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Since December 2019, a novel type of coronavirus disease (COVID-19) in Wuhan led to an outbreak throughout China and the rest of the world. To date, there have been more than 1,260,000 COVID-19 patients, with a mortality rate of approximately 5.44%. Studies have shown that coagulation dysfunction is a major cause of death in patients with severe COVID-19. Therefore, the People's Liberation Army Professional Committee of Critical Care Medicine and Chinese Society on Thrombosis and Hemostasis grouped experts from the frontline of the Wuhan epidemic to come together and develop an expert consensus on diagnosis and treatment of coagulation dysfunction associated with a severe COVID-19 infection. This consensus includes an overview of COVID-19-related coagulation dysfunction, tests for coagulation, anticoagulation therapy, replacement therapy, supportive therapy and prevention. The consensus produced 18 recommendations which are being used to guide clinical work.

Since the onset of the global pandemic in early 2020, coronavirus disease 2019 (COVID-19) has posed a multitude of challenges to health care systems worldwide. In order to combat these challenges and devise appropriate therapeutic strategies, it becomes of paramount importance to elucidate the pathophysiology of this illness. Coronavirus disease 2019, caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV2), is characterized by a dysregulated immune system and hypercoagulability. COVID-associated coagulopathy (CAC) was recognized based on profound d-dimer elevations and evidence of microthrombi and macrothrombi, both in venous and arterial systems. The underlying mechanisms associated with CAC have been suggested, but not clearly defined. The model of immunothrombosis illustrates the elaborate crosstalk between the innate immune system and coagulation. The rendering of a procoagulant state in COVID-19 involves the interplay of many innate immune pathways. The SARS-CoV2 virus can directly infect immune and endothelial cells, leading to endothelial injury and dysregulation of the immune system. Activated leukocytes potentiate a procoagulant state via release of intravascular tissue factor, platelet activation, NETosis, and inhibition of anticoagulant mechanisms. Additional pathways of specific relevance in CAC include cytokine release and complement activation. All these mechanisms have recently been reported in COVID-19. Immunothrombosis provides a comprehensive perspective of the several synergistic pathways pertinent to the pathogenesis of CAC.

SARS-CoV-2 infection (COVID-19) has become a pandemic with a high case fatality rate that mainly affects adults. Most severely ill adult patients develop a coagulopathy that was not described until recently, and which is currently considered a main cause of death. Everything indicates that a similar phenomenon also occurs in children with COVID-19. Anticoagulant treatment has become one of the therapeutic foundations for this infection; however, its implementation in children can be difficult since, until recently, it was not considered in the pediatric population. Evidence regarding the use of anticoagulants in COVID-19 is rapidly generated, changes constantly, it is often difficult to interpret, and can be contradictory. After an extensive review of the published literature, a proposal was generated that offers suggestions for anticoagulant treatment, considering available resources in Mexico., (Copyright: © 2020 Permanyer.)

BACKGROUND Hepatitis B virus (HBV) has been reported as a coinfection with hepatitis C virus (HCV), hepatitis D virus (HDV), cytomegalovirus (CMV), and human immunodeficiency virus (HIV). CASE REPORT A 34-year-old female presented to our clinic with epigastric pain and severe acute hepatitis manifested as jaundice associated with hyperbilirubinemia, elevated transaminases, and coagulopathy. The patient was diagnosed with acute HBV with Epstein-Barr virus (EBV) coinfection leading to subsequent chronic hepatitis B. CONCLUSIONS To our knowledge, this patient case is the first reported case of HBV and EBV coinfection reported in the literature. HBV and EBV coinfection may cause severe acute hepatitis with HBV chronicity.

