Cardoso S.P.,Colindale Center |
Chong W.,Colindale Center |
Lucas G.,Hand I laboratory |
Green A.,Hand I laboratory |
And 2 more authors.
Vox Sanguinis | Year: 2013
Background and Objectives: A number of DNA-based methods to genotype the alleles coding for HNA have been described, but all require the separate amplification and analysis of each allele. The aim was to develop a DNA-based method for simultaneous detection of HNA-1, HNA-3, HNA-4 and HNA-5 alleles. Materials and Methods: An allele-specific primer extension method was used in combination with magnetic beads from Luminex technology. PCR-sequence-specific primers (SSP) was used to resolve the presence of the HNA-1b allele in samples assigned by the Luminex bead assay as HNA-1a/-1b/-1c or HNA-1b/-1c. HNA allele frequencies were determined in a panel of 140 randomly selected English Caucasoid blood donors. Results: HNA allelic types were compared with historical results, and 100% concordance was found. Only eight of the 97 samples used in the validation required additional testing by PCR-SSP. Allele frequencies were determined in the blood donor population as follows: 0·318 for HNA-1a, 0·668 for HNA-1b, 0·014 for HNA-1c, 0·768 for HNA-3a, 0·232 for HNA-3b, 0·882 for HNA-4a, 0·118 for HNA-4b, 0·736 for HNA-5a and 0·264 for HNA-5b. Conclusion: A multiplex Luminex bead assay for the simultaneous detection of HNA-1, HNA-3, HNA-4 and HNA-5 alleles is described that enables rapid typing of donors to support HNA alloimmunized patients who require HNA-compatible blood products. © 2013 International Society of Blood Transfusion.
Win N.,Tooting Center |
Lee E.,Colindale Center |
Needs M.,Tooting Center |
Chia L.-W.,St Georges Hospital |
Stasi R.,St Georges Hospital
Transfusion Medicine | Year: 2012
Background: Hyperhaemolytic transfusion reaction (HHTR) has been well described in patients with sickle cell disease (SCD). It is characterised by a decrease in haemoglobin concentration to levels below those before transfusion and a fall in the absolute reticulocyte count. As red blood cells (RBC) alloantibodies are typically not detected in post-transfusion samples in acute forms of HHTR, we have previously proposed that both the transfused and autologous RBCs cells (HbSS/reticulocytes) are destroyed by activated macrophages. Case reports: We report a patient with SCD who presented with vaso-occlusive sickle cell crisis and developed a severe HHTR attributable to anti-Fy3. In addition to the usual supportive measures, the patient was treated with intravenous immunoglobulin (IVIG) and steroids. Serum ferritin levels were measured as an aspecific marker of macrophage activation. Results: Steroids and IVIG were effective in managing HHTR. Ferritin levels were high at the time of haemolysis, (>10000 μg L -1) whereas recovery and cessation of haemolysis correlated with a decrease in ferritin levels. Conclusion: Serum ferritin values >10 000 μg L -1 are considered pathognomic for conditions characterised by abnormal macrophage activation. In our case, serum ferritin levels correlate well with the disease activity and clinical response. This further supports our previous proposal that the activated macrophages play an important role in HHTR. Serum ferritin is a nonspecific marker of inflammation. A rapid specific bio-marker to measure the activity of macrophages in SCD in HHTR is desirable, and this area warrants further investigation. © 2012 The Authors. Transfusion Medicine © 2012 British Blood Transfusion Society.
Powley L.,Histocompatibility and Immunogenetics Research Group |
Powley L.,University College London |
Brown C.,Colindale Center |
Melis A.,Europdonor Foundation |
And 4 more authors.
