Natural Killer (NK) cells are essential in the biological fight against cancer and intracellular pathogens, and their level of activity has in many settings been used as a biomarker for a functional immune response. Currently, NK cell activity is measured using either ⁵¹Cr-release assays or flow cytometry based assays revealing the cells´ cytotoxic capacity or by stimulating them to produce cytokines. Although very effective, these are cumbersome techniques not suitable for high volume clinical laboratories. Recently, an assay has been introduced to measure NK cell activity in a simple and standardized manner. Following stimulation of NK cells in whole blood with a recombinant protein, it utilizes the concentration of IFNγ released to the plasma as a surrogate marker for NK cell activity. However, whole blood holds several sources of IFNγ which may blur the results and hamper the interpretation of the test. Therefore, the present study aimed at analyzing how specifically the test is measuring the activity of NK cells. Intracellular flow cytometry showed that NK cells, T cells, and Natural Killer T (NKT) cells were producing IFNγ in the assay, however when analyzing the distribution of lymphocytes in the IFNγ-expressing subset, the proportion of NK cells far exceeded the percentage of T-, and NKT cells (p < .0001). Hence, our data indicate that the readout of the test was indicative of the NK cells´ ability to mount a response and thus the results may pave the way for the assay to become applicable in the clinical setting as an estimate of NK cell activity for both diagnostic and prognostic purposes.

Quantitative PCR (qPCR) of reverse-transcribed mRNA has revolutionized gene expression analyses. qPCR analysis is based on the prevalent assumption that mRNA transcript numbers provide an adequate ...

The aim of the present study was to analyze the possible correlation between Natural Killer (NK) cell activity as measured by the NK Vue assay and treatment efficacy in patients with disseminated cancer. The study included four trials encompassing palliative treatment, i.e. one trial on prostate- and ovarian cancer, respectively, and two trials on colorectal cancer. The current results are based on 93 patients with mature data on treatment effect. Blood samples were collected at baseline and prior to each treatment cycle into NK Vue. Following 24 hours of stimulation the level of interferon-gamma (IFNγ) in the plasma was measured as a surrogate for NK cell activity. The relationship between NK cell activity and treatment response was similar across tumor types and treatment. The IFNγ either remained at or dropped to an abnormal level (200 pg/mL), while in group 3 (n = 28) it increased from an abnormal to a normal level. The response rate was 14%, 47%, and 82%, respectively, P < .001. The median progression free survival was 2.6 months (95% confidence interval (CI) 2.1-3.9), 10.0 months (95% CI 6.5-11.1), and 8.3 months (95% CI 6.5-8.7), respectively, P < .001 (log-rank). Patients lacking the ability to mount an immune response during the first 2 months of treatment have a poor prognosis, and their clinical benefit of the treatment is questionable.

Early detection of lung cancer is pivotal for an optimal prognosis. CT screening is currently implemented in USA. To decrease the amount of CT scans, the application of a blood-based biomarker as part of screening criteria is desirable. The EarlyCDT® Lung test was performed in a high-risk cohort composed 246 patients referred from their GP on suspicion of lung cancer. Blood samples were taken at first visit and patients underwent diagnostic workup on suspicion of lung cancer resulting in either a malignant diagnosis or ruled out cancer. Sensitivity and specificity of the EarlyCDT® Lung were calculated in the cohort and subgroups based on age, smoking history, sex and lung cancer stage. Overall sensitivity in the cohort was 33 % for lung cancer and 31 % for primary lung cancer and lung metastases combined. Sensitivity in age groups was 11 % (60 years or below), 31 % (61-75 years) and 55 % (>75 years). In patients with at least 10 tobacco pack years, sensitivity was 33 % while the sensitivity in patients with at least 50 tobacco pack years was 44 %. The assay sensitivity in stage I-II lung cancer patients was 21 %, while this was 40 % in stage III-IV lung cancer patients. In a subgroup of patients that met current CT screening criteria (age 55-80 years and minimum 30 tobacco pack years) the sensitivity was 37 %. The rationale of screening for lung cancer is to find patients in an early and resectable stage. However, the EarlyCDT® Lung test performed best in elderly, late stage lung cancer patients with a heavy smoking history. Based on these results, the current study finds insufficient sensitivity of the EarlyCDT® Lung test to be used as part of inclusion criteria in a low-dose CT program for detection of lung cancer.

Many studies have focused on the prognostic role of soluble programmed death ligand 1 (sPD-L1) in non-small cell lung cancer (NSCLC), but outcomes are ambiguous and further investigations are needed. We addressed the matter by studying sPD-L1 in baseline samples and in longitudinal samples taken prior to three subsequent cycles of anti-PD-1/anti-PD-L1 treatments. Eighty patients with NSCLC were enrolled. Median sPD-L1 level at baseline was 52 pg/mL [95% confidence interval (CI) 49–57]. In patients treated with pembrolizumab and nivolumab, the concentration of sPD-L1 remained rather stable throughout treatment. In contrast, sPD-L1 rose by 50-fold following the first cycle of atezolizumab therapy. We found the baseline level of sPD-L1 to be related to overall survival (OS) after two years of follow-up in simple Cox analysis (p = 0.006) and multiple Cox Regression, hazard ratio 1.02 (95% CI 1.00–1.03) (p = 0.033). There was no association between sPD-L1 and tissue PD-L1 expression, overall response rate, or progression free survival. In conclusion, sPD-L1 measured in baseline serum samples may be associated with OS in NSCLC patients receiving anti-PD1/anti-PD-L1 treatment. Importantly, the results signify that further research is warranted to explore the clinical utility of sPD-L1 in patients treated with anti-PD-L1.