The high rate of hepatitis C virus (HCV) infection among transfusion related risk groups such as patients with inherited bleeding disorders highlighting the investigation on prevalent subtypes and their epidemic history among this group. In this study, 166 new HCV NS5B sequences isolated from patients with inherited bleeding disorders together with 29 sequences related to hemophiliacs obtained from a previous study on diversity of HCV in Iran were analyzed. The most prevalent subtype was 1a (65%), followed by 3a (18.7%),1b (14.5%),4(1.2%) and 2k (0.6%). Subtypes 1a and 3a showed exponential expansion during the 20th century. Whereas expansion of 3a started around 20 years earlier than 1a among the study patients, the epidemic growth of 1a revealed a delay of about 10 years compared with that found for this subtype in developed countries. Our results supported the view that the spread of 3a reached the plateau 10 years prior to the screening of blood donors for HCV. Rather, 1a reached the plateau when screening program was implemented. The differences observed in the epidemic behavior of HCV-1a and 3a may be associated with different transmission routes of two subtypes. Indeed, expansion of 1a was more commonly linked to blood transfusion, while 3a was more strongly associated to drug use and specially IDU after 1960. Our findings also showed HCV transmission through blood products has effectively been controlled from late 1990s. In conclusion, the implementation of strategies such as standard surveillance programs and subsiding antiviral treatments seems to be essential to both prevent new HCV infections and to decline the current and future HCV disease among Iranian patients with inherited bleeding disorders., Competing Interests: The authors have declared that no competing interests exist.

Background: HIV infection and biomarkers of inflammation [measured by interleukin-6 (IL-6)], monocyte activation [soluble CD14 (sCD14)], and coagulation (D-dimer) are associated with morbidity and mortality. We hypothesized that these immunologic processes mediate (explain) some of the excess risk of mortality among HIV infected (HIV+) versus uninfected people independently of comorbid diseases., Methods: Among 2350 (1521 HIV+) participants from the Veterans Aging Cohort Study Biomarker Cohort (VACS BC), we investigated whether the association between HIV and mortality was altered by adjustment for IL-6, sCD14, and D-dimer, accounting for confounders. Participants were followed from date of blood draw for biomarker assays (baseline) until death or July 25, 2013. Analyses included ordered logistic regression and Cox Proportional Hazards regression., Results: During 6.9 years (median), 414 deaths occurred. The proportional odds of being in a higher quartile of IL-6, sCD14, or D-dimer were 2-3 fold higher for viremic HIV+ versus uninfected people. Mortality rates were higher among HIV+ compared with uninfected people [incidence rate ratio (95% CI): 1.31 (1.06 to 1.62)]. Mortality risk increased with increasing quartiles of IL-6, sCD14, and D-dimer regardless of HIV status. Adjustment for IL-6, sCD14, and D-dimer partially attenuated mortality risk among HIV+ people with unsuppressed viremia (HIV-1 RNA ≥10,000 copies per milliliter) compared with uninfected people-hazard ratio (95% CI) decreased from 2.18 (1.60 to 2.99) to 2.00 (1.45 to 2.76)., Conclusions: HIV infection is associated with elevated IL-6, sCD14, and D-dimer, which are in turn associated with mortality. Baseline measures of these biomarkers partially mediate excess mortality risk among HIV+ versus uninfected people.

The pathogenesis of hematologic changes in dengue patients is not clearly understood. Consistent hematological findings include vasculopathy, thrombocytopenia, and coagulopathy. There are evidences suggesting that dengue virus causes pathophysiological changes that involve all of the consistent hematologic findings resulting in vasculopathy, reduction in platelet number as well as platelet dysfunction, and reduction of several coagulation factors. Laboratory evidences of disseminated intravascular coagulation (DIC) are also demonstrated in all degrees of severity in dengue patients. Only in severe dengue cases is profound DIC aggravated, leading to uncontrolled bleeding and death. A study to determine the extent of the activation of endothelial cells and the hemostatic system in correlation with clinical severity and also to detect the best prognostic factor for severe dengue showed plasma von Willebrand factor antigen (VWF:Ag) to be the best indicator of progression to severe dengue.

The assessment and monitoring of liver fibrosis (LF) is a key issue in the management and definition of prognosis of patients with chronic hepatitis C (CHC). In this respect, despite recognized limitations (invasive nature, sampling errors, interobserver variability, nondynamic evaluation of LF), liver biopsy is traditionally considered the reference standard. These limitations stimulated the search for noninvasive approaches for the assessment of LF, particularly attractive in patients with hemophilia and other congenital bleeding disorders (CBD). In patients with congenital bleeding disorders (CBD), who often suffer from CHC because of the past use of nonvirally inactivated plasma-derived products, the risk of bleeding hamper to routinely obtain histological data for LF staging. A variety of methods have been proposed and, in some cases, validated in patients with CHC and other liver diseases, including biomarkers directly or indirectly associated with LF, often combined in scores or algorithms, and the more recently developed physical approaches, evaluating the properties of the liver parenchyma with instrumental techniques studying the propagation of specific signals, that is, transient elastography (TE), acoustic radiation force impulse imaging elastography, and magnetic resonance elastography. This review will describe the available strategies for noninvasive assessment of LF, with more details on the latter promising instrumental approaches. Moreover, although lacking of validation against liver biopsy, recent studies extending the use of noninvasive methods (particularly TE) in the setting of patients with CBD will be discussed., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

