心型脂肪酸结合蛋白金标记免疫层析法的建立

目的建立胶体金免疫层析检测人心型脂肪酸结合蛋白(H-FABP)的方法。方法采用胶体金标记抗H-FABP单克隆抗体67D3,将其与生物素化的抗H-FABP单抗66E2包被于吸水纤维,将链霉亲合素结合于硝酸纤维素膜,制成免疫层析试条,依据试剂条上出现肉[可见的红色线条判定结果。用其检测93例发病6h内的胸痛患者血浆中的H-FABP,与心肌肌钙蛋白Ⅰ(cTnI)和肌酸激酶MB同工酶(CK-MB)的检测结果比较,评价其诊断急性心肌梗死(AMI)的敏感性和特异性。结果金标记试条检测H-FABP的浓度低限值为16.8ng/ml,检测结果与ELISA方法比较符合率达96.9%,诊断发病3h内和6h内AMI的敏感性分别为64.29%和84.38%,高于cTnI(28.57%、53.13%)和CK-MB(21.43%、56.25%)(P<0.05),特异性无显著性差异。结论本法简便、快速、准确,可用于AMI早期筛查。     

血浆心肌脂肪酸结合蛋白在急性胸痛患者诊断中的意义

目的探讨血浆心肌脂肪酸结合蛋白(H-FABP)在急性胸痛患者中的诊断价值。方法对93例胸痛发作6 h内的患者,采用夹心ELISA法检测血浆H-FABP水平,其中急性心肌梗死(AMI)32例、不稳定型心绞痛(UAP)24例、稳定型心绞痛(SAP)22例,非心源性胸痛(NCCP)15例,并选69例健康体检者为对照组。结果AMI组的H-FABP水平(78.58±52.2 ng/mL)最高,UAP组(12.57±5.80 ng/mL)次之,差异有统计学意义(P<0.01);SAP组(3.52±2.29 ng/mL)、NCCP组(4.09±4.18 ng/mL)与对照组(3.30±1.56 ng/mL)比较差异无统计学意义(P>0.05)。以16.8 ng/mL作为H-FABP诊断AMI的最佳临界值,其诊断AMI敏感性为84.4%,特异性为91.8%。结论血浆H-FABP水平可作为心肌坏死或损伤的早期判断指标,可为急性胸痛患者的诊断提供依据。     

Performance of a semi-quantitative whole blood test for human heart-type fatty acid-binding protein (H-FABP)

OBJECTIVES: We evaluated the accuracy of visually reading the whole blood Rapicheck H-FABP panel test using the quantitative plasma H-FABP concentration as the reference. SUBJECTS AND METHODS: Consecutive patients with chest pain (n = 237) who were suspected of having acute myocardial infarction were recruited. The appearance of an evident test line within 5 min was given a grade of +3 (strongly positive), appearance within 15 min +2 (moderately positive) and the appearance of a weak test line within 15 min +1 (weakly positive). RESULTS AND DISCUSSION: The concordance rates were 91.8% for positive, 70.1% for negative and 80.2% for overall. Plasma H-FABP concentrations were above the cut-off value for 9.2% of negative (0) results. Fifty percent of weakly positive (+1) and 25.0% of moderately positive (+2) results had H-FABP concentrations lower than the cut-off value. All of the strongly positive (+3) were above the cut-off value. These results suggested that the false-positive and false-negative results of Rapicheck H-FABP were caused by over or underestimation in visual reading when the plasma H-FABP concentration was near the cut-off concentration. CONCLUSIONS: Low accuracy of visual reading of Rapicheck H-FABP was due to poor estimation by manual reading around the cut-off value.     

