Phenotypic and Transcriptomic Lymphocytes Changes in Allograft Recipients After Intravenous Immunoglobulin Therapy in Kidney Transplant Recipients

High dose intravenous immunoglobulin (IVIG) are widely used after kidney transplantation and its biological effect on T and B cell phenotype in the context of maintenance immunosuppression was not documented yet. We designed a monocentric prospective cohort study of kidney allograft recipients with anti-HLA donor specific antibodies (DSA) without acute rejection on screening biopsies treated with prophylactic high-dose IVIG (2 g/kg) monthly for 2 months. Any previous treatment with Rituximab was an exclusion criterion. We performed an extensive analysis of phenotypic and transcriptomic T and B lymphocytes changes and serum cytokines after treatment (day 60). Twelve kidney transplant recipients who completed at least two courses of high-dose IVIG (2 g/kg) were included in a median time of 45 (12–132) months after transplant. Anti-HLA DSA characteristics were similar before and after treatment. At D60, PBMC population distribution was similar to the day before the first infusion. CD8⁺ CD45RA⁺ T cells and naïve B-cells (Bm2⁺) decreased (P = 0.03 and P = 0.012, respectively) whereas Bm1 (mature B-cells) increased (P = 0.004). RORγt serum mRNA transcription factor and CD3 serum mRNA increased 60 days after IVIG (P = 0.02 for both). Among the 25 cytokines tested, only IL-18 serum concentration significantly decreased at D60 (P = 0.03). In conclusion, high dose IVIG induced limited B cell and T cell phenotype modifications that could lead to anti-HLA DSA decrease. However, no clinical effect has been isolated and the real benefit of prophylactic use of IVIG after kidney transplantation merits to be questioned.

Human Apoptotic Cells, Generated by Extracorporeal Photopheresis, Modulate Allogeneic Immune Response

The induction of specific and sustainable tolerance is a challenging issue in organ transplantation. The discovery of the immunosuppressive properties of apoptotic cells in animal models has paved the way for their use in human transplantation. In this work, we aimed to define a stable, reproducible, and clinically compatible production procedure of human apoptotic cells (Apo-cells). Using a clinically approved extracorporeal photopheresis technique, we have produced and characterized phenotypically and functionally human apoptotic cells. These Apo-cells have immunosuppressive properties proved in vitro and in vivo in NOD/SCID/γC mice by their capacity to modulate an allogeneic response following both a direct and an indirect antigen presentation. These results brought the rationale for the use of Apo-cells in tolerance induction protocol for organ transplantation.

Loss of function mutations in EPHB4 are responsible for vein of Galen aneurysmal malformation

See Meschia (doi:10.1093/brain/awy066) for a scientific commentary on this article.Vein of Galen aneurysmal malformation is a congenital anomaly of the cerebral vasculature representing 30% of all paediatric vascular malformations. We conducted whole exome sequencing in 19 unrelated patients presenting this malformation and subsequently screened candidate genes in a cohort of 32 additional patients using either targeted exome or Sanger sequencing. In a cohort of 51 patients, we found five affected individuals with heterozygous mutations in EPHB4 including de novo frameshift (p.His191Alafs*32) or inherited deleterious splice or missense mutations predicted to be pathogenic by in silico tools. Knockdown of ephb4 in zebrafish embryos leads to specific anomalies of dorsal cranial vessels including the dorsal longitudinal vein, which is the orthologue of the median prosencephalic vein and the embryonic precursor of the vein of Galen. This model allowed us to investigate EPHB4 loss-of-function mutations in this disease by the ability to rescue the brain vascular defect in knockdown zebrafish co-injected with wild-type, but not truncated EPHB4, mimicking the p.His191Alafs mutation. Our data showed that in both species, loss of function mutations of EPHB4 result in specific and similar brain vascular development anomalies. Recently, EPHB4 germline mutations have been reported in non-immune hydrops fetalis and in cutaneous capillary malformation-arteriovenous malformation. Here, we show that EPHB4 mutations are also responsible for vein of Galen aneurysmal malformation, indicating that heterozygous germline mutations of EPHB4 result in a large clinical spectrum. The identification of EPHB4 pathogenic mutations in patients presenting capillary malformation or vein of Galen aneurysmal malformation should lead to careful follow-up of pregnancy of carriers for early detection of anomaly of the cerebral vasculature in order to propose optimal neonatal care. Endovascular embolization indeed greatly improved the prognosis of patients.

