The Mean ApoC1 Serum Level in Postoperative Samples from Neurosurgical Patients Is Lower than in Preoperative Samples and during Chemotherapy

Abstract

Simple SummaryApolipoprotein C1 is mainly synthesized in the liver and helps in the digestion of fatty acids and in their clearance from the bloodstream. Recent reports have described the role of ApoC1 in malignant tumors of internal organs, exerting an impact on tumor growth and prognosis. Only little is known about ApoC1 in patients with diseases affecting the nervous system, so in this study, samples from neurosurgical patients were examined. A total of 219 samples from 85 patients with brain tumors was compared to 11 samples from patients undergoing non-tumor spine surgery. After drawing the blood sample, it was centrifuged to yield the serum supernatant, which was then assessed by a photometric antibody test (ELISA). The results give the concentration of ApoC1 in the probed blood in µg/mL. From a single sample, it was not possible to determine the underlying disease, such as lumbar disc herniation or brain tumor. Of note, the ApoC1 levels of glioblastoma patients fell significantly after the neurosurgical resection of the tumor and then rose again during chemotherapy. Ongoing research deals with a detailed statistical analysis to determine whether ApoC1 serum levels qualify for use as a blood biomarker for glioblastoma.Serum levels of apolipoprotein ApoC1 have been described in a number of systemic tumor entities as potential biomarkers, but little is known about ApoC1 in neurosurgical patients. A total of 230 serum samples from 96 patients were analyzed using an ELISA technique. Patient diagnoses comprised 70 glioblastomas WHO IV°, 10 anaplastic astrocytomas III°, one anaplastic oligodendroglioma III°, one oligodendroglioma II°, one diffuse astrocytoma II°, one pilocytic astrocytoma I°, and a single case of a spindle cell tumor without WHO grading, as well as 11 spinal interventions. The mean ApoC1 level of the 230 samples was 132.03 µg/mL (median 86.83, SD 292.91). In the 176 glioblastoma samples, the mean ApoC1 level was 130.0 µg/mL (median 86.23, SD 314.9), which was neither different from the whole group nor from patients with spinal interventions (215.1 μg/mL, median 63.6, SD 404.9). In the postoperative samples, the mean ApoC1 level was significantly lower (85.81 μg/mL) than in the preoperative samples (129.64 μg/mL) and in samples obtained during adjuvant chemotherapy (168.44 μg/mL). While absolute ApoC1 serum levels in a patient do not allow for the distinction between neurosurgical histological entities, future analyses will examine whether the time course of ApoC1 in an individual patient can be related to certain treatment stages.