Prognostic factors in obstetric patients admitted to an Indian intensive care unit

OBJECTIVES: Obstetric patients form a significant proportion of intensive care unit admissions in countries like India, where maternal mortality is high (440 per 100,000 deliveries). We studied the diseases requiring intensive care and prognostic factors in obstetric patients. DESIGN: Retrospective chart review. Acute Physiology and Chronic Health Evaluation (APACHE) II data were prospectively collected. SETTING: Multidisciplinary intensive care unit of a public hospital in Mumbai, India. PATIENTS: Women admitted during pregnancy or 6 wks post-partum during a 5-yr study period (1997-2001). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Four hundred fifty-three obstetric patients (age 25.5 +/- 4.6 yrs [mean +/- SD], mean gestational age 31 wks) were admitted (548 intensive care unit admissions per 100,000 deliveries), 138 with single organ failure and 152 with multiple organ failure. Ninety-eight women died (mortality rate 21.6%). Mortality was comparable in antepartum (n = 216) and postpartum (n = 247) admissions but increased with increasing number of organs affected. There were 236 fetal deaths (52%), of which 104 occurred before hospital admission. Median APACHE II score was 16 (interquartile range, 10-24), and standardized mortality ratio (observed deaths/predicted deaths) was 0.78. Compared with pregnant patients admitted with obstetric disorders (n = 313), those with medical diseases (n = 140) had significantly lower APACHE II scores (median 14 vs. 17) but higher observed mortality rate (28.6% vs. 18.5%; odds ratio, 1.76; 95% confidence interval, 1.08-2.87) and standardized mortality ratio (1.09 vs. 0.66). On multivariate analysis, increased mortality rate was associated with acute cardiovascular (odds ratio, 5.8), nervous system (odds ratio, 4.73) and respiratory (odds ratio, 12.9) failure, disseminated intravascular coagulation (odds ratio, 2.4), viral hepatitis (odds ratio, 5.8), intracranial hemorrhage (odds ratio, 5.4), absence of prenatal care (odds ratio, 1.94), and >24 hrs interval between onset of acute symptoms and intensive care unit admission (odds ratio, 2.3). CONCLUSIONS: Multiple organ failure is common in obstetric patients; mortality rate increases with increasing organ failure. APACHE II scores overpredict mortality rate. Standardized mortality ratio is lower in obstetric disorders than in medical disorders. Lack of prenatal care and delay in intensive care unit referral adversely affect outcome and are easily preventable.     

Prognostic factors in critically ill cancer patients admitted to the intensive care unit

Objective

The objective of this study is to identify factors predicting intensive care unit (ICU) mortality in cancer patients admitted to a medical ICU.

Patients and methods

We conducted a retrospective study in 162 consecutive cancer patients admitted to the medical ICU of a 1000-bed university hospital between January 2009 and June 2012. Medical history, physical and laboratory findings on admission, and therapeutic interventions during ICU stay were recorded. The study end point was ICU mortality. Logistic regression analysis was performed to identify independent risk factors for ICU mortality.

Results

The study cohort consisted of 104 (64.2%) patients with solid tumors and 58 patients (35.8%) with hematological malignancies. The major causes of ICU admission were sepsis/septic shock (66.7%) and respiratory failure (63.6%), respectively. Overall ICU mortality rate was 55 % (n = 89). The ICU mortality rates were similar in patients with hematological malignancies and solid tumors (57% vs 53.8%; P = .744). Four variables were independent predictors for ICU mortality in cancer patients: the remission status of the underlying cancer on ICU admission (odds ratio [OR], 0.113; 95% confidence interval [CI], 0.027-0.48; P = .003), Acute Physiology and Chronic Health Evaluation II score (OR, 1.12; 95% CI, 1.032-1.215; P = .007), sepsis/septic shock during ICU stay (OR, 8.94; 95% CI, 2.28-35; P = .002), and vasopressor requirement (OR 16.84; 95% CI, 3.98-71.24; P = .0001). Although Acute Physiology and Chronic Health Evaluation II score (OR, 1.30; 95% CI, 1.054-1.61; P = .014), admission through emergency service (OR, 0.005; 95% CI, 0.00-0.69; P = .035), and vasopressor requirement during ICU stay (OR, 140.64; 95% CI, 3.59-5505.5; P = .008) were independent predictors for ICU mortality in patients with hematological malignancies, Sequential Organ Failure Assessment score (OR, 1.83; 95% CI, 1.29-2.6; P = .001), lactate dehydrogenase level on admission (OR, 1.002; 95% CI, 1-1.005; P = .028), sepsis/septic shock during ICU stay (OR, 138.4; 95% CI, 12.54-1528.4; P = .0001), and complete or partial remission of the underlying cancer (OR, 0.026; 95% CI, 0.002-0.3; P = .004) were the independent risk factors in patients with solid tumors.

