Tocilizumab administration in cytokine release syndrome is associated with hypofibrinogenemia after chimeric antigen receptor T-cell therapy for hematologic malignancies.

Chimeric antigen receptor (CAR-) T cell therapy causes serious side effects including cytokine release syndrome (CRS). CRS-related coagulopathy is associated with hypofibrinogenemia that is thus far considered the result of disseminated intravascular coagulation (DIC) and liver dysfunction. We investigated incidence and risk factors for hypofibrinogenemia in 41 consecutive adult patients with hematologic malignancies (median age 69 years, range 38-83 years) receiving CAR-T cell therapy between 01/2020 and 05/2023 at the University Medical Center Regensburg. CRS occurred in 93% of patients and was accompanied by hypofibrinogenemia already from CRS grade 1. Yet, DIC and liver dysfunction mainly occurred in severe CRS (≥ grade 3). After an initial increase during CRS, fibrinogen levels dropped after administration of tocilizumab in a dose dependent manner (r = -0.44, p = 0.004). In contrast, patients who did not receive tocilizumab had increased fibrinogen levels. Logistic regression analysis identified tocilizumab as an independent risk factor for hypofibrinogenemia (odds ratio = 486, p < 0.001). We thus hypothesize that fibrinogen synthesis in CRS is upregulated in an interleukin-6-dependent acute phase reaction compensating for CRS-induced consumption of coagulation factors. Tocilizumab inhibits fibrinogen upregulation resulting in prolonged hypofibrinogenemia. These observations provide novel insights into the pathophysiology of hypofibrinogenemia following CAR-T cell therapy and emphasize the need for close fibrinogen monitoring after tocilizumab treatment of CRS.

Emicizumab for the Treatment of Acquired Hemophilia A: Consensus Recommendations from the GTH-AHA Working Group.

BACKGROUND: Acquired hemophilia A (AHA) is a severe bleeding disorder caused by autoantibodies against coagulation factor VIII (FVIII). Standard treatment consists of bleeding control with bypassing agents and immunosuppressive therapy. Emicizumab is a bispecific antibody that mimics the function of activated FVIII irrespective of the presence of neutralizing antibodies. Recently, the GTH-AHA-EMI study demonstrated that emicizumab prevents bleeds and allows to postpone immunosuppression, which may influence future treatment strategies. AIM: To provide clinical practice recommendations on the use of emicizumab in AHA. METHODS: A Delphi procedure was conducted among 33 experts from 16 German and Austrian hemophilia care centers. Statements were scored on a scale of 1 to 9, and agreement was defined as a score of ≥7. Consensus was defined as ≥75% agreement among participants, and strong consensus as ≥95% agreement. RESULTS: Strong consensus was reached that emicizumab is effective for bleed prophylaxis and should be considered from the time of diagnosis (100% consensus). A fast-loading regimen of 6 mg/kg on day 1 and 3 mg/kg on day 2 should be used if rapid bleeding prophylaxis is required (94%). Maintenance doses of 1.5 mg/kg once weekly should be given (91%). Immunosuppression should be offered to patients on emicizumab if they are eligible based on physical status (97%). Emicizumab should be discontinued when remission of AHA is achieved (97%). CONCLUSION: These GTH consensus recommendations provide guidance to physicians on the use of emicizumab in AHA and follow the results of clinical trials that have shown emicizumab is effective in preventing bleeding in AHA.

Emicizumab prophylaxis in patients with acquired haemophilia A (GTH-AHA-EMI): an open-label, single-arm, multicentre, phase 2 study.

