Increased plasma level of interleukin-6 in disseminated intravascular coagulation

Low-dose hydralazine improves endotoxin-induced coagulopathy and multiple organ dysfunction via its anti-inflammatory and anti-oxidative/nitrosative properties

Coagulopathy is the major cause of organ injury as well as a strong predictor of mortality in septic patients. Systemic inflammatory response and redox imbalance are regarded as the major causes of sepsis-induced coagulopathy. There is growing evidence that a vasodilator hydralazine has beneficial effects on heart failure, hypertension, and ischemia/reperfusion injury via its antioxidant and anti-inflammatory properties. However, the effects of hydralazine on sepsis have not been examined. Therefore, we evaluated the effects of low-dose hydralazine on coagulopathy and multiple organ dysfunction in septic rats induced by endotoxin. Sepsis-induced coagulopathy was established by intravenous injection of rats with lipopolysaccharide (LPS). The changes of blood pressure, heart rate, blood glucose, hemostatic variables, prothrombin time, organ function indices, interleukin-6 (IL-6) concentration, and nitric oxide (NO) level were assessed during the experimental period. In addition, the aortas, lungs, livers, and kidneys were dissected to analyze superoxide levels and protein expressions. LPS induced (i) coagulopathy, multiple organ dysfunction, and circulatory failure successfully, and (ii) excessive superoxide, NO, and IL-6 production, accompanied by the overexpression of iNOS and Wnt5a in animals. Treatment of LPS-induced septic rats with low-dose hydralazine not only improved coagulopathy but also ameliorated multiple organ dysfunction. These could be due to attenuation of the overproduction of superoxide, NO, and IL-6, which were attributed to reduction of the overexpression of iNOS and Wnt5a. Thus, these findings indicate that low-dose hydralazine could be a potential therapy for sepsis-induced coagulopathy and multiple organ dysfunction via its anti-inflammatory and anti-oxidative/nitrosative properties.

Life-Threatening Psoas Hematoma due to Retroperitoneal Hemorrhage in a COVID-19 Patient on Enoxaparin Treated With Arterial Embolization: A Case Report

Respiratory failure is presumptively caused by microvascular thrombosis in some patients with coronavirus disease 2019 (COVID-19) requiring therapeutic anticoagulation. Anticoagulation treatment may cause life-threatening bleeding complications such as retroperitoneal hemorrhage. To the best of our knowledge, we report first case of a COVID-19 patient treated with therapeutic anticoagulation resulting in psoas hematoma due to lumbar artery bleeding. A 69-year-old patient presented with fever, malaise and progressive shortness of breath to our hospital. He was diagnosed with COVID-19 by RT-PCR. Due to an abnormal coagulation profile, the patient was started on enoxaparin. Over the course of hospitalization, the patient was found to have hypotension with worsening hemoglobin levels. Computed tomography scan of the abdomen and pelvis revealed a large psoas hematoma. Arteriogram revealed lumbar artery bleeding which was treated with embolization. Anticoagulation therapy, while indicated in COVID-19 patients, has its own challenges and guidelines describing dosages and indications in this disease are lacking. Rare bleeding complications such as psoas hematoma should be kept in mind in patients who become hemodynamically unstable, warranting prompt imaging for diagnosis and treatment with arterial embolization, thus eliminating need of surgical intervention.

IL-7 and procalcitonin are useful biomarkers in the comprehensive evaluation of the severity of acute cholangitis

BACKGROUND

The incidence of biliary tract infection (BTI), especially healthcare-associated cholangitis, is increasing. However, there are few reports concerning biomarkers of acute cholangitis. We therefore performed an exhaustive investigation of several biomarkers.

METHODS

We retrospectively measured 11 cytokines, six chemokines and procalcitonin (PCT), and endotoxin activity assay (EAA) values (IRB: 110512019) of 61 samples with acute cholangitis.

RESULT

The 28-day mortality rate was 9.8%. The levels of most cytokines and chemokines were significantly correlated with each other. A low IL-7 level was found to predict blood culture positivity. Low IL-7 level was also found to predict disseminated intravascular coagulation. Low IL-7 levels and a high PCT level were found to be predictors of severe cholangitis. The 28-day mortality in the group of patients with an IL-7 level of ≤6.0 and a PCT level of >0.5 was 18.2%. It was significantly higher than in the other group.