Conclusion

Intensive care unit mortality rate was 55% in our cancer patients, which suggests that patients with cancer can benefit from ICU admission. We also found that ICU mortality rates of patients with hematological malignancies and solid tumors were similar.     

Prognostic factors in critically ill patients with hematologic malignancies admitted to the intensive care unit

Objective

Despite an improvement in the prognosis of patients with hematologic malignancies, the mortality of such patients transferred to the intensive care unit (ICU) is high. This study determined the predictors of mortality in a cohort of critically ill patients with hematologic malignancies admitted to the ICU.

Methods

We studied 227 critically ill patients with hematologic malignancies who were admitted to the ICU between April 2009 and December 2011. A cohort of consecutive patients with hematologic malignancies was reviewed retrospectively to identify clinically useful prognostic factors.

Results

The ICU mortality rate was 84.1%, and the in-hospital mortality rate was 89.9%. The ICU mortality was significantly higher in patients with acute leukemia than in those with other malignancies. A significant difference between survivors and nonsurvivors was found in neutropenia and its recovery during the ICU stay, presence of cardiac dysfunction, the need for an invasive mechanical ventilator, use of inotropic/vasopressor agents, platelet count, aspartate transaminase level, pH, and Acute Physiology And Chronic Health Evaluation II score. In the multivariate analysis, acute leukemia, need for invasive mechanical ventilator, use of inotropic/vasopressor agents, and Acute Physiology And Chronic Health Evaluation II scores were independently associated with a worse outcome in patients with hematologic malignancies admitted to the ICU.

Conclusion

Higher mortality in patients with hematologic malignancies admitted to the ICU is associated with more severe illness, as reflected by higher organ failure scores or respiratory or hemodynamic instability. Mortality is higher in patients with acute leukemia as compared with other hematologic malignancies.     

Prognostic factors and outcomes of patients with pulmonary hypertension admitted to the intensive care unit

Purpose

Patients with pulmonary hypertension (PH) can decompensate to the point where they require care in the intensive care unit (ICU). Our objective is to examine the outcomes and characteristics of patients with PH admitted to the ICU.

Methods

This is a retrospective study of 99 patients with PH who were admitted to the medical ICU of a single tertiary care center. Baseline characteristics, interventions during ICU admission, and ICU and 6-month outcome were documented. Univariate and multivariate logistic regressions were used to evaluate association of patient characteristics with mortality.

Results

Intensive care unit mortality was 30%, and 6-month mortality was 40%. Acute Physiology and Chronic Health Evaluation II score, World Health Organization Group 3 PH, and preexisting treatment with a prostacyclin at time of ICU admission were associated with worse outcome. Patients who received cardiopulmonary resuscitation had 100% mortality. The requirement for mechanical ventilation and dialysis was also associated with increased mortality. Pulmonary artery catheter placement was associated with reduced mortality, specifically if it was placed early during ICU admission and if associated with a change in the present management.

Conclusions

Mortality is high in critically ill patients with PH. The identification of prognostic baseline characteristics and interventions in the ICU is important and warrants further investigation.     

Usefulness of heart-type fatty acid-binding protein in patients with severe sepsis

Purpose

The purpose of the study was to evaluate the value of heart-type fatty acid–binding protein (hFABP) as a novel clinical biomarker in patients with severe sepsis.

