Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A plasma free protein S deficiency was detected in 41 of 63 patients infected with the human immunodeficiency virus type I (HIV-1). This study consisted in a prospective analysis of blood samples from 26 patients with confirmed diagnosis of AIDS, two with AIDS-related complex, 10 with polyadenopathy, and 25 who were asymptomatic. Protein S levels were compared to a matched control group of 24 healthy subjects. A deep venous thrombosis occurred in three AIDS patients with free protein S deficiency. A significant decrease in plasma free protein S levels was observed in HIV-1-seropositive patients (mean +/- SD, 56.5 +/- 23.3%) as compared with control subjects (105.3 +/- 18%, p = 0.0001). Free protein S levels were significantly lower in patients with full-blown AIDS (37.6 +/- 12.3%) than in patients without AIDS (69.8 +/- 19.9%, p = 0.0001). Low plasma free protein S levels correlated with high beta 2-microglobulin values (p = 0.0001), low CD4+ T-cell counts (p = 0.0002) and elevated urinary neopterin concentrations (p = 0.005). According to a multiple regression analysis, the progression to stages IVB, IVC1 or IVD of the Centers for Disease Control (CDC) appeared to be the main explanatory variable in free protein S-deficient patients. Such results suggest that free protein S deficiency may coincide with the development of AIDS. This could contribute to hypercoagulability and, in some instances, thromboembolic complications in AIDS patients.
 ...
PMID:Acquired protein S deficiency: correlation with advanced disease in HIV-1-infected patients. 841 70

Previous publications have described thrombotic events with unclear causes in individuals infected with the human immunodeficiency virus (HIV). We stratified the cases of 52 individuals infected with HIV by degree of immunosuppression and the presence of complicating illnesses. Plasma from these individuals was screened for abnormalities that might predispose to thromboses. We found statistically significant differences between patients with CD4 counts < 200/mm3 and those whose CD4 counts were > 400/mm3 in the following: d-dimers, functional protein C, antigenic protein C, total protein S antigen, free protein S antigen, C4b-binding protein (C4b-BP), and von Willebrand antigen (vWD). Free protein S correlated inversely with C4b-BP; vWD directly with total protein S; and protein C inversely with d-dimers. D-dimers were significantly elevated only in immunosuppressed patients with complicating neoplastic/inflammatory disease. We propose that low-grade disseminated intravascular coagulopathy in severely immunosuppressed individuals with HIV and infectious, inflammatory, or neoplastic complications is responsible for depressed protein C, which, together with elevations in total protein S and vWD (markers of endothelial injury), indicates a thrombotic predisposition.
 ...
PMID:Thrombotic tendencies and correlation with clinical status in patients infected with HIV. 748 83

Protein S deficiency, which is associated with thrombosis, can either be inherited or acquired. Recently, we reported that a decrease in free protein S was observed in 19 of 25 persons with HIV/AIDS. The proinflammatory cytokine, tumor necrosis factor-alpha (TNF-alpha), has been reported to be elevated in human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) patients and has been shown to induce a procoagulant state on the surface of endothelial cells. We report here that recombinant TNF-alpha (rTNF-alpha) downregulated protein S synthesis in the SV-40T transfected human microvascular endothelial cell line (HMEC-1) model system by approximately 70% and in primary human umbilical vein and dermal microvascular endothelial cell cultures by approximately 50%. Using the HMEC-1 model, Northern blot analysis showed a decrease in protein S RNA at 24 hours that was corroborated by Western blot analysis and enzyme-linked immunosorbent assay (ELISA) quantification. Evidence supporting the specificity of the TNF-alpha effect included the following: (1) TNF-alpha down-regulation of protein S was completely blocked by TNF neutralizing antibody; (2) the effect was transient, and protein S was restored to near normal levels after TNF was removed from cell cultures; (3) an antibody directed to the TNF RI (55-kD receptor) was shown to mimic the action of TNF-alpha on HMEC-1 cells; and (4) other proinflammatory cytokines, interleukin (IL)-1, IL-6, and TGF-beta, had no effect on protein S secretion. However, TNF-alpha showed no regulatory control over protein S synthesis in the human hepatocellular carcinoma cell line HepG-2. We suggest that TNF-alpha downregulation of protein S may be a mechanism for localized procoagulant activity and thrombosis recently reported in some AIDS patients with associated protein S deficiency.
 ...
PMID:Tumor necrosis factor-alpha downregulates protein S secretion in human microvascular and umbilical vein endothelial cells but not in the HepG-2 hepatoma cell line. 802 76