Crimean-Congo hemorrhagic fever (CCHF) is a widely distributed viral hemorrhagic fever characterized by rapid onset of flu-like symptoms often followed by hemorrhagic manifestations. CCHF virus (CCHFV), a bunyavirus in the Nairovirus genus, is capable of infecting a wide range of mammalian hosts in nature but so far only causes disease in humans. Recently, immunocompromised mice have been reported as CCHF disease models, but detailed characterization is lacking. Here, we closely followed infection and disease progression in CCHFV-infected interferon α/β receptor knockout (IFNAR(-/-)) mice and age-matched wild-type (WT) mice. WT mice quickly clear CCHFV without developing any disease signs. In contrast, CCHFV infected IFNAR(-/-) mice develop an acute fulminant disease with high viral loads leading to organ pathology (liver and lymphoid tissues), marked proinflammatory host responses, severe thrombocytopenia, coagulopathy, and death. Disease progression closely mimics hallmarks of human CCHF disease, making IFNAR(-/-) mice an excellent choice to assess medical countermeasures.

Objective: We describe the coagulopathy and hemorrhagic complications associated with fulminant, secondary hemophagocytic lymphohistiocytosis in a cohort of patients with Epstein-Barr virus-associated T-cell lymphoproliferative disorder., Patients and Methods: Institutional Review Board-approved retrospective review of all patients at our children's hospital over 3 years (2008-2010) with hemophagocytic lymphohistiocytosis secondary to acute Epstein-Barr virus-associated T-cell lymphoproliferative disorder., Results: Four males (2, 3, 17, and 20 yr old) presented with fever, hepatosplenomegaly, and pancytopenia with elevated serum ferritin, and all met clinical and laboratory criteria for secondary hemophagocytic lymphohistiocytosis. d-dimer on admission was elevated in all patients and remained extremely elevated during hospitalization, while the median prothrombin and activated partial thromboplastin times as well as fibrinogen were all in the normal range. Within a few weeks to months following admission, all patients developed multiorgan system failure with episodes of severe, life-threatening hemorrhage; in all four patients, hemorrhage was not associated with a nadir in platelet count. There were no survivors beyond 4 months from diagnosis., Conclusions: A coagulopathy characterized by persistent, extreme elevations in plasma d-dimer and severe, life-threatening hemorrhage was noted in association with hemophagocytic lymphohistiocytosis secondary to Epstein-Barr virus-associated T-cell lymphoproliferative disorder. We speculate that this coagulopathy is a marker of severe hemophagocytic lymphohistiocytosis in this setting.

The analysis of 162 surgical deliveries cases in HIV-positive patients with antiretroviral therapy--induced haemostasis disturbances and thrombocytopenia was carried out. The article gives the perioperative management during surgical delivery.

Unlabelled: We describe two children with significant bleeding: one with multiple ecchymoses and the other with scrotal bleeding. In both patients, the activated partial thromboplastin time (APTT) was prolonged, with positivity for lupus anticoagulants (LA). However, the Owren prothrombin time (PT), usually insensitive for LA, was also prolonged. The presence of LA is associated with diverse clinical manifestations, with most patients being asymptomatic while others present venous or arterial thrombosis. Bleeding in conjunction with LA is rare and it is unusual to see prolongation of the Owren PT assay due to LA. An extended laboratory investigation of one of the patient's plasma revealed not only LA but also a specific nonphospholipid-dependent antiprothrombin antibody causing an acquired hypoprothrombinemia., Conclusion: It is likely that the low prothrombin activity and not the LA caused the bleeding. The bleeding signs and symptoms in both patients subsided when the PT was normalized, although the prolonged APTT and the LA remained.