Diversity and enzymatic profiles of indigenous yeasts isolated from three types of palm wines produced in Côte d'Ivoire

AIMS

To investigate the genotypic diversity and enzymatic activity of yeast flora isolated from spontaneous fermenting saps of various palm trees (Borassus aethiopum, Raphia hookeri, Elaeis guineensis) tapped for palm wines.

METHODS AND RESULTS

PCR-restriction fragment length polymorphism of ITS-5.8S rDNA combined to 26S rRNA gene and/or the partial ACT1 gene sequencing were applied for yeast characterization, and their enzymatic profiles assessed by using API ZYM kits. Thirteen genera and 23 species were identified, with the highest diversity (14 species) in raffia wine. Saccharomyces cerevisiae was dominant and common to all palm wines. Some potentially pathogenic yeasts were also isolated. The majority of tested strains displayed high amylo-peptidase, phosphatase, β-glucosidase and α-glucosidase activities and esterase activity.

CONCLUSIONS

Diverse yeast species colonized palm wines, among which some were related to a specific type of wine and the majority of them have the ability to digest starch, sugar, protein or lipid.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study is a first step in understanding the significance of indigenous yeast flora of palm wines from Côte d'Ivoire. This knowledge is important as a tool for establishing new indigenous yeast collection; which could be used for the product quality improvement and as enzyme sources for biotechnological purposes.

Delayed and short course of rapamycin prevents organ rejection after allogeneic liver transplantation in rats

AIM

To test whether a delayed and short course of rapamycin would induce immunosuppressive effects following allogeneic orthotopic liver transplantation (OLT) in rats.

METHODS

Allogeneic OLTs were performed using Dark Agouti livers transplanted into Lewis recipients, and syngeneic OLTs were performed using the Lewis rat strain. Rapamycin (1 mg/kg per day) was administered by gavage from day 4 to day 11 post-transplantation. Lymphocyte cellular compartments were analyzed by flow cytometry in draining lymph nodes, non-draining lymph nodes and the spleen at days 11 and 42 in rapamycin-treated rats, untreated control rats and syngeneic grafted rats. Skin grafts from Dark agouti or from F344 RT were performed at day 30 on liver grafted rats treated with rapamycin.

RESULTS

An 8-d course of rapamycin treatment initiated 4 d following transplantation resulted in the survival of grafted rats for more than 100 d. In contrast, untreated rats died of liver failure within 13 to 21 d. The analysis of the cellular compartment revealed an increase in two cellular subpopulations, specifically myeloid-derived suppressor cells (MDSCs) and CD8⁺CD45RC^low T cells, without major modifications in the regulatory T cell (Treg) compartment in treated rats in the early stages after grafting. We evaluated the ability of treated rats to reject third-party allogeneic skin grafts to confirm their immune competence. In contrast, when skin was collected from rats syngeneic to the grafted liver, it was not rejected.

CONCLUSION

Our results demonstrate that short and delayed rapamycin treatment allows for tolerance in allogeneic OLT. The results also allowed for the identification of the mechanisms of tolerance induced by rapamycin by identifying MDSCs and CD8⁺CD45RC^low T cells as associated with the state of tolerance.

Intravenous immunoglobulin therapy in kidney transplant recipients with de novo DSA: Results of an observational study

Background

Approximately 25% of kidney transplant recipients develop de novo anti-HLA donor-specific antibodies (dnDSA) leading to acute antibody-mediated rejection (ABMR) in 30% of patients. Preemptive therapeutic strategies are not available.

Methods

We conducted a prospective observational study including 11 kidney transplant recipients. Inclusion criteria were dnDSA occurring within the first year after transplant and normal allograft biopsy. All patients were treated with high-dose IVIG (2 g/kg 0, 1 and 2 months post-dnDSA). The primary efficacy outcome was incidence of clinical and subclinical acute ABMR within 12 months after dnDSA detection as compared to a historical control group (IVIG-).

