Germinal center reactions in tertiary lymphoid structures associate with neoantigen burden, humoral immunity and long-term survivorship in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) has traditionally been thought of as an immunologically quiescent tumor type presumably because of a relatively low tumor mutational burden (TMB) and poor responses to checkpoint blockade therapy. However, many PDAC tumors exhibit T cell inflamed phenotypes. The presence of tertiary lymphoid structures (TLS) has recently been shown to be predictive of checkpoint blockade response in melanomas and sarcomas, and are prognostic for survival in PDAC. In order to more comprehensively understand tumor immunity in PDAC patients with TLS, we performed RNA-seq, single and multiplex IHC, flow cytometry and predictive genomic analysis on treatment naïve, PDAC surgical specimens. Forty-six percent of tumors contained distinct T and B cell aggregates reflective of “early-stage TLS” (ES-TLS), which correlated with longer overall and progression-free survival. These tumors had greater CD8⁺ T cell infiltration but were not defined by previously published TLS gene-expression signatures. ES-TLS⁺ tumors were enriched for IgG1 class-switched memory B cells and memory CD4⁺ T cells, suggesting durable immunological memory persisted in these patients. We also observed the presence of active germinal centers (mature-TLS) in 31% of tumors with lymphocyte clusters, whose patients had long-term survival (median 56 months). M-TLS-positive tumors had equivalent overall T cell infiltration to ES-TLS, but were enriched for activated CD4⁺ memory cells, naive B cells and NK cells. Finally, using a TCGA-PDAC dataset, ES-TLS⁺ tumors harbored a decreased TMB, but M-TLS with germinal centers expressed significantly more MHCI-restricted neoantigens as determined by an in silico neoantigen prediction method. Interestingly, M-TLS⁺ tumors also had evidence of increased rates of B cell somatic hypermutation, suggesting that germinal centers form in the presence of high-quality tumor neoantigens leading to increased humoral immunity that confers improved survival for PDAC patients.

AbbreviationsTLS: tertiary lymphoid structures; GC: germinal center(s); PDAC: pancreatic ductal adenocarcinoma; RNA-seq: RNA sequencing; BCRseq: B cell receptor sequencing; HEV: high endothelial venule; PNAd: peripheral node addressin; TMB: tumor mutational burden; TCGA: the cancer genome atlas; PAAD: pancreatic adenocarcinoma; FFPE: formalin fixed paraffin embedded; TIME: tumor immune microenvironment.

Female gender and diabetes mellitus increase the risk of recurrence after laparoscopic incisional hernia repair

BACKGROUND

Laparoscopic hernia repair is used widely for the repair of incisional hernias. Few case studies have focussed on purely 'incisional' hernias. This multicentre series represents a collaborative effort and employed statistical analyses to provide insight into the factors predisposing to recurrence of incisional hernia after laparoscopic repair. A specific hypothesis (ie, laterality of hernias as well as proximity to the xyphoid process and pubic symphysis predisposes to recurrence) was also tested.

METHODS

This was a retrospective study of all laparoscopic incisional hernias undertaken in six centres from 1 January 2004 to 31 December 2010. It comprised a comprehensive review of case notes and a follow-up using a structured telephone questionnaire. Patient demographics, previous medical/surgical history, surgical procedure, postoperative recovery, and perceived effect on quality of life were recorded. Repairs undertaken for primary ventral hernias were excluded. A logistic regression analysis was then fitted with recurrence as the primary outcome.

RESULTS

A total of 186 cases (91 females) were identified. Median follow-up was 42 months. Telephone interviews were answered by 115/186 (62%) of subjects. Logistic regression analyses suggested that only female sex (odds ratio (OR) 3.53; 95% confidence interval (CI) 1.39-8.97) and diabetes mellitus (3.54; 1-12.56) significantly increased the risk of recurrence. Position of the defect had no statistical effect.

