[Monitoring of organ functions. Dysfunction of kidneys, liver, gastrointestinal tract, and coagulation]

Monitoring of organ function is one of the core tasks of intensive care medicine. Although various monitoring devices and parameters have already been established for some organs, there are no or only few conditionally useful parameters or scores available for the kidneys, liver, gastrointestinal tract, and blood coagulation. Therefore, specific biomarkers and scores as well as combinations of both are currently investigated for better monitoring of these organs. This article gives a critical overview of currently used as well as investigational biomarkers, tests and scores in general, and shows some examples of the implications for common diseases, clinical situations and constellations in the intensive care unit.

Ineffective off-label use of recombinant activated factor VII in a case of bone-marrow transplantation-related gastrointestinal bleeding

BACKGROUND

For patients with a normal coagulation system, who experience serious bleeding, sound evidence for recombinant activated factor VII (rFVIIa) as an effective haemostatic agent is only scarcely available so far from controlled clinical trials. In systematic reviews on the clinical use of rFVIIa, treatment failures were only rarely reported.

CASE PRESENTATION

We present a 45-year old, Caucasian male with persistent intestinal bleeding due to enterocolitis associated with cytomegalovirus infection and acute graft-versus-host-disease. He had received allogeneic peripheral blood stem cell transplantation from an unrelated HLA-identical donor because of chronic myelogenous leukaemia diagnosed two years earlier. Bleeding started at day 18 after transplantation with bloody diarrhea, which was treated with multiple transfusions of fresh frozen plasma, platelet, and red blood cell concentrates, and continued relentlessly, despite all efforts, including continued transfusions, high-dose prednisolone, broad antibiotic and antiviral coverage, and tranexamic acid. Recombinant FVIIa was started at boluses of 90-120 mug/kg every 4-8 hours. Despite more than 10 doses, recurrent severe bleeding progressed to refractory shock, multiorgan failure and death.

CONCLUSIONS

Little can be concluded from single case reports of clinical improvement, because publication bias in favour of positive effects is likely. Our case suggests that rFVIIa is not a panacea, in particular for severe bleeding after bone-marrow transplantation. As long as rigorous, controlled studies or comprehensive registries are lacking, conventional interventions remain the standard of care in non-haemophilic patients with severe bleeding.

Inhibition of plasma-dependent monocyte chemokinesis and cytokine-triggered endothelial activation for neutrophil transmigration by administration of clopidogrel in man

Mediators released by spontaneously activated platelets may contribute to alterations in endothelial and leukocyte dysfunctions. We investigated the roles of clopidogrel and aspirin in ex vivo endothelial activation for interactions with leukocytes. Eight healthy volunteers received clopidogrel or aspirin for 8 days. Blood samples were taken before, during, and after treatment. Levels of adhesion molecules and platelet-derived mediators in these samples were measured using commercially available test kits, and effects of plasma on endothelial cells and leukocytes were investigated in neutrophil transendothelial migration, monocyte-endothelial adhesion and leukocyte migration assays. Plasma samples from clopidogrel-treated persons induced diminished chemokinesis of monocytes. Tumour necrosis factor-induced priming of endothelial cells for enhanced neutrophil transmigration was also diminished by pretreatment of endothelial cells, but not of neutrophils, with plasma derived from subjects during clopidogrel treatment. Plasma from the aspirin group had no such effects. Administration of clopidogrel but not aspirin significantly decreased serum levels of soluble intercellular adhesion molecule-1, whereas no changes in levels of soluble vascular cell adhesion molecule-1, P-selectin, L-selectin, von Willebrand factor, platelet-derived growth factor, vascular-endothelial growth factor, and transforming growth factor-beta were observed. Inhibition of plasma-promoted endothelial activation by clopidogrel may indicate a novel role in the prevention of atherosclerosis.