Results

Acute ABMR occurred in 2 or 11 patients in the IVIG+ group and in 1 of 9 patients in the IVIG- group. IVIG treatment did not affect either class I or class II DSA, as observed at the end of the follow-up. IVIG treatment significantly decreased FcγRIIA mRNA expression in circulating leukocytes, but did not affect the expression of any other markers of B cell activation.

Conclusions

In this first pilot study including kidney allograft recipients with early dnDSA, preemptive treatment with high-dose IVIG alone did not prevent acute ABMR and had minimal effects on DSA outcome and B cell phenotype.

Transcriptomic Signature of the CD24hi CD38hi Transitional B Cells Associated With an Immunoregulatory Phenotype in Renal Transplant Recipients

The role of B cells after transplant regarding allograft rejection or tolerance has become a topic of major interest. Recently, in renal transplant recipients, a B cell signature characterized by the overexpression of CD19⁺ CD38^hi CD24^hi transitional B cells has been observed in operationally tolerant patients and in belatacept-treated patients with significantly lower incidence of donor-specific antibodies. The phenotypic and functional characterization of these transitional B cells is far from exhaustive. We present the first transcriptomic and phenotypic analysis associated with this cell phenotype. Three populations were studied and compared: (i) transitional CD24^hi CD38^hi , (ii) CD24⁺ CD38^- , and (iii) CD24^int CD38^int B cells. Transcriptome bioinformatic analysis revealed a particular signature for the CD24^hi CD38^hi population. Phenotypic analysis showed that CD24^hi CD38^hi transitional B cells also expressed CD9, CD10, CD1b and inducible T cell costimulator ligand (ICOS-L) markers. In addition, we found enrichment of IL-10⁺ cells among CD24^hi CD38^hi cells expressing ICOS-L and CD1b, the latter showing regulatory properties. Renal transplant recipients treated with belatacept exhibited significant expression of CD1b. Our results show that transitional CD24^hi CD38^hi B cells exhibit a distinct and specific profile, and this could be helpful for understanding of immune-regulatory mechanisms and immune monitoring in the field of organ transplant and autoimmune disease.

Th-17 Alloimmune Responses in Renal Allograft Biopsies From Recipients of Kidney Transplants Using Extended Criteria Donors During Acute T Cell-Mediated Rejection

Although renal transplantation using expanded criteria donors has become a common practice, immune responses related to immunosenescence in those kidney allografts have not been studied yet in humans. We performed a retrospective molecular analysis of the T cell immune response in 43 kidney biopsies from patients with acute T cell-mediated rejection including 25 from recipients engrafted with a kidney from expanded criteria donor and 18 from recipients grafted with optimal kidney allograft. The clinical, transplant and acute T cell-mediated rejection characteristics of both groups were similar at baseline. The expression of RORγt, Il-17 and T-bet mRNA was significantly higher in the elderly than in the optimal group (p = 0.02, p = 0.036, and p = 0.01, respectively). Foxp3 mRNA levels were significantly higher in elderly patients experiencing successful acute T cell-mediated rejection reversal (p = 0.03). The presence of IL-17 mRNA was strongly associated with nonsuccessful reversal in elderly patients (p = 0.008). Patients with mRNA IL17 expression detection and low mRNA Foxp3 expression experienced significantly more treatment failure (87.5%) than patients with no mRNA IL17 expression and/or high mRNA Foxp3 expression (26.7%; p = 0.017). Our study suggests that the Th17 pathway is involved in pathogenesis and prognosis of acute T cell-mediated rejection in recipients of expanded criteria allograft.

[Adolescents' knowledge and behavior on sexuality, infectious transmitted diseases, and human papillomavirus vaccination: results of a survey in a French high school]

Teenager sexuality is a public health issue. In teenagers attending a high school, we assessed their knowledge and behavior on sexuality, infectious transmitted diseases, human papilloma virus (HPV) vaccination, and cervical cancer. Then in girls, we estimated the anti-HPV vaccination coverage and focused on factors associated with poor knowledge of these topics.

METHODS

This was a knowledge, attitudes, and practices cross-sectional study conducted at the beginning of the 2010-2011 school year in the Saint-Cyr military high school, using an anonymous self-administered questionnaire.

