3c and 3d) These results are similar to the results of the genom

3c and 3d). These results are similar to the results of the genomic DNA extraction experiment, both confirming that the membranes of viable H. pylori effectively prevent penetration of PMA but allow the passage of EMA. Samples containing predefined ratios of viable and dead cells were prepared to test the accuracy of PCR signals in detecting the amount of genomic DNA after addition of PMA. Viable bacteria were mixed with appropriate amounts of EtOH-killed H. pylori to HDAC inhibitor obtain samples containing 0%, 0.1%, 1%, 10%, 50%, and 100% viable bacteria. Although viable bacteria can contain some dead cells, the percentage of them is small enough to

be irrelevant to the effect of PMA on viable and dead H. pylori mixtures. Each mixture was treated with 50 μM PMA and genomic DNA extracted and evaluated by electrophoresis. Constant amounts of genomic DNA were detected in all samples that had not been treated with PMA, regardless of the mixing ratio. In contrast, there was a gradual decrease in the amount of genomic DNA with decreasing ratios of viable H. pylori in the samples treated with PMA (Fig. 4). Thus, it was confirmed that genomic DNA of dead cells killed by PMA treatment was not detected, only the DNA of viable cells being detected. DNA extracted from PMA-treated H. pylori samples was quantitatively examined by real-time

PCR using SYBR green and primers for the sodB gene of H. pylori.

For the sample Sorafenib molecular weight containing 100% viable H. pylori treated with PMA (50 μM), the number of cells was 5.4 × 107 CFU/mL but this value continuously decreased with decreasing amounts of viable bacteria (to 7.6 × 104 CFU/mL for sample E). In contrast, samples not receiving PMA treatment exhibited similar numbers of cells to 100% viable H. pylori samples (Fig. 4). In addition, no DNA amplification was observed in the PMA-treated sample containing 100% dead H. pylori (sample F, Fig. 4). In order to establish a correct diagnosis and initiate appropriate treatment, detection of pathogens in samples from patients is of great importance. Because most pathogens replicate in the body, abundant amounts are usually found in clinical samples such as feces or blood; therefore their identification SSR128129E does not represent a challenge. In some diseases, the clinical presentation strongly suggests the responsible pathogen, thus further investigation of the infective agent may not be necessary. However, since food- or water-borne pathogens are present in food or water at very low concentrations, highly sensitive molecular-based techniques, such as PCR, are required. Although some methods, including PCR, are highly sensitive, their major disadvantage is their inability to discriminate between viable and dead pathogens.

Interestingly, in

IgA nephropathy, glomerular deposition

Interestingly, in

IgA nephropathy, glomerular deposition of ficolin-2 with local lectin pathway activation was associated with more severe renal disease [37]. According to our findings, pregnant women with low circulating levels of ficolin-2 or ficolin-3 have an increased risk for pre-eclampsia. Low ficolin-2 and ficolin-3 levels have already been linked to various pathological conditions, such as combined allergic and infectious respiratory disease in children [38,39], bronchiectasis [40], prematurity, low birth weight and perinatal infections [41], sarcoidosis [42], susceptibility to fever and neutropenia in pediatric cancer patients [43] and to neonatal sepsis [44]. Moreover, our research group has demonstrated recently that low ficolin-3 levels in early follow-up serum samples https://www.selleckchem.com/products/Adriamycin.html are related to the severity and unfavourable outcome of acute ischaemic stroke [45]. Genetic variations were shown to affect ligand binding or circulating levels of ficolins [46–48] and to associate with several disorders, including rheumatic fever and chronic rheumatic heart disease [49], bacterial and cytomegalovirus infections after orthotopic liver transplantation [50,51], and even immunodeficiency [52]. As pre-eclampsia is a multi-factorial disease with genetic components, the role of ficolin gene polymorphisms should be examined in www.selleckchem.com/screening/gpcr-library.html the

future in the risk of this pregnancy-specific disorder. In our study, the similar plasma ficolin-2 and ficolin-3 levels of pre-eclamptic patients regardless of the severity, the time of onset of the disease or the presence Nutlin-3 in vitro of fetal growth restriction might be explained by the complex aetiology of pre-eclampsia. Several genetic, behavioural and environmental factors need to interact to produce the complete picture of this pregnancy-specific disorder. We reported various genetic and soluble factors that were associated with the severity