Background: Biomarkers of inflammation, altered coagulation, and monocyte activation are associated with mortality and cardiovascular disease (CVD) in the general population and among human immunodeficiency virus (HIV)-infected people. We compared biomarkers for inflammation, altered coagulation, and monocyte activation between HIV-infected and uninfected people in the Veterans Aging Cohort Study (VACS)., Methods: Biomarkers of inflammation (interleukin-6 [IL-6]), altered coagulation (d-dimer), and monocyte activation (soluble CD14 [sCD14]) were measured in blood samples from 1525 HIV-infected and 843 uninfected VACS participants. Logistic regression was used to determine the association between HIV infection and prevalence of elevated (>75th percentile) biomarkers, adjusting for confounding comorbidities., Results: HIV-infected veterans had less prevalent CVD, hypertension, diabetes, obesity, hazardous drinking, and renal disease, but more dyslipidemia, hepatitis C, and current smoking than uninfected veterans. Compared to uninfected veterans, HIV-infected veterans with HIV-1 RNA ≥500 copies/mL or CD4 count <200 cells/µL had a significantly higher prevalence of elevated IL-6 (odds ratio [OR], 1.54; 95% confidence interval [CI],1.14-2.09; OR, 2.25; 95% CI, 1.60-3.16, respectively) and d-dimer (OR, 1.97; 95% CI, 1.44-2.71, OR, 1.68; 95% CI, 1.22-2.32, respectively) after adjusting for comorbidities. HIV-infected veterans with a CD4 cell count <200 cells/µL had significantly higher prevalence of elevated sCD14 compared to uninfected veterans (OR, 2.60; 95% CI, 1.64-4.14). These associations still persisted after restricting the analysis to veterans without known confounding comorbid conditions., Conclusions: These data suggest that ongoing HIV replication and immune depletion significantly contribute to increased prevalence of elevated biomarkers of inflammation, altered coagulation, and monocyte activation. This contribution is independent of and in addition to the substantial contribution from comorbid conditions.

We describe the case of a female patient who presented a condition of dengue hemorrhagic fever that evolved with jaundice and significant coagulation abnormalities. Dengue was diagnosed through the presence of anti-dengue IgM antibodies (MAC-ELISA). This disease needs to be taken into consideration in the differential diagnosis for acute febrile jaundice.

Background: Viral hepatitis B accounts for over 80% of acute hepatic failures in China and the patients die mainly of its complications. A patient with hepatic failure and fever is not uncommon, whereas repeated fever is rare., Methods: A 32-year-old female was diagnosed with subacute hepatic failure and hepatitis B viral infection because of hyperbilirubinemia, coagulopathy, hepatic encephalopathy, serum anti-HBs-positive without hepatitis B vaccination, and typical intrahepatic pathological features of chronic hepatitis B. Plasma exchange was administered twice and she awoke with hyperbilirubinemia and discontinuous fever., Results: Urethritis was confirmed and medication-induced fever and/or spontaneous bacterial peritonitis (Gram-negative bacillus infection) was suspected. The patient was treated with antibiotics, steroids and a Chinese herbal medicine, matrine, for three months and she recovered., Conclusion: The survival rate of patients with hepatic failure might be improved with comprehensive supporting measures and appropriate, timely management of complications.

Chronic hepatitis C is a major comorbidity in patients with haemophilia. Although the current state-of-the-art therapy consists of pegylated interferon (PegIFN) and ribavirin, there are no reports of the efficacy of this combination in the haemophilia population. The aim of this study was to assess the response and side-effects of PegIFN and ribavirin in patients with inherited bleeding disorders. Patients with chronic hepatitis C were treated with PegIFN alpha-2b (1.5 microg kg(-1) week(-1)) and ribavirin (800-1200 mg day(-1)) for 24 (genotype 2 and 3) or 48 weeks (genotype 1) and followed for an additional 24 weeks. In total, 56 patients were enrolled: 31 (55%) had genotype 1, 12 (21%) genotype 2, and 13 (23%) genotype 3. Ten patients (18%) were HIV co-infected and seven (13%) had been previously treated with IFN-alpha with or without ribavirin. The overall response was 55%. In HIV-negative and treatment-naïve patients, the sustained virological response was 70%. Successful treatment was associated with genotypes 2 and 3, absence of HIV, absence of previous IFN treatment, and decrease of hepatitis C virus load at weeks 4 and 12. Although many side-effects occurred, only a minority (11%) discontinued therapy for this reason. Dose reduction of PegIFN was required in 28% and of ribavirin in 35% of patients. Overall, 22% of patients developed a depression requiring antidepressant drugs and one patient developed psychosis. In conclusion, PegIFN and ribavirin is effective in patients with inherited bleeding disorders. Treatment is safe, but severe side-effects may occur and warrant close monitoring during therapy.