CONCLUSIONS

These data suggest an increased risk of recurrence after laparoscopic incisional hernia repair in females and subjects with diabetes mellitus. These data will help inform surgeons and patients when considering laparoscopic management of incisional hernias. We recommend a centrally hosted, prospectively maintained national/international database to carry out additional research.

Root biomass production in populations of six rooted macrophytes in response to Cu exposure: intra-specific variability versus constitutive-like tolerance

Intra-specific variability of root biomass production (RP) of six rooted macrophytes, i.e. Juncus effusus, Phragmites australis, Schoenoplectus lacustris, Typha latifolia, Phalaris arundinacea, and Iris pseudacorus grown from clones, in response to Cu exposure was investigated. Root biomass production varied widely for all these macrophytes in control conditions (0.08 μM) according to the sampling site. Root biomass production of T. latifolia and I. pseudacorus in the 2.5-25 μM Cu range depended on the sampling location but not on the Cu dose in the growth medium. For P. australis, J. effusus, S. lacustris, and P. arundinacea, an intra-specific variability of RP depending on both the sampling location and the Cu-dose was evidenced. This intra-specific variability of RP depending on the sampling location and of Cu-tolerance for these last four species suggests that Cu constitutive tolerance for all rooted macrophytes is not a species-wide trait but it exhibits variability for some species.

Salt or sugar for your injured brain? A meta-analysis of randomised controlled trials of mannitol versus hypertonic sodium solutions to manage raised intracranial pressure in traumatic brain injury

BACKGROUND

Rising intracranial pressure (ICP) is a poor prognostic indicator in traumatic brain injury (TBI). Both mannitol and hypertonic sodium solutions are used to treat raised ICP in patients with TBI.

OBJECTIVE

This meta-analysis compares the use of mannitol versus hypertonic sodium solutions for ICP control in patients with TBI.

DATA SOURCES AND STUDY ELIGIBILITY

Randomised clinical trials in adults with TBI and evidence of raised ICP, which compare the effect on ICP of hypertonic sodium solutions and mannitol.

METHODS

The primary outcome measure is the pooled mean reduction in ICP. Studies were combined using a Forest plot.

RESULTS

Six studies were included, comprising 171 patients (599 episodes of raised ICP). The weighted mean difference in ICP reduction, using hypertonic sodium solutions compared with mannitol, was 1.39 mm Hg (95% CI -0.74 to 3.53).

LIMITATIONS

Methodological differences between studies limit the conclusions of this meta-analysis.

CONCLUSIONS

The evidence shows that both agents effectively lower ICP. There is a trend favouring the use of hypertonic sodium solutions in patients with TBI.

Abstract P4-04-02: Tumor-initiated peripheral myeloid cell expansion is reversed by radiation therapy

Myeloid lineage cells, particularly monocytes and macrophages, have an important role in the development and progression of cancer. Within established tumors, macrophages are critical for angiogenesis, invasion, metastasis, immunosuppression and response to therapy. In addition, both transplantable and transgenic mouse models of mammary cancer are associated with myeloid expansions detectible in the tumor, spleen and peripheral blood, and these myeloid cells are able to suppress T cell activation in vitro. Reducing the tumor burden through chemotherapy and resection has been shown to control the myeloid expansion. However, chemotherapies that reduce tumor burden also have direct effects on myeloid cells, and surgical trauma has been shown to mobilize myeloid cells. Radiation therapy is the third major option to treat cancer, but the consequence of radiation therapy to systemic myeloid populations has not been described. We applied tumor-specific radiation therapy to test the hypothesis that the frequency of myeloid lineage cells correlates with the primary tumor burden. We demonstrate in the MMTV-PyMT model of mammary cancer that myeloid expansion in the blood closely correlates with myeloid involvement in the tumor and with tumor progression. We demonstrate that radiation therapy of 4T1 mammary tumors leads to a decline in myeloid cell numbers in the blood and a decrease in spleen size. The frequency of myeloid cells does not decline to the level seen in tumor-free mice: we demonstrate that metastatic disease can prevent myeloid cell numbers from returning to baseline, and that tumor recurrence from residual disease correlates with re-expansion of myeloid lineage cells. Despite these changes in the frequency of myeloid lineage cells, T cell numbers in the blood and spleen remains constant. However, radiation therapy improves the myeloid cell:CD8+ T cell ratio and results in increased proliferation of T cells in the spleen. Finally, we demonstrate that T cell responses to foreign antigens are not altered by tumor burden or myeloid cell expansion, while T cell responses to tumor-associated antigens are increased after radiation therapy of the tumor. These data demonstrate that myeloid cell numbers are directly linked to primary tumor burden, that this population contracts following radiation therapy, and that radiation therapy may open a therapeutic window for immunotherapy of residual disease.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-04-02.