RESULTS

Among 669 adolescents (M/F sex-ratio, 2.3; mean age, 17 years [IC 95%, 15-20]), 40% had already had sex and 92% had used contraception. Boys and girls had a poor level of knowledge on infectious transmitted diseases. Regarding knowledge on HPV and cervical cancer, a better level was significantly associated with female gender (P=10(-4)). In multivariate analysis, male gender, age under 18 years, lack of dialogue with parents on these subjects, low socioeconomic status of parents, and absence of health education were significantly associated with poor knowledge on these topics.

CONCLUSION

These data should help healthcare providers better target access and content of sexual health education training.

Shigella flexneri bacteremia in two immune-competent adult travelers

Shigella bacteremias are uncommon in immune-competent adults. We report two cases of Shigella flexneri bacteremia that occurred in healthy young travelers, who recovered. Self-medication with loperamide and ibuprofen without antibiotics (case 1) and concomitant falciparum malaria (case 2) were the only co-morbidities found in our two patients.

A controlled trial of corticosteroid injections into facet joints for chronic low back pain

BACKGROUND

Chronic low back pain is a common problem with many treatments, few of which have been rigorously evaluated. This randomized, placebo-controlled trial was designed to evaluate the efficacy of injections of corticosteroid into facet joints to treat chronic low back pain.

METHODS

Patients with chronic low back pain who reported immediate relief of their pain after injections of local anesthetic into the facet joints between the fourth and fifth lumbar vertebrae and the fifth lumbar and first sacral vertebrae were randomly assigned to receive under fluoroscopic guidance injections of either methylprednisolone acetate (20 mg; n = 49) or isotonic saline (n = 48) in the same facet joints. Ninety-five patients were followed for six months and their condition assessed with scales of pain severity, back mobility, and limitation of function.

RESULTS

After one month, none of the outcome measures evaluating pain, functional status, and back flexion differed clinically or statistically between the two study groups. Forty-two percent of the patients who received methylprednisolone and 33 percent of those who received placebo reported marked or very marked improvement (95 percent confidence interval for the difference, -11 to 28 percentage points; P = 0.53). The results were similar after three months. At the six-month evaluation, the patients treated with methylprednisolone reported more improvement, less pain on the visual-analogue scale, and less physical disability. The differences were reduced, however, when concurrent interventions were taken into account. Moreover, only 11 patients (22 percent) in the methylprednisolone group and 5 (10 percent) in the placebo group had sustained improvement from the first month to the sixth month (95 percent confidence interval for the difference, -2 to 26; P = 0.19).

CONCLUSIONS

We conclude that injecting methylprednisolone acetate into the facet joints is of little value in the treatment of patients with chronic low back pain.

[Not Available]

Rheumatoid arthritis is the most common chronic inflammatory joint disease. To overcome joint inflammation and eventually induce disease remission, the physician must often use drugs that are more and more toxic. Indications, method of administration, and common adverse effects of non-steroidal anti-inflammatory drugs, local steroid injections, second-line agents, and steroids are reviewed. The author briefly discusses a new therapeutic concept and emphasizes the importance of patient education and early referral to an interdisciplinary rehabilitation team.

Immunoregulation of lung fibroblast growth: alteration in asbestos-induced pulmonary fibrosis

Initial studies on mononuclear cell-fibroblast interactions have shown that stimulated human lymphocytes produced a fibroblast growth inhibitory factor and that asbestos, a fibrogenic dust, interferes with this process in vitro. To investigate the role of these interactions in pathologies characterized by pulmonary fibrosis, we used a rat model of asbestos-induced fibrosis. Rats received a single intratracheal instillation of either saline or 10 mg of chrysotile asbestos fibres. Three months after treatment, peripheral blood mononuclear leucocytes (PBML) supernatant fractions were prepared and their effects on lung fibroblast growth measured. As for human PBML, rat PBML stimulated with Concanavalin A (Con A) produced 24 h after initiation of the cultures a soluble factor which inhibits lung fibroblast DNA synthesis and growth in a dose-dependent fashion. By contrast, Con A-stimulated PBML from rats exposed to asbestos failed to produce significant levels of fibroblast growth inhibitory activity. No significant change of total PBML number or in the proportion of circulating mononuclear cell populations was observed. Furthermore, upon stimulation with lipopolysaccharide (LPS), monocytes from asbestotic animals retained their capacity to produce interleukin (IL-1), a mediator required for lymphokine production. Our study demonstrates that suppression of FGIF production by circulating PBML occurs in animals with lung fibrosis and suggests that mechanisms other than impairment of IL-1 production may be responsible for the suppressive effect of asbestos on the production of such fibroblast regulatory lymphokine.