Haemophilia patients who received non-virucidally treated large pool clotting factors before 1987 have a high rate of chronic hepatitis C viral infection (HCV). Some patients are coinfected with HIV. Haemophilia patients and other coagulation disorders were treated at one centre since the beginning of the 1970, and the Israeli National Hemophilia Center (INHC) was officially founded in 1987. To characterize patients with HCV as well as patients with HCV/HIV coinfection at the INHC. Patients with haemophilia and other coagulation disorders positive for HCV antibodies were evaluated between 2001 and 2004. Demographic data, type and severity of coagulation disorder, frequency of coagulation factor usage and treatment with concentrated clotting factors prior to 1987 were recorded. Liver enzymes, viral load, genotype and data supporting advanced liver disease were evaluated. About 179 of 239 haemophilia patients (75%) tested positive for anti-HCV antibodies. Our cohort consisted of 165 patients in whom clinical, biochemical and virological data were available. About 117 patients had active HCV infection with HCV-RNA-positive, and 27 were HCV/HIV coinfected. Twenty-one patients (13%) persistently tested HCV-RNA-negative, hence were considered to clear their HCV infection. There was no former USSR immigrants among HCV/HIV coinfected compared with HCV-infected or HCV-RNA-negative groups (0 vs. 30% and 38%, respectively; P < 0.001). HCV-RNA-negative patients used concentrated coagulation factor less frequently than HCV or HCV/HIV-infected patients (48% vs. 73%; P = 0.023, and 48% vs. 74%; P = 0.043, respectively). The use of concentrated clotting factors before 1987 was significantly more frequent in HCV/HIV than in either HCV-infected or HCV-RNA-negative patients (96% vs. 49% and 48%, respectively; P < 0.001). Compared with HCV/HIV subjects, patients with HCV monoinfection were characterized by a higher proportion of infection with genotype 1 (80% vs. 61%; P = 0.027). The rate of persistently normal liver enzymes in these patients was higher (24% vs. 7%; P = 0.05) than in the HCV/HIV-coinfected patients. Advanced liver disease was significantly more common in patients with HCV/HIV-coinfection than in HCV-monoinfected patients (11% vs. 3%; P = 0.045). The majority of haemophilia patients are infected with HCV. Viral clearance occurred in a minority of these patients. HCV monoinfected and HCV/HIV coinfected differ clinically and prognostically.

A 5-day-old newborn presented with neonatal enteroviral infection. The patient's hospital course was complicated by acute liver dysfunction, renal insufficiency, fluid overload, respiratory failure, hypertension, catheter related thrombosis, Klebsiella pneumoniae sepsis, intracerebral and intraventricular hemorrhage, and disseminated intravascular coagulation (DIC). Administration of fresh frozen plasma (FFP) and cryoprecipitate failed to control the patient's hemostasis and led to significant fluid overload. Recombinant activated factor VII (rFVIIa, Novoseven NovoNordisk, Bagsvaerd, Denmark) was given to the neonate as a bolus (rFVIIa at 60-80 microg/kg body weight), followed by a continuous infusion (2.5-16 microg/kg/hr). Recombinant activated factor VII controlled hemostasis, until the patient's liver function recovered. The patient's blood product requirement significantly decreased and his fluid overload resolved. Administration of rFVIIa appears to have stabilized the coagulation process. The patient appears to have fully recovered from the infection's complications., (Copyright 2004 Wiley-Liss, Inc.)

Cardiovascular complications in the course of human immunodeficiency virus (HIV) infection are multifactorial and may be caused by the virus itself or by the related opportunistic infections and neoplasms. Highly active antiretroviral therapy (HAART) has prolonged many patients' lives, but many cardiac sequelae of HIV are not affected by HAART and continue to develop even with treatment. In addition, HAART itself causes in a high proportion of patients a metabolic syndrome, characterized by lipodystrophy/lipoatrophy, dyslipidemia and insulin resistance that may be associated with an increase in peripheral artery and coronary artery diseases. Careful cardiovascular evaluation in the course of HIV disease can identify cardiac complications early enough to treat. All HIV-infected patients candidate to antiretroviral therapy and patients already under treatment should undergo an assessment that includes the evaluation of the cardiovascular risk with the available guidelines.

