Control of Therapeutic Levels of Anticoagulation and Associated Factors: A Prospective Cohort Study.

Maintaining therapeutic levels of anticoagulation is essential to avoid health complications in people who take vitamin K antagonists. This study aimed to analyze the influence of people's characteristics and the presence of changes in their lives in the control of therapeutic levels of anticoagulation. A longitudinal multicenter study with a 1-year follow-up of a cohort of 199 people receiving anticoagulant therapy was performed. The effect of biological, clinical, social, lifestyle, and changes in life on the international normalized ratio (INR) was analyzed. During the follow-up, 46.7% of participants presented good INR control. At baseline, a diagnosis of atrial fibrillation (P = .00), the lack of comorbidities (P = .03), absence of depression (P = .04), and not following a pharmacological treatment with hypoglycemia drugs (P = .01) were associated with good INR control. During the follow-up, the variable of making changes to the usual diet was associated with poor INR control (P = .05). In the binary multiple regression model, factors associated with poor control were taking hypoglycemia drugs (P = .02) and the presence of depression (P = .04), and only the diagnosis of atrial fibrillation was associated with good control (P = .03). People with a diagnosis of atrial fibrillation had good INR control. Having comorbidities, suffering depression, taking hypoglycemia drugs, and making changes to the diet have a negative effect on INR control.

Management of recurrent vulvovaginal candidosis: Narrative review of the literature and European expert panel opinion.

Recurrent vulvovaginal candidosis (RVVC) is a chronic, difficult to treat vaginal infection, caused by Candida species, which affects women of all ages and ethnic and social background. A long-term prophylactic maintenance regimen with antifungals is often necessary. In most clinical practice guidelines, oral fluconazole is recommended as the first-line treatment. Although clinical resistance to antifungal agents remains rare, overexposure to azoles may increase the development of fluconazole-resistant C. albicans strains. In addition, non-albicans Candida species are frequently dose-dependent susceptible or resistant to fluconazole and other azoles, and their prevalence is rising. Available therapeutic options to treat such fluconazole-resistant C. albicans and low susceptibility non-albicans strains are limited. Ten experts from different European countries discussed problematic issues of current RVVC diagnosis and treatment in two audiotaped online sessions and two electronic follow-up rounds. A total of 340 statements were transcribed, summarized, and compared with published evidence. The profile of patients with RVVC, their care pathways, current therapeutic needs, and potential value of novel drugs were addressed. Correct diagnosis, right treatment choice, and patient education to obtain adherence to therapy regimens are crucial for successful RVVC treatment. As therapeutic options are limited, innovative strategies are required. Well- tolerated and effective new drugs with an optimized mechanism of action are desirable and are discussed. Research into the impact of RVVC and treatments on health-related quality of life and sex life is also needed.

Dequalinium chloride use in adult Spanish women with bacterial vaginosis: an observational study.

Bacterial vaginosis (BV) represents the most frequent vaginal infection in women of childbearing age. The aim of this study was to characterise episodes of BV among adult Spanish women and their management with dequalinium chloride (DQC). Data from 573 DQC-treated BV adult women was obtained on medical records and questionnaires. The study shows that 20.6% had presented vaginal infections previously. Comorbid candidosis was significantly associated to other symptoms, such as pruritus or leucorrhoea. Most patients (64.3%) indicated a moderate-strong impact of the BV episode on their sexual life. After treatment, 84.8% of patients reported no BV symptoms. Patients were given instructions to prevent relapses. Most patients (83.1%) rated DQC as 'satisfactory' or 'very/extremely satisfactory' regarding symptom relief, prevention or treatment of the episode of BV. In conclusion, this study provides a better understanding of BV episodes and the impact of the treatment with DQC in real clinical practice in Spanish patients.IMPACT STATEMENTWhat is already known on this subject? Bacterial vaginosis (BV) is the most commonly reported vaginal infection among women of childbearing age. Despite the availability of antibiotic medications for the treatment of BV, management of this condition remains challenging. In fact, recurrence of BV has been reported for up to 50% of cases. However, antiseptic agents are considered an effective option for BV treatment.What the results of this study add? The study provides a better understanding of the prevalent symptomatology and the impact on quality of life of women with BV. Moreover, it has been observed that antiseptic dequalinium chloride (DQC) efficiently reduces symptoms and improves quality of life of the patients during episodes of BV.What the implications are of these findings for clinical practice and/or further research? In the context of the World Health Organisation recommendations on the rational use of antibiotics, we believe that the use of DQC may be a good alternative to antibiotics as a therapy for BV.