Bone Marrow Transplantation | Year: 2016
In cord blood (CB) transplantation, virtual 6/6 HLA matches, whereby the donor-recipient mismatch is identical to the CB noninherited maternal Ag (NIMA), have similar outcomes to inherited 6/6 matches. In the UK-British Bone Marrow Registry (BBMR), 4707 of the total 21 020 CB donors have the NIMA defined. Retrospective searches of these donors, for 1-3 NIMA matches, identified a virtual 6/6 match for 31.4% of 274 European Caucasoid (EC) and 25.4% of 67 other ethnicity (OE) patients. Patients weighing ≤50 kg were also evaluated for a single graft with adequate cell dose. In 125 EC patients, 6/6 HLA matches were identified for 24.0% and virtual 6/6 matches were identified for a further 21.6%. The remaining EC patients had a 5/6 (30.4%) or a 4/6 (22.4%) match. In OE patients, 6/6 HLA matches were identified for 9.3% and virtual 6/6 matches were identified for a further 18.7%. The remaining OE patients had a 5/6 (30.2%) or a 4/6 (37.2%) match. Searches were also performed using the 26 735 Bone Marrow Donors Worldwide CB with defined NIMA and yielded comparable increases. Considering NIMA as permissible mismatches in donor selection therefore increased the availability of a 6/6 match in this cohort. © 2016 Macmillan Publishers Limited.
PubMed | Colindale Center, Europdonor Foundation, Cord Blood Registry and Histocompatibility and Immunogenetics Research Group
Type: Journal Article | Journal: Bone marrow transplantation | Year: 2016
In cord blood (CB) transplantation, virtual 6/6 HLA matches, whereby the donor-recipient mismatch is identical to the CB noninherited maternal Ag (NIMA), have similar outcomes to inherited 6/6 matches. In the UK-British Bone Marrow Registry (BBMR), 4707 of the total 21020 CB donors have the NIMA defined. Retrospective searches of these donors, for 1-3 NIMA matches, identified a virtual 6/6 match for 31.4% of 274 European Caucasoid (EC) and 25.4% of 67 other ethnicity (OE) patients. Patients weighing 50kg were also evaluated for a single graft with adequate cell dose. In 125 EC patients, 6/6 HLA matches were identified for 24.0% and virtual 6/6 matches were identified for a further 21.6%. The remaining EC patients had a 5/6 (30.4%) or a 4/6 (22.4%) match. In OE patients, 6/6 HLA matches were identified for 9.3% and virtual 6/6 matches were identified for a further 18.7%. The remaining OE patients had a 5/6 (30.2%) or a 4/6 (37.2%) match. Searches were also performed using the 26735 Bone Marrow Donors Worldwide CB with defined NIMA and yielded comparable increases. Considering NIMA as permissible mismatches in donor selection therefore increased the availability of a 6/6 match in this cohort.
Horsnell W.G.C.,University of Cape Town |
Vira A.,University of Cape Town |
Kirstein F.,University of Cape Town |
Mearns H.,University of Cape Town |
And 14 more authors.
Mucosal Immunology | Year: 2011
Nippostrongylus brasiliensis infections generate pulmonary pathologies that can be associated with strong TH2 polarization of the host's immune response. We present data demonstrating N. brasiliensis-driven airway mucus production to be dependent on smooth muscle cell interleukin 4 receptor-α (IL-4Rα) responsiveness. At days 7 and 10 post infection (PI), significant airway mucus production was found in IL-4Rα /lox control mice, whereas global knockout (IL-4Rα /) and smooth muscle-specific IL-4Rα- deficient mice (SM-MHC Cre IL-4Rα /lox) showed reduced airway mucus responses. Furthermore, interleukin (IL)-13 and IL-5 cytokine production in SM-MHC Cre IL-4Rα /lox mice was impaired along with a transient reduction in T-cell numbers in the lung. In vitro treatment of smooth muscle cells with secreted N. brasiliensis excretory-secretory antigen (NES) induced IL-6 production. Decreased protein kinase C (PKC)-dependent smooth muscle cell proliferation associated with cell cycle arrest was found in cells stimulated with NES. Together, these data demonstrate that both IL-4Rα and NES-driven responses by smooth muscle cells make important contributions in initiating TH2 responses against N. brasiliensis infections. © 2011 Society for Mucosal Immunology.
Horsnell W.G.C.,University of Cape Town |
Darby M.G.,University of Cape Town |
Hoving J.C.,University of Cape Town |
Nieuwenhuizen N.,University of Cape Town |
And 11 more authors.