In human plasma, heparin cofactor II (HCII) is a thrombin inhibitor, whose deficiency has been reported to be associated with recurrent thrombosis. The finding of two cases of low plasma HCII activity in two patients infected with the human immunodeficiency virus (HIV) led us to investigate this coagulation inhibitor in the plasma of a larger population of HIV-infected patients. The mean plasma HCII activity was significantly lower in 96 HIV-infected patients than in 96 age- and sex-matched healthy individuals (0.75 +/- 0.24 vs 0.99 +/- 0.17 U/ml, p < 0.0001). HCII antigen concentration was decreased to the same extent as the activity. The proportion of subjects with HCII deficiency was significantly higher in the HIV-infected group than in healthy individuals (38.5% vs 2.1%). In addition, HCII was significantly lower in AIDS patients than in other HIV-infected patients, classified according to the Centers for Disease Control (CDC) on the basis of an absolute number of circulating CD4+ lymphocytes below 200 x 10(6)/l. The link between HCII and immunodeficiency is further suggested by significant correlations between HCII activity and both the absolute number of CD4+ lymphocytes and the CD4+ to CD8+ lymphocyte ratio. Nevertheless, the mean HCII level was not different in the various groups of patients classified according to clinical criteria, except in CDC IVD patients in whom HCII levels were significantly lower. In addition, no correlation could be demonstrated between HCII and protein S activities, another coagulation inhibitor whose plasma level was also found to be decreased in HIV-infected patients.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Heparin cofactor II deficiency in patients infected with the human immunodeficiency virus. 812 26

Over a 2-year period, 3 patients with deep venous thrombosis associated to advanced pulmonary tuberculosis have been observed. One of them died suddenly, probably due to thromboembolic complications. In the other two cases, a triggering factor of venous thrombosis, probably related to tuberculosis, was detected and their evolution was satisfactory. The high frequency of antiphospholipid antibodies detected in the tuberculosis and the potential relationship between these and deficit of protein S is mentioned. Advanced pulmonary tuberculosis is described as a risk factor for the development of venous thrombosis in patients with negative serology for human immunodeficiency virus type 1 and 2. We recommend not to use deep venous catheters and we stress the potential value of heparin prophylactic therapy in order to prevent venous thrombosis and its complications.
 ...
PMID:[Tuberculosis as risk factor for venous thrombosis]. 821 87

Decreases in protein S levels have recently been reported in some human immunodeficiency virus (HIV)-infected patients. To examine predisposing factors, 25 men randomly selected from a long-term study of HIV-infected patients were studied. The minimum mean duration of HIV seropositivity in this group was 106.6 months (range 15 to 143 months). No patients were anticoagulated at the time of the study. Three of the 25 randomly selected patients gave a history of thrombosis, in each instance occurring after the onset of HIV positivity. Two of the 3 patients with thrombosis had more than one episode. Coagulation studies showed that 3 of 3 (100%) of the patients with thrombosis and 16 of 22 (72.7%) of those without previous thrombosis had decreased free protein S. Mean-free and total protein S levels were statistically lower for HIV-infected patients with and without previous thrombosis compared with healthy male controls. C4b-binding protein was not increased in study patients with decreased protein S levels. Decreases in protein S levels did not correlate with CD4+ cell levels, CDC class, p24 antigen positivity, zidovudine (AZT) use, or Pneumocystis carinii prophylaxis. The duration of disease statistically correlated with decreases in protein S levels (r = .37, P < .05). A linear correlation existed between increasing IgG anticardiolipin antibody levels and decreasing free protein S antigen (r = .67, P < .005). This study shows that protein S deficiency is common in long-term HIV-infected patients and is caused by a decrease in the free protein, rather than by changes in the bound complex. The data suggest that protein S deficiency is not correlated with HIV disease severity but may predispose patients to thromboembolic complications.
 ...
PMID:Protein S deficiency in men with long-term human immunodeficiency virus infection. 821 43