Alveolar macrophage stimulation of lung fibroblast growth in asbestos-induced pulmonary fibrosis

Asbestotic lesions are characterized by macrophagic accumulation, fibroblast proliferation, and collagen deposition. To evaluate the potential involvement of alveolar macrophages in the subsequent fibrogenic reaction, the authors studied the effects of macrophages from normal and asbestos-treated rats upon lung fibroblast proliferation in vitro. Culture supernatants from bronchoalveolar (BAL) cells (99% macrophages) of normal rats stimulated lung fibroblast DNA synthesis and growth in a dose-dependent manner. Fibroblast growth factor (FGF) release by alveolar macrophages (AMs) was rapid (within 1 hour of incubation) and dependent on the number of AMs in culture. Moreover, culture supernatants from BAL cells of animals exposed to asbestos (single intratracheal injection) stimulated fibroblast proliferation to a greater degree than culture supernatants from BAL cells of control animals. Enhanced FGF production occurred 1 week after asbestos instillation and persisted up to 24 weeks. This change was accompanied in the early stages (1-4 weeks) by an increase in the total number of BAL cells which returned to control values by 12 weeks. Differential analysis of BAL cell populations showed a transient infiltration of neutrophils in the bronchoalveolar compartment followed by a significant accumulation of macrophages which persisted up to 1 month. Furthermore, lungs of asbestos-treated animals showed evidence of pathologic alterations characterized by fibroblast proliferation and collagen deposition. This study demonstrates that increased production of fibroblast growth factor by alveolar macrophages in vitro coincides with the development of asbestos-induced fibrosis. Prolonged stimulation of FGF release may contribute to excessive fibroblast proliferation and fibrosis.

Repeated coronary artery bypass grafting in patients with patent atherosclerotic grafts: a special challenge

The operative risk and results of reoperations in patients with long-standing atherosclerotic vein grafts are not well-known. We have had 38 such patients among our last 102 cases of repeated revascularization procedure (37.2%). Six out of those 38 patients were operated taking special measures to avoid atheromatous material displacement and they were compared to the remaining 32 operated on in a conventional way. In addition, all patients, as a group, were compared to another 64 patients undergoing the same procedure in the same time interval but presenting either healthy or occluded grafts. Perioperative myocardial infarction was specially studied. It was more frequent in those with atherosclerotic grafts (23.7 % versus 9.4%) and, among them, in those operated on in a conventional way (25% versus 16.7%). Operative mortality was also higher in the same groups: 13.2% versus 3.1% for atherosclerotic versus non atherosclerotic graft carriers and 15.6% versus none of those operated on in a conventional way versus those in whom special measures were taken. The late results so far are also suboptimal in the same risk groups, although a mean follow-up of 6 months is too brief a period of time. We can therefore conclude that patients with patent atherosclerotic vein grafts have a higher operative risk and worse long-term results, mainly related to a greater perioperative myocardial infarction rate. Special measures to avoid the latter event are warranted.

Collagenolytic activity from circulating polymorphonuclear leucocytes of patients with asbestosis

Levels of collagenolytic activity produced by circulating polymorphonuclear leucocytes (PMN) of patients exposed to asbestos and patients with asbestosis were found to be similar to those of normal controls.

Clinical and angiographic determinants of early mortality related to aortocoronary bypass surgery

Clinical and angiographic features were identified that influences early mortality in 807 patients who underwent aortocoronary bypass grafting alone among the first 1000 consecutive patients subjected to aortocoronary bypass operations at the Montreal Heart Institute. The early mortality was 4.7% and was related to the patient's age, the duration of the illness from its first clinical manifestation, certain types of clinical presentation, electrocardiographic findings, the number of obstructed arteries and the ejection fraction. The influence of the number of obstructed arteries appeared to be independent of other factors, including the number of grafts and the degree of correction. Early mortality was not influenced by risk factors such as lipid abnormalities, hypertension or diabetes, by the history of previous myocardial infarction or the number of grafts.