A cytokine ELISA panel showed significant increases in IL-2 and IL-12p70 protein content in hippocampal tissue collected from same SCZ subjects when compared to matched control subjects.
Negative symptoms (especially asociality and avolition), along with the inflammatory biomarker interleukin-2, are the most important determining factors of poor real-world functioning in early-stage schizophrenia.
For example, the over-expressing schizophrenia candidate genes, SIRPB1, SYK and LCK, are responsible for signal transduction in cytokine production; immune responses involving IL-2 and TREM-1/DAP12 pathways are relevant for the etiology mechanism of schizophrenia.
This study aimed at investigating the association between schizophrenia susceptibility and selected functional polymorphisms in genes encoding cytokines including: interleukin-2 (IL2 -330T>G, rs2069756), interleukin-6 (IL-6 -174G>C, rs1800795), interferon-γ (IFNG +874T>A, rs2430561) as well as for the first time transforming growth factor-β1 (TGFB1 +869T>C, rs1800470 and +916G>C, rs1800471).
Dysfunction of T-cell mediated immunity, which is indicated by deficient production of interleukin-2 (IL-2) and elevated levels of the soluble interleukin-2 receptor (sIL-2R), has been consistently demonstrated in schizophrenia.
This study does not support an association between schizophrenia and the IL-2R beta gene locus, contrary to the suggestive evidence from linkage analysis in multicase families.