In vitro effects of different sources of fibrinogen supplementation on clot initiation and stability in a model of dilutional coagulopathy.

OBJECTIVES: To analyse which fibrinogen source may improve coagulation using an in vitro 33% dilutional coagulopathy model. BACKGROUND: Uncritical volume resuscitation in the context of trauma haemorrhage contributes to the iatrogenic arm of the acute trauma-induced coagulopathy through dilution and depletion of coagulation factors, with fibrinogen reaching critical levels first. MATERIALS AND METHODS: By using an experimental model of 33% dilutional coagulopathy, we have analysed which fibrinogen source may exert superior effects on improving haemocoagulative capacities and correcting depleted fibrinogen levels. As fibrinogen sources, we supplemented (i) fresh frozen plasma (FFP), (ii) fibrinogen concentrate low-dose (Fiblow ) and (iii) fibrinogen concentrate high-dose (Fibhigh ), the latter both in the presence and absence of additional FXIII. RESULTS: The dilution was associated with decreased haemoglobin and haematocrit levels. Fibrinogen supplementation with fibrinogen-containing formulations led to increased fibrinogen levels (FFP: 172·2 ± 17·4 mg dL-1 ; Fiblow : 211·5 ± 20·61 mg dL-1 ; Fibhigh : 255·8 ± 21·4 mg dL-1 ) than in a diluted-only sample (155·5 ± 19·7 mg dL-1 ). Extrinsically activated assay with tissue factor (EXTEM) clot formation times, α-angles and maximum clot firmness significantly improved in the groups of Fiblow + FXIII (79 ± 12·2 s; 74·3 ± 2·4°; 62 ± 2·3 mm), Fibhigh (70·8 ± 10·6 s; 76·2 ± 2·7°; 64·3 ± 2·3 mm) and Fibhigh + FXIII (69·8 ± 11·5 s; 77·5 ± 2·7°; 64·33 ± 2·5 mm) compared with the dilution groups (104·2 ± 19 s; 69·7 ± 2·9°; 56·5 ± 3·1 mm). In contrast, rotational thromboelastometric trace (ROTEM) measures of samples supplemented with FFP largely remained unchanged. CONCLUSION: Fibrinogen concentrates corrected and improved haemodilution-induced changes in blood clotting in vitro. High-dose fibrinogen supplementation was associated with correction and improvement in clot dynamics and stability.

Determination of unacceptable HLA antigen mismatches in kidney transplant recipients: recommendations of the German Society for Immunogenetics.

One of the major tasks of histocompatibility and immunogenetics laboratories is the pretransplant determination of unacceptable antigen mismatches (UAM) in kidney transplant recipients. In this procedure, human leucocyte antigen (HLA) specificities are defined against which the patient has circulating alloantibodies that are expected to harm the transplanted organ. Using the information on UAM and the potential donor's complete HLA typing, prediction of the crossmatch result, the so called 'virtual crossmatch', is possible. Currently, the laboratories are using different algorithms for the determination of UAM, and depending on the algorithm, more or fewer organ offers are excluded for patients with a similar antibody profile. In order to bring homogeneity into the allocation of organs to immunized patients in Germany, the German Society for Immunogenetics established, on the basis of current knowledge, recommendations for the determination of UAM. The UAM recommendations, which are thought to serve as a common tool for responsible physicians at different transplant centers, contain technical issues that need to be considered and are individualized for sensitized patients with a high or intermediate risk of antibody-mediated rejection. The present review contains these recommendations and puts them into perspective to current international practice.

[Interventional lung assist membrane ventilator. Successful use despite heparin-induced thrombocytopenia type II]. / "Interventional-lung-assist"-Membranventilator. Erfolgreiche Anwendung trotz heparininduzierter Thrombozytopenie II.

Pumpless extracorporeal carbon dioxide elimination using the interventional lung assist (iLA) membrane ventilator is a modern concept for the treatment of hypercapnia due to respiratory failure which cannot be sufficiently treated by conventional strategies. Heparin-induced thrombocytopenia type II (HIT II) is considered to be an absolute contraindication for placement of an iLA because of the system's heparin-coated diffusion membrane. The example demonstrates that iLA therapy can be continued despite occurrence of a HIT II in terms of an "off label use". In the case described, postoperative therapy using the iLA membrane ventilator was installed in a 69-year-old patient with severe ARDS after elective lung resection. Despite a confirmed HIT II detected in the course of iLA, this therapy was continued after changing systemic anticoagulation to argatroban. The platelet count increased again and the patient could be successfully weaned from the iLA membrane and finally transferred to a rehabilitation centre.