Compartmentalization of wards to cohort symptomatic patients at the beginning and end of norovirus outbreaks

BACKGROUND

Outbreaks of norovirus can have a significant operational and financial impact on healthcare establishments.

AIM

To assess whether containment of symptomatic patients in single rooms and bays at the beginning and end of norovirus outbreaks reduced the length of bed closure.

METHODS

In 2007, we introduced a new strategy to limit the operational impact of hospital outbreaks of norovirus. Early in an outbreak, symptomatic patients were cohorted in single rooms or bays in an attempt to contain the outbreak without closing the entire ward. Once a ward had been closed, and as beds became available through discharges, patients were decanted into single rooms or empty bays with doors to facilitate earlier cleaning and opening of affected areas on the same ward. The impact of these changes was assessed by comparing outbreak data for two periods before and after implementation of the new strategy.

FINDINGS

Prior to June 2007, 90% of outbreaks were managed by closure of an entire ward, compared with only 54% from June 2007 onwards. The duration of closure was significantly shorter for bays compared with entire wards, both before (3.5 vs 6, P = 0.0327) and after (3 vs 5, P < 0.0001) June 2007. When considering all outbreaks, there was a significant reduction in duration of closure after the change in strategy (6 vs 5, P = 0.007).

CONCLUSION

Using ward compartmentalization to cohort affected patients at the beginning and end of norovirus outbreaks improved the efficiency of outbreak management and reduced operational disruption.

Laparoscopic single site adrenalectomy using a conventional laparoscope and instrumentation

BACKGROUND AND OBJECTIVES

We present a case of Laparoendoscopic Single Site Surgery (LESS) left adrenalectomy performed with a conventional laparoscope and instruments.

METHODS

A 45-year-old male was diagnosed with hyperaldosteronism. Computed tomography detected a left adrenal nodule. Bilateral adrenal vein sampling was consistent with a left-sided source for hyperaldosteronism.

RESULTS

Total operative time for LESS left adrenalectomy was 120 minutes. The surgery was performed with conventional instruments, a standard 5-mm laparoscope, and a SILS port, with no additional incisions or trocars needed. No complications occurred, and the patient reported an uneventful recovery.

CONCLUSIONS

LESS adrenalectomy is a feasible procedure. Although articulating instruments and laparoscopes may offer advantages, LESS adrenalectomy can be done without these.

Postoperative epidural analgesia following elective major abdominal surgery in high risk patients: a retrospective cohort study

AIM

To describe the effect of post-operative epidural analgesia on morbidity and mortality rates in a group of high-risk patients undergoing elective major abdominal surgery.

METHODS

Retrospective chart review of patients in American Society of Anaesthetists Physical Status (ASA) category III or IV, who underwent elective major I or II general surgical procedures between 01/01/1996 and 01/09/1998. Patients were identified from a prospective audit database. Patients who had epidural analgesia or conventional parenteral opioids were compared for outcome measures.

RESULTS

There were 167 patients identified (72 epidural, 95 non-epidural group). There was no significant difference in demographic data, inpatient stay, intensive care unit stay, or mortality rates (11% epidural v 17% non-epidural, p>0.05). There was no significant difference in morbidity rates, however there was a non-significant trend towards a lower morbidity in the epidural group.