Methods

Serum concentrations of hFABP and traditional cardiac biomarkers including cardiac troponin I, creatine kinase–MB, and B-type natriuretic peptides levels were measured within 6 hours after admission in 93 severe septic patients. The value of hFABP for the diagnosis of sepsis-related myocardial dysfunction (SRMD) and for the prediction of 28-day mortality was evaluated by receiver operating characteristics curve analysis. The prognostic value of elevated hFABP was subsequently confirmed by multivariate Cox proportional hazards analysis and Kaplan-Meier survival analysis.

Results

Heart-type fatty acid–binding protein was elevated (≥4.5 ng/mL) in 58 (62.4%) patients; patients with elevated hFABP appeared more likely to have SRMD (84.5% vs 31.4%, P < .001) and have higher prevalence of 28-day death (37.9% vs 8.6%, P = .002). Heart-type fatty acid–binding protein offered superior value over conventional biomarkers in both diagnosis of SRMD (area under the curve, 0.767; P < .001) and prediction of 28-day death (area under the curve, 0.805; P < .001).

Conclusions

Serum hFABP is frequently elevated among patients with severe sepsis and appears to be associated with SRMD. Elevated hFABP independently predicts 28-day mortality in severe sepsis.     

心肌型脂肪酸结合蛋白联合血浆D-二聚体对肺栓塞预后评估的临床意义

目的探讨心肌型脂肪酸结合蛋白(H-FABP)联合血浆D-二聚体在评价急性肺栓塞(APE)患者预后中的临床价值。方法选取本院2011年1月至2014年12月确诊的APE患者120例为研究对象,采用酶联免疫吸附法分别测定外周血H-FABP及D-二聚体浓度。根据病情严重程度将APE患者分为低危组、中危组及高危组;根据临床转归,分为存活组和死亡组,比较不同组间H-FABP和D-二聚体差异,评价H-FABP和D-二聚体对评估APE患者预后的临床价值。结果随着APE患者病情严重程度的增加,H-FABP和D-二聚体指标水平显著升高(P<0.05);死亡组H-FABP和D-二聚体水平显著高于存活组(P<0.05)。相关性分析显示,血浆H-FABP与D-二聚体水平呈正相关(r=0.693,P=0.000)。ROC曲线分析显示,H-FABP曲线下面积为0.845(95%CI:0.752~0.918),其最佳工作点为8.65μg/L,此时诊断APE的敏感性为81.24%,特异性为84.14%;D-二聚体曲线下面积为0.832(95%CI:0.728~0.899),其最佳工作点为1.25 mg/L,此时诊断APE的敏感性为83.72%,特异性为82.65%。结论 H-FABP联合D-二聚体可有效的评估APE患者病情严重程度及预后,可为临床APE患者个体化治疗,降低其死亡率提供客观依据。     

胶体金免疫层析法测定血清心肌型脂肪酸结合蛋白及临床应用

目的探讨国内研制的胶体金免疫层析法(GICA)试剂测定血清心肌型脂肪酸结合蛋白(H-FABP)及其在急性心肌梗死(AMI)诊断中的应用价值.方法使用心肌型脂肪酸结合蛋白快速检测试剂盒检测血清H-FABP.观察急性心肌梗死患者30例,在不同时间段检测H-FABP、cTnI、CK-MB,并与35例健康人检测结果比较.结果 H-FABP快速诊断试剂盒使用简单、方便、快速,手指血检测10～15 min,血清检测只需3 min.其检测灵敏度较高(6.5 ng/ml),特异性较高.CK-MB在AMI发生后0～4 h阳性检出率极低,4～12 h有一定的检出率,只有在12～24 h有较高的阳性检出率;cTnI在6 h内有较低的阳性检出率,在6 h后检出率较高,维持时间较长.H-FABP在AMI发生后0～4 h即有较高的阳性检出率,4～12 h维持高水平的检出率.结论胶体金免疫层析法(GICA)测定H-FABP简便、快捷,灵敏度、特异性较高,适用于急诊检验.H-FABP在AMI发生6 h内较cTnI、CK-MB对早期AMI更具诊断价值.     