Plasminogen activators in inflammation and sepsis

Mortality of severe sepsis remains at 40% to 50%. Intensive efforts over the past two decades have only marginally improved outcome. Improving outcome in sepsis depends on understanding its pathophysiology, which involves triggers, responses of the organism, and dysfunction. Stress, injury, or infection trigger host responses, including local and systemic orchestrated mechanisms. Dysfunction and outcome depend on both trigger and response. Blood coagulation, inflammation, immunity, and fibrinolysis are critical components of the organism's responses. Understanding their role in sepsis pathophysiology is the key to effective treatment. Relevant studies were identified by a systematic literature search, complemented by manual search of individual citations. Using PubMed, 'sepsis' yields more than 62,000 references, 'plasminogen activators' more than 21,000. The selection of citations was guided by preference for reviews that expand important threads of argumentation. Single original studies were included when relevant to critical points. This analytical review describes the essential elements of pathophysiology and the current status of sepsis treatment. Based on this context, an emerging therapeutic option will be discussed: plasminogen activators.

Antithrombin and near-fatal exertional heat stroke

Heat waves result in excess deaths, excess emergency department visits, and intensive care unit admissions for heat stroke. We describe the clinical features and 3-month outcome of a patient with near-fatal heat stroke, admitted to our intensive care unit in July, 2001. After heavily working for hours at a construction site during a heat wave, the 28-year-old male presented with 41.4 degrees C body temperature and multiorgan failure, consisting of neurological impairment, rhabdomyolysis, acute renal failure, disseminated intravascular coagulation, and acute respiratory distress syndrome (ARDS). In the first week there was no evidence of infection. Treatment included cooling, aggressive volume resuscitation, administration of antithrombin-III concentrates and steroids. The patient survived and recovered normal neurological, renal, respiratory and haematological function, and no disability persisted. This case illustrates survival and complete recovery after multiorgan failure in heat stroke with vigorous intensive care. Treatment with antithrombin and steroids and may well have contributed to the favourable outcome. Correction of reduced antithrombin III levels to supranormal by therapeutic administration of antithrombin III concentrate in disseminated intravascular coagulation of heat stroke was not associated with any bleeding complications.

Intravascular large B-cell lymphoma with a fulminant clinical course: a case report with definite diagnosis post mortem

A patient is described who presented with pancytopenia, splenomegaly and excessively elevated lactate dehydrogenase levels in concurrence with signs of extramedullary hematopoiesis. Although initially considered in the differential diagnostic spectrum, a highly aggressive lymphoma could not be identified before the patient died, 6 weeks after admission. Even an intensive diagnostic work-up including splenectomy and repeated bone marrow biopsies was inconclusive. Finally, the diagnosis of an intravascular large B-cell lymphoma, a highly aggressive clinical subtype of a diffuse large B-cell lymphoma, spreading within vascular structures of multiple organs was established by autopsy. Intravascular large B-cell lymphoma is often not diagnosed before death due to the exclusive intravascular growth pattern of the tumor cells and a fulminant clinical course. The heterogeneous clinical features of this lymphoma subtype are discussed.

Hypersensitivity reactions associated with recombinant tissue-type plasminogen activator and urokinase

Anaphylaxis or angioedema in response to recombinant tissue-type plasminogen activator or urokinase have been reported in only a few isolated cases. Both agents are endogenous proteins and thus considered non-antigenic. Activation of fibrinolysis may per se facilitate anaphylactoid reactions by pathophysiologic pathways that are not well understood. We report a unique case, review the literature and discuss implication for the clinician. The 25-year-old patient underwent thrombolytic treatment for extensive thrombosis of pelvic and deep lower extremity veins. The patient developed protracted anaphylactoid reactions during recombinant tissue-type plasminogen activator continuous intravenous infusion. After changing treatment to urokinase, the same symptoms recurred with more severe intensity, despite corticosteroid premedication. Symptoms resolved within hours after treatment with histamine receptor blockers. This unique observation, i.e. sequential occurrence of anaphylactoid reactions during recombinant tissue plasminogen activator and urokinase treatments, adds to existing evidence for an unspecific non-antigenic pathomechanism, and for a class effect of thrombolytics. Steroids do not prevent, but histamine receptor blockers seem to be an effective treatment of this unusual complication of thrombolytic therapy.

