Anticardiolipin Autoantibodies as Useful Biomarkers for the Prediction of Mortality in Septic Patients.

Background: The detection of antiphospholipid antibodies (aPL) is of interest because of their importance in the pathogenesis of arterial or venous thrombosis. They could be a "second hit" of an inflammatory event such as infection. The aim of our study was to assess the performance of antiphospholipid antibody biomarker to predict in-hospital mortality in intensive care unit (ICU) septic patients. Methods: We conducted a prospective single-center observational study including consecutive critically ill septic adults admitted to the intensive care unit. Clinical and laboratory data including enzyme-linked immunosorbent assay for antiphospholipid antibodies (anticardiolipin (aCL), antiphosphatidylserine (aPS)) were obtained. Blood samples were collected on days 1, 3, 5, 8, and 10 of hospitalization. The primary study endpoint was ICU mortality defined as death before ICU discharge. Secondary end points included correlation between SOFA score and biological parameters. Results: A total of 53 patients were enrolled. 18.8% of patients were aPL positive. In-hospital mortality rate was 60%. Multivariate analysis showed that age and aCL at days 3 and 5 along with SOFA at day 3 were independent outcome predictors. A significant positive correlation existed between SOFA at days 3, 5, and 8 and antiphospholipid antibody concentrations. Conclusions: Our data showed that antiphospholipid was useful biomarkers for the prediction of mortality in critically ill septic patients. We found a positive correlation between SOFA score and antiphospholipid antibodies.

HLA DRB1/DQB1 alleles and DRB1-DQB1 haplotypes and the risk of rheumatoid arthritis in Tunisians: a population-based case-control study.

Rheumatoid arthritis (RA) is an inflammatory disease, which affects synovial joints, and is influenced by environmental and genetic factors, in particular the human leucocyte antigen (HLA) system. In our study, we investigated the association of HLA class II DRB1 and DQB1 alleles and DRB1-DQB1 haplotypes with RA susceptibility in Tunisian subjects. Therefore, HLA class II low-resolution genotyping was done in 110 RA patients and 116 controls, with a HLA-DRB1*04 high-resolution typing. Our results showed a strong association between HLA-DRB1*04/DRB1*04:05 alleles and RA presence, which persisted after correcting for multiple comparisons (Pc < 10-3, Pc = 0.020, respectively), in contrast to the protective effect of HLA-DRB1*04:03 allele (Pc = 15.2 × 10-4). However, increased frequency of DQB1*05 (Pc = 0.020) and decreased frequency of DRB1*04:03 subtype (Pc = 0.032) were seen in RF+ patients than controls. Moreover, when RA patients were compared to controls, DRB1*04-DQB1*03 haplotype was associated with RA susceptibility in Tunisians (Pc = 16.8 × 10-5), independently of RF status. Conversely, DRB1*01 allele and DRB1*01-DQB1*05 haplotype was highly present in RF+ vs RF- groups (Pc < 10-3, Pc = 5.6 × 10-3, respectively) and seems to be linked to seropositivity. Investigation of HLA class II alleles and haplotypes association with RA susceptibility with secondary Sjögren's syndrome (sSS) showed a predisposing effect of DRB1*04 (Pc < 10-3) and DRB1*04-DQB1*03 haplotype when RA with sSS/without sSS groups were compared to healthy controls. Our results confirms the association of HLA-DRB1*04, specifically HLA-DRB1*04:05 subtype, and DRB1*04-DQB1*03 haplotype with RA susceptibility in Tunisians, independently of seropositivity or the sSS presence.

Pro- and anti-inflammatory cytokines in post-infarction left ventricular remodeling.

OBJECTIVES: Acute myocardial infarction (MI) leads to molecular, structural, geometric and functional changes in the heart during a process known as ventricular remodeling. Myocardial infarction is followed by an inflammatory response in which pro- and anti-inflammatory cytokines play a crucial role, particularly in left ventricular remodeling. This study aimed at evaluating serum concentrations of interleukin-8 (IL8), tumor-necrosis-factor-alpha (TNFα) and interleukin-10 (IL10), pro- and anti-inflammatory cytokines, and at correlating them with left ventricular remodeling as assessed by echocardiographic parameters. METHODS: In a case-control study 30 MI patients were compared with 30 healthy controls. Serum concentrations of IL8, TNFα and IL10 were measured on day 2 and day 30 post-MI by chemiluminescence immunoassay and correlated with echocardiographic parameters. RESULTS: There was an increase of IL8, and TNFα together with a decrease of IL10 at both time points. IL8 was negatively correlated with the left ventricular end-diastolic diameter (LVEDD) and positively with left ventricular systolic volume. IL10 was negatively correlated with LVEDD and left atrial volume 30days post-MI. CONCLUSION: The increase of pro-inflammatory cytokines TNFα and IL8 was accompanied by decreased anti-inflammatory IL10. This imbalance between pro- and anti-inflammatory cytokines might contribute to the progression of left ventricular remodeling and may lead to heart failure.