心型脂肪酸结合蛋白在心血管疾病中作用研究进展

心型脂肪酸结合蛋白是一种小型细胞质蛋白,主要在心肌组织表达。心肌受损时,心型脂肪酸结合蛋白快速释放入血,胸痛发作1 h时血液中心型脂肪酸结合蛋白表达明显升高。心型脂肪酸结合蛋白与心血管疾病关系密切。本文就心型脂肪酸结合蛋白在急性冠状动脉综合征、心力衰竭、心房颤动中作用的研究进展作一综述。     

Nursing home patients admitted to a medical intensive care unit

To investigate admissions from nursing homes to a medical intensive care unit (ICU), the authors detailed the major interventions, costs, and outcomes for such patients (n = 67) over a 3-year period and then compared them with those for ICU patients receiving home care or visiting nurse services (240 patients) before admission and all others older than 65 years of age (949 patients). These three groups comprised 37% of total ICU admissions. In contrast to younger patients admitted primarily with acute ischemic heart disease, nursing home patients were more likely to be admitted with cardiopulmonary arrest, infection, and gastrointestinal bleeding. Major interventions of intubation and mechanical ventilation were most frequent for nursing home patients, but total hospital charges differed little among the groups. In-hospital mortality for the nursing home group (28%) was significantly higher than for the home care group (7%) and others older than 65 years of age (7%). Cumulative mortality for the nursing home group reached 66% by 8 months, versus 32% and 26% in the other groups, respectively.     

心肌脂肪酸结合蛋白在脓毒症临床预后的预测价值研究

目的 探讨心肌脂肪酸结合蛋白(heart-type fatty acid-binding protein,H-FABP)在脓毒症患者临床预后的预测价值,提高脓毒症患者救治率.方法 采用前瞻性病例对照研究,纳入2014年10月至2015年10月就诊于新疆医科大学第一附属医院脓毒血症患者共50例,根据2012年脓毒症诊疗指南分为脓毒症组(16例)、严重脓毒症组(14例)、脓毒性休克组(20例);根据28 d后是否存活分为死亡组(22例)与存活组(28例).记录性别、年龄、族别等基本资料,入急诊6h内完善急性生理与慢性健康状况(APACHEⅡ)评分,H-FABP,B型脑钠利肽(B-typenatriuretic,BNP)、肌酸激酶(creatine kinase,CK)、肌酸激酶同工酶(creatine kinase isoenzymes,CK-MB)、肌钙蛋白(troponin-T,cTn-T)等指标.统计学采用SPSS 21.0软件,计量资料t检验或秩和检验、计数资料采用x2检验,非正态分布资料采用秩合检验,对生存状况进行ROC曲线分析.结果 脓毒性休克组的H-FABP明显高于严重脓毒症组和脓毒症组(P＜0.01).脓毒性休克组28天死亡率(80％)与严重脓毒症组28 d病死率高于脓毒症组28天死亡率(12.5％)(P＜0.01).死亡组H-FABP、BNP、cTn-T、CK、CK-MB均明显高于存活组,两组间差异具有统计学意义(P＜0.05);对H-FABP和BNP行ROC曲线结果提示H-FABP (AUC=0.748,P=0.003,95％CI:0.605 ～0.890)优于BNP (AUC =0.714,P=0.010,95％ CI:0.573 ～0.856),当H-FABP取 9.902 ng/mL,敏感度82.1％,特异度63.6％.H-FABP对28 d病死率的预测具有一定价值.结论 脓毒性休克组病死率明显高于严重脓毒血症及脓毒症组.H-FABP相比BNP、CK、CK-MB,对脓毒症患者预后具有较大的预测价值,随病情加重而增高.H-FABP可以预测28 d病死率.     

Thyroid hormone levels improve the prediction of mortality among patients admitted to the intensive care unit.