BACKGROUND: Acquired haemophilia A is caused by neutralising autoantibodies against coagulation factor VIII, leading to severe bleeding. Standard treatment involves immunosuppressive therapy, which is associated with adverse events and mortality in the frail population of patients with acquired haemophilia A. This study investigated whether emicizumab, a factor VIIIa mimetic antibody, protects patients with acquired haemophilia A from bleeding and allows deferral of immunosuppression during the first 12 weeks after diagnosis. METHODS: We report final results of an open-label, single-arm, phase 2 clinical trial. Adult patients with acquired haemophilia A from 16 haemophilia treatment centres in Germany and Austria were eligible if they had not previously received immunosuppression. Patients received emicizumab subcutaneously (6 and 3 mg/kg on days 1 and 2, 1·5 mg/kg weekly until week 12), but no immunosuppression. Follow-up was until week 24. The primary endpoint was the number of clinically relevant bleeds per patient-week until week 12. Emicizumab was considered effective if the mean bleeding rate was significantly below 0·15 bleeds per patient-week, the rate observed in a previous study of patients with acquired haemophilia A treated with bypassing agents and immunosuppression but no emicizumab. The study is registered with clinicaltrials.gov, NCT04188639 and is complete. FINDINGS: Of 49 patients screened from March 25, 2021, to June 10, 2022, 47 were enrolled (23 women, 24 men). Median age was 76 years (IQR 66-80), 46 (98%) of 47 patients were White, median factor VIII activity was 1·4 IU/dL (0·3-5·6), and median inhibitor concentration was 11·4 Bethesda units per mL (3·9-42·7). Mean breakthrough bleeding rate was 0·04 bleeds per patient-week (upper 97·5% CI 0·06). 33 (70%) of 47 patients had no bleeding events, seven patients (15%) had one bleed, six patients (13%) had two bleeds, and one patient (2%) had three bleeds. Adverse events of grade 3 or worse included COVID-19 (n=2), acute kidney injury (n=2), and stroke (n=1). Four of 47 patients died, including two deaths related to bleeding, one from COVID-19, and one from cardiac arrest (none were judged as related to emicizumab). INTERPRETATION: This study suggests that emicizumab prophylaxis prevents bleeding in patients with acquired haemophilia A and that immunosuppressive therapy can be deferred while patients are receiving this treatment. The low number of thromboembolic events, severe infections, and fatalities observed in this study are promising. FUNDING: This study was supported by funding from Hoffman-La Roche.

Quantification of bulk lipid species in human platelets and their thrombin-induced release.

Lipids play a central role in platelet physiology. Changes in the lipidome have already been described for basal and activated platelets. However, quantitative lipidomic data of platelet activation, including the released complex lipids, are unavailable. Here we describe an easy-to-use protocol based on flow-injection mass spectrometry for the quantitative analysis of bulk lipid species in basal and activated human platelets and their lipid release after thrombin activation. We provide lipid species concentrations of 12 healthy human donors, including cholesteryl ester (CE), ceramide (Cer), free cholesterol (FC), hexosylceramide (HexCer), lysophosphatidylcholine (LPC), lysophosphatidylethanolamine (LPE), phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylserine (PS), sphingomyelin (SM) and triglycerides (TG). The assay exhibited good technical repeatability (CVs < 5% for major lipid species in platelets). Except for CE and TG, the inter-donor variability of the majority of lipid species concentrations in platelets was < 30% CV. Balancing of concentrations revealed the generation of LPC and loss of TG. Changes in lipid species concentrations indicate phospholipase-mediated release of arachidonic acid mainly from PC, PI, and PE but not from PS. Thrombin induced lipid release was mainly composed of FC, PS, PC, LPC, CE, and TG. The similarity of the released lipidome with that of plasma implicates that lipid release may originate from the open-canalicular system (OCS). The repository of lipid species concentrations determined with this standardized platelet release assay contribute to elucidating the physiological role of platelet lipids and provide a basis for investigating the platelet lipidome in patients with hemorrhagic or thrombotic disorders.

Targets of autoantibodies in acquired hemophilia A are not restricted to factor VIII: data from the GTH-AH 01/2010 study.

