John Eggington Posted September 12, 2015 Share Posted September 12, 2015 Has anyone had experience of testing patients being treated with anti-CD38? Link to comment Share on other sites More sharing options...
Malcolm Needs ☆ Posted September 12, 2015 Share Posted September 12, 2015 I haven't John! John Eggington 1 Link to comment Share on other sites More sharing options...
tbostock Posted September 13, 2015 Share Posted September 13, 2015 Ooh, very interesting! http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3667209/ Link to comment Share on other sites More sharing options...
John Eggington Posted September 14, 2015 Author Share Posted September 14, 2015 Samples were referred to us (the reference laboratory) and were found to contain a pan reactive antibody detected by all IAT techniques available to us (including two gel technologies, and tube techniques perfomed with a range of different media). The 'Auto' and DAT were negative. An elution of the patient's red cells was also 'negative'. The patient had been transfused a single red cell unit, about 6 weeks prior to referral (no previous transfusion history), when their IAT red cell antibody screen was negative. Reactivity with test cells was now a, relatively, uniform positive grade 3 (on a scale of 1-5), but some stronger and weaker reactions were noted. Reaction strength increased when an enzyme IAT was performed, using papain treated red cells. We initially investigated for the possible presence of an antibody to a higher frequency antigen, but found no negative results with, for example, Csa-, Lan-, Vel-, Lub-, Kpb-, CR1-, Yta-, k-, red cells. The plasma hade a titre of 2048 against each of the red cells of a 3 cell antibody screening 'set'. We were then informed that the patient had started treatment with anti-CD38, immediately after their transfuson, 6 weeks ago. We treated a standard red cell antibody identification panel with DTT, and found that this failed to react with the sample. This result, in combination with results from an extended phenotype, allowed us to rule out most significant antibodies (other than those with antigens that are sensitive to DTT treatment and that the patient lacked) and be fairly confident taht the antibody we were detecting was the anti-CD38. What I want to know is why are the patient's 'Auto' and DAT negative, where has their CD38 antigen gone? Also, has anyone who has encountered this antibody come up with any other methods for 'dealing' with it? Yanxia 1 Link to comment Share on other sites More sharing options...
galvania Posted September 14, 2015 Share Posted September 14, 2015 I saw a papers about this recently - see below abstract. BACKGROUND: Daratumumab (DARA), a promising novel therapy for multiple myeloma, is an IgG1 monoclonal antibody that recognizes CD38 on myeloma cells. During routine compatibility testing, we observedthat the plasma of five of five DARA-treated patients demonstrated a positive antibody screen and panreactivity on red blood cell (RBC) panel testing. We hypothesized that the observed panreactivity reflectedDARA binding to CD38 on reagent RBCs, and we investigated methods to prevent this binding.STUDY DESIGN AND METHODS: DARA binding to CD381 or CD38– HL60 cells was assessed by flow cytometry. To remove cell surface CD38, cells were incubated with dithiothreitol (DTT) or trypsin. SolubleCD38 or anti-DARA was used to neutralize DARA in solution. Routine blood bank serologic methods were used to test samples from DARA-treated patients and normal plasma samples spiked with DARA and/or alloantibodies.RESULTS: Normal plasma samples spiked with DARA (0.1-10 mg/mL) and incubated with reagent RBCs recapitulated the interference observed with samples from DARA-treated patients. Flow cytometry experimentsconfirmed DARA binding to CD381 HL60 cells, but not to CD38– controls. DTT treatment of CD381 HL60 cells reduced DARA binding by 92% by denaturing cell surface CD38. Treating DARA-containing plasma with soluble CD38 or anti-DARA idiotype also inhibited DARA binding.CONCLUSION: DARA causes panreactivity in vitro by binding to CD38 on reagent RBCs. Treating reagent RBCs with DTT is a robust method to negate the DARA interference, enabling the safe provision of blood toDARA-treated patients. Because DTT denatures Kell antigens, K– units are provided to these patients. Resolving the daratumumab interference with blood compatibility testing, Chapuy et al. TRANSFUSION 2015;00;00–00 As to why the patient's DAT and auto were neg, my guess would be that the treatment had already neutralised, maybe even destroyed???? their own CD38, so that their cells are no longer reacting 'normally' in that respect. I don't know. I have no actual experience with this at all. Yanxia 1 Link to comment Share on other sites More sharing options...