Historically, the leading cause of death among persons with haemophilia and other congenital coagulation disorders was uncontrolled bleeding. Mortality was associated with severe deficiency of coagulation factors VIII or IX and especially with high-titre antifactor neutralizing antibodies (inhibitors). The catastrophic contamination of plasma donor pools with human immunodeficiency virus (HIV) resulted in acquired immunodeficiency syndrome replacing haemorrhage as the leading cause of death among persons with haemophilia. Rather little has been written, however, about mortality among those not infected with HIV. The objective of this study was to identify conditions associated with all-cause mortality among HIV-uninfected patients who were followed for a mean of 8.8 years in the Multicentre Hemophilia Cohort Study. Among the 364 children (mean age 8 years), there were four deaths; two related to cancer, one to trauma, and the fourth to haemorrhage, end-stage liver disease and sepsis. Among the 387 HIV-uninfected adults (mean age 35 years) there were 29 deaths, with haemorrhage the leading cause of death, followed by hepatic, stroke and cancer deaths. Prognostic factors for all-cause mortality among the adults included haemophilia Type A with neutralizing antibodies [age-adjusted relative rate (RR) 3.1, 95% confidence interval (CI) 1.4-6.9] and serologic evidence of both hepatitis B and C virus (RR 4.1, 95% CI 0.97-17.6). Although hepatitis C viral load was slightly lower in patients with hepatitis B virus surface antigenaemia, it was unrelated to vital status. We conclude that causes of death and prognostic factors for current HIV-uninfected haemophilia patients are similar to those noted before the HIV epidemic. Better understanding, prevention and control of neutralizing antibodies and hepatitis infections may substantially improve longevity for people with haemophilia.

We studied hepatitis C virus (HCV) clearance and antibody reactivity patterns in a cohort of 100 haemophiliacs exposed to unsterilized blood products, of whom 25 were antiHCV negative and 75 were antiHCV positive [49 human immunodeficiency virus (HIV) negative and 26 HIV positive]. HCV RNA was measured by the 2.0 bDNA assay and an 'in-house' polymerase chain reaction assay. Antibody reactivity patterns were examined using a recombinant immunoblot assay (RIBA). Prior HCV infection was found in two (8%) of 25 antiHCV negative patients. HCV viraemia persisted in all 26 antiHCV+ patients who were coinfected with HIV. HCV RNA clearance was found in 12 (25%) of 49 antiHCV+, HIV- patients. Viral clearance was associated with younger current age (P < 0.01) and age at infection (P < 0.001), but not with duration of infection or with dose or frequency of clotting factor use. RIBA ratios reflecting an index of each patient's overall reactivity to four HCV epitopes were significantly lower in those with viral clearance (P < 0.0001). Over a period of 15 years, those with viral clearance demonstrated significant loss of reactivity to the NS3, NS4 and NS5 epitopes, while those with viral persistence demonstrated relatively stable reactivities to all epitopes. We conclude that spontaneous HCV RNA clearance in haemophiliacs is age-related and is unlikely to occur in those coinfected with HIV. The loss of antibody reactivity for some epitopes, especially c22 (core), may be a marker for the natural resolution of chronic HCV infection.

Viral hemorrhagic fever (VHF) denotes a virus-induced acute febrile, hemorrhagic disease reported from wide areas of the world. Hemorrhagic fever (HF) viruses are encapsulated, single-stranded RNA viruses that are associated with insect or rodent vectors whose interaction with humans defines the mode of disease transmission. There are 14 HF viruses, which belong to four viral families: Arenaviridae, Bunyaviridae, Filoviridae and Flaviviridae. This review presents, in order, the following aspects of VHF: (1) epidemiology, (2) anomalies of platelets and coagulation factors, (3) vasculopathy, (4) animal models of VHFs, (5) pathogenic mechanisms, and (6) treatment and future studies. HF viruses produce the manifestations of VHFs either by direct effects on cellular functions or by activation of immune and inflammatory pathways. In Lassa fever, Rift Valley fever and Crimean-Congo HF, the main feature of fatal illness appears to be impaired/delayed cellular immunity, which leads to unchecked viremia. However, in HF with renal syndrome and dengue HF, the immune response plays an active role in disease pathogenesis. The interplay of hemostasis, immune response, and inflammation is very complex. Molecular biologic techniques and the use of animal models have helped to unravel some of these interactions.