or complications of pre-eclampsia, including HELLP syndrome and fetal growth restriction [53–56]. Nevertheless, it is also possible that the relatively small sample size of this study prevented the detection of an effect in the subgroup analyses. Although pre-eclampsia is predominantly a disease of primiparas, multiparous women, especially with advanced age or over weight, can also be affected, as in our cases. In conclusion, circulating levels of ficolin-2 are decreased in the third trimester of normal pregnancy. There is a further decrease in plasma ficolin-2 concentrations in pre-eclampsia, which might contribute to the development of the maternal syndrome of the disease through impaired removal of the trophoblast-derived material released into the maternal circulation by the hypoxic and oxidatively stressed pre-eclamptic placenta. We thank Veronika Makó, László Cervenak and Levente Lázár for measuring plasma von Willebrand factor antigen and cell-free fetal DNA concentrations.

The FLICE-inhibitory protein (FLIP) potently blocks TRAIL-mediate

The FLICE-inhibitory protein (FLIP) potently blocks TRAIL-mediated cell death by interfering with caspase-8 activation [22, 23]. In our previous studies, we showed that apoptosis of mesenteric lymph node cells is reduced during H. polygyrus infection [10, 24]. To determine whether antiapoptotic pathways are activated by H. polygyrus antigens, we measured the expression of FLIP or Bcl-2 and NF-κΒ protein. These may explain the potent resistance of cells to induced apoptosis. In this study, the parasitic factors that regulate the activity of immune cells were investigated in vitro after induction of proliferation

with anti-CD3/CD28 monoclonal antibodies as inducers of T-cell proliferation via TCR and CD28 receptors, respectively [25]. Apoptosis was induced by exposure of cells to DEX and rTNF-α. click here We evaluated which fractions of the parasitic antigen have an antiapoptotic effect on CD4+CD25−, CD4+CD25hi and CD3+CD8+ cells. The nematode was maintained by serial passage

in BALB/c mice. Infective stage larvae, L3 were harvested from Y 27632 faecal culture. Mice were alimentary inoculated with 120 larvae, and after 24 days nematodes were isolated from the intestine. About 400 adult nematodes were lysed on ice in 0.5 mL of PBS using a ultrasonic device. The samples were then centrifuged 18 000 g, 5 min, 4°C, and Baf-A1 nmr the supernatant was sterile-filtered using 0.2 μm syringe filter (Milipore, Tullagreen,

Cork, Ireland), and protein concentration was measured in Bradford assay. Separation of somatic antigen fractions was carried out using high-pressure liquid chromatography (HPLC Alliance 2695 coupled to photodiode array detector, Waters) on ProteinPak column (Waters, Milford, MA, USA); 100 μL of antigen solution was loaded onto the column and eluted isocratically with PBS (pH 7.4), flow rate 0.4 mL/min and fractions of 0.5 mL were collected starting when protein presence was detected at λ = 280 nm. Protein concentration in each fraction was estimated. The chromatogram and the SDS-PAGE shown are typical for each independent fractionation. Samples were stored at −80°C until use. The study was performed on control mice, free of pathogens and 12 days after H. polygyrus infection. The mesenteric lymph nodes (MLN) were isolated aseptically and pressed through a nylon cell strainer (BD Falcon, Erembodegem, Belgium) to produce a single-cell suspension. MLN cells were washed and resuspended in complete medium RPMI 1640 (Gibco, Paisley, UK) supplemented with 10% heat inactivated foetal bovine serum (FBS), penicillin (100 U/mL), streptomycin (100 μg/mL), l-glutamine (2 mm) and β-mercaptoethanol (1 U/mL) (Gibco, Inchinnan, UK). Cell viability, as determined by trypan blue exclusion, was greater than 96%.

, PhD Winthrop-University Hospital Atkinson, Mark, PhD University

, PhD Winthrop-University Hospital Atkinson, Mark, PhD University of Florida Bradshaw, Elizabeth, PhD Harvard Medical School Buckner, Jayne, MD Benaroya Research Institute at Virginia Mason Cambier, John, https://www.selleckchem.com/products/yap-tead-inhibitor-1-peptide-17.html PhD National Jewish Health Chaussable, Damien, PhD Benaroya Research Institute at Virginia Mason Clish, Clary, PhD Broad Institute of MIT and Harvard Eisenbarth, George, MD, PhD (teleconference) University of Colorado – Denver Faustman, Denise,

MD, PhD Harvard Medical School Greenbaum, Carla, MD (teleconference) Benaroya Research Institute at Virginia Mason Hendrikson, Ronald, PhD Memorial Sloan–Kettering Cancer Center Hessner, Marty, PhD Medical College of Wisconsin Kappler, John, PhD National Jewish Health Kent, Sally, PhD UMASS Medical College Kenyon, Norma, PhD University of Miami McKinney, Eoin, PhD University of Cambridge Miller, Steve, PhD Northwestern University Nepom, Jerry, MD, PhD – Chair Benaroya Research Institute at Virginia Mason Peakman, Mark, PhD.