CONCLUSION

The combined use of IL-7 and PCT may be useful for evaluating severe acute cholangitis; these results may suggest that severe acute cholangitis is affected by immunosuppressive changes.

Increased Plasma Soluble-adhesion Molecules in Thrombotic Thrombocytopenic Purpura and Disseminated Intravascular Coagulation

We measured plasma-soluble adhesion molecules (granule membrane protein [GMP]-140, endothelial leukocyte adhesion molecule [ELAM]-1, intracellular adhesion molecule [ICAM]-1, and vascular adhesion molecule [VCAM]-1) in 21 patients with thrombotic thrombocytopenic purpura (TTP), 10 with mitomycin C-induced hemolytic uremic syndrome (MMC-HUS) and 59 with disseminated intravascular coagula tion (DIC) or pre-DIC. The plasma levels of soluble GMP-140 in the three groups were significantly higher than the levels in healthy volunteers, suggesting that platelets and vascular en dothelial cells are activated in these diseases. The plasma- soluble GMP-140 level of the DIC patients with nonhemato poietic malignancy was significantly higher than in the DIC patients with hematopoietic malignancy, perhaps due to the release of GMP-140 mainly from platelets. The plasma levels of soluble VCAM-1 in the TTP and DIC patients were signifi cantly higher than the levels in healthy volunteers. The plasma levels of ICAM-1 in DIC patients were significantly higher than those in healthy volunteers, but the levels in the TTP and MMC-HUS groups were not significantly high. The plasma ELAM-1 levels in the TTP and MMC-HUS groups were sig nificantly lower than those in healthy volunteers and DIC pa tients. Since elevated plasma cytokine levels have been ob served in TTP and DIC patients, the adhesion molecules might be upregulated in these diseases. However, plasma ELAM-1 is thought to be reduced in severe vascular endothelial cell dis eases such as TTP.

Heat stroke

Heat stroke is a life-threatening condition clinically diagnosed as a severe elevation in body temperature with central nervous system dysfunction that often includes combativeness, delirium, seizures, and coma. Classic heat stroke primarily occurs in immunocompromised individuals during annual heat waves. Exertional heat stroke is observed in young fit individuals performing strenuous physical activity in hot or temperature environments. Long-term consequences of heat stroke are thought to be due to a systemic inflammatory response syndrome. This article provides a comprehensive review of recent advances in the identification of risk factors that predispose to heat stroke, the role of endotoxin and cytokines in mediation of multi-organ damage, the incidence of hypothermia and fever during heat stroke recovery, clinical biomarkers of organ damage severity, and protective cooling strategies. Risk factors include environmental factors, medications, drug use, compromised health status, and genetic conditions. The role of endotoxin and cytokines is discussed in the framework of research conducted over 30 years ago that requires reassessment to more clearly identify the role of these factors in the systemic inflammatory response syndrome. We challenge the notion that hypothalamic damage is responsible for thermoregulatory disturbances during heat stroke recovery and highlight recent advances in our understanding of the regulated nature of these responses. The need for more sensitive clinical biomarkers of organ damage is examined. Conventional and emerging cooling methods are discussed with reference to protection against peripheral organ damage and selective brain cooling.

Primary angiosarcoma of the breast complicated by the syndrome of disseminated intravascular coagulation (DIC): Case report and literature review

Primary angiosarcoma of the breast (PAB) accounts for 0.04% of all breast malignant tumors. It affects young women usually at third or fourth decades of life. PAB clinically manifests as a painless, movable mass with sharp limits. A bluish red discoloration of the overlying skin is often observed. Enlargement of axillary lymph nodes generally does not occur. Angiosarcoma of the breast has a very poor prognosis due to the tendency to metastasize haematogenously and high frequency of local recurrence. Mastectomy and chemotherapy are preferable treatment choices. This paper presents a case of primary angiosarcoma of the breast with a syndrome of disseminated intravascular coagulation (DIC).