Endoscopic Ultrasound (EUS)-Guided Drainage of a Postsleeve Gastrectomy Subphrenic Collection Using a Lumen Apposition Stent.

Sleeve gastrectomy is currently the most frequently performed bariatric surgery. Postoperative leaks represent the main cause of morbidity in up to 8% of patients with a mortality rate ranging between 0.1 and 5%. However, management of these leaks remains controversial. We report the case of a patient presenting with sepsis 2 weeks after surgery. A subphrenic collection and a leak were found on CT. Despite medical treatment, the patient did not show clinical improvement. Hence, we considered a transgastric endosonographic-guided drainage of the collection using an electrocautery-enhanced lumen-apposing metal stent (LAMS). The procedure underwent uneventfully, and the patient status improved rapidly. Two weeks later, the stent was withdrawn. A follow-up endoscopy 6 weeks later showed closure of the gastric wall defect.

Mannan-binding lectin pathway deficiencies and invasive fungal infections following allogeneic stem cell transplantation.

OBJECTIVE: The Mannan-binding lectin (MBL) pathway involves recognition of fungal surfaces by MBL and cleavage of C2 and C4 by MBL-associated serine protease (namely, MASP-2). Recent data show that MBL pathway deficiency might result not only from polymorphisms of the MBL2 gene but also of MASP2. The aim of the study was to assess whether polymorphisms of these genes are associated with invasive fungal infections (IFIs) following allogeneic stem cell transplantation (allo-SCT). METHODS: The promoter and the exon 1 of MBL2 and the exon 3 of MASP2 were sequenced in 106 donor-recipient pairs from HLA-identical sibling allo-SCTs performed in a single institution. RESULTS: Ten percent of the donors and 11% of the recipients carried the MBL-low (O/O, LXA/O) genotypes; 7% of the donors and 3% of the recipients were heterozygous for the MASP2 Asp105Gly variant. Factors associated with a higher probability of IFIs were donor's MBL-low genotype (38% vs 12%, p = 0.01), recipient's MASP2 variant (67% vs 14%, p = 0.01), and acute graft-versus-host disease (GVHD) grades II to IV (27% vs 11%, p = 0.04); in the multivariate analysis MBL-low genotype (relative risk [RR] 7.3, p = 0.003), MASP2 variant (RR 6.4, p = 0.002), and acute GVHD II to IV (RR 3.8, p = 0.02) retained independent prognostic value. CONCLUSION: These results show for the first time that polymorphisms responsible for not only MBL but also MASP-2 deficiency are independent predictive factors for IFI after allo-SCT.

Mitogen-activated protein kinase pathway activation by the CD6 lymphocyte surface receptor.