The root cause of autoantibody formation against factor VIII (FVIII) in acquired hemophilia A (AHA) remains unclear. We aimed to assess whether AHA is exclusively associated with autoantibodies toward FVIII or whether patients also produce increased levels of autoantibodies against other targets. A case-control study was performed enrolling patients with AHA and age-matched controls. Human epithelial cell (HEp-2) immunofluorescence was applied to screen for antinuclear (ANA) and anticytoplasmic autoantibodies. Screening for autoantibodies against extractable nuclear antigens was performed by enzyme immunoassay detecting SS-A/Ro, SS-B/La, U1RNP, Scl-70, Jo-1, centromere B, Sm, double-stranded DNA, and α-fodrin (AF). Patients with AHA were more often positive for ANA than control patients (64% vs 30%; odds ratio [OR] 4.02, 1.98-8.18) and had higher ANA titers detected than controls. Cytoplasmic autoantibodies and anti-AF immunoglobulin A autoantibodies were also more frequent in patients with AHA compared with controls. Autoantibodies against any target other than FVIII were found in 78% of patients with AHA compared with 46% of controls (OR 4.16, 1.98-8.39). Results were similar preforming sensitivity analyses (excluding either subjects with autoimmune disorders, cancer, pregnancy, or immunosuppressive medication at baseline) and in multivariable binary logistic regression. To exclude that autoantibody staining was merely a result of cross-reactivity of anti-FVIII autoantibodies, we tested a mix of 7 well-characterized monoclonal anti-FVIII antibodies. These antibodies did not stain HEp-2 cells used for ANA detection. In conclusion, a diverse pattern of autoantibodies is associated with AHA, suggesting that a more general breakdown of immune tolerance might be involved in its pathology.

Women's Health Issues in Thrombosis and Haemostasis.

In the last couple of years sex specific health issues have continually been gaining attraction by physicians of different medical specialities. Sex differences have been described e.g. in the pathogenesis and mortality in patients affected by COVID-19, in metabolic regulation and cancer mechanisms.1 2 3 In the field of haemostasis, many aspects concerning risk factors, clinical presentation and management of thromboembolic disease and bleeding disorders also display sex differences.

Venous Thromboembolism Issues in Women.

The lifetime risk of venous thromboembolism (VTE) is slightly higher in women than in men. There are several issues related to VTE that are unique to women. Combined hormonal contraceptives and pregnancy increase the risk of VTE in women of childbearing age, whereas hormone replacement therapy increases the VTE risk of postmenopausal women. Hereditary thrombophilia and risk factors such as older age, obesity, or smoking contribute to the risk increase. In women diagnosed with acute hormone-related VTE who are treated with oral anticoagulants, adequate contraception is mandatory to avoid unwanted pregnancies. According to current knowledge, hormonal contraception may be continued during anticoagulant therapy but must be switched to an estrogen-free contraception method at least 6 weeks before the termination of anticoagulation. VTE is also a major cause of maternal morbidity and mortality during pregnancy and the postpartum period. Currently, assisted reproduction technologies such as in vitro fertilization are widely used to treat couples affected by infertility. Complications of fertility treatment comprise VTE cases, especially in women with ovarian hyperstimulation syndrome. With this review, we intended to focus on VTE issues in women and summarize current evidence and guideline recommendations.

Management of Antithrombin Deficiency in Pregnancy.

Antithrombin (AT) deficiency is a high-risk thrombophilia and a rare condition. The risk of venous thromboembolism (VTE) is increased in AT-deficient women during pregnancy and the postpartum period and is especially high in women with a prior history of VTE. A thorough assessment of VTE risk is recommended in pregnant AT-deficient women, comprising the degree and type of AT deficiency, genetic mutations, personal and family history, and additional preexisting or pregnancy-specific risk factors. Due to a lack of adequate study data, there is limited guidance on the management of AT deficiency in pregnancy, including the need for prophylactic anticoagulation, the appropriate dose of low-molecular-weight heparin (LMWH), and the role of AT substitution. LMWH is the medication of choice for the pharmacological prophylaxis and treatment of VTE in pregnancy. Patients with a history of VTE should receive full-dose LMWH during pregnancy and the postpartum period. AT concentrates are a treatment option when anticoagulation is withheld in potentially high-risk events such as childbirth, bleeding, or surgery and in cases of acute VTE despite the use of therapeutic dose anticoagulation. Women with AT deficiency should be counseled at specialized centers for coagulation disorders or vascular medicine, and close cooperation between obstetricians and anesthesiologists is warranted before delivery and during the peripartum period.