PLoS Pathogens | Year: 2013
In this study, B cell function in protective TH2 immunity against N. brasiliensis infection was investigated. Protection against secondary infection depended on IL-4Rα and IL-13; but not IL-4. Protection did not associate with parasite specific antibody responses. Re-infection of B cell-specific IL-4Rα-/- mice resulted in increased worm burdens compared to control mice, despite their equivalent capacity to control primary infection. Impaired protection correlated with reduced lymphocyte IL-13 production and B cell MHC class II and CD86 surface expression. Adoptive transfer of in vivo N. brasiliensis primed IL-4Rα expressing B cells into naïve BALB/c mice, but not IL-4Rα or IL-13 deficient B cells, conferred protection against primary N. brasiliensis infection. This protection required MHC class II compatibility on B cells suggesting cognate interactions by B cells with CD4+ T cells were important to co-ordinate immunity. Furthermore, the rapid nature of these protective effects by B cells suggested non-BCR mediated mechanisms, such as via Toll Like Receptors, was involved, and this was supported by transfer experiments using antigen pulsed Myd88-/- B cells. These data suggest TLR dependent antigen processing by IL-4Rα-responsive B cells producing IL-13 contribute significantly to CD4+ T cell-mediated protective immunity against N. brasiliensis infection. © 2013 Horsnell et al.
Cardoso S.P.,Colindale Center |
Patel R.,Colindale Center |
Brown C.,Colindale Center |
Navarrete C.,Colindale Center |
Navarrete C.,University College London
Tissue Antigens | Year: 2011
Type 1 hereditary haemochromatosis (HH) is a common genetic disorder in Caucasoids resulting from mutations in the HFE gene. Routine diagnostic testing for type 1 HH involves genotyping for two of these described HFE mutations, C282Y and H63D. In some cases typing of a third mutation, S65C is also performed. Several techniques have been reported for HFE genotyping and these include polymerase chain reaction (PCR)-sequence-specific primers (SSP), PCR-restriction fragment length polymorphism (RFLP), PCR-sequence-specific oligonucleotide probe (SSOP), real-time PCR followed by melting curve analysis and TaqMan assay. The aim of this study was to develop an alternative method to both conventional PCR and real-time PCR/TaqMan assay to detect all three HFE mutations in a single assay using Luminex technology. DNA controls of known genotypes (n = 109) were used to evaluate this approach. These controls were selected to represent the three possible genotypes (wild type, mutant, heterozygous) for each mutation. Subsequently, blind DNA samples (n = 100) were used to validate this method. This new assay was then compared with current techniques (in-house PCR-SSP and TaqMan assay). Comparison of genotypes obtained with the Luminex method with those previously reported by both in-house PCR-SSP and TaqMan assay showed 100% concordance for both DNA controls and blind DNA samples and no discrepancies were observed. Allelic frequency for C282Y, H63D and S65C mutations were 22%, 16% and 2%, respectively. We report here a high-throughput, accurate and robust multiplex luminex bead assay for routine clinical testing of C282Y, H63D and S65C mutations in the HFE gene. © 2011 John Wiley & Sons A/S.
Hewitt P.E.,Colindale Center |
Davison K.,NHSBT HPA Epidemiology Team |
Howell D.R.,NHSBT HPA Epidemiology Team |
Taylor G.P.,NHSBT HPA Epidemiology Team
Transfusion | Year: 2013
Background Leukoreduction of blood components was introduced in the United Kingdom during 1998. Human T-lymphotropic virus (HTLV) screening of blood donations was introduced in 2002. NHS Blood and Transplant conducted an HTLV lookback on blood components issued before 2002. A proportion of included components were nonleukoreduced, although the majority were subject to white blood cell reduction measures. Study Design and Methods A standard lookback was conducted on untested cellular blood components from donors later confirmed to be HTLV positive, for the 4 to 5 years before 2002, and on the last tested negative donation from donors who had seroconverted. Results A total of 437 red blood cell and platelet components were included and an outcome was reported for 84% of these. Just over half of identified recipients were dead at the time of lookback; blood samples for testing were obtained from 77% of identified living recipients. HTLV infection was confirmed in seven recipients, but one was discounted as not transfusion transmitted. Conclusion Although numbers are small, our results provide evidence of the efficacy of leukoreduction in reducing the likelihood of HTLV transmission through transfusion of cellular blood components. The HTLV-positive rate in recipients of leukoreduced components was 3.7%, a reduction of 93% compared with nonleukoreduced components. Importantly, the one infected recipient of a leukoreduced component had existing risk factors for HTLV infection. HTLV lookback was much less efficient in identifying infected recipients than was hepatitis virus C lookback. © 2013 American Association of Blood Banks.
