Preanalytical stability of molecular forms of prostate-specific antigen in serum samples (PSA, free PSA, [-2]proPSA) and their impact on fPSA/tPSA ratio and PHI.

BACKGROUND: Prostate cancer is a common cancer in men. Detection methods include the measurement of biomarkers: prostate-specific antigen (PSA), free PSA, [-2]proPSA, and the calculated indices: fPSA/tPSA ratio and Prostate Health Index (PHI). Proper preanalytical conditions are crucial for precise measurement and failure to adhere to protocols or regulations can influence the diagnostic algorithm. We assessed the stability of the above-mentioned biomarkers, fPSA/tPSA ratio and PHI, under various pre-analytical conditions. METHODS: Serum samples from 45 males were collected and stored under specific conditions before tPSA, fPSA, and [-2]proPSA were measured. Subsequently, the fPSA/tPSA and PHI were calculated. RESULTS: tPSA, fPSA, and [-2]proPSA remained stable during the two freeze-thaw cycles. Storage at 4°C and 22°C resulted in stable tPSA concentrations. However, fPSA levels decreased and [-2]proPSA levels increased over time. The fPSA/tPSA ratio remained stable for 72 h, at which point a decrease was observed in the samples kept at 4°C and 22°C. A gradual increase in PHI was observed in the samples kept at 4°C and 22°C. CONCLUSIONS: All biomarkers remained stable during two freeze-thaw cycles. tPSA was the most stable analyte when stored at 4°C, as well as at RT. A gradual increase of [-2]proPSA and a slight decrease in fPSA were observed during the storage test. This led to a decrease in the fPSA/tPSA ratio and an elevation in the PHI. We therefore recommend measuring prostate biomarkers promptly following blood collection. IMPACT: Understanding the pre-analytical stability of prostate biomarkers helps prevent false positive results and improve the accuracy of diagnostics for prostate cancer.

A Case Study of Vitamin D Supplementation Therapy and Acute Respiratory Tract Infection.

BACKGROUND: Low serum concentrations of 25-hydroxyvitamin D correlate with higher susceptibility to acute respiratory tract infections (ARTIs). The case study presented here aims at sheding light on the correlation between vitamin D levels, the vitamin D supplement dose, and the incidence of ARTIs. CASE REPORT: A 23-year-old female patient with a vitamin D insufficiency was able to successfully increase her vitamin D levels from 45.60 nmol/l to 85.91 nmol/l (reference ranges 75-200 nmol/l) through the use of supplements. However, it was surprising to observe a decrease in vitamin D levels even though the patient continued taking supplements. Further examination indicated that the patient was experiencing common symptoms of an acute respiratory tract infection (ARTI). This case highlights the intricate connection between ARTIs and vitamin D intake. CONCLUSION: This case study clearly demonstrates the intricate connection between vitamin D levels, supplement treatment, and ARTIs. The observed decrease in vitamin D levels during the course of supplementation, while the patient was suffering from an ARTI, suggests that respiratory infections may affect vitamin D metabolism.

The Stability of the Anti-Müllerian Hormone in Serum and Plasma Samples under Various Preanalytical Conditions.

The anti-Müllerian hormone (AMH) is a glycoprotein that plays an important role in prenatal sex differentiation. It is used as a biomarker in polycystic ovary syndrome (PCOS) diagnostics, as well as for estimating an individual's ovarian reserve and the ovarian response to hormonal stimulation during in vitro fertilization (IVF). The aim of this study was to test the stability of AMH during various preanalytical conditions that are in accordance with the ISBER (International Society for Biological and Environmental Repositories) protocol. Plasma and serum samples were taken from each of the 26 participants. The samples were then processed according to the ISBER protocol. AMH levels were measured in all the samples simultaneously using the chemiluminescent kit ACCESS AMH in a UniCel® DxI 800 Immunoassay System (Beckman Coulter, Brea, CA, USA). The study proved that AMH retains a relatively high degree of stability during repeated freezing and thawing in serum. AMH was shown to be less stable in plasma samples. Room temperature proved to be the least suitable condition for the storage of samples before performing the biomarker analysis. During the testing of storage stability at 5-7 °C, the values decreased over time for all the plasma samples but remained stable in the serum samples. We proved that AMH is highly stable under various stress conditions. The anti-Müllerian hormone retained the greatest stability in the serum samples.

