[Antimicrobial peptides: A new alternative for the treatment of aspergillosis]

Aspergillus fumigatus is the predominant fungal species causing pulmonary aspergillosis. The present-day anti-aspergillosis arsenal is limited, with a number of molecules occasioning severe side effects (amphotericin B) or provoking significant drug interactions (azole derivatives). Moreover, the recent emergence of azole-resistant A. fumigatus strains is a cause for concern. In this context, antimicrobial peptides (AMPs) are emerging as a promising therapeutic approach and alternative or complement to conventional antifungals.

Splicing Patterns in SF3B1-Mutated Uveal Melanoma Generate Shared Immunogenic Tumor-Specific Neoepitopes

Disruption of splicing patterns due to mutations of genes coding splicing factors in tumors represents a potential source of tumor neoantigens, which would be both public (shared between patients) and tumor-specific (not expressed in normal tissues). In this study, we show that mutations of the splicing factor SF3B1 in uveal melanoma generate such immunogenic neoantigens. Memory CD8⁺ T cells specific for these neoantigens are preferentially found in 20% of patients with uveal melanoma bearing SF3B1-mutated tumors. Single-cell analyses of neoepitope-specific T cells from the blood identified large clonal T-cell expansions, with distinct effector transcription patterns. Some of these expanded T-cell receptors are also present in the corresponding tumors. CD8⁺ T-cell clones specific for the neoepitopes specifically recognize and kill SF3B1-mutated tumor cells, supporting the use of this new family of neoantigens as therapeutic targets. SIGNIFICANCE: Mutations of the splicing factor SF3B1 in uveal melanoma generate shared neoantigens that are uniquely expressed by tumor cells, leading to recognition and killing by specific CD8 T cells. Mutations in splicing factors can be sources of new therapeutic strategies applicable to diverse tumors.This article is highlighted in the In This Issue feature, p. 1861.

Tumor invasion in draining lymph nodes is associated with Treg accumulation in breast cancer patients

Tumor-draining lymph node (TDLN) invasion by metastatic cells in breast cancer correlates with poor prognosis and is associated with local immunosuppression, which can be partly mediated by regulatory T cells (Tregs). Here, we study Tregs from matched tumor-invaded and non-invaded TDLNs, and breast tumors. We observe that Treg frequencies increase with nodal invasion, and that Tregs express higher levels of co-inhibitory/stimulatory receptors than effector cells. Also, while Tregs show conserved suppressive function in TDLN and tumor, conventional T cells (Tconvs) in TDLNs proliferate and produce Th1-inflammatory cytokines, but are dysfunctional in the tumor. We describe a common transcriptomic signature shared by Tregs from tumors and nodes, including CD80, which is significantly associated with poor patient survival. TCR RNA-sequencing analysis indicates trafficking between TDLNs and tumors and ongoing Tconv/Treg conversion. Overall, TDLN Tregs are functional and express a distinct pattern of druggable co-receptors, highlighting their potential as targets for cancer immunotherapy.

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.

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.

How to improve the preoperative staging of presumed early-stage endometrioid endometrial cancer?

PURPOSE OF INVESTIGATION

Accurate preoperative staging of early-stage endometrioid endometrial cancer (EEC) is necessary to avoid under or over surgical treatment. The objective is to determine the rate of understaging and to evaluate the accuracy of different methods: hysteroscopy-curettage versus endometrial biopsy in predicting the final stage.

MATERIALS AND METHODS

This retrospective single-centre study led from 2000 to 2010, included women with EEC preoperatively assessed at low- or intermediate-risk. Understaging was defined as a postoperative FIGO Stage > 1 or a determination of high risk after the final histopathologic diagnosis.

RESULTS

The study included 101 women (75 low-risk and 26 intermediate-risk). Final diagnosis was upstaged for 26 of them, more frequently in the presumed intermediate-risk group (57.7% vs 14.7%, p < 0.001). The rate of preoperative understaging was higher in the women with endometrial biopsies than those with curettage (34.5% vs 15.2%, p = 0.04).