The high prevalence of free protein S deficiency in human immunodeficiency virus (HIV)-infected patients is poorly understood. We studied 38 HIV seropositive patients. Free protein S antigen values assayed using the polyethylene-glycol precipitation technique (PEG-fS) were statistically lower in patients than in controls. These values using a specific monoclonal antibody-based ELISA (MoAb-fS) and the values of protein S activity (S-act) were not statistically different between patients and controls. C4b-binding protein values were not different from control values. In patients, PEG-fS values were lower than MoAb-fS values. Ten patients had a PEG-fS deficiency, 4 patients had a MoAb-fS deficiency and 8 had a S-act deficiency. Protein S activity and MoAb-fS were lower in clinical groups with poor prognosis and in patients with AIDS but PEG-fS was not. A trend for reduced S-act/MoAb-fS ratios was observed in patients. PEG-fS was negatively correlated with anticardiolipin antibody titers whereas MoAb-fS was not. The plasma of PEG-fS deficient HIV-patients contained high amounts of flow cytometry detectable microparticles which were depleted from plasma by PEG precipitation. The microparticles were partly CD42b and CD4 positive but CD8 negative. These micro-particles were labelled by an anti free protein S monoclonal antibody. The observed differences between MoAb-fS and PEG-fS values were correlated with the amount of detectable plasma microparticles, just like the differences between MoAb-fS and S-act. Plasma microparticles correlated with anticardiolipin antibody titers. In summary, free protein S antigen in HIV infected patients is underestimated when the PEG precipitation technique is used due to the presence of elevated levels of microparticles that bind protein S. The activity of free protein S is also impaired by high levels of microparticles. The prevalence of free protein S deficiency in HIV positive patients is lower than previously published (4/38, approximately 10%) and is correlated with poor prognosis. By implication, use of a PEG precipitation technique might give artefactually low free protein S antigen values in other patient groups if high numbers of microparticles are present. In HIV patients, high titers of anticardiolipin antibodies are associated with high concentrations of cell-derived plasma microparticles.
 ...
PMID:The relationship between plasma microparticles, protein S and anticardiolipin antibodies in patients with human immunodeficiency virus infection. 881 49

We reviewed the clinical records of 6 patients with osteonecrosis and human immunodeficiency virus (HIV) infection. We conducted a literature search for the putative mechanism by which this association may occur. None of these 6 patients had other known conditions associated with a predisposition to osteonecrosis. Avascular necrosis (AVN) frequently occurred in multiple sites and early in the course of HIV infection. We suggest that HIV infection is a systemic disorder that may predispose to osteonecrosis of bone. The most likely mechanism involves thrombosis, which may be mediated by anticardiolipin antibodies and/or acquired deficiency of protein S. In patients with idiopathic osteonecrosis that involves multiple sites we recommend careful evaluation for HIV risk factors.
 ...
PMID:Osteonecrosis and human immunodeficiency virus infection. 1009 Jan 98

Thrombosis of upper extremity arteries is most commonly due to atherosclerosis of the proximal subclavian artery, trauma, or catheter-related injury. In the absence of an identifiable cause, a search for a hypercoagulable state is indicated. Hematologic manifestations of human immunodeficiency virus (HIV) infection and AIDS are frequent occurrences (Coyle TE. Med Clin N Am 1997;81:449-476). The most important of these are cytopenias (anemia, neutropenia, and thrombocytopenia). The incidence and severity of cytopenia are generally correlated to the stage of the HIV infection. In addition, various coagulation abnormalities have been reported in HIV-infected patients. Apart from thrombocytopenia, these have included a prolonged APTT due to the presence of lupus anticoagulant, an increased prevalence of protein S and heparin cofactor II deficiency, and hypoalbuminemia-related fibrin polymerization defects (Toulon P. Ann Bio Clin (Paris) 1998;56:153-160). HIV infection has also been associated with endothelial dysfunction. Although for the most part asymptomatic, elevated D-dimer levels have been found in HIV-infected patients, suggesting the existence of a prethrombotic state. In fact, clinical thrombosis eventuates in 2% of these patients (Toulon, 1988). Documented thromboses have involved both veins and arteries. We hereby present a patient who developed an acute thrombosis of his brachial artery as the initial manifestation of HIV infection.
 ...
PMID:Acute brachial artery thrombosis as the initial manifestation of human immunodeficiency virus infection. 1081 96

The array of clinicopathologic factors associated with acquired immune deficiency syndrome (AIDS) patients continues to increase and surprise many physicians. The recent literature contains reports of thrombotic episodes occurring in patients with human immunodeficiency virus (HIV) infection. Various abnormalities predisposing to a hypercoagulable state have also been reported in AIDS patients including the presence of antiphospholipid antibodies and the lupus anticoagulant; deficiencies of protein C, protein S, heparin cofactor II, and antithrombin and increased levels of von Willebrand factor, and d-dimers. These abnormalities correlate with the severity of HIV-associated immunosuppression as measured by the CD4 cell counts and with the presence of concurrent infectious or neoplastic diseases. The authors reviewed the medical literature and describe various abnormalities predisposing to a hypercoagulable state in AIDS patients along with the management of such complications. This issue is important because deep venous thrombosis (DVT), pulmonary embolus (PE), or thrombosis at other sites can develop in patients with AIDS who are ambulatory and have no known risk factors for pathologic thrombus formation, providing another challenge in an already difficult clinical situation. This also provides a strong rationale for careful prospective studies focusing on the prevalence and risk factors involved in the development of thromboembolic complications in patients with AIDS.
 ...
PMID:HIV and thrombosis: a review. 1117 84


1 2 3 Next >>