Recombinant tissue plasminogen activator during cardiopulmonary resuscitation in 108 patients with out-of-hospital cardiac arrest

BACKGROUND

Thrombolytic therapy during cardiopulmonary resuscitation (CPR) is a controversial issue in emergency medicine practice. This study was conducted to determine whether administration of recombinant tissue plasminogen activator (rt-PA) in out-of-hospital cardiac arrest of non-traumatic aetiology improves CPR outcome.

METHODS AND RESULTS

A retrospective chart review of 401 patients with out-of-hospital cardiac arrest who were resuscitated by the emergency medical services (EMS) during a 6 year period was performed. A total of 108 patients received rt-PA during CPR and were compared to 216 controls, closely matched according to baseline characteristics, arrival status and ECG findings. Administration of rt-PA was optional. Return of spontaneous circulation (ROSC) occurred in 76 patients under rt-PA treatment (70.4 vs. 51.0% in controls; P=0.001). Fifty-two patients from the lysis group survived the first 24 h (48.1 vs. 32.9% in controls; P=0.003), while 27 (25.9%) survived to discharge. Autopsy reports revealed major bleeding complications in six patients receiving rt-PA treatment. Fulminant intracranial haemorrhage was observed in one patient who received rt-PA and in two cases from the control group.

CONCLUSIONS

Thrombolytic therapy may improve frequency of return of spontaneous circulation substantially and increase primary survival in patients with non-traumatic cardiac arrest. Serious bleeding complications are not frequently observed under rt-PA treatment.

Incidence and risk of potential adverse drug interactions in the emergency room

OBJECTIVE

To determine the incidence and risk factors of potential adverse drug interactions occurring in patients in the emergency department.

DESIGN

Survey of a random sample of medical records of elderly persons and other adults seeking care at an emergency department. The interactions were determined by a computer programme, reviewed using explicit criteria, and excluded if of uncertain or trivial clinical significance.

SETTING

University Hospital Medical Emergency Department.

PATIENTS

A total of 423 randomly selected adults seeking care at a university hospital emergency department. Attendances made by 195 persons over age 60 and 228 younger adults were evaluated. All subjects were treated on an outpatient basis.

MAIN OUTCOME MEASURES

Seventy percent of attendances led to the prescription of an added medication. In 5.4% of the attendances in which at least one medication was added, the new medication introduced a potential adverse interaction. The number of medications used at attendance was the best predictor of whether a potential interaction would occur. Additional medications prescribed in the emergency department that accounted for most of the added interactions were theophylline, macrolid antibiotics, digitalis glycosides, nonsteroidal anti-inflammatory agents, angiotensin converting-enzyme inhibitors and calcium antagonists.

CONCLUSIONS

Potential adverse drug interactions were more common in elderly patients because of the higher number of concurrent medications rather than age-based factors. Safeguards need to be introduced to prevent patients from receiving medications in the emergency departments that have the potential to cause adverse interactions.

The inhibition of oxygen radical release from human neutrophils by resting platelets is reversed by administration of acetylsalicylic acid or clopidogrel

Resting platelets inhibit oxygen radical release from neutrophils. Antiplatelet therapy may support this function by preventing platelet activation. Whether antiplatelet agents affect the antioxidative action of resting platelets in the absence of platelet activation is unknown. The effect of acetylsalicylic acid or clopidogrel administration on the antioxidative action of resting platelets was therefore studied in ten healthy volunteers. Preparations of resting platelets were obtained from 5 subjects each - before, during and after an eight-day course of daily treatment with 100 mg of acetylsalicylic acid or 75 mg of the thienopyridine clopidogrel. Human peripheral blood neutrophils were pretreated with the platelets at a ratio of (1/5)0 for 45 min; then formyl-Met-Leu-Phe-triggered oxygen radical release was measured fluorometrically. The inhibitory effect of platelets on oxygen radical release from neutrophils which was seen before treatment was abolished by antiplatelet therapy with either of the drugs, and inhibition was restored gradually after discontinuing acetlsalicylic acid/ clopidogrel intake. Results suggest that the protective role of resting platelets in controlling oxygen radical release from neutrophils in the absence of platelet activation may be impaired by antiplatelet therapy.