Long-Term Monitoring of the Antibody Response to a SARS-CoV-2 Infection.

A group of 110 patients from the West Bohemian region who had been infected with COVID-19 was monitored for the purposes of this study. We focused on cases of mild or moderate COVID-19; statistically the most likely to occur. Day zero was defined as the day on which a positive PCR test was first established. The mean length of observation was 6.5 months, the maximum length 12 months. The first blood samples were taken from a smaller cohort during the 1-3 months following the first positive PCR test. We assumed that SARS-CoV-2 antibodies would be present during this period and therefore a limited number of samples were taken for the purpose of detecting antibodies. More samples were collected, starting 4 months after the first positive PCR test. A subsequent set of blood samples were drawn, mostly 6 months after the first ones. Our study confirmed the presence of total IgG SARS-CoV-2 antibodies up to 1 year after the onset of the disease. The peak of antibody production was observed in the third month after the first positive PCR test. A mathematical estimate of the median duration of antibody positivity was calculated to be 18 months from the onset of the COVID-19 infection.

Five Commercial Immunoassays for SARS-CoV-2 Antibody Determination and Their Comparison and Correlation with the Virus Neutralization Test.

There is an ongoing debate as to whether SARS-CoV-2 antibodies can be found in patients who have recovered from COVID-19 disease. Currently, there is no consensus on whether the antibodies, if present, are protective. Our regular measurements of SARS-CoV-2 antibodies, starting in July 2020, have provided us with the opportunity of becoming acquainted with the five different immunoassays. A total of 149 patients were enrolled in our study. We measured the samples using each immunoassay, then performing a virus neutralization test and comparing the results of SARS-CoV-2 antibodies with this test. We observed that the production of neutralizing antibodies is age-dependent. Elderly patients have a higher proportion of high neutralizing titers than young patients. Based on our results, and in combination with the literature findings, we can conclude that the serological SARS-CoV-2 antibody measurement is a helpful tool in the fight against COVID-19. The assays can provide information about the patient's previous contact with the virus. Anti-spike protein assays correlate well with the virus neutralization test and can be used in the screening of potential convalescent plasma donors.

Risk of Postoperative Bleeding in Tonsillectomy for Peritonsillar Abscess, as Opposed to in Recurrent and Chronic Tonsillitis-A Retrospective Study.

Tonsillectomy is a routine surgery in otorhinolaryngology and the occurrence of postoperative bleeding is not a rare complication. The aim of this retrospective, observational, analytic, cohort study is to compare the incidence of this complication for the most common indications. A group of patients indicated for tonsillectomies for peritonsillar abscess (group I) was compared to a group of patients indicated for chronic and recurrent tonsillitis (group II). There are a lot of pathophysiological differences in patients indicated for acute tonsillectomy for peritonsillar abscess and in patients indicated for elective tonsillectomy for chronic or recurrent tonsillitis. No technique to minimize the risk of bleeding after tonsillectomy has been found and a large part of postoperative bleeding occurs in postoperative home-care, which makes this issue topical. In total, 2842 unilateral tonsillectomies from the years 2014-2019 were included in the study. Bleeding occurred in 10.03% and, surprisingly, despite completely different conditions in the field of surgery (oedema, acute inflammation in peritonsillar abscess), there was no statistically significant difference between incidence of postoperative bleeding in the studied groups (p = 0.9920). The highest incidence of bleeding was found in the patients of group I on the eighth postoperative day, with those aged 20-24 years (p = 0.0235) being the most at risk, and in group II, on the sixth postoperative day, with those aged 25-29 years (p = 0.0128) and 45-49 years (p = 0.0249) being the most at risk.

OPG, OPN, EGF and VEGF Levels at Individual Breslow Score Stages in Malignant Melanoma.

BACKGROUND/AIM: Melanoma represents one of the most aggressive forms of cancer. With the rapid increases in the incidence of melanoma in the United States, Australia and Europe over the last decades, melanoma has been considered an epidemic cancer in these areas. The aim of our study was to evaluate the utility of osteoprotegerin (OPG), osteopontin (OPN), epidermal growth factor (EGF) and vascular endothelial growth factor VEGF for the diagnosis and prognosis of melanoma. PATIENTS AND METHODS: Overall, 322 individuals were assessed: 183 melanoma patients and 139 healthy individuals. Melanoma patients were divided into four subgroups according to the Breslow score. OPN, OPG, EGF, and VEGF were determined in each plasma sample. RESULTS: The serum levels of the following biomarkers were statistically significantly higher in the melanoma group compared to the control group: OPG and, OPN (p<0.0001), EGF (p=0.0379). In the first stage, OPG (p=0.0236) and OPN (p=0.0327) showed a statistically significant increase. Concerning positive and negative sentinel node metastases a statistically significant change was observed in: OPN (p<0.0001), EGF (p=0.0114), VEGF (p=0.0114). CONCLUSION: OPG and OPN are promising biomarkers of early-stage melanoma. EGF and VEGF appear to be prognostic biomarkers.

