Treatment of bleeding episodes in haemophilia A complicated by a factor VIII inhibitor in patients receiving Emicizumab. Interim guidance from UKHCDO Inhibitor Working Party and Executive Committee

Emicizumab is a bispecific antibody that activates FX to FXa in the absence of FVIII. It has been shown to reduce bleeding episodes in people with haemophilia A complicated by a FVIII inhibitor. Despite the protection against bleeds, some breakthrough bleeds are inevitable and these may require additional haemostatic treatment. Emicizumab has been associated with severe adverse events when co-administered with activated prothrombin complex concentrate. To minimize the risk of adverse events, the UK Haemophilia Centre Doctors' Organisation issues the following updated interim guidance to its Inhibitor Guidelines for managing patients receiving Emicizumab based on the limit published information available in February 2018.

Expression of angiogenic factors and hypoxia inducible factors HIF 1, HIF 2 and CA IX in non-Hodgkin's lymphoma

AIMS

Angiogenesis in solid tumour pathology is well established but less is known about its role in haematological malignancies. Our study investigated the immunohistochemical expression of a variety of angiogenic and hypoxic factors and microvessel densities on 110 cases of high- and low-grade non-Hodgkin's lymphomas and reactive lymphoid tissues. methods and results: Expression of vascular endothelial growth factor (VEGF) was present in 82 (96%) of the non-Hodgkin's cases and 35 (100%) of the reactive lymphoid tissue cases. Both hypoxia inducible factors 1 alpha and 2 alpha (HIF 1 alpha, 2 alpha) were weakly expressed in the majority of high- and low-grade lymphomas. Carbonic anhydrase IX (CA IX), a HIF-inducible membrane-bound enzyme, expression was not abundant with membranous staining being present in seven (8%) of the lymphoma cases and none of the reactive cases. Thymidine phosphorylase (TP) was distributed amongst macrophages and follicular dendritic cells but was not present in the neoplastic population. The vasculature was stained using CD34 which gave rise to a distinct vascular, predominantly paracortical network present in low-grade lymphomas and reactive lymphoid tissue but which was lost in high-grade lymphomas.

CONCLUSION

Our results suggest that non-Hodgkin's lymphomas may be less angiogenic and hypoxically driven than most solid tumours, which has implications for possible future therapies.

Relation of hypoxia inducible factor 1 alpha and 2 alpha in operable non-small cell lung cancer to angiogenic/molecular profile of tumours and survival

Hypoxia inducible factors HIF1alpha and HIF2alpha are important proteins involved in the regulation of the transcription of a variety of genes related to erythropoiesis, glycolysis and angiogenesis. Hypoxic stimulation results in rapid increase of the HIF1alpha and 2alpha protein levels, as a consequence of a redox-sensitive stabilization. The HIFalphas enter the nucleus, heterodimerize with the HIF1beta protein, and bind to DNA at the hypoxia response elements (HREs) of target genes. In this study we evaluated the immunohistochemical expression of these proteins in 108 tissue samples from non-small-cell lung cancer (NSCLC) and in normal lung tissues. Both proteins showed a mixed cytoplasmic/nuclear pattern of expression in cancer cells, tumoural vessels and tumour-infiltrating macrophages, as well as in areas of metaplasia, while normal lung components showed negative or very weak cytoplasmic staining. Positive HIF1alpha and HIF2alpha expression was noted in 68/108 (62%) and in 54/108 (50%) of cases respectively. Correlation analysis of HIF2alpha expression with HIF1alpha expression showed a significant association (P< 0.0001, r = 0.44). A strong association of the expression of both proteins with the angiogenic factors VEGF (P< 0.004), PD-ECGF (P< 0.003) and bFGF (P< 0.04) was noted. HIF1alpha correlated with the expression of bek-bFGF receptor expression (P = 0.01), while HIF2alpha was associated with intense VEGF/KDR-activated vascularization (P = 0.002). HIF2alpha protein was less frequently expressed in cases with a medium microvessel density (MVD); a high rate of expression was noted in cases with both low and high MVD (P = 0.006). Analysis of overall survival showed that HIF2alpha expression was related to poor outcome (P = 0.008), even in the group of patients with low MVD (P = 0.009). HIF1alpha expression was marginally associated with poor prognosis (P = 0.08). In multivariate analysis HIF2alpha expression was an independent prognostic indicator (P = 0.006, t-ratio 2.7). We conclude that HIF1alpha and HIF2alpha overexpression is a common event in NSCLC, which is related to the up-regulation of various angiogenic factors and with poor prognosis. Targeting the HIF pathway may prove of importance in the treatment of NSCLC.