Plasma levels of procalcitonin and interleukin-6 in acute myocardial infarction

Estimation of cardiac morbidity in patients after major surgery is a difficult problem. In addition, infectious complications seriously decrease potential beneficial outcome after cardiovascular surgery. The present study assessed the use of a newer marker of the inflammatory response, procalcitonin, in the field of myocardial infarction, in conjunction with measurements of interleukin-6. Forty-four consecutive cases with acute myocardial infarction were included in the study 4+/-1.3 h after the onset of symptoms. Plasma levels of procalcitonin and interleukin-6 were obtained at admission, and after 3, 6, 12, 18, 24 and 48 h, using commercially available test kits. The range of levels of interleukin-6 and procalcitonin was about normal at admission. Interleukin-6 levels increased significantly following myocardial infarction, whereas procalcitonin were essentially unchanged, i.e. remained close to the normal level threshold of 0.5 ng/ml; only minor variability occurred with a mean peak level of procalcitonin of 1+/-0.4 ng/ml. Data demonstrate that, in contrast to the acute phase reactant interleukin-6, plasma levels procalcitonin are not significantly elevated during uncomplicated acute myocardial infarction. This observation may support the role of procalcitonin measurements in the differential diagnosis of infectious and cardiovascular complications after major surgery.

Imported malaria: six cases of severe Plasmodium falciparum infection in Innsbruck, Austria, within a period of five weeks (February/March 1999)

Six patients (age, 30-76; 3 male, 3 female) with severe malaria tropica were admitted to the Department of Internal Medicine of the Innsbruck University Hospital within a time period of five weeks. All patients had recently visited classical malaria regions some days before admission: five patients the sub-Saharan Africa and one patient Thailand and Vietnam. All six patients had to be treated in the Intensive Care Unit. Three patients developed an acute respiratory distress syndrome. Two patients died of multi-organ failure. All six patients were treated with quinine and doxycycline intravenously. In one case, exchange transfusion was performed. Only two of six patients had taken prophylactic medication: one patient chloroquine and proguanil and the other mefloquine (she suffered from a severe gastroenteritis during the journey).

Thrombolytic therapy in adult meningococcal purpura fulminans with acute renal failure and severe perfusion deficits to the extremities

OBJECTIVE

To investigate whether systemic administration of recombinant tissue plasminogen activator would improve organ perfusion in an adult patient with fulminant meningococcal disease.

DESIGN

Descriptive case report.

PATIENT

A 45-year-old female with meningococcal septic shock, purpura fulminans and multiple organ failure who was treated in an eight-bed medical intensive care unit of a University hospital.

INTERVENTION

In addition to standard aggressive treatment, on each of three consecutive days the patient received recombinant tissue plasminogen activator infusions at a dose of 20 mg over 4 hrs.

RESULTS

Urine output was recorded before, during, and after the recombinant tissue plasminogen activator infusions. In addition, the patient's peripheral perfusion status was documented by clinical assessment. The patient showed a dramatic improvement in urine output, as well as a perceived increase in skin perfusion after recombinant tissue plasminogen activator therapy. The amount of exogenous vasopressor and inotropic support required to maintain the patient's hemodynamic status also rapidly decreased.

CONCLUSIONS

In this adult patient, recombinant tissue plasminogen activator therapy resulted in improved organ perfusion similar to that reported for paediatric patients. The findings indicate a need for controlled studies concerning the use of thrombolytics in severe meningococcal disease.