Objective As hormones are strongly associated with mortality in critically ill patients, we investigated whether mortality prediction based on the Acute Physiology and Chronic Health Evaluation (APACHE) is improved by combining this score with hormone measurements.Design and setting Intensive care units in three hospitalsPatients and participants 113 patients admitted to.Measurements Within the first hour after ICU admission we measured total triiodothyronine, total thyroxine, free thyroxine, thyrotropin, cortisol, growth hormone, dehydroepiandrosterone, and prolactin levels and administered the APACHE. Patients were followed until they died or were discharged from the ICU.Results The best logistic regression model for ICU mortality included the APACHE score and thyroid-stimulating hormone and triiodothyronine levels. This model had an area under the receiver operating characteristic curve of 0.88, significantly higher than the APACHE score alone with 0.75. The model with hormone levels and APACHE score was also significantly better calibrated than the model with only the APACHE score.Conclusions The addition of thyroid hormones to the APACHE score improves the prediction of mortality for ICU patients     

Prediction of fluid responsiveness in patients admitted to the medical intensive care unit

Purpose

Accurate prediction of fluid responsiveness is of importance in the treatment of patients admitted to the intensive care unit (ICU). We investigated whether physical examination, central venous pressure (CVP), central venous oxygen saturation (ScvO₂), passive leg raising (PLR) test, and transpulmonary thermodilution (TPTD)–derived parameters can predict volume responsiveness in patients admitted to the ICU.

Materials and Methods

In this prospective study, structured clinical examination, measurement of CVP and ScvO₂, a PLR test, and TPTD measurements were performed in 31 patients. A fluid challenge test was performed in 24 patients (fluid responsiveness was defined as a cardiac index [CI] increase of ≥ 15%).

Results

Physical examination, CVP, ScvO₂, the PLR test, and the TPTD-derived volumetric preload parameter global end-diastolic volume index showed poor prognostic capabilities regarding prediction of fluid responsiveness. Twenty-nine percent of patients were fluid responsive. There was a statistically significant correlation between the fluid challenge–induced increase in CI and changes in global end-diastolic volume index (r = 0.666, P < .001). In only 17% of patients, CI did not increase after fluid loading.

Conclusions

Prediction of fluid responsiveness is difficult using physical examination, CVP, ScvO₂, PLR maneuver, or TPTD-derived variables in critically ill patients. A volume challenge test should be considered for the assessment of fluid responsiveness in critically ill patients admitted to the ICU.     

Predictors of mortality in stroke patients admitted to an intensive care unit

OBJECTIVE: Improved pathophysiologic insight and prognostic information regarding in-hospital risk of mortality among stroke patients admitted to an intensive care unit. DESIGN: Retrospective analysis. SETTING: Neurology/neurosurgery intensive care unit in a tertiary care university medical center. PATIENTS: A total of 63 consecutive ischemic stroke patients. INTERVENTIONS: Patients were classified according to in-hospital mortality. Charts were reviewed to retrospectively generate an admitting Acute Physiology and Chronic Health Evaluation (APACHE) II score. The APACHE II score and its individual components were assessed for predicting subsequent death. MEASUREMENTS AND MAIN RESULTS: Of 63 patients, 13 died and 50 survived to either discharge or surgical intervention. The mean admitting APACHE II score of survivors (6.9) was lower than that of patients who died (17.2; p < .0001). None of the 33 patients with a score <9 died, compared with 43% of those with a score > or =9. A score > or =18 was uniformly associated with fatal outcome (n = 8). Univariate analysis identified APACHE II total score, Glasgow Coma Scale score, temperature, pH, and white blood cell count as significant predictors of death. Among multivariate logistic regression models examining the components of the APACHE II score, the model containing white blood cells, temperature, and creatinine best predicted death. CONCLUSIONS: Several features of the APACHE II score are associated with risk of death in this patient population. The findings suggest particular physiologic derangements that are associated with, and may contribute to, increased mortality in critically ill patients with acute ischemic stroke.     

Human heart-type cytoplasmic fatty acid-binding protein (H-FABP) for the diagnosis of acute myocardial infarction. Clinical evaluation of H-FABP in comparison with myoglobin and creatine kinase isoenzyme MB.