Prevalence and outcomes of patients developing heparin-induced thrombocytopenia during extracorporeal membrane oxygenation.

OBJECTIVES: Unfractionated heparin (UFH) is the commonly used anticoagulant to prevent clotting of the ECMO circuit and thrombosis of the cannulated vessels. A side effect of UFH is heparin-induced thrombocytopenia (HIT). Little is known about HIT during ECMO and the impact of changing anticoagulation in ECMO patients with newly diagnosed HIT. The aim of the study was to determine the prevalence, complications, impact of switching anticoagulation to argatroban and outcomes of patients developing heparin-induced thrombocytopenia (HIT) during either veno-venous (VV) or veno-arterial (VA) ECMO. METHODS: Retrospective observational single centre study of prospectively collected data of consecutive patients receiving VV ECMO therapy for severe respiratory failure and VA ECMO for circulatory failure from January 2006 to December 2016 of the Medical intensive care unit (ICU) of the University Hospital of Regensburg. Treatment of HIT on ECMO was done with argatroban. RESULTS: 507 patients requiring ECMO were included. Further HIT-diagnostic was conducted if HIT-4T-score was ≥4. The HIT-confirmed group had positive HIT-enzyme-linked-immunosorbent-assay (ELISA) and positive heparin-induced-platelet-activation (HIPA) test, the HIT-suspicion group a positive HIT-ELISA and missing HIPA but remained on alternative anticoagulation until discharge and the HIT-excluded group a negative or positive HIT-ELISA, however negative HIPA. These were compared to group ECMO-control without any HIT suspicion. The prevalence of HIT-confirmed was 3.2%, of HIT-suspicion 2.0% and HIT-excluded 10.8%. Confirmed HIT was trendwise more frequent in VV than in VA (3.9 vs. 1.7% p = 0.173). Compared to the ECMO control group, patients with confirmed HIT were longer on ECMO (median 13 vs. 8 days, p = 0.002). Different types of complications were higher in the HIT-confirmed than in the ECMO-control group, but in-hospital mortality was not different (31% vs. 41%, p = 0.804). CONCLUSION: HIT is rare on ECMO, should be suspected, if platelets are decreasing, but seems not to increase mortality if treated promptly.

Covid19 vaccination-associated portal vein thrombosis-An interdisciplinary clinical challenge.

Despite one of the largest vaccination campaigns in human history, the COVID-19 pandemic has not been yet defeated. More than 10 billion doses of COVID-19 vaccine have been administered worldwide. AstraZeneca's Vaxzevria (ChAdOx1 nCoV-19 / AZD1222) was approved as the first viral vector-based vaccine in the EU on 29 January 2021. Thromboembolic events are a rare complication of vaccination with ChAdOx1 nCoV-19 in the context of, now known as vaccine-induced immune thrombotic thrombocytopenia (VITT), with an incidence of 1.5-3 in 100,000 vaccinations. VITT is clinically as well as pathophysiologically comparable to heparin-induced thrombocytopenia. Illustrated by a fulminant patient case, a multidisciplinary step-by-step guideline was developed for the recognition, diagnosis, and management of patients with severe acute portosplanchic venous thrombosis with mesenteric ischemia due to vaccine-induced immunogenic thrombotic thrombocytopenia.

Distinct Mechanisms of IgM Antibody-Mediated Acquired von Willebrand Syndrome and Successful Treatment with Recombinant von Willebrand Factor in One Patient.

Acquired von Willebrand Syndrome (AVWS) is a rare coagulation disorder which can be associated with IgM paraproteinaemia. Recently, recombinant von Willebrand factor (rVWF) has become available for the treatment of bleedings in patients with inherited von Willebrand disease, but experience in patients with AVWS is limited. We report on 2 patients with AVWS with underlying IgM paraproteinaemia with distinct underlying pathomechanisms. In 1 patient, the paraprotein built unspecific complexes with von Willebrand factor (VWF). In the other patient, we were able to detect an IgM antibody against VWF. Bleeding in this patient was successfully treated with rVWF. To our knowledge, this is the first report about the successful use of rVWF in a patient with AVWS with the detection of a VWF-specific antibody.

