Plasma and hepatic tissue levels of thrombomodulin, tissue factor, NFkappaB and nitric oxide in responders and nonresponders to IFNalpha therapy.

Hepatitis C virus (HCV) infects hepatocytes and utilizes the hepatocyte to replicate. In so doing, many hepatocyte activities are shifted from their native state to one reflecting liver cell stress. Thrombomodulin and tissue factor are endothelial cell proteins that are expressed as a result of tissue injury or stress. Urokinase is a serine protease, which has been implicated in a number of physiologic and pathologic processes related to cellular stress and or injury. Nitric oxide is produced by cells in response to injury and functions both as a vasodilator and as an activator of a large number of cytokine cascades. NFkappaB is a transcription factor that forms one of the first lines of cellular defense against infection and hepatocellular stress. The levels of these four factors in plasma, hepatocyte cytosol and hepatocyte nuclear extracts provide a precise panoramic measure of cellular stress. Plasma, hepatocyte cytosol and nuclear extracts of hepatocytes were assayed for these four factors in 17 patients treated with alphaIFN for chronic hepatitis C. Five of the 17 were responders while 12 were nonresponders. Ten normal controls and 1 normal control liver were assayed also for each parameter. Nonresponders had 2x the plasma urokinase levels of responders and normals. The cytosol prepared from hepatocytes of nonresponders had a urokinase level 15-fold that of the controls and responders to IFN therapy. Plasma thrombomodulin levels in nonresponders were sixfold greater than those of responders and controls. The levels of all of the other measures in plasma, cytosol and nuclear extracts of liver tissue varied minimally between responders and nonresponders and the normal controls. These data demonstrate that: (i) urokinase levels in plasma and more clearly in cytosol are greater in nonresponders than responders, and (ii) plasma thrombomodulin levels in nonresponders are sixfold greater than those of responders and controls. These data suggest that urokinase and thrombomodulin may be unique markers of cellular and endothelial stress present in individuals with chronic hepatitis C. These markers might be useful during the clinical course of chronic hepatitis C, as a means of gauging the tissue response to therapy.

Serial measurements of hematologic counts during the active phase of human granulocytic ehrlichiosis.

To describe the changes that occur in blood count parameters during the natural course of human granulocytic ehrlichiosis, we designed a retrospective cross-sectional case study of 144 patients with human granulocytic ehrlichiosis and matched controls who had a different acute febrile illness. Patients from New York State and the upper Midwest were evaluated from June 1990 through December 1998. Routine complete blood counts and manual differential leukocyte counts of peripheral blood were performed on blood samples that were collected during the active illness, and values were recorded until the day of treatment with an active antibiotic drug. Thrombocytopenia was observed more frequently than was leukopenia, and the risk of having ehrlichiosis varied inversely with the granulocyte count and the platelet count. Patients with ehrlichiosis displayed relative and absolute lymphopenia and had a significant increase in band neutrophil counts during the first week of illness. Knowledge of characteristic complete blood count patterns that occur during active ehrlichiosis may help clinicians to identify patients who should be evaluated specifically for ehrlichiosis and who should receive empiric antibiotic treatment with doxycycline.

Serology of culture-confirmed cases of human granulocytic ehrlichiosis.

We evaluated the antibody responses in the sera of 24 patients with culture-confirmed human granulocytic ehrlichiosis (HGE). Antibody titers were measured by an indirect immunofluorescent-antibody assay (IFA) by using a local human isolate as the source of antigen. All patients received appropriate antimicrobial treatment. One hundred five serum specimens collected at baseline and at periodic intervals for up to 14 months were included in the study. Seroconversion was observed in 21 of 23 patients (91.3%) from whom convalescent-phase sera were obtained. Antibodies were first detected at an average of 11.5 days after onset of symptoms. Peak titers (>/=2,560 for 71.4% of patients and >/=640 for 95.2% of patients) were obtained an average of 14.7 days after onset of symptoms. Eleven of 13 patients (84.6%) from whom sera were collected between 6 and 10 months after onset of symptoms were still seropositive, and sera from 5 of 10 (50%) patients tested positive between 11 and 14 months after onset of symptoms. For a subset of 71 serum specimens from 17 patients with culture-confirmed HGE also tested by IFA by using either a human isolate from Wisconsin or an Ehrlichia equi isolate from a horse, there was qualitative agreement for 62 serum specimens (87. 3%). Peak titers were higher, however, with the local human HGE isolate, but the difference was not statistically significant. In summary, most patients with culture-confirmed HGE develop antibodies within 2 weeks of onset of symptoms. Antibodies reach high titers during the first month and remain detectable in about one-half of patients at 1 year after onset of symptoms.