Melanoma tumour markers S100B and MIA: evaluation of stability in serum and blood upon storage and processing

Combination of serum 5-S-cysteinyldopa, melanoma inhibitory activity and IL-8 improves the diagnostic accuracy of malignant melanoma compared with individual markers

Early diagnosis of malignant melanoma is critical for effective treatment and reduced patient mortality. However, current clinical and histological variables show limited accuracy in diagnosis. Serum or urine level of 5-S-cysteinyldopa (5-S-CD) is a commonly used melanoma biomarker in Japan owing to its increased sensitivity compared with other melanoma markers. However, its use as a diagnostic marker has shown some limitations. Therefore, here we examined the combination of 5-S-CD with melanoma inhibitory activity, which showed sensitivity in detecting melanoma comparable with that of 5-S-CD, and interleukin-8, a cytokine linked with melanoma progression, in a cohort of Japanese patients with melanoma. Our results revealed that the triple combination of 5-S-CD, melanoma inhibitory activity, and interleukin-8 showed high diagnostic accuracy in detecting melanoma compared with each of the individual factors. Importantly, the triple marker showed specificity and utility in detecting early-stage melanoma. Our results suggest the utility of the triple marker as a diagnostic biomarker for melanoma patients.

Measurement of S100B protein: evaluation of a new prototype on a bioMérieux Vidas® 3 analyzer

Background

The addition of S100B protein to guidelines for the management of mild traumatic brain injury (mTBI) decreases the amount of unnecessary computed tomography (CT) scans with a significant decrease in radiation exposure and an increase in cost savings. Both DiaSorin and Roche Diagnostics have developed automated assays for S100B determination. Recently, bioMérieux developed a prototype immunoassay for serum S100B determination. For the first time, we present the evaluation of the S100B measurement using a bioMérieux Vidas® 3 analyzer.

Methods

We evaluated the matrix effects of serum and plasma, and their stability after storage at 2–8 °C, −20 °C and −80 °C. The new measurement prototype (bioMérieux) was compared with an established one (Roche Diagnostics), and a precision study was also conducted. Lastly, clinical diagnostics performance of the bioMérieux and Roche Diagnostics methods were compared for 80 patients referred to the Emergency Department for mTBI.

Results

Stability after storage at 2–8 °C, −20 °C, and −80 °C and validation of the serum matrix were demonstrated. The bioMérieux analyzer was compared to the Roche Diagnostics system, and the analytical precision was found to be efficient. Clinical diagnosis performance evaluation confirmed the predictive negative value of S100B in the management of mTBI.

Conclusions

The study’s data are useful for interpreting serum S100B results on a bioMérieux Vidas® 3 analyzer.

Evaluation of the Roche® Elecsys and the Diasorin® Liaison S100 kits in the management of mild head injury in the emergency room

INTRODUCTION

The aim of this single-center prospective study is to compare two commercially available S100ß kits (the Roche® Elecsys and the Diasorin® Liaison S100 kits) in terms of analytical and clinical performances in a population admitted in the emergency room for mild traumatic brain injury (mTBI).

MATERIAL AND METHOD

110 patients were enrolled from September 2014 to May 2015. Blood sample draws were performed within 3h after head trauma and the study population was split into pediatric and adult subpopulations (>18years of age).

RESULTS

Although both kits correlated well, we observed a significant difference in terms of S100ß levels (P value<0.05) in both subpopulations. In the pediatric subpopulation, both kits showed elevated S100ß levels for the only patient (3.5%) who displayed abnormal findings on a CT-scan. However, we observed a poor agreement between both kits (Cohen's kappa=0.345, P value=0.077). In the adult subpopulation, a total of 10 patients (12.2%) had abnormal head computed tomography scans. Using the Roche® (cut off=0.1μg/L) and the Diasorin® (cut off=0.15μg/L) S100ß kits, brain injuries were detected with a sensitivity of 100% (95% CI: 65-100%) and 100% (95% CI: 63-100%) and a specificity of 15.28% (95% CI: 7.9-25.7%) and 24.64% (95% CI: 15-36.5) respectively. Finally, a moderate agreement was concluded between both kits (Cohen's kappa=0.569, P value=0.001).