Septicaemia and endomyocarditis caused by Aerococcus urinae

Aerococcus urinae, an uncommon urinary tract pathogen, was recently shown to cause septicaemia and endocarditis in a few patients in Denmark and the Netherlands. In Austria this is the first report of a fatal course of endomyocarditis by Aerococcus urinae, associated with multiple septic infarcts.

Decreased levels of beta-endorphin in circulating mononuclear leukocytes from patients with acute myocardial infarction

Lymphocytes can be activated to produce and release opioid peptides. We investigated the levels of immunoreactive beta-endorphin in peripheral blood mononuclear cells from 11 patients with acute myocardial infarction. The concentrations of beta-endorphin in mononuclear leukocytes of 30.2 +/- 6.9 pg/10(6) cells on admission were in the normal range of 20-40 pg/10(6) cells and decreased significantly to 6.9 +/- 1.9 pg/10(6) cells after 48 h (p < 0.05). Decreased levels of mononuclear leukocyte-associated beta-endorphin in acute myocardial infarction may be due to the release of endogenous opioid after stimulation by stress and acute-phase reactants and play a role in inflammation and pain.

Plasma levels of troponin T after electrical cardioversion of atrial fibrillation and flutter

To establish possible myocardial damage by direct-current countershock, we measured plasma levels of troponin T after electrical cardioversion in 33 nonselected patients with atrial fibrillation or flutter. Unchanged normal levels of troponin T indicate that significant myocardial cell injury by shocks in the usual dosage is unlikely to occur.

On the bioisosteric potential of diazines: diazine analogues of the combined thromboxane A2 receptor antagonist and synthetase inhibitor Ridogrel

In this SAR study the bioisosteric potential of diazines in the field of combined antithrombotic thromboxane A2 synthetase inhibitors and receptor antagonists was investigated. In this context, two series of (E)- and (Z)-omega-[[(aryldiazinylmethylene)amino]oxy]alkanoic acids were synthesized of which pentanoic acid derivatives with a 2-pyrazinyl, 4-pyridazinyl, or 5-pyrimidinyl group were found to exhibit this dual activity, while 4-pyrimidinyl as well as 3-pyridazinyl analogues showed only receptor antagonistic activity and 2-pyrimidinyl congeners were inactive. In the series of diazine analogues of Ridogrel (1), replacement of the 3-pyridyl group by a 2-pyrazinyl, 4-pyridazinyl, or 5-pyrimidinyl moiety led to compounds that inhibit thromboxane A2 synthetase in gel-filtered human platelets comparable to 1 (IC50 of 0.006, 0.016, and 0.039 microM, respectively, versus 0.007 microM). Radioligand-binding studies with [3H]SQ 29,548 in washed human platelets revealed that these diazine analogues block the thromboxane A2 receptor with an IC50 of 11, 6.0, and 1.5 microM, respectively. This compares well with the IC50 = 1.7 microM of 1. Finally, testing of inhibition of collagen-induced platelet aggregation in human platelet aggregation in human platelet-rich plasma with 2-pyrazinyl, 4-pyridazinyl, or 5-pyrimidinyl congeners of Ridogrel indicated that these heteroaromatic moieties may serve as bioisosteric substitutes of a 3-pyridyl group in dual-acting antiplatelet agents.

Serum neopterin concentrations in chronic liver disease

Neopterin is produced by macrophages after stimulation with interferon gamma or lipopolysaccharide. Its production is increased in many infectious, autoimmune, and malignant diseases. The aim of this study was to examine whether, on the basis of neopterin as a marker, liver diseases could be classified according to aetiology and stage of disease. A cohort of 264 patients with chronic liver diseases (viral, metabolic, autoimmune, toxic) and 150 normal controls were studied; 136 of the patients had cirrhosis. Increased serum neopterin concentrations were found in 41% of all patients (controls 6.0 (2.2) nmol/l), with patients in the cirrhotic stage of disease showing higher neopterin values (mean (SD) 15.7 (23.6) nmol/ml) than those in the non-cirrhotic stage (9.9 (5.5)). There were no statistically significant differences in the serum neopterin concentrations that could be considered characteristic for different stages of disease classified according to the Child criteria. Such differences in concentrations of neopterin that were found in patients with liver diseases grouped according to underlying causes were only marginal. Serum neopterin concentrations were found to be significantly lower than in any other disease group only in patients with Wilson's disease. The results suggest that activated macrophages participate in the development of chronic liver disease. Measurement of serum neopterin does not offer a reliable method for differentiating between various aetiologies of chronic liver diseases and does not help to predict severity of cirrhosis.