Stanniocalcin 1 is overexpressed in multipotent mesenchymal stromal cells from acute myeloid leukemia patients.

Objectives: Multipotent mesenchymal stromal cells (MSC) play a pivotal role in the bone marrow (BM) niche. Stanniocalcin 1 (STC1) secreted by MSC has been demonstrated to promote the survival of neoplastic cells and was suggested a marker for minimal residual disease of acute myeloid leukemia (AML). Therefore, we evaluated the expression of STC1 in MSC from AML patients (MSCAML) compared to MSC from healthy donors (MSCHD).Methods: Liquid culture assays of MSCAML and MSCHD were performed to compare expansion capacity. Gene expression profiles of MSCAML vs. MSCHD were established. Secretion of STC1 was tested by ELISA in MSCAML vs. MSCHD and expression of STC1 in AML- vs. HD-BM by immunohistochemistry. In addition, co-cultures of AML cells on MSC were initiated and ultrastructural intercellular communication patterns were investigated. Finally, the effect of blocking STC1 on AML cells was evaluated.Results: MSCAML showed significant decreased expansion capacity compared to MSCHD. Gene analysis revealed marked overexpression of STC1 in MSCAML. ELISA and immunohistochemical findings confirmed this observation. Electron microscopy analysis showed reciprocal stimulation between AML cells and MSC. Blockade of STC1 did not significantly affect AML cell proliferation and apoptosis.Discussion: Characteristics of MSC differ depending on whether they originate from AML patients or from HD. STC1 was mostly overexpressed in MSCAML compared to MSCHD. In vitro blockade of STC1, however, was not associated with AML cell proliferation and apoptosis.Conclusion: Differences in expression levels of glycoproteins from MSCAML compared to MSCHD not necessarily assume that these molecules are niche-relevant in leukemic disease.

Primary Thromboprophylaxis in Patients with Malignancies: Daily Practice Recommendations by the Hemostasis Working Party of the German Society of Hematology and Medical Oncology (DGHO), the Society of Thrombosis and Hemostasis Research (GTH), and the Austrian Society of Hematology and Oncology (ÖGHO).

Patients with cancer, both hematologic and solid malignancies, are at increased risk for thrombosis and thromboembolism. In addition to general risk factors such as immobility and major surgery, shared by non-cancer patients, cancer patients are exposed to specific thrombotic risk factors. These include, among other factors, cancer-induced hypercoagulation, and chemotherapy-mediated endothelial dysfunction as well as tumor-cell-derived microparticles. After an episode of thrombosis in a cancer patient, secondary thromboprophylaxis to prevent recurrent thromboembolism has long been established and is typically continued as long as the cancer is active or actively treated. On the other hand, primary prophylaxis, even though firmly established in hospitalized cancer patients, has only recently been studied in ambulatory patients. This recent change is mostly due to the emergence of direct oral anticoagulants (DOACs). DOACs have a shorter half-life than vitamin K antagonists (VKA), and they overcome the need for parenteral application, the latter of which is associated with low-molecular-weight heparins (LMWH) and can be difficult for the patient to endure in the long term. Here, first, we discuss the clinical trials of primary thromboprophylaxis in the population of cancer patients in general, including the use of VKA, LMWH, and DOACs, and the potential drug interactions with pre-existing medications that need to be taken into account. Second, we focus on special situations in cancer patients where primary prophylactic anticoagulation should be considered, including myeloma, major surgery, indwelling catheters, or immobilization, concomitant diseases such as renal insufficiency, liver disease, or thrombophilia, as well as situations with a high bleeding risk, particularly thrombocytopenia, and specific drugs that may require primary thromboprophylaxis. We provide a novel algorithm intended to aid specialists but also family practitioners and nurses who care for cancer patients in the decision process of primary thromboprophylaxis in the individual patient.

[Hormonal contraception and venous thromboembolism]. / Hormonelle Kontrazeption und Thrombose.