King’s College London Phippard, Deborah, PhD Immune Tolerance Network Pugliese, Alberto, MD University of Miami Qiu, Ji, PhD Arizona State University Quintana, Fransisco J., PhD Harvard Medical School Roep, Bart, MD, PhD Leiden University Medical Center Sewell, Andy, PhD Cardiff University Ueno, Hideki, MD, PhD

Baylor Health von Herrath, Matthias, MD (teleconference) La Jolla Institute for Allergy and PD 332991 Immunology Waldron-Lynch, Frank, MD University of Cambridge None. “
“In recent years, the role of high mobility group box-1 (HMGB1) protein and its receptors in autoimmune diseases has received increasing attention. It has been documented that HMGB1 is associated with disease activity in patients with systemic lupus erythematosus (SLE). This study was undertaken to determine the potential role of receptor for advanced glycation end products (RAGE), one receptor for HMGB1, in the pathogenesis of SLE. Plasma levels of soluble RAGE (sRAGE) from 105 patients with clinical diagnosis of SLE Mirabegron and 43 healthy controls were determined by ELISA. Associations between sRAGE levels and clinical, laboratory characteristics were assessed. The data showed that plasma levels of sRAGE in patients with SLE were significantly lower than those in healthy controls (HC) (P = 0.003). Plasma sRAGE in patients receiving short-period treatment showed an immediate decrease compared with the untreated patients (P = 0.023). In contrast, plasma sRAGE in patients receiving long-period treatment were significantly increased compared to those with short-period treatment (P = 0.000) and comparable with those in HC (P = 0.305).

We undertook sequence and structure analysis to highlight common

We undertook sequence and structure analysis to highlight common and different features between VG1-VD4 and VG2-VD4 and their mutated cDNA counterparts, RTS124/VD4 and 5R2S127/VD4. VG1 and RTS124 clone (Supporting Information

Fig. 4) show a high amino acid sequence identity (91.8%) and consequently their structure is also rather similar (RMSD of 0.16 Å) (Fig. 6A). Eight AA change when considering the alignment among VG1 and RTS124, highlighted in red and listed in Fig. 6A. Among these, four (L25>M, F54>I, D96>E, I125>M) 3-deazaneplanocin A mw conserve the physicochemical [26] properties of the correspondent VG1 lateral side chains and are found exposed at the surface of the domains. In turn, four AA changes (F44>S, Y62>N, A83>P, and R103>L) do not conserve physicochemical properties. Modeling of the domains highlights that two of these nonconservative AA changes (F44>S and R103>L) are to be found at the domain interface, one (Y62>N) is in CDR2, whereas the last one (A83>P) is at the protein surface. This is in agreement with the IMGT C225 Colliers de Perles (Fig. 6C) [27, 28]. No AA change is present in CDR1. VG2 and 5R2S127 clone (Fig. 4) share a high sequence identity (91.5%) and a similar folded structure (RMSD = 0.35 Å) (Fig. 6B). Seven AA changes are found, all of them are nonconservative [26]. One (Y38>F) is localized in CDR1, one (Y42>H)

at the domain interface, two (R63>S, D64>N) in CDR2 and three (T37>I, T122>I and T127>S) ioxilan at the surface. AA changes in the CDR3 (Fig. 6A and B) result from the junctional analysis. In this study, we present a genomic and expression analysis of C. dromedarius TCRG genes. According to comparative analyses, the TCRG locus is the most variable, but least complex of the TCR loci [2, 29, 30]. Similar in structure to the Bovidae TCRG loci, dromedary TCRG genes are arranged

in two juxtaposed cassettes, distributed over only 45 kb and each consisting of one V, two J, and one C genes. As in all the species studied, the locus is flanked at its 3′ end by the STARD3NL gene [29, 31]. Both camel TCRGV genes and two of the four TCRGJ have been found to be functional and to be expressed in the spleen. Each TCRGC gene is encoded by five exons and consists of a well-conserved C domain (C-GAMMA), a connecting region (CO), and transmembrane and cytoplasmic regions. In vertebrates, the connecting region is the most variable in length, due to the different number and length of exon 2 [15, 16, 21, 32, 33]. As in ovine TCRGC2, TCRGC4, and TCRGC6 genes [15] and human polymorphic TCRGC2 gene [2, 16], exon 2 of the camel TCRGC regions is triplicated. The biological significance of this variability remains unclear. The CO length variation might affect processes such as signal transduction or interaction with other cell surface molecules [33].