CONCLUSIONS

Hysteroscopy-curettage combined with magnetic resonance imaging (MRI) may improve preoperative staging of early-stage EEC, especially for presumed intermediate-risk disease.

Kidney transplant recipients treated with belatacept exhibit increased naïve and transitional B cells

Phase III clinical studies have shown that kidney transplant (KT) recipients treated with the costimulation blocker belatacept exhibited a better renal allograft function and lower donor-specific anti-HLA immunization when compared to recipients treated with calcineurin inhibitors (CNI). We analyzed B cell phenotype in KT recipients treated with belatacept and stable renal function (N = 13). Results were compared to those observed in stable patients treated with CNI (N = 12), or with chronic antibody-mediated rejection (N = 5). Both transcriptional profile and phenotypic characterization of peripheral B cells were performed by real-time polymerase chain reaction and flow cytometry, respectively. In belatacept group, the frequency and absolute number of transitional B cells as defined by both phenotypes: CD19(+) CD24(hi) CD38(hi) and CD19(+) IgD(hi) CD38(hi) CD27(-) , as well as naïve B cells were significantly higher compared with CNI group. B cell activating factor (BAFF) and BAFF receptor mRNA levels were significantly lower in belatacept group than in CNI group. These results show for the first time that belatacept influences B cell compartment by favoring the occurrence of transitional B cells with potential regulatory properties, as described in operational tolerant patients. This role may explain the lower alloimmunization rate observed in belatacept-treated patients.

[Esophageal atresia: prevalence, prenatal diagnosis and prognosis]

Esophageal atresia (EA) is a rare congenital malformation (1 in 2,500 to 3,500 births). Prenatal diagnosis (PN) is particularly interesting allowing search for associated malformations related to worse prognosis forms (reference ultrasound, MRI and amniocentesis) and planning the birth in an adapted medico-surgical center. Diagnosis of EA is usually suspected because of indirect and non-specific signs: association of polyhydramnios and absent or small stomach bubble. The visualization in ultrasound or MRI of cervical or thoracic fluid image corresponding to the expansion of the bottom of upper esophageal ("pouch sign") increases the specificity of diagnosis. However, prenatal diagnosis remains difficult and less than 50 % of EA are diagnosed prenatally. Biochemical analysis could improve these results. If EA is confirmed at birth, surgical management consists in a primary end-to-end anastomosis in first days of life, or in two-steps surgery if the defect is too large. Although current prognosis of EA is good, frequency of surgical complications and esophageal lesions secondary to gastroesophageal reflux justify a systematic and multidisciplinary extended follow-up.

Progressive anterior vertebral fusion: a report of three cases

We report a series of three cases of progressive anterior vertebral fusion diagnosed and monitored in our establishment. This very rare condition was discovered in young children while exploring a spinal deformity. With X-rays of the thoracolumbar spine it was possible to make a positive diagnosis and ensure follow-up. The radiographic semeiotics are characteristic and combine anterior pinching of the disc, well-delimited erosion of the anterior vertebral corners and anterior then posterior intervertebral ankylosis. MRI is very useful for assessing the extent of the intervertebral ankylosis and the condition of the residual discs, without irradiation. The condition develops over several months or years. Conservative treatment is usually sufficient.

Value of fat-suppression gradient-echo MR imaging in the diagnosis of ovarian cystic teratomas

Gradient-echo MR imaging (MRI) was evaluated for the diagnosis of ovarian mature cystic teratomas (MCTs). The FLASH technique was applied to T1-weighted images with and without fat suppression in 18 surgical operated patients with 19 MCTs, and findings were compared to those of conventional spin-echo (SE) T1-weighted-SE. Seventeen out of 19 MCTs were correctly diagnosed using FLASH and SE T1-weighted MR images with and without fat saturation. This study suggests that gradient-echo MRI can replace conventional SE T1-weighted MRI for the diagnosis of ovarian MCTs.

