Serum neuron specific enolase (S-NSE) reference interval evaluation by time-resolved immunofluorometry compared with a radioimmunoassay

Age-stratified and gender-specific reference intervals of six tumor markers panel of lung cancer: A geographic-based multicenter study in China

Background

Serum biomarkers have been widely adopted in clinical practice for assisting lung cancer diagnoses, therapeutic monitoring, and prognostication. The function of a well‐performing tumor biomarker depends on a reliable reference interval (RI) with consideration of the study subjects’ age, gender, and geographical location. This study aimed to establish a RI for each of 6 lung cancer biomarkers for use in the whole country of China on Mindray platform.

Methods

The levels of serum 6 lung cancer biomarkers—namely progastrin‐releasing peptide (ProGRP), neuron‐specific enolase (NSE), squamous cell carcinoma antigen (SCC), carcinoembryonic antigen (CEA), cytokeratin‐19 fragment (CYFRA21‐1), and human epididymis protein 4 (HE4)—were measured utilizing the chemiluminescence immunoassay on the Mindray CL‐6000i platform following the laboratory standard operating procedures in apparently healthy Chinese individuals on large cohort, multicenter, and geographical consideration bases. The CLSI EP28‐A3C guideline was followed for the enrollment of study subjects.

Results

The age‐stratified, gender‐specific RIs for ProGRP, NSE, SCC, CEA, CYFRA21‐1, and HE4 lung cancer biomarkers in the Chinese population have been established as described in the results and discussion in this work. In addition, various levels of the six lung cancer biomarkers among nine geographical locations in China have been observed.

Conclusions

The sample volume of study cohort, age, and geographical location should be considered upon establishing a reliable biomarker RI. A RI for each of six lung cancer biomarkers has been established. The results from this study would be helpful for clinical laboratories in interpreting the analytical results and for clinicians in patient management.

Correction of serum NSE reference intervals includes the unidentified hemolysis sample: 1-year data analysis from healthcare individuals

BACKGROUND

Reference intervals (RIs) are important for interpretation of laboratory results. Neuron-specific enolase (NSE) can be utilized to aid the diagnosis of various tumors. However, while red blood cells contain NSE αγ-isozymes, unrecognized slight hemolysis will result in increasing of NSE levels in serum. The aim of this study was to correct the NSE RIs from healthcare individuals results which may have unidentified microhemolysis.

METHODS

A total of 15 047 healthy individuals undergoing regular health care were recruited to redefine the NSE reference interval according to the CA28-A3 document. Volunteers with NSE level between 16.3 ng/mL and the upper limit of new RIs were performed venipuncture for NSE retest. Simultaneously, serum free hemoglobin (fHb) was performed with o-tolidine test.

RESULTS

Reestablishment of NSE RIs is 0-18.9 ng/mL, which is wider than 0-16.3 ng/mL provided by the manufacturer. Seventy-four volunteers with the NSE level between 16.3 and 18.9 ng/mL were performed venipuncture for NSE retest. The ratio of NSE level drop to normal is 85.1% (63/74) in the subsequent results; there are significant differences between the median NSE of two groups (18.15 vs 14.15 ng/mL). Subsequently, the fHb concentration of 22 healthy individuals from 74 individuals was measured; there are significant differences between the median fHb of two groups (58 vs 30 mg/L).

CONCLUSIONS

Some specimens with slightly elevated NSE may be attributed to the unrecognized slight hemolysis. The correction RIs may be expected to decrease the abnormal NSE results.

Neuroendocrine neoplasms: current and potential diagnostic, predictive and prognostic markers

Some biomarkers for functioning and non-functioning neuroendocrine neoplasms (NENs) are currently available. Despite their application in clinical practice, results should be interpreted cautiously. Considering the variable sensitivity and specificity of these parameters, there is an unmet need for novel biomarkers to improve diagnosis and predict patient outcome. Nowadays, several new biomarkers are being evaluated and may become future tools for the management of NENs. These biomarkers include (1) peptides and growth factors; (2) DNA and RNA markers based on genomics analysis, for example, the so-called NET test, which has been developed for analyzing gene transcripts in circulating blood; (3) circulating tumor/endothelial/progenitor cells or cell-free tumor DNA, which represent minimally invasive methods that would provide additional information for monitoring treatment response and (4) improved imaging techniques with novel radiolabeled somatostatin analogs or peptides. Below we summarize some future directions in the development of novel diagnostic and predictive/prognostic biomarkers in NENs. This review is focused on circulating and selected tissue markers.

Neuron-specific enolase in nasal secretions as a novel biomarker of olfactory dysfunction in chronic rhinosinusitis

BACKGROUND

Olfactory dysfunction is a diagnostic criterion for chronic rhinosinusitis (CRS). During chronic inflammation and olfactory neuronal damage in CRS, it is likely that neuron-specific enolase (NSE) can leak into nasal secretions (NS) and serum. Therefore, we postulated that NSE levels in NS and in circulation may be indicative of olfactory dysfunction in CRS.

OBJECTIVE

To evaluate the relationship between the NS and serum concentrations of NSE with olfactory dysfunction in subjects with CRS.