CD6 is a cell surface receptor primarily expressed on immature thymocytes and mature T and B1a lymphocytes. Through its binding to activated leukocyte cell adhesion molecule (ALCAM/CD166), CD6 is considered to play an important role in lymphocyte development and activation. Accordingly, CD6 associates with the TCR/CD3 complex and colocalizes with it at the center of the mature immunological synapse on T lymphocytes. Moreover, the CD6-ALCAM interaction has been shown to be critical for proper immunological synapse maturation and T cell proliferative responses. However, the precise biological effects of CD6 ligation and its signaling pathway are still not well understood. The present study shows that CD6 ligation with three different specific mAbs (161.8, SPV-L14.2, and MAE1-C10) induces time- and dose-dependent activation of ERK1/2 on normal and leukemic human T cells. This effect was also observed upon CD6 ligation with a chimerical ALCAM protein (ALCAM-Fc). The C-terminal cytoplasmic region of CD6, as well as Src tyrosine kinases, was critical for CD6-induced ERK1/2 activation. Synergistic effects were observed upon coligation of the TCR/CD3 complex with CD6. The ligation of CD6 induced the transcriptional activation of reporter genes under the control of the c-Fos serum responsive element and AP-1. Accordingly, CD6-mediated activation of p38 and JNK was also observed. These findings indicate that the CD6-ALCAM interaction results in activation of the three MAPK cascades, likely influencing the dynamic balance that determines whether resting or activated lymphocytes survive or undergo apoptosis.

Expression of interleukin-8 receptors (CXCR1 and CXCR2) in premenopausal women with recurrent urinary tract infections.

The migration of neutrophils through infected tissues is mediated by the CXC chemokines and its receptors (CXCR1 and CXCR2). It has been proposed that a CXCR1 deficiency could confer susceptibility to acute pyelonephritis in children. The objective of the study is to assess the surface expression of CXCR1 and CXCR2 and the existence of polymorphisms in the CXCR1 gene in premenopausal women with recurrent urinary tract infections. The study included 20 premenopausal women with recurrent urinary infections, with normal urinary tracts, and without diseases potentially associated with relapsing urinary infections and 30 controls without previous urinary infections. The levels of CXCR1 and CXCR2 expression on neutrophils were measured and analyzed by flow cytometry by measuring the mean fluorescence intensity (MFI) channel. The promoter and coding regions of the CXCR1 gene were analyzed for the presence of polymorphisms by a sequence-based typing method. Patients with recurrent urinary tract infections exhibited median levels of CXCR1 expression, determined from MFI values, similar to those of the controls. The analysis of CXCR2 showed that patients with recurrent urinary infections had lower median levels of expression, determined from the MFI values, than the controls (P = 0.002, Mann-Whitney U test). No polymorphisms were detected at the promoter or at the exon 1 region of the CXCR1 gene either in the patients or in the controls. Polymorphisms were detected at the exon 2 of CXCR1, but their frequencies did not differ between patients and controls. We have found a low level of CXCR2 expression in patients with recurrent urinary tract infections. These results suggest that a low level of CXCR2 expression may increase the susceptibilities of premenopausal women to urinary tract infections.

Polymorphisms in the interleukin-4 receptor alpha chain gene influence susceptibility to HIV-1 infection and its progression to AIDS.

Interleukin (IL) 4 is a key T helper-2 cytokine that downregulates and upregulates CCR5 and CXCR4, respectively, the main coreceptors for HIV. Our objective is to investigate whether single-nucleotide polymorphisms (SNPs) in the IL-4 receptor alpha chain gene (IL4RA) affect HIV infection and its progression to AIDS. The I50V SNP in exon 5 and the haplotypes of six SNPs in exon 12 (E375A, C406R, S411L, S478P, Q551R, and V554I) were studied by polymerase chain reaction and sequencing in 30 HIV+ long-term nonprogressors (LTNP), 36 HIV+ typical progressors (TP), 55 highly exposed but uninfected individuals (EU), 25 EU-sexuals (EU-Sex; mostly women) and 30 EU-hemophiliacs (EU-Hem; hepatitis C virus+), and 97 healthy controls (HC), all Caucasians and lacking CCR5Delta32 homozygosity. V50 homozygosity was increased in LTNP (44%) compared with the other groups [p = 0.005; relative risk ratio = 3.4, 95% confidence interval (CI) = 1.12-10.6, p = 0.03]. The most common (C) exon 12 haplotype, ECSSQV, predominated in all groups, but uncommon (U) haplotypes were increased in HIV+ individuals (n = 64), especially in those (51 of 64) infected via parenteral exposure (35.3%) compared with HC (20.4%) and EU-Hem (18.4%) [p = 0.01; odds ratio (OR) = 2.14, 95% CI = 1.25-3.67, p = 0.01]. EU-Sex also had an increased frequency of U-haplotypes (34.8%) (OR = 2.10, 95% CI = 1.03-4.21, p = 0.01) as well as an increased frequency of CU + UU genotypes (60.9%) compared with HC (38.2%) and EU-Hem (26.6%) (p = 0.043). Distributions of genotypes fitted Hardy-Weinberg equilibrium. Data suggest that V50 homozygosity associates with slow progression and that exon 12 U-haplotypes might be associated with both susceptibility to infection via parenteral route and resistance to infection via sexual exposure. Further studies are required to confirm these findings.