Acute renal failure as the presenting sign of disseminated intravascular coagulation in a patient with metastatic prostate cancer

Disseminated intravascular coagulation (DIC) is the most frequent coagulation disorder in patients with prostate cancer. However, renal involvement in DIC associated with prostate cancer has rarely been documented. Herein, we present a case of metastatic prostate cancer presenting with acute renal failure (RF) triggered by DIC. An 80 year old man with metastatic prostate cancer was treated with antihormone therapy at an outpatient clinic. He was admitted to our hospital because of severe dyspnea and progressive RF. A hemorrhagic tendency was not clinically evident. Laboratory tests exhibited a significant coagulation disorder, suggestive of DIC. Despite treatment, his RF and dyspnea worsened, and he eventually passed away. An autopsy study revealed hypertensive nephrosclerosis superimposed by fibrin rich thrombi formation involving glomerular capillaries and arterioles characteristic of DIC. Additionally, focal segmental glomerulosclerosis was identified, which was presumably secondary to the glomerular endothelial and/or podocyte injury augmented by DIC. Those findings showed that glomerular injury, which was induced and subsequently exacerbated by DIC associated with prostate cancer, highly contributed to the progression of RF in our case. A differential diagnosis of DIC should be considered when a patient with prostate cancer presents with renal dysfunction.

Effect of recombinant canine interleukin-6 and interleukin-8 on tissue factor procoagulant activity in canine peripheral blood mononuclear cells and purified canine monocytes

BACKGROUND

Inflammation is a major cause of disseminated intravascular coagulation (DIC) in dogs, but underlying mechanisms for its initiation are unknown. We hypothesized that pro-inflammatory cytokines, interleukin (IL)-6 and IL-8, induce tissue factor (TF) expression on canine monocyte surfaces, which may contribute to DIC initiation.

OBJECTIVES

The objectives of this study were to determine if (1) IL-6 and IL-8 would induce TF activity on canine monocytes, (2) fetal bovine serum or autologous plasma was required for IL-6- or IL-8-induced TF responses in canine monocytes, and (3) these pro-inflammatory cytokines would enhance TF activity on canine monocytes in response to low concentrations of lipopolysaccharide (LPS).

METHODS

Canine monocytes were isolated from EDTA-anticoagulated blood as peripheral blood mononuclear cells (PBMC) by double-density gradient centrifugation and adhesion to plastic. Adherent cells were stimulated for 4 hours with recombinant canine (rc)-IL-6 or rc-IL-8 (10-5000 pg/mL) with or without 10% heat-inactivated (HI) fetal bovine serum, untreated autologous canine plasma (ACP), or HI-ACP. Lipopolysaccharide (100 ng/mL) served as a positive control. Cells were also costimulated with either cytokine (100 pg/mL) or low concentrations of LPS (0.1 and 1 ng/mL). Monocytes immunopurified from PBMC with anti-CD14 antibodies were also stimulated with both cytokines (100 and 5000 pg/mL). TF activity on cell surfaces was measured by a 2-stage amidolytic assay, based on activated factor X generation.

RESULTS

Neither rc-IL-6 nor rc-IL-8 consistently stimulated TF procoagulant activity in canine PBMC or purified monocytes after 4 hours. Serum, plasma, or low concentrations of LPS did not enhance the TF response to these cytokines.

CONCLUSIONS

IL-6 or IL-8 at evaluated concentrations may not play major roles in coagulation activation by induction of TF expression on monocytes in dogs with inflammation.