Stability of total prostate-specific antigen and free prostate-specific antigen after 10 years' storage.

INTRODUCTION: PSA is a serine protease composed of 240 amino acids in a single polypeptide chain and is a routine parameter in prostate cancer diagnostics. The aim of our study was to test the long-term stability of tPSA and fPSA after 10 years' storage at -80°C. MATERIALS AND METHODS: We analyzed two aliquots from 55 serum samples. The first was assayed in routine testing at the time of establishing the diagnosis. The second was thawed for further testing after approximately 10 years' storage at -80°C. The mean of storage time was 10.41 years (min-max: 9.35-11.40 years). We compared the results of tPSA and fPSA. We calculated the fPSA/tPSA ratio and compared the results of clinical evaluation. Serum tPSA and fPSA levels were assayed using chemiluminescent kits Access Hybritech PSA and free PSA. All measurements were performed using the instrument UniCel® DxI 800. RESULTS: tPSA decreased 3.59% on average with a correlation r=0.9213, and fPSA increased at an average of 2.41% with a correlation r=0.9338. The fPSA/tPSA ratio increased 0.80% on average with a correlation r=0.9174. On clinical evaluation, five samples had fallen to a less malignant category and three samples had risen to a higher malignant category compared with the original results. CONCLUSION: The stability of tPSA and fPSA levels in serum is sufficient after 10 years' storage at -80°C. Calculation of the fPSA/tPSA ratio is not recommended due to the change in the category of malignancy of 15% of the samples.

Searching for New Biomarkers and the Use of Multivariate Analysis in Gastric Cancer Diagnostics.

AIM: The first aim of this study was to search for new biomarkers to be used in gastric cancer diagnostics. The second aim was to verify the findings presented in literature on a sample of the local population and investigate the risk of gastric cancer in that population using a multivariant statistical analysis. PATIENTS AND METHODS: We assessed a group of 36 patients with gastric cancer and 69 healthy individuals. We determined carcinoembryonic antigen, cancer antigen 19-9, cancer antigen 72-4, matrix metalloproteinases (-1, -2, -7, -8 and -9), osteoprotegerin, osteopontin, prothrombin induced by vitamin K absence-II, pepsinogen I, pepsinogen II, gastrin and Helicobacter pylori for each sample. RESULTS: The multivariate stepwise logistic regression identified the following biomarkers as the best gastric cancer predictors: CEA, CA72-4, pepsinogen I, Helicobacter pylori presence and MMP7. CONCLUSION: CEA and CA72-4 remain the best markers for gastric cancer diagnostics. We suggest a mathematical model for the assessment of risk of gastric cancer.

The Role of TPS and TPA in the Diagnostics of Distant Metastases.

AIM: The aim of the study was to assess the degree to which tissue polypeptide antigen (TPA) and tissue polypeptide-specific antigen (TPS), as well as carcinoembryonic antigen (CEA), can assist in the detection of distant metastases. PATIENTS AND METHODS: We assessed 157 patients with colorectal and breast cancer divided into two groups. The first was a group of patients with cancer at stages 1, 2 and 3; the second was a group of patients with cancer at stage 4 with metastasis. RESULTS: We found significantly higher levels of all biomarkers in the metastatic group compared to the group with cancer at stages 1-3 (p<0.0001). The calculated area under the receiver operating characteristic (ROC) curve was 0.9929 for TPS, 0.9337 for TPA and 0.7234 for CEA. The cut-off was calculated for each biomarker at 95% specificity, TPS cut-off=255 IU/l (sensitivity 95%), TPA cut-off=200 IU/l (sensitivity 70%) and CEA cut-off=18 µg/l (sensitivity 37%). CONCLUSION: We suggest combining CEA with TPS or TPA in the detection of distant metastases or using only cytokeratins. This approach can significantly increase the quality of detection of the metastatic process.

