TSA Therefore, in this case the ELISA that detect Ma2 autoantibodies can reliably identify about 47% of the SI-NET patients at the primary stage of the disease and the levels of autoantibodies correlate with the progression and recurrence free survival of the patients. Circulating levels of Ma2 autoantibodies did not seem to reflect the tumor mass per se as circulating levels for patients with lymph node or liver metastases with higher tumor load did not show significantly higher levels of autoantibodies. This supports the notion that Ma2 autoantibodies appear early during SI-NET development. These data pave the way for the possibility of using Ma2 autoantibodies as a reliable marker for tumor detection and progression of SI-NETs growth.

Furthermore, the identification of Ma2 as a target of the autoimmune response in patients with SI-NET may provide the first insights into the molecular mechanisms of paraneoplastic syndrome in patients with these tumors. We also presented preliminary results dealing with TLC and ALC. All blood and tumor samples of lung carcinoids tested so far by ELISA and immunohistochemistry on paraffin sections showed increased expression of Ma2 in comparison with normal internal tissues. This supports the view that Ma2 protein accumulation and the presence of Ma2 autoantibodies is closely associated with the development of several types of differentiated NETs. Our study shows that lower titer of Ma2 autoantibodies correlates to a lower probability of recurrence with longer survival of SI-NET patients. This finding contradicts those reported in other studies, for instance Graus et al.

detected autoantibodies, denoted anti-Hu antibodies, which recognize antigens expressed by neurons, in small-cell lung carcinoma that have been associated to patients’ longer survival [27]. Pujol et al. reported the presence of autoantibodies and spontaneous complete remission of a non-small cell lung cancer (SCLC) patient associated with anti-Hu syndrome. Moreover, like Graus et al, they concluded that the anti-Hu humoral immunology is associated to a positive tumor response [28]. However, a more recent study reported that onconeural antibodies, such as anti-Hu and anti-CV2/CRMP5 have a different behavior in different tumor types. Therefore, the prognosis of the same type of tumor may differ according to the type of analyzed onconeural antibodies [29].

The human immune system normally produces antibodies in response to foreign proteins, such those of pathogens, and ignores the body’s own cells proteins to avoid to trigger disease. Anacetrapib When the immune system fails to discriminate self from non-self, proteins start producing antibodies against self proteins denoted autoantibodies. A variety of theories have tried to explain why autoantibodies appear in different patient conditions. However, why humoral autoimmunity can cause diseases is not fully understood.