CONCLUSIONS

This study does not show any benefit from post-operative epidural analgesia on morbidity and mortality rates in high risk patients undergoing major abdominal surgery. It does illustrate that ASA 3 and 4 patients undergoing major abdominal surgery have a high morbidity and mortality.

Hospital library service and the changes in national standards

Two important sets of standards affecting hospital libraries were significantly revised in 1994, those of the Medical Library Association (MLA) and the Joint Commission on Accreditation of Healthcare Organizations (JCAHO). As part of its continuing efforts to monitor library services within its region, the University of California, Los Angeles Biomedical Library, Regional Medical Library for the Pacific Southwest Region of the National Network of Libraries of Medicine (NN/LM) conducted a survey in late 1994, in part to determine the effects of these revised standards on regional hospital libraries. Data from the survey were also used to provide a view of hospital libraries in the Pacific Southwest region, and to make comparisons with similar data collected in 1989. Results showed that while libraries remained stable in overall number, size, and staffing, services, especially those associated with end-user searching and interlibrary loan, increased enormously. With respect to the MLA standards, results show a high compliance level. Interesting differences were seen between the perceptions of library staff concerning their rate of compliance with the JCAHO standards and their actual compliance as measured by the MLA criteria. While some libraries appear to measure up better than their own perceptions would indicate, others may be fully aware of their actual compliance level.

The efficacy of Decapinol mouthwash 2 mg/mL in preventing gingivitis

In vitro studies and early clinical trials have shown promising results for Delmopinol HCl solution as an effective mouth rinse for reducing experimentally induced gingivitis in the absence of mechanical plaque control. The efficacy of Decapinol mouthwash 2 mg/mL (Delmopinol HCl) in preventing gingivitis in a double-blind, randomized clinical study with parallel group design was studied. Forty-seven healthy young adults were randomly assigned to the Delmopinol or placebo groups. After an initial period of four weeks of intensive oral hygiene including bi-weekly professional cleaning of the teeth and oral hygiene instruction, all subjects achieved a low degree of gingivitis or a plaque score close to zero. At baseline, Bleeding on Probing, Modified Gingival Index and Plaque Index were recorded and the teeth were professionally cleaned. All forms of plaque control were then suspended and subjects were supervised in a one-minute rinsing of Decapinol mouthwash 2 mg/mL or placebo twice daily. Measurements of efficacy variables were then repeated after two and three weeks treatment and adverse events were recorded. After the study period of three weeks all previous plaque control measures were resumed. At week four, all subjects were reassessed for the resolution of gingival inflammation and where residual gingival inflammation persisted, appropriate treatment was given. Only mild and short-lasting adverse events were noted for the use of Delmopinol in the study period. However, for all teeth sites measured, significant differences between Delmopinol and placebo groups were found in Bleeding on Probing (p < 0.05) and Plaque Index (p < 0.0005).(ABSTRACT TRUNCATED AT 250 WORDS)

Tobramycin and ticarcillin as empiric therapy for febrile patients with granulocytopenia: a reevaluation

The combination of tobramycin and ticarcillin is an established regimen used to empirically treat patients with granulocytopenia and fever. However, the clinician now has a plethora of newer alternative antibiotic combinations from which to choose. In this retrospective study of 25 granulocytopenic patients recently treated with tobramycin and ticarcillin, a combined favorable or partial response rate of 78% was achieved, without loss of efficacy over time as a result of emerging resistance of organisms. Our reevaluation of this antibiotic regimen emphasizes that it continues to be as efficacious and safe as newer antibiotic combinations, and supports its continued use until a newer regimen is shown to have significant advantages. This study also emphasizes the significance of staphylococci as pathogens in granulocytopenia, and suggests the need to add specific antistaphylococcal coverage whenever catheter-related infection is suspected.