Mallory-Weiss syndrome in a patient with hemophilia A and chronic liver disease

Eighty percent of hemophiliacs exposed to plasma products are seropositive to hepatitis B and an even higher percentage are seropositive to hepatitis C. Post-transfusion hepatitis is followed by cirrhosis in up to 25% of the cases. In the wake of portal hypertension, the development of oesophageal varices entails the risk of life-threatening hemorrhage. We report on a patient with moderate hemophilia A (factor VIII:C 4-11%) who suffered from massive hematemesis, melaena and evolving shock after excessive alcohol ingestion. The diagnosis of Mallory-Weiss syndrome and the differential diagnosis of bleeding oesophageal varices as well as prognostic consequences are discussed.

HDL and plasma phospholipids in coronary artery disease

Lipid fractions of native plasma and of high-density lipoprotein (HDL) were analyzed, and the clotting times of native platelet-rich and -poor plasma were recorded in patients with coronary artery disease and age-matched control subjects not taking any medication known to alter plasma lipid levels, coagulation, or platelet aggregation. Patients with coronary artery disease had lower HDL cholesterol and particularly HDL phospholipids but elevated HDL triglycerides, plasma triglycerides and diglycerides, and fibrinogen. Plasma lysolecithin was diminished. Accelerated coagulation was observed in native plasma and may be related to these changes in plasma lipids. The HDL content in cholesterol may be less relevant than that in phospholipids, which, because of their amphiphilic properties, may be essential for the removal and transport of hydrophobic cholesterol. The lower lysolecithin levels also suggest diminished esterification of cholesterol and reduced degradation of phospholipids, which may add to the poor lysability of platelet-rich and thus phospholipid-rich thrombi. Coagulation inhibition may be related to HDL phospholipids: in control subjects they correlated directly with clotting times of platelet-rich and -poor plasma and inversely with fibrinogen. In contrast, the enhanced thrombus formation in coronary artery disease may be related to altered HDL and plasma phospholipids, in particular to increased phosphatidylethanolamine. These adverse changes, particularly diminished HDL phospholipids, may result in increased deposition and reduced degradation and transport of lipids from arteriosclerotic lesions and thrombi and may therefore be significant in the development of coronary artery disease.

Motor symptoms similar to parkinsonism in heavy smokers

The major objective in this study was a comparison of the motor performance of young male smokers and non-smokers. We tested the endurance capacity, maximal isometric strength, speed of whole-body movements, flexibility and balancing ability of 74 smokers and 118 non-smokers. Then we measured the balancing ability, the visual reaction time and the speed of limb movements of non-smokers and heavy smokers depending on the time of abstinence from smoking. The balancing ability of heavy smokers deteriorates in comparison with non-smokers after an abstinence period of 11-120 min by 42% (p < 0.05), and after more than 120 min by 51% (p < 0.01). Heavy smokers had a longer reaction time both after 2 hours of abstinence and after smoking. The speed of limb movements is decreased after not smoking for a brief period compared to non-smokers and clearly improved immediately after smoking. This deterioration of motor performance of heavy smokers after a short period of abstinence appears similar to the motor symptoms of Parkinsonism and is "treated" by cigarette smoking.