Heart-type fatty acid-binding protein (H-FABP) is a low molecular weight cytoplasmic protein and present abundantly in the myocardium. When the myocardium is injured, as in the case of myocardial infarction, low molecular weight cytoplasmic proteins including H-FABP are released into the circulation and H-FABP is detectable in a blood sample. We have already developed a direct sandwich-ELISA for quantification of human H-FABP using two distinct types of monoclonal antibodies specific for human H-FABP. In this study we investigated the clinical validity of H-FABP as a biochemical diagnostic marker in the early phase of acute myocardial infarction (AMI). To evaluate the diagnostic usefulness of H-FABP in the early phase of AMI, blood samples were obtained from the following patients within 12 hours after the appearance of symptoms, and serum levels of H-FABP were compared with those of conventional diagnostic markers, such as myoglobin and creatine kinase isoenzyme MB (CK-MB). Blood samples were collected from patients with confirmed AMI (n=140), patients with chest pain who were afterwards not classified as AMI by normal CK-MB levels (non-AMI) (n=49) and normal healthy volunteers (n=75). The serum concentration of H-FABP was quantified with our direct sandwich-ELISA. The concentration of myoglobin mass was measured with a commercial RIA kit. The serum CK-MB activity was determined with an immuno-inhibition assay kit. The overall sensitivity of H-FABP, within 12 hours after the appearance of symptoms, was 92.9%, while it was 88.6% with myoglobin and 18.6% with CK-MB. The overall specificity of H-FABP was 67.3%, while it was 57.1% with myoglobin and 98.0% with CK-MB. The diagnostic efficacy rates with these markers were 86.2% (H-FABP), 80.4% (myoglobin) and 39.2% (CK-MB), respectively. The diagnostic validity of H-FABP was further assessed by receiver operating characteristic (ROC) curve analysis. The area under the curve (AUC) of H-FABP was 0.921, which was significantly greater than with myoglobin (AUC: 0.843) and CK-MB (AUC: 0.654). These parameters, such as sensitivity, specificity, diagnostic efficacy and diagnostic accuracy, obtained for patients with chest pain within 3 hours and/or 6 hours after the onset of symptoms were almost the same as those for patients within 12 hours after symptoms. H-FABP is more sensitive than both myoglobin and CK-MB, more specific than myoglobin for detecting AMI within 12 hours after the onset of symptoms, and shows the highest values for both diagnostic efficacy and ROC curve analysis. Thus, H-FABP has great potential as an excellent biochemical cardiac marker for the diagnosis of AMI in the early phase.     

Verification of an immunoturbidimetric assay for heart-type fatty acid-binding protein (H-FABP) on a clinical chemistry platform and establishment of the upper reference limit

BackgroundHeart-type fatty acid-binding protein (H-FABP) is an early biomarker of cardiac injury. Randox Laboratories developed an immunoturbidimetric H-FABP assay for non-proprietary automated clinical chemistry analysers that could be useful in the emergency department. We verified the analytical performances claimed by Randox Laboratories on Roche Cobas 6000 clinical chemistry platform in use in our laboratory, and we defined our own 99th percentile upper reference limit for H-FABP.MethodsFor the verification of method performances, we used pools of spared patient samples from routine and two levels of quality control material, while samples for the reference value study were collected from 545 blood donors. Following CLSI guidelines we verified limit of blank (LOB), limit of detection (LOD), limit of quantitation (LOQ), repeatability and within-laboratory precision, trueness, linearity, and the stability of H-FABP in EDTA over 24 h.Results and discussionThe LOQ (3.19 μg/L) was verified with a CV% of 10.4. The precision was verified for the low (mean 5.88 μg/L, CV = 6.7%), the medium (mean 45.28 μg/L, CV = 3.0%), and the high concentration (mean 88.81 μg/L, CV = 4.0%). The trueness was verified as well as the linearity over the indicated measurement interval of 0.747–120 μg/L. The H-FABP in EDTA samples is stable throughout 24 h both at room temperature and at 4 °C. The H-FABP 99th percentile upper reference limit for all subjects (3.60 μg/L, 95% CI 3.51–3.77) is more appropriate than gender-specific ones that are not statistically different.