A role for human Sp alpha as a pattern recognition receptor.

Human Sp alpha is a soluble protein belonging to group B of the scavenger receptor cysteine-rich (SRCR) superfamily for which little functional information is available. It is expressed by macrophages present in lymphoid tissues (spleen, lymph node, thymus, and bone marrow), and it binds to myelomonocytic and lymphoid cells, which suggests that it may play an important role in the regulation of the innate and adaptive immune systems. In the present study we show that recombinant human Sp alpha (rSp alpha) binds to the surface of several gram-positive and gram-negative bacterial strains. Competition studies indicated that such binding is mediated by the recognition of lipoteichoic acid (LTA) and lipopolysaccharide (LPS), respectively, through nonoverlapping sites on the Sp alpha molecule. The most conserved part of LPS (2-keto-3-deoxyoctulosonic acid and lipid A) was shown to be involved in the recognition by Sp alpha. Bacterial binding studies using the SRCR domain 1 of Sp alpha showed that this domain retains both the LPS and LTA binding activities, indicating that both bacterial interacting sites are retained in a single SRCR domain. Furthermore, rSp alpha induced aggregation of gram-positive and gram-negative bacteria strains. On the other hand, rSp alpha inhibited tumor necrosis factor-alpha secretion by human monocytes stimulated with LPS or LTA. Binding of Sp alpha to conserved components of bacterial surfaces and modulation of the monocyte response indicate that this molecule is an active constituent of the innate immune response of the host.

The lymphocyte receptor CD6 interacts with syntenin-1, a scaffolding protein containing PDZ domains.

CD6 is a type I membrane glycoprotein expressed on thymocytes, mature T and B1a lymphocytes, and CNS cells. CD6 binds to activated leukocyte cell adhesion molecule (CD166), and is considered as a costimulatory molecule involved in lymphocyte activation and thymocyte development. Accordingly, CD6 partially associates with the TCR/CD3 complex and colocalizes with it at the center of the mature immunological synapse (IS) on T lymphocytes. However, the signaling pathway used by CD6 is still mostly unknown. The yeast two-hybrid system has allowed us the identification of syntenin-1 as an interacting protein with the cytoplasmic tail of CD6. Syntenin-1 is a PDZ (postsynaptic density protein-95, postsynaptic discs large, and zona occludens-1) domain-containing protein, which functions as an adaptor protein able to bind cytoskeletal proteins and signal transduction effectors. Mutational analyses showed that certain amino acids of the most C-terminal sequence of CD6 (-YDDISAA) and the two postsynaptic density protein-95, postsynaptic discs large, and zona occludens-1 domains of syntenin-1 are relevant to the interaction. Further confirmation of the CD6-syntenin-1 interaction was obtained from pull-down and co-immunoprecipitation assays in mammalian cells. Image analyses also showed that syntenin-1 accumulates at CD6 caps and at the IS. Therefore, we propose that syntenin-1 may function as a scaffolding protein coupling CD6 and most likely other lymphocyte receptors to cytoskeleton and/or signaling effectors during IS maturation.

Etanercept plus colchicine treatment in a child with tumour necrosis factor receptor-associated periodic syndrome abolishes auto-inflammatory episodes without normalising the subclinical acute phase response.