METHODS

The patients with CRS were classified into two groups, depending on the presence of polyps: CRS without nasal polyps (CRSsNP) and CRS with nasal polyps (CRSwNP). A group of age- and sex-matched healthy volunteers served as controls. Olfactory function assessment was performed by using Sniffin' Sticks. NSE concentrations in serum and NS were analyzed by using the enzyme immunometric assay kit specific for the γ subunit.

RESULTS

The study included 46 patients with CRSsNP, 25 women (54.3%) and 21 men (45.7%), mean (standard deviation [SD]) age, 34.1 ± 12.3 years; and 54 patients with CRSwNP, 24 women (44.4%) and 30 men (55.6%), mean (SD) age, 37.9 ± 17.5 years. A group of 40 healthy volunteers who were matched for age and sex served as controls. Significantly higher serum and NS levels of NSE were measured in patients with CRS compared with healthy controls (p < 0.001). In the CRSwNP group, both mean (SD) serum (83.5 ± 37.6 ng/mL) and mean (SD) NS (6.1 ± 2.3 ng/mL) levels of NSE were significantly higher than in the CRSsNP group (46.4 ± 7.3 ng/mL [p < 0.001] and 1.7 ± 0.5 ng/mL [p < 0.001], respectively). In both the CRSsNP and CRSwNP groups (but not in the healthy controls), significant negative correlations between NS NSE levels and TDI scores (r = -0.63, p < 0.001 for the CRSwNP group, and r = -0.51, p < 0.001 for CRSsNP group) were observed, which meant that higher NSE was associated with worse olfactory function.

CONCLUSIONS

The study demonstrated a contribution of CRS to NSE and olfactory dysfunction.

Neuron-specific enolase is elevated in asymptomatic carriers of Leber's hereditary optic neuropathy

PURPOSE

Neuron-specific enolase (NSE) is a biomarker for neuronal stress. Leber's hereditary optic neuropathy (LHON) is a mitochondrial disease affecting retinal ganglion cells (RGC). These RGCs and their axons in the retinal nerve fiber layer (RNFL) and optic nerve head may show subclinical pathology in unaffected mutation carriers, or undergo cell death in affected patients. We hypothesize that increased levels of blood NSE may characterize LHON carriers as a biomarker of ongoing RGC stress.

METHODS

Serum was obtained from 74 members of a Brazilian pedigree with LHON carrying the homoplasmic 11778/ND4 mitochondrial DNA mutation. Classified by symptoms and psychophysical metrics, 46/74 patients were unaffected mutation "carriers," 14/74 were "affected," and 14/74 were "off-pedigree" controls. Serum NSE levels were determined by ELISA specific for the γ subunit of NSE.

RESULTS

Serum NSE concentrations in carriers (27.17 ± 39.82 μg/L) were significantly higher than affected (5.66 ± 4.19 μg/L; P = 0.050) and off-pedigree controls (6.20 ± 2.35 μg/L; P = 0.047). Of the 14/46 (30.4 %) carriers with significantly elevated NSE levels (mean = 75.8 ± 42.3 μg/L), 9/14 (64.3%) were male. Furthermore, NSE levels were nearly three times greater in asymptomatic male carriers (40.65 ± 51.21 μg/L) than in asymptomatic female carriers (15.85 ± 22.27 μg/L; P = 0.034).

CONCLUSIONS

Serum NSE levels are higher in LHON carriers compared with affected and off-pedigree individuals. A subgroup of mostly male carriers had significantly elevated serum NSE levels. Thus, male carriers are at higher risk for LHON-related neuronal stress.

Reference intervals for carcinoembryonic antigen (CEA), CA125, MUC1, Alfa-foeto-protein (AFP), neuron-specific enolase (NSE) and CA19.9 from the NORIP study

OBJECTIVE

Adhering to current IFCC recommendations, we calculated upper 97.5 % reference limits for serum tumor markers.

MATERIAL AND METHODS

Serum samples from 498 healthy individuals from the Nordic reference interval project (NORIP) were investigated for carcinoembryonic antigen (CEA), CA125 and MUC1 (episialin, CA15.3) using in-house immunofluorometric assays and, for alpha-foetoprotein (AFP), a PerkinElmer Life Sciences assay, neuron-specific enolase (NSE) using an in-house immunoradiometric assay and CA19.9 using a Beckman Access assay. All assays participate in external quality assessment programs.

RESULTS

CEA concentrations increased with age and smoking. Upper reference limits for non-smokers were 3.59 microg/L at 50 years and 4.12 microg/L at 70 years. CA125 concentrations were age-independent and the upper reference limit was 35.8 kU/L. MUC1 increased with age and body mass index (BMI). Upper reference limits were 31.7 kU/L at 40 years and BMI 24, 37.5 kU/L at 70 years and BMI 24, and 33.7 kU/L at 40 years and BMI 30. AFP increases with age, and the upper reference limits were 3.82 kU/L at 20 years and 8.70 kU/L at 60 years. An upper reference limit for NSE was 8.91 microg/L in non-smokers; smokers exhibited significantly lower levels. The upper reference limit for individuals expressing CA19.9 was 28.3 kU/L.

CONCLUSIONS

For AFP, CA125 and CA19.9, the reference levels obtained were close to previously reported reference ranges. Smoking and age were confirmed as covariates for CEA. The associations between MUC1 with age and BMI and between NSE and smoking have not been reported previously.