The use of combined hormonal contraceptives (CHC) is a well-established risk factor for venous thromboembolism (VTE). The VTE risk depends on the specific combination of oestrogen and gestagen components. Progestin-only contraceptives with the exception of depot medroxyprogesterone acetate are not associated with a significant VTE risk and can therefore be offered to women with known thrombophilia or a prior VTE. The recent German S3 guideline "Contraception" advises to carefully assess individual VTE risk factors before prescribing CHC. According to recent data there is no evidence suggesting that VTE risk is increased during oral anticoagulation. To reduce the risk of vaginal bleeding complication and the risk of unplanned pregnancy, the use of CHC can be continued under anticoagulation treatment provided that the patient is switched to an oestrogen-free contraception no later than six weeks before the end of anticoagulation. The risk of recurrence is low in women with hormone-associated VTE. Anticoagulation is therefore in general discontinued after 3-6 months. Thromboprophylaxis with low molecular heparin is recommended for women with prior hormone-associated VTE during pregnancy and the postpartum period.

Prevention of Venous Thromboembolism during Pregnancy and the Puerperium with a Special Focus on Women with Hereditary Thrombophilia or Prior VTE-Position Paper of the Working Group in Women's Health of the Society of Thrombosis and Haemostasis (GTH).

Venous thromboembolism (VTE) is a major cause of maternal morbidity during pregnancy and the postpartum period. Because there is a lack of adequate study data, management strategies for the prevention of VTE during pregnancy have mainly been deduced from case-control and observational studies and extrapolated from recommendations for non-pregnant patients. The decision for or against pharmacologic thromboprophylaxis must be made on an individual basis weighing the risk of VTE against the risk of adverse side effects such as severe bleeding complications. A comprehensive, multidisciplinary approach is often essential as the clinical scenario is made more complex by the specific obstetric context, especially in the peripartum period. As members of the Working Group in Women's Health of the Society of Thrombosis and Haemostasis (GTH), we summarize the evidence from the available literature and aim to establish a more uniform strategy for VTE risk assessment and thromboprophylaxis in pregnancy and the puerperium. In this document, we focus on women with hereditary thrombophilia, prior VTE and the use of anticoagulants that can safely be applied during pregnancy and the lactation period.

[Thromboprophylaxis in ambulatory patients with cancer]. / Thromboseprophylaxe beim ambulanten Tumorpatienten.

Ambulatory cancer patients receiving systemic cancer therapy are at varying risk for venous thromboembolism (VTE). The VTE risk depends on different cancer types, cancer stage, anti-cancer treatment and individual patient risk factors. Whereas pharmacologic thromboprophylaxis is recommended in most hospitalized cancer patients with an acute medical condition and in patients undergoing major cancer surgery, the role of primary thromboprophylaxis in the ambulatory setting is not clear. A VTE risk stratification using specific scoring systems, e. g. the Khorana score or the recently published CAT-score should be performed. Recently, two large randomized controlled studies using rivaroxaban (CASSINI trial) and apixaban (AVERT trial) versus placebo as primary VTE prevention in high-risk ambulatory cancer patients were published. When considered together, the two trials showed a significant benefit for the prevention of VTE with a low incidence of major bleeding. The DOAC had no effect on mortality. Primary thromboprophylaxis may be offered to high-risk outpatients with cancer, e. g. patients with advanced pancreatic carcinoma, provided there are no risk factors for bleeding and no drug-interactions. The patient's preference should also be respected. Current guidelines differ in their recommendations concerning the choice of anticoagulation. Whereas LMWH is still preferred to DOAC in the current German guideline, the ISTH guidance suggest to use DOAC in high-risk ambulatory cancer patients with no drug-drug interactions and not at high risk for bleeding. Of note, DOAC are currently not approved in this indication.

How Do We Treat Pregnancy-Related Venous Thromboembolism?