UNLABELLED: We investigated the cause of hereditary periodic fever syndrome in a Spanish child with recurrent long episodes of fever, migratory skin rash, myalgia, arthralgia, conjunctivitis and abdominal pain. Infectious and autoimmune causes were ruled out. No familial history was reported. Analysis of the tumour necrosis factor receptor superfamily 1A (TNFRSF1A) gene identified a missense mutation (G36E) on exon 3. The absence of this variant in the patient's parents and in controls identified it as a de novo disease-associated mutation. Clinical symptoms disappeared with administration of etanercept; however, levels of acute-phase reactants remained increased and could not be stabilised by the addition of colchicine. We believe that this patient gained some symptomatic relief with etanercept therapy, although not enough to completely avoid the risk of amyloidosis. Thus it is debatable whether etanercept alone or combined with other drugs, is the treatment of choice for patients with tumour necrosis factor receptor-associated periodic syndrome. CONCLUSION: Since there is variability in treatment responses among different patients with tumour necrosis factor receptor-associated periodic syndrome, we suggest that a systematic evaluation of acute-phase reactants, especially SAA-1, could be useful in maintaining or modifying a given therapeutic approach in these patients.

Clinical and genetic heterogeneity among Spanish patients with recurrent autoinflammatory syndromes associated with the CIAS1/PYPAF1/NALP3 gene.

OBJECTIVE: To investigate the involvement of the CIAS1/PYPAF1/NALP3 gene in 7 unrelated Spanish families with recurrent autoinflammatory diseases characterized by early onset, recurrent fever, and a chronic urticarial rash, in whom a clinical diagnosis of cryopyrin-associated periodic syndromes (CAPS) is suspected. METHODS: Clinical symptoms, results of laboratory analyses, and data on previous treatments in members of the 7 families were recorded on a questionnaire specific for hereditary autoinflammatory diseases. All coding regions and intronic flanking boundaries of the CIAS1/PYPAF1/NALP3 gene were amplified by polymerase chain reaction and sequenced. RESULTS: Five different missense mutations, including 2 de novo and 1 previously unreported mutation (R488K), were identified in exon 3 of the CIAS1/PYPAF1/NALP3 gene in 5 of the 7 affected families. Expanded genetic analysis among the healthy individuals identified incomplete penetrance in 2 families. No mutations were found in 2 of the 3 patients with chronic infantile neurologic, cutaneous, articular (CINCA) syndrome/neonatal-onset multisystem inflammatory disease (NOMID). CONCLUSION: The clinical data suggested a diagnosis of familial cold-induced autoinflammatory syndrome in 3 families, CINCA/NOMID syndrome in 3 others, and a possible Muckle-Wells syndrome, whereas mutational analysis showed different CIAS1/PYPAF1/NALP3 missense mutations in 5 families. These data are consistent with a common molecular basis of these diseases and highlights the phenotypic heterogeneity among CIAS1/PYPAF1/NALP3 gene-associated syndromes. The previously unreported mutation and the incomplete penetrance found in 2 families expand the genetic basis underlying these autoinflammatory syndromes. These findings should alert clinicians to the possible genetic basis of these conditions, even in the absence of a family history, in their attempts to establish an accurate diagnosis and the optimal therapeutic approach.

Relevance of CD6-mediated interactions in T cell activation and proliferation.

CD6 is a cell surface receptor expressed on immature thymocytes and mature T and B1a lymphocytes. The ultimate function of CD6 has not been deciphered yet, but much evidence supports a role for CD6 in T cell activation and differentiation. In this study, we show that a fraction of CD6 molecules physically associates with the TCR/CD3 complex by coimmunoprecipitation, cocapping, and fluorescence resonance energy transfer experiments. Image analysis of Ag-specific T-APC conjugates demonstrated that CD6 and its ligand, activated leukocyte cell adhesion molecule (CD166), colocalize with TCR/CD3 at the center of the immunological synapse, the so-called central supramolecular activation cluster. The addition of a soluble rCD6 form significantly reduced the number of mature Ag-specific T-APC conjugates, indicating that CD6 mediates early cell-cell interactions needed for immunological synapse maturation to proceed. This was in agreement with the dose-dependent inhibition of CD3-mediated T cell proliferation induced by soluble rCD6. Taken together, our data illustrate the important role played by the intra- and intercellular molecular interactions mediated by CD6 during T cell activation and proliferation processes.