Heat stroke and cytokines

Heat stroke is a life-threatening illness that affects all segments of society, including the young, aged, sick, and healthy. The recent high death toll in France (Dorozynski, 2003) and the death of high-profile athletes has increased public awareness of the adverse effects of heat injury. However, the etiology of the long-term consequences of this syndrome remains poorly understood such that preventive/treatment strategies are needed to mitigate its debilitating effects. Cytokines are important modulators of the acute phase response (APR) to stress, infection, and inflammation. Current data implicating cytokines in heat stroke responses are mainly from correlation studies showing elevated plasma levels in heat stroke patients and experimental animal models. Correlation data fall far short of revealing the mechanisms of cytokine actions such that additional research to determine the role of these endogenous substances in the heat stroke syndrome is required. Furthermore, cytokine determinations have occurred mainly at end-stage heat stroke, such that the role of these substances in progression and long-term recovery is poorly understood. Despite several studies implicating cytokines in heat stroke pathophysiology, few studies have examined the protective effect(s) of cytokine antagonism on the morbidity and mortality of heat stroke. This is particularly surprising since heat stroke responses resemble those observed in the endotoxemic syndrome, for which a role for endogenous cytokines has been strongly implicated. The implication of cytokines as mediators of endotoxemia and the presence of circulating endotoxin in heat stroke patients suggests that much knowledge can be gained from applying our current understanding of endotoxemic pathophysiology to the study of heat stroke. Heat shock proteins (HSPs) are highly conserved proteins that function as molecular chaperones for denatured proteins and reciprocally modulate cytokine production in response to stressful stimuli. HSPs have been shown repeatedly to confer protection in heat stroke and injury models. Interactions between HSPs and cytokines have received considerable attention in the literature within the last decade such that a complex pathway of interactions between cytokines, HSPs, and endotoxin is thought to be occurring in vivo in the orchestration of the APR to heat injury. These data suggest that much of the pathophysiologic changes observed with heat stroke are not a consequence of heat exposure, per se, but are representative of interactions among these three (and presumably additional) components of the innate immune response. This chapter will provide an overview of current knowledge regarding cytokine, HSP, and endotoxin interactions in heat stroke pathophysiology. Insight is provided into the potential therapeutic benefit of cytokine neutralization for mitigation of heat stroke morbidity and mortality based on our current understanding of their role in this syndrome.

[Clinical usefulness of plasma interleukin-6 and interleukin-10 in disseminated intravascular coagulation]

BACKGROUND

Disseminated intravascular coagulation (DIC) is a syndrome characterized by a systemic activation of coagulation leading to the intravascular deposition of fibrin and the simultaneous consumption of coagulation factors and platelets. Inflammatory cytokines can activate the coagulation system. This study investigated the diagnostic and prognostic usefulness of the plasma level of interleukin-6 (IL-6) and interleukin-10 (IL-10) for predicting DIC.

METHODS

The study populations were 15 healthy controls and 81 patients who were clinically suspected of having DIC and were requested to perform DIC battery tests. The presence of overt DIC was defined by the International Society on Thrombosis and Haemostasis Subcommittee cumulative score of 5 or above. The 28 day mortality was used to assess the prognostic outcome. The plasma levels of the cytokines were measured by ELISA.

RESULTS

The plasma levels of IL-6 and IL-10 in patients (N=81) were higher than those of control (N=15). IL-6 and IL-10 levels of overt DIC group (N=31) were 3 times and 1.5 times higher than those, respectively, of non-overt DIC group (N=50). In infection group (N=48), IL-6 and IL-10 levels of overt DIC group (N=18) were 5 times and 3 times higher than those, respectively, of non-overt DIC group (N=30). The diagnostic efficiency of IL-6 (optimal cut off >40.4 pg/mL) and IL-10 (>9.7 pg/mL) for the diagnosis of overt DIC were 67% and 69%, respectively, which were similar to that of D-dimer. Plasma levels of IL-6 and IL-10 were also higher in non-survivors than in survivors. The patients with higher levels of IL-6 and IL-10 showed a poorer prognosis.

CONCLUSIONS

The proinflammatory cytokine, IL-6 and anti-inflammatory cytokine, IL-10 were useful for the diagnosis of overt DIC and the prediction of its prognosis. These results also showed the evidence of a close interaction between coagulation and inflammation.

Umbilical vein interleukin-6 levels in very low birth weight infants developing intraventricular hemorrhage

To assess the relationship between perinatal infection/inflammation as reflected by umbilical vein interleukin-6 (IL-6) levels and the development of periventricular-intraventricular hemorrhage (IVH) in very low birth weight (VLBW) infants, we tested the hypothesis that VLBW infants who develop IVH have higher concentrations of IL-6 in an umbilical vein sample compared to infants without IVH. An inception cohort of 69 VLBW infants was followed from birth until discharge or death to determine the development of IVH by serial neuroultrasounds. Umbilical vein IL-6 levels were measured using commercially available ELISA kit (Endogen Laboratories, Woburn, MA) and compared in IVH and control cohorts. Twenty-two (32%) infants developed IVH, including 18 (82%) with grade I or II and 4 (18%) with grade III or IV. One of these infants also developed periventricular leukomalacia. The umbilical vein IL-6 levels were significantly elevated in infants with IVH with median value of 87 pg/ml (25th percentile value 30 pg/ml and 75th percentile value 310 pg/ml) compared with infants without IVH, with a median value of 0 pg/ml (25th percentile value 0 pm/ml and 75th percentile value 4 pg/ml) (P = 0.007). Umbilical vein IL-6 levels are elevated in neonates who subsequently develop IVH.