Correlation Between the Transplant Evaluation Rating Scale (TERS) and Medical Outcomes in Living-Donor Kidney Transplant Recipients: A Retrospective Analysis.

BACKGROUND: Pretransplant psychosocial evaluation of living-donor kidney transplantation (LDKT) candidates identifies recipients with potentially inferior posttransplant outcomes. Rating instruments, based on semi-standardized interviews, help to improve and standardize psychosocial evaluation. The goal of this study was to retrospectively investigate the correlation between the Transplant Evaluation Rating Scale (TERS) and transplant outcome in LDKT recipients. METHODS: TERS scores were retrospectively generated by 2 raters based on comprehensive interviews of 146 LDKT recipients conducted by mental health professionals (interrater reliability, 0.8-0.9). All patients were eligible for transplantation according to pretransplant psychosocial evaluation. Patients were classified into 2 groups according to their TERS scores, in either two thirds excellent risk (TERS <29) and one third at least moderate risk (TERS ≥29) candidates. Analyzed medical parameters were change in estimated glomerular filtration rate and acute rejection (AR) episodes within the first year posttransplant. In addition, a subgroup of 65 patients was tested for de novo donor-specific HLA antibodies (DSA) posttransplant. RESULTS: There was no significant difference between the excellent (n = 97) and at least moderate (n = 49) risk candidates according to TERS in terms of organ function (estimated glomerular filtration rate decline >25%: 17 of 97 vs 11 of 49; P = .51) and episodes of AR (19 of 97 vs 15 of 49; P = .15). Patients developing de novo DSA (n = 18 [28%]) did not have higher pretransplant TERS scores (DSA positive, 11 of 42 vs 7 of 23; P = .78). CONCLUSIONS: Classifying LDKT recipients according to TERS score did not predict medical outcome at 1 year posttransplant or the occurrence of de novo DSA.

[Autologous transfusion--organization and results of preoperative blood donation by heart surgery patients]. / Autologe Transfusion--Organisation und Ergebnisse der präoperativen Eigenblutspende kardiochirurgischer Patienten.

This study presents our preoperative autologous blood donation programme that is in use since 1987. 246 patients of cardiothoracic surgery participated in this program. 77% of all patients had preoperative concentrations of haemoglobin above 12g/dl despite frequent donations. 36.5% of patients were transfused exclusively with their own blood products. Reduction of homologous blood transfusion has been achieved with second preoperative plasmaphereses and more restricted indication for blood transfusion. More blood donation could be performed with application of erythropoietin resulting in more frequent preoperative blood donations.

[Preoperative autologous blood donation]. / Präoperative Eigenblutspende.

This presentation shows our experiences with the preoperative autologous blood donation existing since 1987, 246 patients of the cardiothoracic surgery participated in this program. The preoperative concentration of hemoglobin was above 12g/dl 76.8% of the patients despite the frequent donations, 36.5% of the participants could be transfused with their own blood products. Further reduction of homologous blood transfusion could be achieved with a second preoperative plasmapheresis and the donation of erythropoietin.

RHCE-D-CE hybrid genes can cause false-negative DNA typing of the Rh e antigen.

BACKGROUND AND OBJECTIVES: DNA typing of the human Rh blood groups generally shows good agreement with serologically defined phenotypes. However, in the present report we describe four individuals who were declared Rh e negative by genotyping although they express the Rh e antigen. MATERIALS AND METHODS: Serotyping was performed using mono- and polyclonal Rh antisera. Fluorescent multiplex sequence-specific polymerase chain reactions (PCR-SSPs) identified RHD exons and the polymorphisms usually associated with the Rh E/e or Rh C/c/C(W) antigens. Additional PCR amplification reactions, which were carried out to reveal RHCE-D-CE hybrid genes, analysed exon 5 of the RH genes, the location of the polymorphism (676C-->G) coding for the Rh E and Rh e antigens. RESULTS: Four individuals were identified who expressed Rh e antigens but were negative by PCR-SSP typing for common Rhe-coding sequences. In one family analysed in detail, an RHCE-D5-CE hybrid gene associated with Rh e antigen expression was identified. A concomitant RHcE allele accounted for a seemingly regular typing pattern by conventional RH PCR. CONCLUSIONS: The presence of RHCE-D5-CE hybrid alleles may cause false-negative DNA-typing results for the Rh e antigen that are easily overlooked unless appropriate RH hybrid PCR-SSPs are incorporated into conventional DNA-typing protocols. These and previous data strongly caution against an uncritical interpretation of RH DNA-typing results.