Portal vein embolisation with application of haematopoietic stem cells in patients with primarily or non-resectable colorectal liver metastases.

BACKGROUND: Insufficient future liver remnant volume (FLRV) is the main cause of low resectability of liver metastases from colorectal cancer (CLMs). One option for enhancing FLVR growth is the use of portal vein embolisation (PVE) with the application of autologous haematopoietic stem cells (HSCs). PATIENTS AND METHODS: PVE with the application of HSCs was used in 11 patients (group 1) with primarily non-resectable CLMs due to insufficient FLRV without signs of extrahepatic metastases. The control group (group 2) consisted of 14 patients in whom only PVE was performed. We evaluated the product quality, FLRV growth, CLM volume, median survival and progression-free survival (PFS). RESULTS: Product quality was achieved in all collections. In all group-I patients, sufficient FLRV growth occurred within three weeks. In the first and second weeks, FLRV increased optimally in most patients (p<0.006). In 13 out of the 14 group-2 patients, optimum FLVR growth was observed within three weeks following PVE (p<0.002). More rapid FLVR growth was observed in group 1 patients (p<0.01). CLM volume was significantly increased in both the group-2 (p<0.0005) and group-1 (p<0.008) patients at the time of liver resection. There was no significant difference in the growth of the CLM volume between the groups (p<0.18). The median survival was 7.3 and 6.8 months for group 1 and 2 patients, respectively, and the two-year PFS was 28% and 22% (p<0.18), respectively. CONCLUSION: PVE with HSC application is a promising method for effectively stimulating FLRV growth in patients with primarily non-resectable CLMs.

Surgical treatment of colorectal cancer pulmonary metastases: 12-year results.

UNLABELLED: The objective of the present study was to retrospectively analyze a cohort of patients who underwent surgery for colorectal cancer pulmonary metastases during a 12-year period. PATIENTS AND METHODS: The sample included 75 patients who were monitored in terms of overall survival (OS) and disease-free interval (DFI) in relation to patient's age, preoperative values of biomarkers, type of surgery, number and size of metastases, occurrence of complications and length of hospitalisation. RESULTS: A total of 95 surgical interventions were performed and 133 metastases were removed. Out of these, 28% of patients were free of any signs of relapse or disease progression for 5 years after metastasectomy. Those with two or more metastases are 2.3-times more at risk of disease progression. Tissue polypeptide specific antigen (TPS) values above the 140 IU/l cut-off point increase the risk of progression 3.9-times. The five-year survival rate among the group was 45%. Patients with 2 or more metastases are 2.7-times more at risk of death. TPS values above the 140 IU/l cut-off increase the risk of death 5.5 times, and carbohydrate antigen CA19-9 values above the 28 IU/ml cut-off point increase the risk of death by 3.2 times. CONCLUSION: The number of metastases and the preoperative TPS values are decisive prognostic factors influencing both OS and DFI.

Radiofrequency ablation of non-resectable lung tumors.

BACKGROUND: Radiofrequency thermal ablation (RFA) is a minimally invasive, image guided technique for destroying tumour cells without damage to adjacent healthy tissue. It is used for partial or complete ablation of non resectable lung cancers and cancers of metastases to lung, providing an effective, relatively safe option for patients ineligible for surgery. We describe our experience with it. METHODS: In 2005 and 2006, we performed radiofrequency ablation of 7 lung lesions in 6 patients. RFA was done percutaneously under image guided CT scan in 5 patients and in one patient during thoracotomy when we found a radically unresectable tumor necessitating debulking. CT lung screening was performed after 6 months and PET/CT was done within 12 months. RESULTS: In the course of the screening, we diagnosed regression in 2 patients, a stationary state in 2 cases and local tumor progression in 2 patients, using computed tomography within 6 months after RFA. Using PET/CT within 12 months, we diagnosed non-ablation and liver metastases (there were none before) in one of the two patients with a stationary state diagnosed by means of CT before and recurrence of primary tumor in another patient. In one case of diagnosed regression, we diagnosed tumor progression. The patients survived an average of 30 months (range 9 to 60 months). CONCLUSION: RFA of lung tumors is an easy method with little patient discomfort. It can be performed percutaneously using guided CT under general anaesthesia. RFA of lung tumors possibly alone or in combination with oncology treatment can prolong patient life.