Cold Injury Syndrome and Neurodevelopmental Changes in Survivors

BACKGROUND

The aim of this study was to extend and develop knowledge of the clinical parameters of cold injury syndrome (CIS) in hypothermic infants and newborns, so that morbidity, mortality, and neurodevelopmental disturbances associated with the condition can be reduced.

METHODS

This retrospective, 10-year cohort study investigated 103 hypothermic infant and newborn patients (aged 0-60 days) admitted to the Pediatric Department between January 1, 1976 and December 31, 1985. Medical records of 67 survivors and 36 children who died were analyzed. Of the survivors, 24 consented to undergo assessment of neuropsychological and neurodevelopmental outcomes.

RESULTS

At presentation, all patients manifested cold skin and limbs, while 96 (93.2%) were sleepy, hypotonic and inactive. Cyanosis with bradycardia, bradypnea, and apneic crisis (AC) was observed in 80 (77.7%) patients, and 65 (63.1%) demonstrated diffuse intravascular coagulation (DIC). Pulmonary hemorrhage, AC, respiratory distress syndrome, and DIC represented the primary causes of death. Higher body temperatures on admission reduced the risk of death. Of the 24 patients assessed for neuropsychological and neurodevelopmental outcomes, all but one had normal intellectual capabilities, whereas 16 (66.7%) showed signs of neurodevelopmental disturbances.

CONCLUSIONS

The severity of hypothermia, leukopenia, and thrombocytopenia with DIC correlates with prognosis and death rate. Hypothermia in infants and newborns can cause psychological and neurodevelopmental disturbances in survivors.

Elevated levels of leukocyte tissue factor mRNA in patients with venous thromboembolism

Tissue factor (TF) mRNA levels in leukocyte and TF antigen in plasma were examined in patients with deep vein thrombosis (DVT). Although TF mRNA levels in leukocytes were higher in patients with DVT than in healthy volunteers, they were lower in patients with DVT than in those with solid cancer and those with disseminated intravascular coagulation (DIC). On the other hand, the plasma levels of TF antigens were markedly high in patients with DVT/pulmonary embolism (PE). Analysis of the role of underlying disease of DVT showed no significant difference in TF mRNA levels and TF antigens among patients with solid cancer, post-surgical, other diseases and those free of underlying diseases. In patients with VTE, plasma levels of D-dimer, soluble fibrin, GE-XDP and plasminogen activator inhibitor-1 did not correlate with TF mRNA or TF antigen. In analysis of 18 patients with PE with and without DVT, TF mRNA levels in leukocytes correlated with the plasma levels of D-dimer. These findings suggest that TF in leukocytes is more likely to be involved in the development of thrombosis in PE than DVT.

Changes of hemostatic molecular markers after gynecological surgery

The authors evaluated the hemostatic abnormalities occurring in the postoperative period of eight patients with malignant tumors and compared them with those occurring in the postoperative period of eight patients with benign tumors. Two of the patients with malignant tumor presented pulmonary embolism after operation. Plasma fibrinogen and fibrin degradation product levels in patients with malignant tumors were already high before operation and further increased significantly after operation. The plasma levels of D-dimer, thrombin-antithrombin complex, and free-tissue factor pathway inhibitor were increased in both groups after operation, but they were higher in patients with malignant tumors than in patients with benign tumors. The plasma levels of protein C and antithrombin were significantly decreased in both groups after operation. but they were significantly lower in patients with malignant tumors than in those with benign tumors. The decreased activity of protein C or antithrombin may be not only a risk factor of thrombotic disease, such as pulmonary embolism, but also the cause of thrombosis. In patients with malignant tumors, the operation time was significantly longer than that in patients with benign tumors. This long operative period might cause vascular endothelial cell injury which is reflected by the plasma levels of free-tissue factor pathway inhibitor, antithrombin, and protein C.