albicans and C glabrata at a concentration of 0 49 μg ml−1; P3,

albicans and C. glabrata at a concentration of 0.49 μg ml−1; P3, the N,N′,N′′,N′′′-hexamethyl-derivative, also showed inhibitory activity selleck compound against C. albicans and C. glabrata, but in higher concentrations (250 μg ml−1). The N,N′,N′′,N′′′-tetramethylated amine (P5) only inhibited the growth of C. glabrata, but its corresponding N,N′,N′′,N′′′-octamethyl derivative (P6) was also active against C. glabrata (125 μg ml−1) and it was the only compound active against C. parapsilosis. P2 and P4

showed no significant antifungal activity. The structure–activity relationship of the thioureido-substituted derivatives indicates that the molecular branching and the alkylation levels can influence the antifungal activity.

This study demonstrated that thioureido derivatives exhibited significant antifungal activity against Candida species and that they can be considered as a very promising bioactive lead compound to develop novel antifungal agents. “
“Pneumocystis spp. are peculiar fungi, because they lack ergosterol in their cytoplasmic membrane. Furthermore, they go through various sexual and non-sexual stages in a living host; the cysts, which are able to survive in the environment, are the infectious agents. The various species are more or less specific for a mammalian host. Pneumocystis jirovecii is pathogenic for humans. Transient colonisation of children and adults with this fungus occurs frequently. As a typical opportunist

it can induce an overt disease in immunocompromised patients only. In particular Selleckchem Ensartinib those patients with an impaired cell-mediated immune system, namely AIDS patients or transplant recipients taking immunosuppressive agents, are affected. The leading clinical feature is a bilateral interstitial pneumonia characterised by progressive dyspnoea, tachypnoea and non-productive cough. Finally, the interstitial pneumonia will lead to hampered gas exchange resulting in a marked decrease in paO2 and consequently to a rather Fludarabine ic50 low haemoglobin saturation. Pneumocystsis spp. do not grow on artificial media. Diagnosis is made by demonstration of fungal cells on microscopy preferentially by immunofluorescence staining or by the highly sensitive PCR method. A standardisation of the molecular methods is still lacking, since different DNA sequences are amplified in each case. Quantification by real-time PCR can help to differentiate between infection and mere colonisation. Among the common antifungals only the echinocandins are active at least against the cyst forms. The principal therapeutic agents remain, however, antibacterial and anti-parasitic agents, such as cotrimoxazole, clindamycin, primaquine, pentamidine and atovaquone. In addition, an improvement of the immunosuppression is warranted. Prophylaxis is indicated in those individuals with a prolonged cell-mediated immunodeficiency.

The clinical experience just reviewed outlines the difficulties o

The clinical experience just reviewed outlines the difficulties of treating patients with established T1D. The preventive effect of infections on the progression of β cell aggression, which represents the basis of the hygiene hypothesis, applies to the early phases of the natural history of the disease [31]. It is thus logical to postulate that intervention aimed at ‘reprogramming’ the β cell-specific autoimmune response, as did infections in

the past, might represent a simple and robust way to prevent T1D, inasmuch as the treatment proposed is totally safe (because by definition it will concern Selleckchem MLN8237 very young and still ‘healthy’ subjects). The search for such treatments is strictly dependent upon a better understanding of the immune mechanisms underlying the hygiene hypothesis. Subsets of helper CD4+ T lymphocytes could be identified Adriamycin purchase on the basis of the array of cytokines they produced. T helper type 1 (Th1) CD4+ T cells produce preferentially interleukin (IL)-2 and interferon (IFN)-γ that essentially support T cell growth, macrophage activation and cell-mediated immunity. Th2 cells produce IL-4, IL-6, IL-10 and IL-13, which contribute to antibody production. More recently described Th17 cells are a major source of IL-17 and IL-21.