Venous thromboembolism (VTE) is a major cause of maternal morbidity and mortality during pregnancy and the postpartum period. Due to a lack of adequate study data, therapeutic strategies for pregnancy-related VTE are deduced from observational studies and extrapolated from recommendations for nonpregnant patients. Because heparins do not cross the placenta, weight-adjusted therapeutic-dose low-molecular-weight heparins (LMWHs) are the anticoagulant treatment of choice in cases of VTE during pregnancy. Once- and twice-daily dosing regimens are suitable. There is no evidence that measurement of factor Xa activities and consecutive LMWH dose adjustments improve clinical outcomes. There is no support for the routine use of vitamin K antagonists, direct oral thrombin or factor Xa inhibitors, fondaparinux, or danaparoid in uncomplicated pregnancy-related VTE. Management of delivery deserves special attention, and treatment strategies depend on the time interval between the diagnosis of acute VTE and the expected delivery date. In lactating women, an overlapping switch from LMWH to warfarin is possible. Anticoagulation should be continued for at least 6 weeks postpartum or for a minimum period of 3 months.

Effects of continuous high-dose G-CSF administration on hematopoietic stem cell mobilization and telomere length in patients with amyotrophic lateral sclerosis - a pilot study.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease of complex and still poorly understood etiology. Loss of upper and lower motoneurons results in death within few years after diagnosis. Recent studies have proposed neuroprotective and disease-slowing effects of granulocyte-colony stimulating factor (G-CSF) treatment in ALS mouse models as well as humans. In this study, six ALS patients were monitored up to 3.5 years during continuous high-dose G-CSF administration. Repetitive analyses were performed including blood count parameters, CD34+ hematopoietic stem and progenitor cell (HSPC) and colony forming cell (CFC) counts, serum cytokine levels and leukocyte telomere length. We demonstrate that continuous G-CSF therapy was well tolerated and safe resulting in only mild adverse events during the observation period. However, no mobilization of CD34+ HSPC was detected as compared to baseline values. CFC mobilization was equally low and even a decrease of myeloid precursors was observed in some patients. Assessment of telomere length within ALS patients' leukocytes revealed that G-CSF did not significantly shorten telomeres, while those of ALS patients were shorter compared to age-matched healthy controls, irrespective of G-CSF treatment. During G-CSF stimulation, TNF-alpha, CRP, IL-16, sVCAM-1, sICAM-1, Tie-2 and VEGF were significantly increased in serum whereas MCP-1 levels decreased. In conclusion, our data show that continuous G-CSF treatment fails to increase circulating CD34+ HSPC in ALS patients. Cytokine profiles revealed G-CSF-mediated immunomodulatory and proteolytic effects. Interestingly, despite intense G-CSF stimulation, telomere length was not significantly shortened.

Laboratory Diagnostics in Thrombophilia.

A thrombophilic disorder is a hereditary or acquired condition that increases the risk of thrombosis. The most common hereditary thrombophilias that predispose to venous thrombosis in the Caucasian population are the heterozygous forms of the factor V Leiden and prothrombin G20210A mutation that are generally detected by direct DNA genotyping. Immunologic antigen assays and chromogenic or clot-based activity assays are used to identify deficiencies in the natural coagulation inhibitors antithrombin, protein C and protein S. Because pre-analytical errors and acquired causes of low antithrombin, protein C or protein S levels are considerably more common than hereditary deficiencies, all potential conditions that may lower activity levels of the natural coagulation inhibitors (e.g. concomitant liver disease, pregnancy, anticoagulant therapy) must be considered and excluded before the diagnosis of an inhibitor deficiency can be made. To avoid misclassification, the diagnosis should not be made based on a single abnormal test result. Thus, repetitive testing when the patient is not on anticoagulant therapy is mandatory to confirm the diagnosis. Screening for antiphospholipid syndrome (APS) comprises testing for lupus anticoagulants (LAs) and the presence of IgG or IgM antibodies directed against phospholipids and phospholipid-binding proteins such as ß-2-glycoprotein-I. A combination of clot-based assays has been recommended to demonstrate LA activity, whereas solid-phase immunoassays allow the detection of anti-cardiolipin and anti-ß-2-glycoprotein-I antibodies. The diagnosis of APS requires the persistence of antiphospholipid antibodies for at least 12 weeks together with thrombotic and/or obstetric features of APS.