Increased D-dimer levels correlate with binding of activated protein C, but not tissue factor expression, on peripheral blood monocytes in cancer patients

Monocyte tissue factor expression is supposed to play an important role in the hypercoagulability of blood in cancer patients. The relation between coagulation parameters and the expression of monocyte membrane proteins involved in hemostasis or monocyte activation was studied in 21 patients with a disseminated malignancy and 21 age- and sex-matched healthy controls. In the cancer patient group no increase of monocyte tissue factor expression was found (8. 4% vs. 7.8%; P = 0.83), but a significant increase of monocyte-bound activated protein C (APC) (28.8% vs. 13.4%; P = 0.009) and monocyte CD16 expression (34.5% vs. 27.0%; P = 0.007) was observed. There was also a significant increase of D-dimers (2.0 vs. 0.2 microg/ml; P = 0.001), a decrease of antithrombin (83.5% vs. 102.0%; P = 0.004), but no increase of TAT complexes (1.7 vs. 1.5 microg/l; P = 0.38) or factor VII(a) (68.5% vs. 75.0%; P = 0.52). The increase of D-dimers was significantly correlated with the monocyte APC (R = 0.60; P = 0. 005), but not with monocyte tissue factor levels (R = -0.22; P = 0. 35) or TAT complexes (R = 0.12; P = 0.60). These results reflect a local rather than systemic thrombin and fibrin formation. It is suggested that the APC formed locally enters the circulation and binds to peripheral blood monocytes. APC bound on monocytes is known to inhibit monocyte cytokine production and might therefore be involved in regulatory responses of monocytes in cancer patients.

Elevated tissue factor levels in leukemic cell homogenate

Tissue factor (TF) antigen and activity were measured in leukemic cell homogenates. In leukemic cell homogenate, especially that of acute promyelocytic leukemia (APL), both TF antigen and activity were significantly higher than these levels in the mononuclear cells obtained from healthy volunteers. Both TF antigen and activity were significantly higher in myelocytic leukemia than in lymphocytic leukemia cells. In leukemic cell homogenates, there was a close correlation between TF antigen and TF activity. The TF activity/TF antigen ratio was significantly higher in myelocytic leukemia than in lymphocytic leukemia cells. As the TF activity was not increased in lymphocytic leukemia cell homogenates to which were added phospholipids, the decrease in TF activity in lymphocytic leukemia might not be due to phospholipid in the leukemic cell membrane. Values for TF activity, TF antigen, and the TF activity/TF antigen ratio in leukemic cell homogenate from patients with disseminated intravascular coagulation (DIC) were significantly higher than those in patients without DIC. Therefore, the measurement of TF antigen and activity in leukemic cells could be useful for the prediction of DIC.

Aberrations of the tissue factor pathway in patients positive for lupus anticoagulant

To evaluate the relationship between the tissue factor (TF) pathway and lupus anticoagulant (LA), in the present study, we measured the plasma levels of TF antigen and TF pathway inhibitor (TFPI) antigen in patients positive for LA. Plasma TF and TFPI levels in LA-positive patients were significantly higher than levels in healthy volunteers (p < 0.01). In LA-positive patients, there were no significant differences in plasma TF and TFPI levels between patients with and without thrombosis. In patients with thrombosis, there was no significant difference in the plasma TF level between LA-positive and LA-negative patients; however, the plasma TFPI level in LA-positive patients was significantly lower than that in LA-negative patients (p < 0.01). We also examined the TF pathway in human umbilical venous endothelial cells (HUVEC) incubated with plasma of LA-positive patients, LA-negative patients, and healthy volunteers. TF activity was significantly higher (p < .05) in HUVECs incubated with the plasma of LA-positive patients than in cells incubated with the plasma of the other two groups (p < .01). However, there was no significant difference in TFPI antigen levels among the media of HUVECs incubated with the plasma of all groups. The viability of HUVEC incubated with the plasma of LA-positive patients with thromboses, LA-positive patients without thromboses, and LA-negative patients with thromboses were significantly lower than that of HUVECs incubated with the plasma of healthy volunteers (p < .01). These findings suggest that abnormalities of the TF pathway plays an important role in the mechanism of hypercoagulability in LA-positive patients. LA may affect vascular endothelial cells causing thrombogenesis.