The development of most autoimmune diseases involves cell co-operation processes with Th1 and Th17 CD4+ cells, whereas the development of allergic diseases requires IL-4 and IL-5 produced by Th2 cells. Based on initial reports pointing to the reciprocal down-regulation of Th1 and Th2 cells, oxyclozanide some authors have suggested that in developed countries the lack of microbial burden in early childhood, which normally favours strong Th1-biased immunity, redirects the immune response towards a Th2 phenotype

and therefore predisposes the host to allergic disorders. The problem with such an explanation was, however, that Th1 responses in the case of autoimmunity are not protective but pathogenic. These observations would fit with the concept of a common mechanism underlying infection-mediated protection against autoimmunity and allergy. Specialized subsets of T lymphocytes defined generally as regulatory T cells will be suitable candidates, as there is compelling data to show that they are highly effective in controlling both Th1- and Th2-mediated responses. A second mechanism with relevance to the influence of infection on allergy and autoimmunity is antigenic competition, in which the immune response to an antigen is decreased by a concomitant immune response against an unrelated antigen. The competition is maximal when the unrelated antigen is administered a few days after the administration of the first antigen.

[64] Examples of

hsp-based therapeutics in cancer trials

[64] Examples of

hsp-based therapeutics in cancer trials are detailed in Table 3. To date, one hsp vaccine, Vitespen, is licensed and marketed. The hsp gp96, the master chaperone for Toll-like receptors[65], is the major component of Vitespen. Chaperoning by gp96 selleck compound increases uptake over unchaperoned peptides in vitro by two orders of magnitude and immunization of mice with 5 ng gp96–peptide complexes, results in generation of a peptide-specific CD4+ T-cell response.[66] In April 2008, Vitespen was approved in Russia as a patient-specific adjuvant treatment of kidney cancer for individuals at intermediate-risk for disease recurrence. Outside Russia, Vitespen is an investigational vaccine designed to treat cancer with the intent of minimizing side-effects. It has been studied extensively in clinical trials in Phase I and II settings, demonstrating efficacy in some but not all trials. Phase III studies have been

completed in which over 1300 patients with renal cell carcinoma or malignant melanoma have been treated. Essentially neither toxicity nor autoimmunity induced by Vitespen was observed.[67] Marketed (Russia) Disease-dependent Phase II and III Although pre-clinical studies with Vitespen were promising, check details clinical studies show limited efficacy.[68] This outcome may be a consequence of differences in the hsp content of Vitespen used for Phosphoglycerate kinase initial in vivo models compared with the vaccine used for clinical trials.[69] Pre-clinical studies reported utilised vaccines containing gp96 or hsp70, while clinical studies utilised vaccine containing only gp96. Critically, gp96 and hsp70 have distinct functions as endoplasmic reticulum (ER) luminal and cytoplasmic chaperones, respectively, and thus bind distinct client proteins. Heat-shock protein 70 binds a variety of cytoplasmic proteins and isolation of this hsp from tumour cells will result in the purification of intact hsp–client protein complexes. In contrast, gp96 binds membrane proteins such as

integrins and Toll-like receptors and is essential for chaperoning peptides in the ER.[70] As the clinical production processes used do not contain detergents,[71] peptides bound to gp96 in Vitespen are unlikely to result from tumour client proteins. Hence differences between the bound peptides in gp96 isolated from the homogeneous tumour tissue in the animal models and the heterogeneous tumour tissue from patients in the clinical trials may also account for the limited efficacy reported for Vitespen.[68] Other key issues concerning the future development of such a vaccine are the correct and effective dose of hsp, and which patients to target. Other hsp provide alternatives to gp96 for cancer vaccine development. Vaccination with hsp70 derived from the Meth A sarcoma, established dose-dependent immunity to challenge with Meth A sarcoma in mice.

n once with

n. once with RG7420 allergen alone produced a significant amount of IgE (4.5 ± 1.2 ng/mL; mean ± SD; n= 12) and served as a positive control. A small amount of IgE (1.4 ± 0.4 ng/mL; mean ± SD; n= 12) was produced by the mixture of lymphocyte- and macrophage-rich populations from mice that had been treated once i.n. with a mixture of allergen and adjuvant and these served as a negative control. A combination of the lymphocyte-rich population (for IgG production) with the macrophage-rich fraction (for IgE production)

produced a significant amount of IgE (3.3 ± 0.8 ng/mL; mean ± SD; n= 12). In contrast, a combination of the lymphocyte-rich population (for IgE production) with the macrophage-rich fraction (for IgG production) produced a small amount of IgE (1.1 ± 0.5 ng/mL; mean ± SD; n= 12). Similarly, a mixture of cells in the lymphocyte-rich and macrophage-rich populations from mice that had been treated i.n. once with BI 2536 solubility dmso a mixture of allergen and adjuvant produced a large amount of IgG (477.0 ± 135.0 ng/mL; mean ± SD; n= 12) Ab and served as a positive control. A small amount