HLA class II polymorphisms in Tunisian patients with dilated cardiomyopathy.

Cardiomyopathies (CMs) are primary disorders of cardiac muscle. They are a major cause of morbidity and mortality for all ages and, like acquired forms of cardiovascular disease, often result in heart failure. Molecular genetic studies have made remarkable progress in defining the pathogenesis of CM. The present study was the first report to evaluate the relationship between class II major histocompatibility complex (MHC) genes (HLA-DRB1 and HLA-DQB1) and the genetic susceptibility to primary dilated cardiomyopathy (DCM) in Tunisian patients. The human leukocyte antigen (HLA)-DRB1 and -DQB1 alleles were analyzed in 76 patients with primary DCM and 111 ethnically matched healthy controls using polymerase chain reaction-sequence specific primers technique. An increased frequencies of HLA-DRB1*0401 (OR = 2.67, P < 0.001), HLA-DQB1*0302 (OR = 3.28, P = 0.001) and HLA-DQB1*0401 (OR = 6.26, P = 0.005) alleles were found in the patients with primary DCM compared with healthy controls. Individuals with HLA-DRB1*1301 (OR = 0.24, P < 0.001) and HLA-DQB1*0201 (OR = 0.49, P = 0.002) alleles have a protective effect against primary DCM. Two haplotypes were associated with increased risk of primary DCM: DRB1*0401/DQB1*0302 (OR = 4.53, P = 0.002) and DRB1*0401/DQB1*0401 (OR = 9.42, P = 0.004). In conclusion, our data suggest that the variation in class II HLA alleles could be a genetic factor involved in the susceptibility to primary DCM in the Tunisian population.

[The ABO system polymorphism in Tunisian blood donors]. / Polymorphisme ABO dans une population de donneurs de sang tunisiens.

The present survey was carried out in the Military Center of Blood Transfusion from January 1998 to December 2001. 63,375 blood donors were concerned coming from different regions of Tunisia. Gene frequencies were found as follows: O = 0.686, A = 0.196 and B = 0.120. Important variations are observed between different regions of the country. The comparison with other countries' results traces the history of the Tunisian population, Tunisia being a strategic point in the Mediterranean region.

Validation of a flow cytometric assay detecting in vitro basophil activation for the diagnosis of muscle relaxant allergy.

BACKGROUND: Anaphylactic reactions during anesthesia are mainly the result of muscle-relaxant (MR) drugs. Skin tests, serologic detection of specific IgE, and in vitro leukocyte histamine release are used to investigate MR allergy. OBJECTIVE: We describe a new assay that is based on the detection by flow cytometry of the altered expression of plasma membrane molecules of MR-activated basophils. METHODS: For this assay, which we have named the BASIC assay, basophils are incubated in vitro with MR, after which they are fixed and then triple labeled with fluorescein-conjugated anti-CD63, tandem dye R-phycoerythrin-cyanin 5.1 conjugated anti-CD45, and R-phycoerythrin conjugated anti-IgE. The resulting B asophils' A ltered S urface I mmunofluorescence is detected by flow C ytometry (BASIC). RESULTS: Forty-one patients who had an allergic reaction during general anesthesia and 23 control subjects without such a history were studied. All included subjects' basophils were tested in the BASIC assay with at least 4 MR: suxamethonium, gallamine, vecuronium, and pancuronium. After reaction of the basophils of the MR-allergic patients with MRs, increased surface expression of CD63 and CD45 and decreased expression of IgE were detected. Increased expression of CD63 was observed most frequently and it was stronger than the alteration of the 2 other markers. Cross-reactivity between MRs commonly occurred. MRs diluted 10(-1) activate the basophils of the control subjects, suggesting that at relatively high concentrations MRs are also nonspecific basophil activators. CONCLUSION: In the diagnosis of MR allergy, the BASIC assay has a good specificity but a low sensitivity, and it correlates strongly with skin test results. It is currently appraised for the diagnosis of anaphylactic reaction induced by other classes of drugs.