Transcriptional regulation of human CD5: important role of Ets transcription factors in CD5 expression in T cells.

CD5 is a surface receptor constitutively expressed on thymocytes and mature T and B-1a cells. CD5 expression is tightly regulated during T and B cell development and activation processes. In this study we shown that the constitutive expression of CD5 on human T cells correlates with the presence of a DNase I-hypersensitive (DH) site at the 5'-flanking region of CD5. Human CD5 is a TATA-less gene for which 5'-RACE analysis shows multiple transcriptional start sites, the most frequent of which locates within an initiator sequence. Luciferase reporter assays indicate that a 282-bp region upstream of the initiation ATG displays full promoter activity in human T cells. Two conserved Ets-binding sites (at positions -239 and -185) were identified as functionally relevant to CD5 expression by site-directed mutagenesis, EMSAs, and cotransfection experiments. A possible contribution of Sp1 (-115 and -95), c-Myb (-177), and AP-1-like (-151) motifs was also detected. Further DH site analyses revealed an inducible DH site 10 kb upstream of the human CD5 gene in both T and B CD5(+) cells. Interestingly, a 140-bp sequence showing high homology with a murine inducible enhancer is found within that site. The data presented indicate that the 5'-flanking region of human CD5 is transcriptionally active in T cells, and that Ets transcription factors in conjunction with other regulatory elements are responsible for constitutive and tissue-specific CD5 expression.

The west side story: MEFV haplotype in Spanish FMF patients and controls, and evidence of high LD and a recombination "hot-spot" at the MEFV locus.

Mutations at the MEFV gene cause, with various degrees of penetrance, familial Mediterranean fever (FMF). This disease is more prevalent in the Middle East than elsewhere, and most studies have focused on those populations. However, FMF occurs also in the Western Mediterranean and these populations should be taken into account for a complete view of FMF. We have analyzed intragenic MEFV SNPs in Spanish and Chueta (descendants of converted Jews) FMF patients and controls, and this constitutes the first systematic survey of normal MEFV SNP haplotype structure and variability. Our findings have allowed us to systematize the nomenclature of MEFV haplotypes and show that there is strong linkage disequilibrium (LD) at the MEFV locus and an intragenic recombination hot spot. The high local LD, regardless the recombination hot spot, is responsible for the limited diversity of the MEFV control haplotypes found in the Spanish population and it suggests that it may be a common feature to all Mediterranean populations. The MEFV mutation spectrum in Spain is quite diverse, and similar to those of France and Italy. On the contrary, the Chueta spectrum was poorer and closer to that of North African Jews, suggesting a direct connection with the Jewish diaspora.

A severe autosomal-dominant periodic inflammatory disorder with renal AA amyloidosis and colchicine resistance associated to the MEFV H478Y variant in a Spanish kindred: an unusual familial Mediterranean fever phenotype or another MEFV-associated periodic inflammatory disorder?