John Eggington Posted September 14, 2015 Author Share Posted September 14, 2015 It's odd; nothing in the literature suggest that the antigen is destroyed, only that the (white) cells that express it are destroyed. A few theories as to the nature of the destruction are postulated. Link to comment Share on other sites More sharing options...
goodchild Posted September 14, 2015 Share Posted September 14, 2015 So well bound in vivo, inhibited in vitro? Very interesting, thanks for the articles. Link to comment Share on other sites More sharing options...
EDibble Posted September 19, 2015 Share Posted September 19, 2015 I attended the MABB this Spring and sat in on this presentation. Very interesting indeed. Link to comment Share on other sites More sharing options...
John Eggington Posted September 20, 2015 Author Share Posted September 20, 2015 The impression I get, from reading about this antibody (and others), is that we may be seeing a lot more these types of cases in the (near?) future... Malcolm Needs 1 Link to comment Share on other sites More sharing options...
galvania Posted September 24, 2015 Share Posted September 24, 2015 We got our first one yesterday - antibody panel in gel a uniform weak, but nonetheless clear, reaction with all panel cells, negative auto and DAT (like John's patient). Antibody in tube (ratio 4 to 1 with no LISS) gave moderate reactions with all cells. We DTT treated the red cells and the antibody then disappeared. Exciting. Felt like doing REAL science! Auntie-D, Malcolm Needs, John Eggington and 1 other 4 Link to comment Share on other sites More sharing options...
Auntie-D Posted September 24, 2015 Share Posted September 24, 2015 We got our first one yesterday - antibody panel in gel a uniform weak, but nonetheless clear, reaction with all panel cells, negative auto and DAT (like John's patient). Antibody in tube (ratio 4 to 1 with no LISS) gave moderate reactions with all cells. We DTT treated the red cells and the antibody then disappeared. Exciting. Felt like doing REAL science! I'm jealous! Almost... Link to comment Share on other sites More sharing options...
Mabel Adams Posted November 18, 2015 Share Posted November 18, 2015 And now it is FDA approved in the US. Multiple myeloma drug from J&J receives FDA approval Johnson & Johnson has won FDA approval for the use of Darzalex, or daratumumab, in multiple myeloma patients who have received at least three lines of standard therapies. The decision was backed by data from two trials, including a 42-patient study showing that tumors were completely or partially reduced in 36% of patients who took the drug. Reuters (11/16) Do all patients taking the drug show the effects outlined on this thread or do some have a weaker or undetectable effect? I need to have a discussion with our oncologists (among other things). AMcCord and goodchild 2 Link to comment Share on other sites More sharing options...
goodchild Posted November 18, 2015 Share Posted November 18, 2015 Thanks for the heads up Mabel. Link to comment Share on other sites More sharing options...
Mabel Adams Posted November 19, 2015 Share Posted November 19, 2015 A colleague in Montana suggested that we do an antibody screen and K type any patient before they are started on the drug so we have a baseline antibody screen. Her oncologists have said they will be using this drug. I figured advance testing also would give us time to send out k typing on any K pos patient since we don't keep that antiserum. Of course I still need to find out if this is going to be a rarely used drug or if the patients on it will have a reduced need for transfusion. Other questions like half-life and how often it is given and for how long may help determine how likely we are to see a case in the BB. I heard at AABB that cord cells don't react with it but would there be any way to validate a process for using cord cells for this? We might have to get in some DTT and write up a protocol for dealing with this antibody if it is going to be used much in our area. Yanxia 1 Link to comment Share on other sites More sharing options...
galvania Posted November 19, 2015 Share Posted November 19, 2015 I would fully recommend the DTT treatment. It isn't difficult to do. Just make sure you always transfuse K- Link to comment Share on other sites More sharing options...
Mabel Adams Posted November 23, 2015 Share Posted November 23, 2015 We wouldn't want to transfuse K neg if the patient is k neg, right? I know, only 1% chance of them being k neg and even less of them having anti-k. Malcolm Needs 1 Link to comment Share on other sites More sharing options...
Mabel Adams Posted December 24, 2015 Share Posted December 24, 2015 Does anyone know what would happen if someone mistook this situation for a warm auto and did a PEG autoadsorption on the sample? Or maybe an alloadsorption? Can this antibody be adsorbed out? Link to comment Share on other sites More sharing options...
Mabel Adams Posted December 24, 2015 Share Posted December 24, 2015 I found the answer in the Transfusion article. Looks like it doesn't adsorb out. I now have an oncologist saying this problem isn't turning out to be as common as expected. Anyone else able to corroborate this? Malcolm Needs 1 Link to comment Share on other sites More sharing options...