Anticoagulant profile of iopamidol and meglumine amidotrizoate and their lack of thrombin generation: an in vitro study.

The aim of this in vitro study was to sketch the subtle anticoagulant profile of iopamidol 300 mg l/ml (low osmolality non ionic contrast medium) and meglumine amidotrizoate 370 mg l/ml (high osmolality ionic contrast medium) in situations where variable amounts of clotting factors are observed and to check whether thrombin-generation significantly occurred in non anticoagulated blood-contrast materials mixtures. In the first experiment, mixtures of deficient plasmas with a routine plasma pool provided different ranges with variable amounts of clotting factors II, V, VIII, X, XI and XII. For each clotting factor level studied within these ranges, an activated partial thromboplastin time was determined with either contrast material loaded thromboplastin (5% v/v) or glucose loaded thromboplastin (5% v/v) used as a control. In the second experiment fibrino-peptide A (FpA) or modified antithrombin III (ATM) assays were performed in either (9:1) non anti-coagulated blood contrast materials mixtures or blood-glucose mixtures (control). Differing aPTT prolongation profiles were observed when clotting factors V, VIII, XI and XII were lowered in the plasma. However, neither iopamidol nor amidotrizoate induced an aPTT prolongation with decreasing clotting factor II. In the second experiment no significant thrombin generation was observed as both blood-contrast materials mixtures showed significantly lower FpA and ATM levels (p < 0.001) than glucose control after 5 minutes and 10 minutes incubation at room temperature. These findings provide evidence that the use of iopamidol in angiographic procedures does not increase risk of clotting or hemorrhage.

Antiphospholipid antibodies: lupus anticoagulants, anticardiolipin and antiphospholipid isotypes in patients with sickle cell disease.

Antiphospholipid antibodies were investigated in 37 individuals with sickle cell disease and compared to a control group of 30 healthy subjects. Sickle cell patients included 18 homozygous sickle cell patients, 8 S/beta thalassemic patients and 11 sickle cell trait subjects. In all individuals, antiphospholipid antibodies were explored by lupus anticoagulant (LA) detection and the quantification of IgG and IgM anticardiolipin (aCL) isotypes, total antiphospholipid antibodies (APA) and IgM, IgG and IgA antiphospholipid classes. In homozygous sickle cell patients, mean level of IgG aCL and total APA were significantly increased (17.02 +/- 8.88 GPL/ml, p < 0.05 and 10.64 +/- 10.58 UPL/ml, p < 0.05 respectively). The IgG aCL, total APA and LA frequencies were 22.2%, 44.4% and 62.2%, respectively. APA isotypes were mostly IgG or IgG and IgA. In S/beta thalassemic patients, mean levels of APA were significantly increased (10.81 +/- 7.82 UPL/ml, p< 0.05). Their frequency was 71.4% and they were mostly IgG or IgG and IgA. In patients with sickle cell trait, mean levels of APA were significantly increased (10.84 +/- 5.84 UPL/ml, p < 0.01). Their frequency was 72.7% and mostly of IgG isotype. Our study showed a close association between high APA levels and sickle cell syndrome, however there was no relationship between high levels of antiphospholipid antibodies and the major complications of sickle cell disease.

Fibrinolytic response to venous occlusion in patients with homozygous sickle cell disease.

The fibrinolytic potential was evaluated in 37 patients with homozygous sickle cell disease and compared to a control group of 30 age- and sex-matched healthy volunteers. In all individuals, the euglobulin clot lysis time and plasma antigen levels of t-Pa and PAI-1 were measured before and after venous occlusion (v.o) for 10 min. The global fibrinolytic activity was normal in 4 patients (good responders to v.o), while it was decreased in 33 patients (poor responders to v.o). Among the latter, 22 patients had significantly increased baseline levels of PAI-1 Ag (82.6 +/- 27.5 ng/ml, p < 0.001) and a normal release of t-Pa Ag after v.o. In contrast, 11 patients had basal values of PAI-1 Ag comparable to those in controls with a defective release of t-Pa Ag after v.o (11.4 +/- 5.2 ng/ml, p < 0.01). These data provide evidence for reduced fibrinolytic capacity resulting from either increased basal levels of PAI-1 or defective release of t-PA.