of 25(OH)D than the control group (25± 7 ng/mL vs 29± 4 ng/mL; P<0.05). The normal vitamin D group had the highest asthma control rate, followed by the vitamin D insufficiency group and the vitamin D deficiency group (P<0.05). There was no significant difference in pulmonary function among the three groups (P>0.05).</p><p><b>CONCLUSIONS</b>Asthmatic children have a lower serum level of 25(OH)D than healthy children. The serum level of 25(OH)D is associated with the level of asthma control and has no association with pulmonary function.</p>