Programmed cell death (PCD) or apoptosis is a common form of cellular demise during embryogenesis, tumorigenesis and clonal selection in the immune system. The bcl‐2 proto‐oncogene has been recently implicated as a potential physiological regulator of the PCD pathway. Gene transfer studies have shown that overexpression of bcl‐2 blocks apoptosis mediated by several stimuli in cultured cell lines and promotes the survival of B and T lymphocytes in transgenic mice. However, it remains unclear whether under normal conditions bcl‐2 is responsible for controlling cell death. We have investigated the role of bcl‐2 in the antimembrane IgM (mIgM)‐induced apoptotic death of WEHI‐231 B cell lymphoma, a model that mimics clonal deletion of immature B cells by antigen. Signalling of mIgM receptors triggered downregulation of both bcl‐2 RNA and protein, and induced apoptosis in WEHI‐231 B cells. This effect appeared to be specific since (i) the levels of beta 2‐microglobulin and beta‐actin RNA remain unchanged and (ii) signalling of the apoptosis‐resistant B cell lymphoma line BAL‐17 with anti‐mu was not associated with downregulation of bcl‐2 RNA. However, stable expression of bcl‐2 by transfection did not rescue WEHI‐231 B cells from apoptosis, yet WEHI‐231 cells overexpressing bcl‐2 were more resistant to programmed cell death induced by heat‐shock.(ABSTRACT TRUNCATED AT 250 WORDS)

BackgroundThe aim of this work was to analyze the number and distribution of circulating monocytes, and of their CD14+highCD16−, CD14+highCD16+ and CD14+lowCD16+ subset cells, in treatment-naive patients with rheumatoid arthritis (RA), and to determine their value in predicting the clinical response to methotrexate (MTX) treatment.MethodsThis prospective work investigated the number of circulating monocytes, and the numbers of CD14+highCD16−, CD14+highCD16+ and CD14+lowCD16+ subset cells, in 52 untreated patients with RA before MTX treatment, and at 3 and 6 months into treatment, using flow cytometry.ResultsThe absolute number of circulating monocytes, and the numbers of CD14+highCD16−, CD14+highCD16+ and CD14+lowCD16+ subset cells, were significantly higher in MTX non-responders than in responders and healthy controls before starting and throughout treatment. Responders showed normal numbers of monocytes, and of their subset cells, over the study period. The pre-treatment absolute number of circulating monocytes, and the numbers of CD14+highCD16− and CD14+highCD16+ subset cells, were found to be predictive of the clinical response to MTX, with a sensitivity and specificity of >70% and >88%, respectively.ConclusionsTreatment-naive patients with RA showed an anomalous distribution of circulating monocyte subsets, and an anomalous number of cells in each subset. A higher pre-treatment number of circulating monocytes, and higher numbers of CD14+highCD16− and CD14+highCD16+ subset cells, predict a reduced clinical response to MTX in untreated patients with RA.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-014-0375-y) contains supplementary material, which is available to authorized users.

IntroductionThe treatment of rheumatoid arthritis (RA) patients with anti-tumor necrosis factor alpha (TNFα) biological drugs has dramatically improved the prognosis of these patients. However, a third of the treated patients do not respond to this therapy. Thus, the search for biomarkers of clinical response to these agents is currently highly active. Our aim is to analyze the number and distribution of circulating monocytes, and of their CD14+highCD16-, CD14+highCD16+ and CD14+lowCD16+ subsets in methotrexate (MTX) non-responder patients with RA, and to determine their value in predicting the clinical response to adalimumab plus MTX treatment.MethodsThis prospective work investigated the number of circulating monocytes, and of their CD14+highCD16-, CD14+highCD16+ and CD14+lowCD16+ subsets, in 35 MTX non-responder patients with RA before and after three and six months of anti-TNFα treatment using multiparametric flow cytometry. The number of circulating monocytes in an age- and sex-matched healthy population was monitored as a control.ResultsNon-responder patients with RA show an increased number of monocytes and of their CD14+highCD16-, CD14+highCD16+ and CD14+lowCD16+ subsets after three months of adalimumab plus MTX treatment that remained significantly increased at six months. In contrast, significant normalization of the numbers of circulating monocytes was found in responders at three months of adalimumab plus MTX treatment that lasts up to six months. CX3CR1 expression is increased in monocytes in non-responders. At three months of anti-TNFα treatment the number of circulating monocytes and their subsets was associated with at least 80% sensitivity, 84% specificity and an 86% positive predictive value (PPV) in terms of discriminating between eventual early responders and non-responders.ConclusionsThe absolute number of circulating monocytes and of their CD14+highCD16-, CD14+highCD16+ and CD14+lowCD16+ subsets at three months of adalimumab plus MTX treatment, have a predictive value (with high specificity and sensitivity) in terms of the clinical response after six months of anti-TNFα treatment in patients with RA.

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