Background: Hepatitis C virus (HCV) infected hemophiliacs respond at low rate to interferon (IFN) monotherapy., Aims: To assess efficacy of IFN and RBV in HIV negative hemophiliacs with chronic hepatitis C and identify early predictive factors of response., Methods: Twenty naive patients were treated with interferon and RBV for twelve months. Response was assessed by both serial ALT and HCV RNA levels., Results: Normalization of ALT with clearance of HCV RNA occurred in seven (35%) patients. Age and age at infection were the only features associated with a higher likelihood of response. In all responders the viral load had decreased by at least one log within two months of starting treatment., Conclusions: Combination of interferon and ribavirin is well tolerated by hemophiliacs who achieve similar sustained response rates to non-hemophiliacs. Quantitative assessment of viral load at two months of treatment is a useful method to identify non-responders at an early stage.

A link between cytomegalovirus (CMV) infection and atherosclerosis has been suggested by experimental, clinical, and epidemiologic studies. We investigated the association between CMV antibody titers in serum collected in 1974 in 300 adult residents in Washington County, Md, and hemostatic parameters in plasma collected in 1987 through 1989, when these individuals participated in the baseline examination of the Atherosclerosis Risk in Communities Study. The cross-sectional association of CMV serum antibodies and hemostatic parameters was also explored in another set of Atherosclerosis Risk in Communities cases and controls. In the longitudinal analyses, CMV titers in 1974 were directly associated with 1987 through 1989 plasma levels of von Willebrand factor, factor VIII, and protein C and negatively associated with activated partial thromboplastin time. In the cross-sectional analyses, CMV titers were directly related to antithrombin III and fibrinogen levels. When the association between CMV antibodies and atherosclerosis was examined in stratified analyses, a significant association was restricted to individuals with high levels of lipoprotein(a) and fibrinogen. These results are compatible with previous evidence suggesting that CMV virus might have procoagulant properties. The possible synergism of CMV infection and resulting hypercoagulability with reduced fibrinolysis due to increased lipoprotein(a) levels deserves further investigation.

The hepatitis G virus (HGV) has recently been identified as a new member of the Flaviviridae family. Infection by this virus is thought to be associated with blood borne hepatitis. In this study, the presence of HCV- and HGV-RNAs in serum or plasma (175 patients) and in peripheral blood mononuclear cells (PBMC) (133 patients) was investigated in patients with clotting disorders using a sensitive reverse transcriptase polymerase chain reaction (RT-PCR). HGV-RNA was detected in serum of 26 patients (14.8%). In apparently healthy blood donors, serum HGV-RNA was detected in 4 of 358 individuals investigated (1.12%). Ninety two percent of the 26 serum HGV-RNA positive patients had coinfection with the hepatitis C virus (HCV), especially with HCV genotype 1b, the most common genotype in Belgium. Of these coinfected patients, 15 (62.5%) showed elevated serum ALT levels. Two patients who were solely infected with HGV had normal serum ALT.HGV-RNA in PBMC was found in 18 patients, of whom 3 were negative for serum HGV-RNA. As in case of HCV, HGV-RNA in PBMC is preferentially sensitive to interferon treatment. Nevertheless, rapid reappearance of HGV-RNA in PBMC was observed after cessation of treatment. In one patient, persistent serum ALT elevation seems to be associated with continued HGV viremia, despite the disappearance of serum HCV-RNA.

Hematologic complications of HIV disease are commonly encountered by physicians and other health-care workers caring for patients infected with this virus. Ineffective hematopoiesis, infiltrative diseases of the bone marrow, nutritional deficiencies, peripheral destruction of blood cells secondary to splenomegaly or immune dysregulation, and drug effects all contribute to the variety of hematologic abnormalities seen in these patients. This review explores the causes of isolated or trilineage cytopenias and coagulopathies; the utility of bone marrow biopsy examination; and the role of colony-stimulating factors as therapeutic agents in patients with HIV disease.