Davidson L.R.R.,Western General Hospital |
Llewelyn C.A.,Cambridge Center |
Mackenzie J.M.,Western General Hospital |
Hewitt P.E.,Colindale Center |
Will R.G.,Western General Hospital
Vox Sanguinis | Year: 2014
Background and Objectives: In this study, we compare variant Creutzfeldt-Jakob disease (vCJD) cases definitely linked to blood transfusion, those with a history of blood transfusion in which no donor has developed vCJD and primary cases with no history of blood transfusion. The aim is to determine whether there are any differences in the demographics or clinical phenotype in these groups that might suggest additional cases of transfusion transmission of vCJD. Materials and Methods: All cases of vCJD who are old enough to donate blood (i.e. >17 years old) are notified to the UKBTS at diagnosis, regardless of whether they are known to have a blood donation history. A search is then made for donor records and, if found, all components produced and issued to hospitals are identified and their fate determined. Recipient details are then checked against the NCJDRSU register to establish whether there is a match between these individuals and patients who have been diagnosed with vCJD. In the reverse study, attempts are made to trace the donors to all cases reported to have received a blood transfusion and donors' details are checked against the register to determine if any have developed vCJD. Results: Of the 177 cases of vCJD diagnosed in the UK as of 1 February 2014, the TMER study identified 15 cases reported to have received a blood transfusion. Transfusion records were unavailable for 4 of these cases, all pre-1980, and in one other case there was no transfusion recorded in the medical notes. Transfusion records were found for 10 cases. One case transfused at symptom onset was excluded from this analysis. The mean age at onset of symptoms of the remaining nine transfusion recipients (four female and five male) was 42·9 years; 57·6 years in the three known transfusion-transmitted cases and 35·5 years in the six not linked cases. In one of these cases, details of components transfused were unavailable, and the remaining five cases received a total of 116 donor exposures with 112 donors identified, none of whom is known to have developed clinical vCJD. To date, five of the 112 identified donors have died and none was certified as dying of vCJD or any other neurological disorder. Two of the transfusion-transmitted cases did not fulfil diagnostic criteria for probable vCJD during life but were confirmed at post-mortem. Both cases were in the older age range (68 and 74 years, respectively), and neither had a positive MRI brain scan. The remaining cases all fulfilled the criteria for the diagnosis of vCJD in life, but two of these had atypical features and were older than the expected age at onset for vCJD. Conclusion: In conclusion, it is possible that one or more of the vCJD cases that received a blood transfusion derived from an individual not known to have vCJD were infected by the blood transfusion. However, the evidence for this is weak, and the absence of a past history of transfusion in most cases of vCJD excludes a large number of unrecognised transfusion-transmitted cases. © 2014 International Society of Blood Transfusion.
PubMed | Colindale Center, Western General Hospital and Cambridge Center
Type: Journal Article | Journal: Vox sanguinis | Year: 2016
This paper reports the results to 31 May 2015 of an ongoing UK study to look for additional cases of variant Creutzfeldt-Jakob disease (vCJD) transmission by blood transfusion, and to seek evidence whether other subtypes of Creutzfeldt-Jakob disease (CJD) may be transmissible via blood components.All vCJD cases of appropriate age and any sporadic CJD (sCJD) or familial CJD (fCJD) cases with a history of blood donation or transfusion are notified to the UKBS. Donation records are sought and the usage of all donations is determined by look back. Death certificates are obtained for all donors to patients with CJD and recipients of transfused components from patients with CJD who are deceased.The study identified 29 sCJD blood donors, of 370 reported, with transfusion to 211 recipients. Five of these recipients were reported to have died with or of dementia, but were not believed to be cases of CJD. The vCJD arm found 18 vCJD blood donors who had donated blood which was issued for clinical usage, of 24 traced donors from 177 UK vCJD cases. To date, 3 cases of vCJD have occurred in 67 recipients identified in this recipient group, and one recipient had post-mortem confirmation of abnormal prion protein deposition in the spleen (all previously reported).The results of the ongoing TMER study show no new cases of transfusion-associated vCJD since 2007 and no evidence of transfusion transmission of sCJD.