Disseminated intravascular coagulation: clinical and laboratory aspects

Disseminated intravascular coagulation (DIC) is a complex acquired coagulopathy resulting from excessive thrombin formation. Abnormal tissue factor (TF) expression is a major mechanism initiating DIC in many disorders, including obstetrical complications, sepsis, cancer, and trauma. Numerous laboratory tests are available to monitor DIC, but most patients are adequately managed using only routine hemostasis screening tests, and assays for fibrinogen and D-dimer. Treatment of DIC should focus on reversing the underlying disorder initiating the coagulopathy. Novel treatments are being investigated for treating DIC; many of these experimental modalities target the excessive TF activity that characterizes DIC.

Maternal intrauterine infection, cytokines, and brain damage in the preterm newborn

To evaluate the hypothesis that the proinflammatory cytokines IL-1, IL-6, and tumor necrosis factor-alpha might be the link between prenatal intrauterine infection (IUI) and neonatal brain damage, the authors review the relevant epidemiologic and cytokine literature. Maternal IUI appears to increase the risk of preterm delivery, which in turn is associated with an increased risk of intraventricular hemorrhage, neonatal white matter damage, and subsequent cerebral palsy. IL-1, IL-6, and TNF-alpha have been found associated with IUI, preterm birth, neonatal infections. and neonatal brain damage. Unifying models not only postulate the presence of cytokines in the three relevant maternal/fetal compartments (uterus, fetal circulation, and fetal brain) and the ability of the cytokines to cross boundaries (placenta and blood-brain barrier) between these compartments, but also postulate how proinflammatory cytokines might lead to IVH and neonatal white matter damage during prenatal maternal infection. Interrupting the proinflammatory cytokine cascade might prevent later disability in those born near the end of the second trimester.

Effect of FR167653, a cytokine suppressive agent, on endotoxin-induced disseminated intravascular coagulation

FR167653 (1-[7-(4-fluorophenyl)-1,2,3,4-tetrahydro-8-(4-pyridyl)pyrazolo[5-1-c] [1,2,4]triazin-2-yl]-2-phenylethanedione sulfate monohydrate) is a low molecular weight inflammatory cytokine inhibitor that inhibits the production of interleukin-1 alpha, interleukin-1 beta and tumor necrosis factor-alpha (TNF-alpha) in human monocytes stimulated with lipopolysaccharide, and in human lymphocytes stimulated with phytohemagglutinin-M. FR167653 inhibited these cytokines in a dose-dependent manner (IC50 values were 0.84, 0.088, 1.1 microM and 0.072, respectively). However, FR167653 did not inhibit even at 10 microM interleukin-6 production by human monocytes, and the production of interleukin-2 and interferon-gamma by human lymphocytes. We evaluated the effect of FR167653 on lipopolysaccharide-induced disseminated intravascular coagulation in rats. FR167653 (0.032-0.32 mg/kg/h for 4 h, intravenous infusion) markedly improved thrombocytopenia and plasma coagulation parameters in a dose-dependent manner, but not leukopenia in this mode. Plasma interleukin-1 and TNF-alpha levels were elevated by lipopolysaccharide administration and the treatment with FR167653 (0.31 mg/kg/h for 4 h) inhibited the increased plasma interleukin-1 (100.0%) and plasma TNF-alpha (89.2%) levels. These results suggest that interleukin-1 and TNF-alpha may play a pivotal role in the pathogenesis of DIC. FR167653 can act as a protective drug in lipopolysaccharide-induced DIC, and this protection is due to an inhibition of increased plasma interleukin-1 and TNF-alpha.

Inhibitory effects of interleukin-6 on release of PGI2 by cultured human pulmonary artery smooth muscle cells

We evaluated the effect of interleukin-6 (IL-6) on the production of prostacyclin (PGI2) by cultured human pulmonary artery smooth muscle cells (HPASMC). Incubation of these cells for up to 48 h with IL-6 led to a dose- and time-dependent decrease in the concentration of PGI2 in the culture medium. The incubation of HPASMC with 10 micrograms/ml of lipopolysaccharide (LPS), 200 U/ml of IL-1 beta, or 500 U/ml of TNF alpha for 24 hr significantly increased the concentration of PGI2 in the medium. However, the addition of IL-6 to a medium containing LPS, IL-1 beta, or TNF alpha significantly inhibited the stimulatory effect of those substances on PGI2 production. Such inhibition was closely related to the concentration of IL-6. IL-6 may counteract the roles of LPS and of other cytokines on the regulation of pulmonary vascular tension in endotoxin- and cytokine-mediated disorders such as sepsis and the acute respiratory distress syndrome (ARDS).