Familial Mediterranean fever (FMF) is an autosomal recessive disease characterized by recurring short attacks of fever and serositis. Secondary AA amyloidosis is the worst complication of the disease and often determines the prognosis. The MEFV gene, on chromosome 16p13.3, is responsible for the disease and around 30 mutations have been reported to date. Colchicine is the standard FMF treatment today, and prevents both attacks and amyloid deposition in 95% of patients. Here we describe a three-generation Spanish kindred with five family members affected by a severe periodic inflammatory disorder associated with renal AA amyloidosis and colchicine unresponsiveness. Clinical diagnosis of definite FMF disease was made based on the Tel-Hashomer criteria set. Genetic analyses revealed that all subjects were heterozygous for the new H478Y MEFV variant, segregating with the disease. In addition, mutations in the TNFRSF1A and CIAS1/PYPAF1/NALP3 genes, related to the dominantly inherited autoinflammatory periodic syndromes, were ruled out. However, the dominant inheritance of the disease, the long fever episodes with a predominant joint involvement, and the resistance to colchicine in these patients raise the question of whether the periodic syndrome seen in this kindred is a true FMF disease with unusual manifestations or rather another MEFV-associated periodic syndrome. We conclude that the new H478Y MEFV mutation is the dominant pathological variant causing the inflammatory periodic syndrome in this kindred and that full-length analyses of the MEFV gene are needed to obtain an adequate diagnosis of patients with clinical suspicion of a hereditary periodic fever syndrome, especially those from non-ancestral populations.

Regulation of CD43-induced U937 homotypic aggregation.

CD43 (leukosialin, sialophorin), a prominent component of the hemopoietic cell surface, has an enigmatic role in cell-cell interaction. The observation that CD43 ligation triggers homotypic aggregation of monoblastoid U937 cells has permitted analysis of this: CD43-induced aggregation was distinguishable from CD29- (also known as beta1 integrin) or CD98- (also known as 4F2, or fusion-related protein 1) induced aggregation, with different energy requirements and with partial dependence on beta2 integrins. Previous studies have focused on the role of CD43 ligation in tyrosine phosphorylation. However, in the homotypic adhesion assay, although there is initial tyrosine phosphorylation, protein tyrosine kinase inhibitors did not block aggregation. Therefore, other signaling pathways were examined. CD43 ligation induced protein tyrosine dephosphorylation, and protein tyrosine phosphatase inhibitors blocked aggregation. Activation of MAP kinases was not necessary. Cytoskeletal inhibitors amplified aggregation. Protein kinase C (PKC) inhibitors amplified aggregation, implicating PKC as a negative regulator. CD43 ligation up-regulated surface adhesion molecules and enhanced CD29- and CD98-induced aggregation. Thus, CD43 participation in cell-cell adhesion is under stringent control, involving both surface events and several different intracellular signaling pathways, acting together to regulate the process. These mechanisms add a further dimension to the potential role of CD43 in tissue immune responses.

Pharmacodynamic approach to immunosuppressive therapies using calcineurin inhibitors and mycophenolate mofetil.

BACKGROUND: Graft survival depends on adequate immunosuppression. To evaluate the effect on the immune system of immunosuppressive therapies using calcineurin inhibitors (CNIs), several pharmacodynamic indices have been proposed to complement pharmacokinetic data. In this preliminary study we compared some of these parameters during combined immunosuppressant therapies. METHODS: We treated 65 stable renal transplant recipients with cyclosporin A (CsA; n = 16), tacrolimus (TRL; n = 10); CsA + mycophenolate mofetil (MMF; n = 14); TRL + MMF (n = 13), and MMF (n = 12). Twelve nontreated healthy controls were also included. Calcineurin activity (CNA) in peripheral blood mononuclear cells was measured using (32)P-labeled peptide. Interleukin-2 (IL-2) and interferon-gamma production in phytohemagglutinin-activated whole blood were measured at 0 and 2 h postdose. The areas under the curves, c(min), c(max), and concentration at 2 h (c(2 h)) were also measured. RESULTS: We found no differences in CNA between groups receiving CNIs alone or combined with MMF [median (25th-75th percentiles)]: CsA(2 h), 3.87 (3.00-6.85)% alkaline phosphatase (AP); CsA+MMF(2 h), 3.90 (1.78-5.19)% AP; TRL(2 h), 5.68 (3.02-16.00)% AP; TRL+MMF(2 h), 11.80 (4.05-14.63)% AP. In vitro IL-2 production was significantly lower in the groups receiving combined therapy than in groups receiving CNIs alone [median (25th-75th percentiles)]: CsA(2 h), 276.52 (190.41-385.25) ng/L; CsA+MMF(2 h), 166.48 (81.06-377.01) ng/L (P <0.001); TRL(2 h), 249.34 (127.48-363.50) ng/L; TRL+ MMF(2 h), 122.13 (51.02-180.00) ng/L (P <0.001). The correlations (r) between c(2 h) and CNA 2 h postdose were as follows: CsA, r = -0.74; CsA+MMF, r = -0.84; TRL, r = -0.70; TRL+ MMF, r = -0.70 (P <0.001 in all cases). CONCLUSIONS: The measurement of CNA may be of help in following the effect on the immune system of CNI treatments, even in combined therapies, but does not reflect the additional effect of MMF. In contrast, IL-2 in vitro production reflects the effect of both MMF and CNIs.