John Eggington Posted December 27, 2015 Author Share Posted December 27, 2015 The failure of adsorption is probably a mix of the high titre of the antibody (in the 'thousands' if a the high dose is given) and a lowi density of cd38 on red cells used for adsorption. Maybe if you spent a week adsorbing the same sample you'd get rid of it! As for how common the phenomenon is; I would have thought you'd find it every time you looked for it, so maybe it's just that the test isn't requested after therapy starts, in a lot of the patients. I still wonder why the auto/DAT is negative in some patients; maybe the DAT positive ones already had a positive DAT before the therapy started? Link to comment Share on other sites More sharing options...
Mabel Adams Posted December 28, 2015 Share Posted December 28, 2015 The oncologist referred to a "positive Coombs" so I don't know if we were actually talking about the same problem. When they say "Coombs" they usually mean a direct antiglobulin test not a screen. I wonder if some of his buddies have been ordering DATs on these patients, finding them negative and concluding that there isn't much of a problem--until they need to crossmatch them anyway. At least we have begun the conversation. Malcolm Needs 1 Link to comment Share on other sites More sharing options...
Malcolm Needs ☆ Posted December 28, 2015 Share Posted December 28, 2015 6 hours ago, Mabel Adams said: The oncologist referred to a "positive Coombs" so I don't know if we were actually talking about the same problem. When they say "Coombs" they usually mean a direct antiglobulin test not a screen. I wonder if some of his buddies have been ordering DATs on these patients, finding them negative and concluding that there isn't much of a problem--until they need to crossmatch them anyway. At least we have begun the conversation. Ah, the need to use correct terminology rears its ugly head again!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Linda0623 1 Link to comment Share on other sites More sharing options...
John Eggington Posted December 28, 2015 Author Share Posted December 28, 2015 What you say, Mabel, could well be the case. The (limited) published work implies that the patients will be DAT positive, but my (again, limited) experience is that they are DAT negative (and remain so). Could the apparent lack of cd38 on patient red cells be the effect of a prior therapy (the use of gel cards (and other results) rules out 'insufficient washing' , and 'prozone' doesn't 'fit')? Malcolm Needs and galvania 2 Link to comment Share on other sites More sharing options...
Mabel Adams Posted December 29, 2015 Share Posted December 29, 2015 I wonder if it might be that any patient red cells that express cd38 strongly get coated with antibody and removed from circulation thereby selecting for rbcs with lower expression of cd38. Maybe this even happens to precursor cells (assuming they express the antigen) so that fewer strong cd38 cells get released from the marrow. Just speculating. galvania 1 Link to comment Share on other sites More sharing options...
John Eggington Posted December 29, 2015 Author Share Posted December 29, 2015 I wondered this too, but the patients don't seem to be particularly anaemic, which is what I'd expect if red cells were being destroyed. Maybe antigen is being removed without red cell destruction? Just had a new 'cd38' case and this one has a positive DAT', with therapy starting only a week or so ago. DAT wasn't done before therapy started. Titre of the antibody is almost 4000. kirkaw, Malcolm Needs and galvania 3 Link to comment Share on other sites More sharing options...
Bb_in_the_rain Posted December 30, 2015 Share Posted December 30, 2015 (edited) I have recently done an oral presentation about our research project on anti-CD38(Daratumumab) during this recent AABB meeting in Anaheim. I have some abstract references that I have attached here. Hope it helps. Also a full article here. http://onlinelibrary.wiley.com/doi/10.1111/trf.13069/full 3 of 8 patients(i have seen to date) has positive DAT and 2 of them were on IVIG. We found that this antibody is non-reactive with In(Lu) cells by tube method. By tube method, DTT treated cells were non reactive, cord cells were weakly reactive to non-reactive.(not enough cord cells were tested yet to find pattern) Our flow cytometry data wiith florusecnt labeled anti-CD38 shows that DTT treated cells has very low percentage of CD38 (2%-4%), cord cells has about 21%-24% and positive control varies from (53-82%), In(Lu) cells has about >20%. These data were presented orally during AABB meeting but not yet been published. SKMBT_75115100213120.pdf NEJM Aug 2015 editorial on Dara.pdf cord rule out.pdf abstract-ARC and NYBC.pdf abstract-ARC and NYBC.pdf Edited December 30, 2015 by dothandar Malcolm Needs, AMcCord, carolyn swickard and 4 others 7 Link to comment Share on other sites More sharing options...
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