Increased lipid binding to thrombi in coronary artery disease. Findings in patients without premedication in native (not anticoagulated) test systems

Thrombi and clots were produced from native (i.e., not anticoagulated) platelet-rich and platelet-poor plasma from patients with coronary artery disease and control subjects who had not taken any medication known to influence plasma lipids, coagulation, or platelet aggregation. The clotting times were recorded, and the lipid content of clots, thrombi, platelets, plasma, and high density lipoprotein was analyzed. Thrombi produced from native platelet-rich plasma were 46% heavier in coronary artery disease patients and contained about 20% more phospholipids and free cholesterol and about twice the amount of triglycerides and esterified cholesterol in both absolute and relative amounts with respect to the corresponding lipids of plasma plus platelets. The elevated content of lipids not only increases the size of the thrombi but also changes their quality because of an increased content in plasmatic lipids, as platelets contain only trace amounts of triglycerides and cholesterol esters. In agreement herewith, fibrinogen and maximal amplitude on the thrombelastogram were increased in coronary artery disease patients, whereas the thrombus-forming time and clotting times of platelet-poor and platelet-rich plasma were shortened, indicating accelerated coagulation and activation of platelets. Analysis of these results suggests a disturbed interrelation in coronary artery disease between lipids and hemostasis, in which platelets, high density lipoprotein, and lipoproteins rich in triglycerides and cholesterol esters may play a role.

[Scurvy in trisomy 21]

We report a case of Down's syndrome in a 22-year-old woman who developed vitamin C deficiency with subsequent appearance of the characteristic joint pains and cutaneous and mucosal lesions of scurvy. A low intake of vitamin C due to peculiar eating habits and reduced absorption due to cardiac insufficiency and treatment with a platelet-aggregation inhibitor were considered to have caused the deficiency. Follicular purpura is a diagnostic skin sign of scurvy.

Influence of oral contraceptives on coagulation tests in native blood and plasma

Routine coagulation laboratory tests, clotting times in native (not anticoagulated) whole blood, platelet-rich and platelet-poor plasma, and recalcification times in citrated whole blood, platelet-rich and platelet-poor plasma were performed in 14 healthy premenopausal women. Blood was taken before and after one or two cycles of low-dose oral contraceptives. After oral contraceptives a reduction in clotting time in native platelet-rich plasma and activated partial thromboplastin time were observed. Recalcification times in whole blood and platelet-rich plasma were shorter than clotting times in their native counterparts. The observed changes are compatible with a procoagulant effect seen soon after the start of oral contraceptive use. The absence of these changes in the recalcification times in citrate systems suggests a masking effect of citrate. The reduction in clotting times in native platelet-rich but not in platelet-poor plasma indicates that the hypercoagulability in oral contraceptives users is mainly related to platelets.

Abnormal megakaryopoiesis in patients with myelodysplastic syndromes: analysis of cellular and humoral defects

In 13 patients with myelodysplastic syndrome (MDS) mature and immature erythropoietic (CFU-E, BFU-E), granulopoietic (CFU-GM) and megakaryopoietic (CFU-Meg) colony formation from human bone marrow mononuclear cells was evaluated in a microagar culture system. All but three patients exhibited abnormal CFU-Meg. The defect of CFU-Meg paralleled the reduction of BFU-E, whereas CFU-GM number declined to a lesser extent. Not only the CFU-Meg number, but also the number of megakaryocytes (Mk) per colony was reduced suggesting an additional functional CFU-Meg defect. Megakaryocytic growth factor (Meg-CSF) abnormalities in MDS patients were detected using normal nonadherent T-lymphocyte depleted bone marrow cells as target cells for serum testing. Even for sera from patients with a reduction of platelets and bone marrow megakaryocytes Meg-CSF levels were not increased. No cellular or humoral inhibition could be detected in an MDS patient with a 5q- karyotype, who had an isolated defect of the megakaryocytic cell lineage at presentation. Some patients revealed a spontaneous formation of mixed erythrocytic, granulocytic and megakaryocytic clusters in the presence of fetal calf serum or autologous patient serum, probably representing autonomous proliferation of the malignant clone. In conclusion, both cellular and humoral factors can cause abnormalities of the megakaryocytic cell lineage in MDS patients.