Monitoring of TNFR1, IL-2Rα, HGF, CCL8, IL-8 and IL-12p70 following HSCT and their role as GVHD biomarkers in paediatric patients

No predictive factors are currently available to establish patient-specific GVHD risk. A panel of six serum cytokines (TNF receptor 1, IL-2 receptor alfa (IL-2Rα), hepatocyte growth factor (HGF), monocyte chemo-attractant protein-2, IL-8, IL-12p70) were monitored at established time points (days -1, +1, +7, +14, +21, +28 and +60) in 170 paediatric hematopoietic SCT (HSCT) recipients. We found that higher concentrations of IL-2Rα on days +14 and +21 together with HGF on days +14 and +21 were significantly associated at a higher probability of both grade II-IV GVHD (on day +14 it was: 60% vs 28%, P=0.007) and grade III-IV (on day +14 it was: 40% vs 15%, P=0.001). The higher IL-8 serum concentration on day +28 was associated with a lower probability of chronic GVHD being 4% vs 29% (P=0.01) for patients with higher vs lower IL-8 serum concentration. These findings were confirmed when the analysis was restricted to the the matched unrelated donor group. In conclusion, even if the serum cytokine levels were related to several variables associated with HSCT, we identified two cytokines as predictors of GVHD II-IV and III-IV, translating into a higher TRM risk (17% vs 3%, P=0.004).

Correlation between NK function and response to trastuzumab in metastatic breast cancer

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Background: Trastuzumab is a monoclonal antibody selectively directed against Her2 approved for the treatment of Her2 overexpressing breast cancer patients. Its proposed mechanisms of action include also a role in mediating antibody-dependent cellular cytotoxicity (ADCC), through the triggering of the FcγRIII on natural killer (NK) cells. This study addressed the correlation between overall NK function and clinical trastuzumab activity. Methods: Between March and September 2006 22 metastatic patients in treatment with trastuzumab alone (8 mg/kg load and then 6 mg/kg every 3 weeks until disease progression) as maintaining therapy after chemotherapy were analyzed for clinical and immunological responses. According to RECIST criteria, 14 patients obtained a response to trastuzumab, while 8 patients had a disease progression. Patient’s peripheral blood mononuclear cells were tested for cytotoxic activity against standard NK target (the MHC class I-negative K562 cell line) and trastuzumab-coated MCF7 (Her2-negative) and SKBR3 (Her2-positive) human cell lines in a 4-h 51Cr-release cytotoxicity assay in the presence of grading concentrations of effector cells. Results: NK activity was significantly (p<0.05) higher in responder compared to non responder patients at all the four effector:target (50:1 to 6:1) ratios tested. NK activity of non responder patients was significantly lower than that of 25 sex and age matched controls (p<0.02) and this was not merely due to chemotherapy- or tumor-associated immunosuppression, since the values of responder patients did not significantly differ from those of controls. ADCC activity against Her2-positive SKBR3 cells was also significantly higher in responder compared to non responder patients (p<0.05) and markedly so when compared to controls (p<0.001). Conclusions: The fact that, as shown here, normal levels of FcγR- independent and higher than normal levels of FcγR-dependent cytotoxicity are required for trastuzumab response, lends support to a paramount role of NK cells in the mechanism of action of this drug.

No significant financial relationships to disclose.