[Determination of the best diagnostic criteria of sacroiliitis with MRI]

AIM

To determine which signs are the most accurate in the diagnosis of sacroiliitis with MRI.

MATERIAL AND METHODS

40 consecutive patients with inflammatory low back pain underwent MRI at 1.5 T with FSE T2 and SE T1 weighted-images before and after Gadolinium-DOTA injection. 22 patients were suffering from spondylarthropathy while the other 18 patients constituted the control group. Each examination was interpreted by two independent observers who analysed 11 different signs.

RESULTS

Intra and inter observer reproducibility were high (respectively 76% and 70%). Inter observer reproducibility was excellent for bone marrow edema (89%) but low for bone productions (38%). Three lesions displayed a high positive predictive value: ligamentous contrast enhancement (86%), bone marrow edema (80%) and bone erosions (70%). Intra articular enhancement of the sacro-iliac joint was a less sensitive sign than bone marrow edema.

CONCLUSION

This study confirms the excellent positive predictive value of MRI for an early diagnosis of active sacroiliitis. Bone marrow edema seems to be a more pertinent sign than intra articular enhancement.

Utility of CT scan for the diagnosis of chest wall tuberculosis

The objective of this study was to determine the utility of CT scan findings for the diagnosis of chest wall tuberculosis, excluding the spine. We reviewed 15 patients (13 Africans and 2 Indians) with chest wall tuberculosis, retrospectively. The radiologic examination consisted of a plain X-ray and a CT scan of the chest for each patient. The site of disease was the rib in 13 patients or the body of the sternum in 2 patients. One rib was involved in 11 patients, 2 contiguous ribs (one site) in 2 patients, and bilateral disease (two sites) was observed in the remaining patient. The 14 rib sites involved the posterior arc or costovertebral joint in 11 cases, the anterior arc in 2 cases, and the anterior and middle arc in 1 case. The CT scan findings were an abscess (n = 14) or a soft tissue mass (n = 2), osteolytic lesions (n = 13), periosteal reaction (n = 10), and sequestrum (n = 14). Bone sclerosis was observed only in 3 cases of rib involvement. The association of a soft tissue abscess, an osteolytic lesion, and sequestrum, especially in immigrants to France, suggests chest wall tuberculosis on CT scan.

Effects of low temperature on nitrate uptake, and xylem and phloem flows of nitrogen, in Secale cereale L. and Brassica napus L

The effect of low temperature on nitrate uptake and subsequent N translocation and cycling was investigated in Secale cereale L. and Brassica napus L. transferred to 7 °C for 9 d or kept at a warm temperature (20 °C). Some plants were grown with a split root system and ¹⁵ NO₃ ^- , labelled to measure NO₃ ^- uptake, root-to-shoot and shoot-to-root translocation of N from NO₃ ^- , taken up. Other plants with single-root system were subjected to ¹⁵ N pulse-chase labelling to quantify endogenous N remobilization. Lowering growth temperature from 20 to 7 °C reduced nitrate uptake more strongly in rye (-59%) than in winter rape (-28%). A very large proportion of the nitrate taken up was further translocated to shoots in both species. However, lowering the temperature decreased, xylem N translocation by about 60 and 30% in S. cereale and B. napus, respectively. Most root N in the latter species came directly from root absorption, while in rye roots the proportions ascribe able to direct root allocation and phloem flow were well balanced. Cold treatment did not significantly modify the imbalance between the two origins. Mobilization of endogenous N from roots to shoot, estimated by pulse-chase labelling, was limited in B. napus and significant in S. cereale despite a depressive effect of low temperature. In general, low temperature led to an increase in root N concentration in both species. It is Suggested that low temperature may directly affect the nitrate uptake system, and also that N accumulation in the roots (resulting from greater inhibition of N xylem flow than of NO₃ ^- uptake) might increase the inhibition of uptake by higher cellular NO₃ , and/or amino acid content. The usefulness (for spring growth) of root N accumulation triggered by low temperature is discussed.