Plasma tissue factor and tissue factor pathway inhibitor levels in patients with disseminated intravascular coagulation

We measured the plasma levels of tissue factor (TF) and tissue factor pathway inhibitor (TFPI) in patients with disseminated intravascular coagulation (DIC) to examine the relationship between TFPI and vascular endothelial cell injury. Plasma TF (273 +/- 90 pg/ml) and TFPI (252 +/- 125 ng/ml) levels were significantly increased in patients with DIC compared with non-DIC patients. Plasma TF antigen level was significantly increased in pre-DIC patients (285 +/- 85 pg/ml), while the plasma TFPI level (152 +/- 54 ng/ml) was not markedly increased in such a state. The plasma TF/TFPI ratio was high in the pre-DIC patients (2.10 +/- 0.90), and low in the DIC patients (1.40 +/- 0.87) and healthy volunteers (0.84 +/- 0.26). There was no significant difference between the DIC patients with a good outcome and those with a poor outcome in terms of plasma TF levels, although the plasma TFPI level in the DIC patients with a good outcome (289 +/- 133 ng/ml) was significantly higher than that in those with a poor outcome (187 +/- 75 ng/ml). During the clinical course of DIC, plasma TF antigen was increased first, and an increase of the plasma TFPI level followed the increase in plasma TF level. These findings suggest that plasma TFPI is released from vascular endothelial cells and it may reflect vascular endothelial cell injury. It is conceivable that TF and TFPI may play an important role in the onset of DIC.

Hemostatic abnormalities and increased vascular endothelial cell markers in patients with red cell fragmentation syndrome induced by mitomycin C

We examined red cell fragmentation syndrome (RCFS) induced by mitomycin C (MMC) (13 patients), by thrombotic thrombocytopenic purpura (TTP) (17 patients), and by disseminated intravascular coagulation (DIC) (15 patients). Plasma cytokine levels were increased in the TTP and DIC patients, but not in those whose RCFS was induced by MMC, suggesting that the activation of the immune system plays an important role in the pathogenesis of RCFS due to TTP and DIC but did not in RCFS due to MMC. Plasma thrombomodulin, tissue type plasminogen activator, and plasminogen activator inhibitor-I levels were increased in all RCFS patients, suggesting that RCFS, whether MMC induced, or due to TTP or DIC, might be associated with vascular endothelial cell injury. In TTP, von Willebrand factor (vWF) antigen and high molecular weight vWF multimer levels were reduced, possibly as a result of microthrombus consumption. The hemostatic data in this study showed that the TTP patients were in a hypercoagulable state without hyperfibrinolysis, and that DIC patients were in both a hypercoagulable and a hyperfibrinolytic state, whereas hemostatic abnormalities were slight in patients with MMC induced RCFS. These findings suggest that vascular endothelial cell injuries might be associated with RCFS, and that those injuries in MMC-induced RCFS might not be related to microthrombi or an activated immune system.

Protection against endotoxic shock by bactericidal/permeability-increasing protein in rats

Bactericidal/permeability-increasing protein (BPI) is a neutrophil primary granule protein that inhibits effects of LPS in vitro. The current study examined the effects of BPI on hemodynamics, mortality, and circulating endotoxin and cytokines in conscious rats with endotoxic shock. Catheters were implanted into the right femoral artery and vein. 1 d later, human recombinant BPI (10 mg/kg) or vehicle was intravenously injected immediately, 30 min, or 2 h after intravenous injection of LPS (7.5 mg/kg). Mean arterial pressure (MAP) and heart rate were monitored and blood was collected before and after injection. BPI given immediately or 30 min after LPS prevented the LPS-induced reduction in MAP at 4-8 h and markedly reduced mortality. BPI given 2 h after LPS injection had no protective effect. BPI treated immediately after LPS reduced the circulating levels of endotoxin and IL-6 but increased the circulating levels of TNF. We propose that BPI exerts its protective effect through a TNF-independent mechanism, by inhibiting endotoxin-stimulated production of IL-6.