CONCLUSION

Although a good correlation could be found between both kits, emergency physicians should be aware of discrepancies observed between both methods, making those immunoassays not interchangeable. Furthermore, more studies are still needed to validate cut off used according to technique and to age, especially in the population below the age of 2years.

Protein S100B in umbilical cord blood as a potential biomarker of hypoxic-ischemic encephalopathy in asphyxiated newborns

BACKGROUND

Neonatal hypoxic ischemic encephalopathy (HIE) is a devastating condition resulting from a sustained lack of oxygen during birth. The interest in identifying a relevant biomarker of HIE has thrown into limelight the role of protein S100B as a clinical diagnostic marker of hypoxic brain damage in neonates.

AIMS

To evaluate the diagnostic value of protein S100B, measured in umbilical cord blood immediately after birth, as a useful biomarker in the diagnosis of HIE Sarnat stages II-III as well as a marker for long-term mortality and morbidity.

STUDY DESIGN

Protein S100B was analyzed in cord blood sampled at birth from 13 newborns later diagnosed with stage II-III HIE and compared with 21 healthy controls. S100B concentrations were related to cord artery pH, amplitude-integrated electroencephalography (aEEG), stage of HIE, and death/sequelae up to an age of 6years. Both parametric and non-parametric statistics were used with a two-sided P<0.05 considered significant.

RESULTS

The difference in S100B concentration was marginally statistically significant between HIE cases and controls (P=0.056). Cord blood acidosis (P=0.046), aEEG pattern severity (P=0.030), HIE severity (P=0.027), and condition at 6-year follow-up (healthy/permanent sequelae/death; P=0.027) were all related to an increase in S100B concentration.

CONCLUSIONS

Protein S100B in neonates suffering from HIE stages II-III appeared elevated in umbilical cord blood at birth. The S100B concentrations were positively associated to the severity of disease and the risk of suffering from neurodevelopmental sequelae and even death.

Biomarker value and pitfalls of serum S100B in the follow-up of high-risk melanoma patients

BACKGROUND AND OBJECTIVES

Serum levels of S100B are standard in monitoring advanced malignant melanoma patients in order to discriminate progressive from non-progressive disease. False-positive results lead to distress among patients and increase the amount of cost-intensive diagnostics. We therefore analyzed reported comorbid diseases as putative sources of excessive S100B release.

PATIENTS AND METHODS

Here, we report a single-center experience on serum S100B levels in 2,664 blood samples from 1,113 stage IB to IV melanoma patients (AJCC) who presented for follow-up examinations over a period of 24 months.

RESULTS

Overall, 295 (11%) of patients developed disease progression. In patients with a high tumor load, the rate of false-negative results was 30/185 (16%). The rate of false-positive results was 247/2369 (12%). One hundred and six false-positive results (69%) compared to 46 true-positive results (31%) were found in patients with cardiovascular diseases such as arrhythmia (50/32) or previous myocardial infarction (22/14). Moreover, obesity (85/14), liver cirrhosis (31/10), migraine (18/2), chronic kidney disease (13/2), and previous stroke (11/1) were found to be associated with false-positive S100B levels.

CONCLUSIONS

Serum S100B is a useful quantitative biomarker in routine follow-up of high-risk melanoma patients. While false-negative results are frequent in patients with low tumor load, false-positive results are associated with several comorbid diseases and warrant careful reevaluation.

Serummarker des malignen Melanoms

Tumor markers in the serum of cancer patients have an important role in clinical diagnosis and in prognosis, and also in the monitoring of the patients' disease and response to therapy over time. The serum markers currently available for melanoma have only limited clinical use. Those most widely used in clinical applications are S100-beta, melanoma inhibitory activity, and lactate dehydrogenase; there are close correlations between the serum concentrations of these and tumor load. Regular determination of S100-beta and MIA levels during follow-up can therefore be used for early detection of a tumor relapse in melanoma patients, increased serum concentrations of these marker proteins being indicative of tumor growth. Patients with distant metastases from melanoma who present with elevated serum levels of S100-beta, MIA, or LDH have poorer overall survival than do patients whose serum concentrations are within normal ranges. These three markers can also be used to monitor the course of disease and therapy outcome in patients with distant metastases. Since there are no marker proteins for melanoma that are not dependent on tumor load, it is not currently possible to forecast the survival of patients who are tumor free after surgery. Serum markers are also not suitable for screening or for the diagnosis of primary melanomas.