Lymph node core biopsies reliably permit diagnosis of lymphoproliferative diseases. Real‐World Experience from 554 sequential core biopsies from a single centre

INTRODUCTION: Whilst excision biopsy is traditionally preferred, advances in radiological and histological techniques warrant a re-look at core biopsy as a viable primary diagnostic method. METHOD: Over a 3-year period, all patients who underwent core biopsy to investigate lymphoma at our centre were included. RESULTS: 554 consecutive patients were included (40.1% prior lymphoma and 59.4% new presentations). Three or more cores were taken in 420 (75.8%) cases. Median time from request to biopsy and biopsy to histology report was 2 (0-40) days and 7 (1-24) days respectively. 510/544 (93.8%) biopsies were diagnostic. There was no difference in whether the biopsy was diagnostic based on indication (new vs. relapsed lymphoma) (p=0.445), whether biopsy was PET-directed (p=0.507), for T-cell lymphoma (p=0.468) or nodal vs. extra-nodal (p=0.693). Thirty-eight patients (6.9%) required a second biopsy due to inadequate tissue. In a patient experience survey, only 13.9% reported any complications (1 self-limiting minor bleeding, 4 bruising) whilst 16.7% reported any discomfort beyond 12 hours. CONCLUSION: Core biopsy performed by experienced radiologists and analysed by expert haemato-pathologists is a reliable, well-tolerated method for diagnosing lymphoma and confirming relapse. Multiple cores can be obtained under local anaesthetic yielding sufficient material in the majority of cases

Netrin-1 reduces monocyte and macrophage chemotaxis towards the complement component C5a

Netrin-1, acting at its cognate receptor UNC5b, has been previously demonstrated to inhibit CC chemokine-induced immune cell migration. In line with this, we found that netrin-1 was able to inhibit CCL2-induced migration of bone marrow derived macrophages (BMDMs). However, whether netrin-1 is capable of inhibiting chemotaxis to a broader range of chemoattractants remains largely unexplored. As our initial experiments demonstrated that RAW264.7 and BMDMs expressed high levels of C5a receptor 1 (C5aR1) on their surface, we aimed to determine the effect of netrin-1 exposure on monocyte/macrophage cell migration induced by C5a, a complement peptide that plays a major role in multiple inflammatory pathologies. Treatment of RAW264.7 macrophages, BMDMs and human monocytes with netrin-1 inhibited their chemotaxis towards C5a, as measured using two different real-time methods. This inhibitory effect was found to be dependent on netrin-1 receptor signalling, as an UNC5b blocking antibody was able to reverse netrin-1 inhibition of C5a induced BMDM migration. Treatment of BMDMs with netrin-1 had no effect on C5aR1 proximal signalling events, as surface C5aR1 expression, internalisation and intracellular Ca2+ release following C5aR1 ligation remained unaffected after netrin-1 exposure. We next examined receptor distal events that occur following C5aR1 activation, but found that netrin-1 was unable to inhibit C5a induced phosphorylation of ERK1/2, Akt and p38, pathways important for cellular migration. Furthermore, netrin-1 treatment had no effect on BMDM cytoskeletal rearrangement following C5a stimulation as determined by microscopy and real-time electrical impedance sensing. Taken together these data highlight that netrin-1 inhibits monocyte and macrophage cell migration, but that the mechanism behind this effect remains unresolved. Nevertheless, netrin-1 and its cognate receptors warrant further investigation as they may represent a potential avenue for the development of novel anti-inflammatory therapeutics

Netrin-1 reduces monocyte and macrophage chemotaxis towards the complement component C5a

Netrin-1, acting at its cognate receptor UNC5b, has been previously demonstrated to inhibit CC chemokine-induced immune cell migration. In line with this, we found that netrin-1 was able to inhibit CCL2-induced migration of bone marrow derived macrophages (BMDMs). However, whether netrin-1 is capable of inhibiting chemotaxis to a broader range of chemoattractants remains largely unexplored. As our initial experiments demonstrated that RAW264.7 and BMDMs expressed high levels of C5a receptor 1 (C5aR1) on their surface, we aimed to determine the effect of netrin-1 exposure on monocyte/macrophage cell migration induced by C5a, a complement peptide that plays a major role in multiple inflammatory pathologies. Treatment of RAW264.7 macrophages, BMDMs and human monocytes with netrin-1 inhibited their chemotaxis towards C5a, as measured using two different real-time methods. This inhibitory effect was found to be dependent on netrin-1 receptor signalling, as an UNC5b blocking antibody was able to reverse netrin-1 inhibition of C5a induced BMDM migration. Treatment of BMDMs with netrin-1 had no effect on C5aR1 proximal signalling events, as surface C5aR1 expression, internalisation and intracellular Ca2+ release following C5aR1 ligation remained unaffected after netrin-1 exposure. We next examined receptor distal events that occur following C5aR1 activation, but found that netrin-1 was unable to inhibit C5a induced phosphorylation of ERK1/2, Akt and p38, pathways important for cellular migration. Furthermore, netrin-1 treatment had no effect on BMDM cytoskeletal rearrangement following C5a stimulation as determined by microscopy and real-time electrical impedance sensing. Taken together these data highlight that netrin-1 inhibits monocyte and macrophage cell migration, but that the mechanism behind this effect remains unresolved. Nevertheless, netrin-1 and its cognate receptors warrant further investigation as they may represent a potential avenue for the development of novel anti-inflammatory therapeutics

Rapid response to single agent daratumumab is associated with improved progression-free survival in relapsed/refractory AL amyloidosis

Background: Daratumumab is a monoclonal antibody, which targets CD38; an antigen expressed on malignant plasma cells in AL amyloidosis thus providing a rationale for its use.Method: Patients treated with daratumumab monotherapy (2016-2019) for relapsed/refractory systemic AL amyloidosis were identified from the database at the UK National Amyloidosis Centre.Results: Of 50 evaluable patients, haematological responses at 3 months were: CR - 19 (38%), VGPR - 14 (28%), PR - 9 (18%) and no response - 8 (16%). Median time to response was 1 (1-6) month. Of assessable patients, cardiac, renal and hepatic responses were seen in 43.8%, 25.0% and 0% of patients whilst progression occurred in 25.0%, 12.5% and 37.5% respectively. Patients achieving a CR had longer median OS (not reached vs. 22.7 months [95% CI 17.0-28.4 months]) (p = .036). Furthermore, patients achieving a rapid response (at 1 month) had a longer median PFS (not reached vs. 9 months [95% CI 5.8-12.2 months]) (p = .013).Conclusion: Daratumumab monotherapy is effective in multiply-relapsed systemic AL amyloidosis and should be considered, if available, in patients who have not received prior daratumumab therapy. Responses are achieved rapidly and overall response rate was 84%. CR predicts overall survival whilst speed of response is predictive of a longer PFS