Human hepatic stellate cells show features of antigen-presenting cells and stimulate lymphocyte proliferation.

Following cell activation, hepatic stellate cells (HSCs) acquire proinflammatory and profibrogenic properties. We investigated whether activated HSCs also display immune properties. Here we show that cultured human HSCs express membrane proteins involved in antigen presentation, including members of the HLA family (HLA-I and HLA-II), lipid-presenting molecules (CD1b and CD1c), and factors involved in T-cell activation (CD40 and CD80). Exposure of HSCs to proinflammatory cytokines markedly up-regulates these molecules. Importantly, cells freshly isolated from human cirrhotic livers (in vivo activated HSCs) highly express HLA-II and CD40, suggesting that HSCs can act as antigen-presenting cells (APCs) in human fibrogenesis. We also explored whether human HSCs can efficiently process exogenous antigens. Activated HSCs internalize low- and high-molecular-weight dextran and transferrin, indicating that they can perform fluid-phase and receptor-mediated endocytosis. Moreover, HSCs can perform phagocytosis of macromolecules because they internalize latex particles as well as bacteria. Interestingly, both culture-activated and in vivo activated HSCs express high levels of CD68, a protein involved in antigen trafficking. Finally, we studied whether HSCs modulate T-lymphocyte proliferation. In basal conditions, coculture of irradiated HSCs barely induces allogeneic T-lymphocyte proliferation. However, cytokine-stimulated HSCs stimulate the allogeneic T-lymphocyte response in an HLA-II-dependent manner. In conclusion, human activated HSCs express molecules for antigen presentation, internalize macromolecules, and modulate T-lymphocyte proliferation. These results suggest that HSCs may play a role in the immune function of the liver.

The accessory molecules CD5 and CD6 associate on the membrane of lymphoid T cells.

CD5 and CD6 are closely related lymphocyte surface receptors of the scavenger receptor cysteine-rich superfamily, which show highly homologous extracellular regions but little conserved cytoplasmic tails. Both molecules are expressed on the same lymphocyte populations (thymocytes, mature T cells, and B1a cells) and share similar co-stimulatory properties on mature T cells. Although several works have been reported on the molecular associations and the signaling pathway mediated by CD5, very limited information is available for CD6 in this regard. Here we show the physical association of CD5 and CD6 at the cell membrane of lymphocytes, as well as their localization at the immunological synapse. CD5 and CD6 co-immunoprecipitate from Brij 96 but not Nonidet P-40 cell lysates, independently of both the co-expression of other lymphocyte surface receptors and the integrity of CD5 cytoplasmic region. Fluorescence resonance energy transfer analysis, co-capping, and co-modulation experiments demonstrate the physical in vivo association of CD5 and CD6. Analysis of T cell/antigen-presenting cells conjugates shows the accumulation of both molecules at the immunological synapse. These results indicate that CD5 and CD6 are structurally and physically related receptors, which may be functionally linked to provide either similar or complementary accessory signals during T cell activation and/or differentiation.