of IgG (9.4 ± 1.2 ng/mL; mean ± SD; n= 12) was produced by a mixture of lymphocyte- and macrophage-rich populations from mice that had been treated i.n. once with allergen and these served as a negative control. A combination of the lymphocyte-rich population (for IgE production) with the macrophage-rich population (for IgG production) produced a large amount of IgG (359.5 ± 65.0 ng/mL; mean ± SD; n= Megestrol Acetate 12). In contrast, a combination of the lymphocyte-rich fraction (for IgG production) with the macrophage-rich fraction (for IgE production) produced a small amount of IgG (181.6 ± 57.6 ng/mL; mean ± SD; n= 12). These results taken together indicate that cells in the macrophage-rich population are involved in class switching to IgE or IgG after i.n. sensitization by allergen alone or with complete Freund’s adjuvant, respectively. Interleukin-4 is essential for in vitro or in vivo production of nonspecific IgE Abs in lymphocytes after sensitization with cedar

pollen i.n. once (8). Therefore, we assessed the cellular source of IL-4 and its amount in the culture medium (Fig. 9). Bulk submandibular lymph node cells from mice that had been injected once i.n. with allergen alone produced a large amount of IL-4 (96.1 ± 8.6 pg/mL; mean ± SD; n= 9). In contrast, the lymphocyte-rich (fraction 3) fraction of the lymph node cells produced a small amount (31.3 ± 10.9 pg/mL; mean ± SD; n= 9); and the macrophage-rich (fraction 2) fraction was almost inactive (20.1 ± 6.9 pg/mL; mean ± SD; n= 9). Surprisingly, mixed cultures of the lymphocyte-rich fraction with the macrophage-rich fraction produced a large amount of IL-4 (75.3 ± 9.9 pg/mL; mean ± SD; n= 9) that was released into the culture medium (Fig. 9a). In contrast, the amounts of IL-4 produced by cells in the damaged cell (fraction 1; 11.5 ± 2.

If a low-level DSAb is responsible for the positive flow crossmat

If a low-level DSAb is responsible for the positive flow crossmatch, then it may be reasonable to proceed; however, many clinicians would use a desensitization protocol to decrease the risk of early Quizartinib mouse rejection. In order to confirm the presence of anti-HLA antibodies as the cause of the positive flow crossmatch (as opposed to antibodies to non-HLA antigens) antibody specificity should be determined by Luminex testing. This will also provide some information regarding the antibody levels.

Flow crossmatching is performed using the same initial base ingredients as CDC crossmatching (i.e. donor lymphocytes and recipient serum) and was first described in 1983.18 The two are mixed to allow antibody binding and after washing, fluoresceinated AHG is added to bind attached DSAbs and hence allow detection by flow cytometry (see Fig. 2). The read-out may be reported simply as positive or negative or can be further quantitated. Intensity of fluorescence above control, referred to as channel shifts, may be reported while another means of quantitation is to determine the number of dilutions BAY 73-4506 solubility dmso of recipient serum required to generate a negative result. The subtype of antibody can also be determined by the isotype specificity of the fluorescently labelled detection antibody. Hence if only IgG antibodies are of interest the detection antibody chosen will

be of the type that binds only to IgG and not IgM or IgA.20 Furthermore the subtype of IgG can be elucidated by choosing a detection antibody that binds only to IgG1, 2, 3 or 4. Refining the analysis in this way provides information about the likelihood of complement activation in vivo as IgG4 does not activate complement. The role of flow crossmatching in the pre-transplant assessment is controversial. The significance of a positive result is mainly of interest when the CDC crossmatch is negative. In

this setting the positive flow crossmatch is likely to be caused by a 4��8C non-complement fixing antibody, a non-HLA antibody or a low-level antibody. In patients who are not known to be sensitized several studies have suggested that a positive T- or B-cell flow crossmatch was not predictive of increased rejection rates or worse graft survival while in sensitized patients other studies have suggested inferior graft survival.5,14,16,17,20–22 A possible reason for this difference is that there would be a higher false positive rate in non-sensitized patients than in sensitized patients given that they are not expected to have a positive result. Another factor determining the significance of the result is the cut-off values used to determine a positive test.20 These are not applied uniformly between centres and those that apply a very low cut-off value will increase sensitivity at the expense of specificity.