Granzyme B in peripheral blood mononuclear cells as a measure of cell-mediated immune response in paraneoplastic neurological syndromes and malignancy.

BACKGROUND: Paraneoplastic neurological syndromes (PNS) may coexist with ovarian or lung cancers. Some tumors coexisting with PNS are smaller and have a better prognosis than tumors without PNS. PNS may constitute an opportunity to observe a natural immune antitumor response. We aimed to investigate a cytotoxic immune response by measuring granzyme B (GrB) in peripheral blood mononuclear cells (PBMC) in patients affected with ovarian or lung malignancy, with and without accompanying PNS. METHODS: We enrolled patients with: nonmalignant lesions (n = 21), ovarian cancer (n = 19), lung cancer (n = 57), and PNS (n = 30). PBMC were isolated by density gradient centrifugation with Ficoll-Paque. We evaluated the expression of GrB in PBMC lysates by ELISA and normalized to protein content as measured by the Lowry method. RESULTS: GrB levels in PBMC in the group with malignant tumors-median 1650 pg/mg protein (interquartile range 663-3260 pg/mg) and in patients with PNS-median 1890 pg/mg protein (range 1290-2640 pg/mg) was lower than in control group with nonmalignant lesions-median 5240 pg/mg protein (range 2160-7440 pg/mg), p = 0.0003 and p = 0.0038, respectively. The differences in GrB levels in PBMC between these groups were independent of epidemiological factors-age, sex, body mass index (BMI), and the number of immune cells, as confirmed by multiple regression analysis. Within the group of patients with malignancy and PNS, GrB levels in PBMC were elevated if onconeural antibodies were detected (2610; 2390-3700 pg/mg protein) as compared to patients without antibodies (1680; 970-1880 pg/mg protein, p = 0.035). GrB in PBMC was higher if the malignancy was diagnosed at the low (3060; 2120-5220 pg/mg protein) as compared to the high stage (1330; 348-2140, p = 0.00048). In patients with lung cancer, the expression of GrB in PBMC was lower (1430; 635-2660 pg/mg protein) than in the group with ovarian cancer (2580; 1730-3730, p = 0.02). CONCLUSION: The cytotoxic response measured in peripheral blood by GrB in PBMC is impaired both in the course of malignancy and PNS. Levels of GrB in PBMC were higher if onconeural antibodies were detected. Tracking reactive immune responses, such as GrB in PBMC may have diagnostic and monitoring value in malignancy and PNS.

Autoimmune response in lung cancer patients with neurological paraneoplastic syndromes.

AIM OF THE STUDY: The aim of this study was to evaluate granzyme B, perforin and FasL expression in peripheral blood mononuclear cells (PBMCs) in lung cancer patients and in paraneoplastic neurological syndromes (PNS). CLINICAL RATIONALE FOR THE STUDY: Cellular immune response is activated as part of anti-tumour reaction of the malignancy-bearing host. Paraneoplastic neurological syndromes (PNS) are defined as indirect effects of cancer on the nervous system and are considered immune-mediated. Such stimulation of the immune system may limit the aggressiveness of cancer and the development of metastasis, and thereby improve survival. Granzyme B and perforin pathway, and Fas ligand (FasL) - Fas receptor interaction play an important role in cytotoxic response. MATERIALS AND METHODS: Fifty-two patients were included in the study: 28 subjects with PNS and 24 subjects with lung cancer. PNS cases were diagnosed according to the Graus criteria. The presence of onconeural antibodies (anti-Hu/anti-Ri/anti-Yo/anti-Ma/Ta/anti-CV2/anti-amphiphysin/anti-myelin/anti-neuroendothelium/anti-MAG/anti-GAD) was detected with indirect immunofluorescence and confirmed with Line Blotting. The expression of granzyme B, perforin and FasL was detected in PBMCs with ELISA. RESULTS: PPBMC-FasL expression was increased in lung cancer compared to other patient groups. The granzyme to FasL ratio was significantly higher in lung cancer patients with peripheral than with central PNS involvement. In a multiple regression model, sex was an independent factor influencing PBMC expression of granzyme and perforin. CONCLUSIONS: FasL expression in PBMCs is up-regulated in lung cancer patients. The interplay between granzyme B and FasL may be involved in the development of PNS at the level of the peripheral and the central nervous systems in different manners. Gender is associated with PBMC expression of granzyme B and perforin in lung cancer patients. CLINICAL IMPLICATIONS: The novel findings that we report broaden the current knowledge on PNS pathomechanism, with aspects that have not been previously explored. Our findings provide a rationale for further exploration of the granzyme B/FasL pathway with regards to its potential diagnostic value. However, our study is preliminary and needs further research, especially in the context of the prognostic value of the proposed markers.