Risk factors for the failure of treatment of Pseudomonas aeruginosa bacteremia in critically ill patients

Pseudomonas aeruginosa bacteremia is associated with high morbidity and mortality in critically ill patients. In this study, we assessed risk factors for clinical failure of first definitive therapy for P. aeruginosa bacteremia in critically ill patients. All patients with P. aeruginosa bacteremia who entered the intensive care unit in Gifu University Hospital from January 2006 to December 2015 were retrospectively identified from electronic records. Risk factors associated with clinical failure of the first definitive therapy for P. aeruginosa bacteremia were analyzed by logistic regression analysis. A total of 28 patients were enrolled in the analysis. On multivariate analysis, severe burns (odds ratio [OR] = 70.9, 95% CI 2.9-1720.3; p = 0.009) and SOFA score ≥ 10 (OR = 28.5, 95% CI 1.1-754.3; p = 0.045) were significant factors in the clinical failure of first definitive therapy for P. aeruginosa bacteremia. The clinical success rate of first definitive therapy was significantly reduced in patients with these risk factors compared with those without them (p < 0.001). Severe burns and a SOFA score (≥ 10) were significant risk factors associated with the clinical failure of first definitive therapy for P. aeruginosa bacteremia in critically ill patients. We therefore recommend the use of therapeutic drug monitoring to optimize antibiotic dosing in these critically ill patients.

Abstract P4-08-07: PIK3CA mutation, reduced AKT serine 473 phosphorylation, and increased ERα serine 167 phosphorylation are positive prognostic indicators in postmenopausal estrogen receptor-positive, HER2-negative early breast cancer

Background: Endocrine therapy is the most important treatment option for women with estrogen receptor (ER)-positive breast cancer. We recently reported that approximately two-thirds of patients who relapsed within 5 years had received anthracyclins and/or taxanes as adjuvant or neoadjuvant chemotherapy in addition to adjuvant endocrine therapy. New strategies, such as signal transduction inhibitors together with endocrine therapy are required to improve survival. PIK3CA mutations are detected in almost 40% of early ER-positive breast cancers, and are therefore the most frequent genetic alterations in this subtype. PIK3CA mutation status is reported to affect activation of AKT and ERα. Moreover, recent studies demonstrate that patients had a better prognosis when tumors expressed ER, androgen receptor (AR), and vitamin D receptor (VDR).

Methods: Expression of AR and VDR, phosphorylation of AKT serine (Ser) 473 (AKT phospho-Ser473) and ERα Ser167 (ERα phospho-Ser167) were examined by immunohistochemistry in ER-positive, HER2-negative early breast cancer tissues. Seventeen mutations in exons 1, 4, 7, 9, and 20 of the PIK3CA gene were detected in genomic DNA extracted from formalin-fixed paraffin-embedded tumor blocks. Correlations between these biological markers and clinicopathological factors and prognosis were analyzed separately in pre- and postmenopausal women.

Results: Levels of AKT phospho-Ser473 were significantly higher in premenopausal women (n = 62) than in postmenopausal women (n = 152) (P &lt; 0.0001 and P = 0.014, respectively). In contrast, expression levels of AR were significantly higher in postmenopausal women than in premenopausal women (P &lt; 0.0001). In premenopausal women, 26 tumors (43%) had a single mutation of PIK3CA gene, and 3 tumors (5%) had mutations at two sites. In postmenopausal women, 64 tumors (44%) had a single PIK3CA mutation, 6 tumors (4%) had mutations at two sites, and one tumor (1%) had mutations at three sites. In premenopausal women, wild type PIK3CA was associated with smaller tumor size, higher ER expression levels, and lower AR expression levels when compared with women in the same cohort with PIK3CA mutant tumors. In postmenopausal women, patients with PIK3CA wild-type tumors had higher Ki67 labeling index, higher AKT phospho-Ser473, and lower ERα phospho-Ser167 when compared to patients with PIK3CA mutant tumors. Postmenopausal women with PIK3CA wild-type tumors had significantly worse disease-free survival than patients with PIK3CA mutant tumors (P = 0.007). In contrast, PIK3CA mutation status was not correlated with survival in premenopausal women. Low levels of AKT phospho-Ser473 and high levels of ERα phospho-Ser167 were strongly associated with increased disease-free survival in postmenopausal women (P = 0.016 and P = 0.0016, respectively).

Conclusion: ERα activation, in addition to PIK3CA mutation, may be biomarkers for highly endocrine-responsive tumors. This would facilitate the selection of postmenopausal ER-positive breast cancer patients who are likely to benefit from endocrine therapy alone from those who are not.

Citation Format: Ishida N, Hatanaka Y, Baba M, Hagio K, Okada H, Hatanaka KC, Matsuno Y, Yamashita H. PIK3CA mutation, reduced AKT serine 473 phosphorylation, and increased ERα serine 167 phosphorylation are positive prognostic indicators in postmenopausal estrogen receptor-positive, HER2-negative early breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-08-07.

Next-generation sequencing for patients with non-obstructive azoospermia: implications for significant roles of monogenic/oligogenic mutations

Azoospermia affects up to 1% of adult men. Non-obstructive azoospermia is a multifactorial disorder whose molecular basis remains largely unknown. To date, mutations in several genes and multiple submicroscopic copy-number variations (CNVs) have been identified in patients with non-obstructive azoospermia. The aim of this study was to clarify the contribution of nucleotide substitutions in known causative genes and submicroscopic CNVs in the genome to the development of non-obstructive azoospermia. To this end, we conducted sequence analysis of 25 known disease-associated genes using next-generation sequencing and genome-wide copy-number analysis using array-based comparative genomic hybridization. We studied 40 Japanese patients with idiopathic non-obstructive azoospermia. Functional significance of molecular alterations was assessed by in silico analyses. As a result, we identified four putative pathogenic mutations, four rare polymorphisms possibly associated with disease risk, and four probable neutral variants in 10 patients. These sequence alterations included a heterozygous splice site mutation in SOHLH1 and a hemizygous missense substitution in TEX11, which have been reported as causes of non-obstructive azoospermia. Copy-number analysis detected five X chromosomal or autosomal CNVs of unknown clinical significance, in addition to one known pathogenic Y chromosomal microduplication. Five patients carried multiple molecular alterations. The results indicate that monogenic and oligogenic mutations, including those in SOHLH1 and TEX11, account for more than 10% of cases of idiopathic non-obstructive azoospermia. Furthermore, this study suggests possible contributions of substitutions in various genes as well as submicroscopic CNVs on the X chromosome and autosomes to non-obstructive azoospermia, which require further validation.

Successful combination immunotherapy of anti-gamma aminobutyric acid (GABA)A receptor antibody-positive encephalitis with extensive multifocal brain lesions

A 78-year old woman who presented with akinetic mutism was admitted to our hospital. Brain MRI showed multifocal increased T₂/FLAIR signal with extensive cortical-subcortical involvement. We suspected autoimmune encephalitis and the patient received methylprednisolone pulse. Her conscious level gradually recovered, but later relapsed again and presented with refractory status epilepticus. We treated her with intravenous immunoglobulin, plasma exchange and pulsed cyclophosphamide, with satisfactory response. A brain biopsy showed perivascular lymphocytic infiltrates and reactive gliosis. Anti-gamma aminobutyric acid (GABA)_A receptor antibodies test came back to be positive after her recovery, and the diagnosis of anti-GABA_A receptor antibody-positive encephalitis was made. This is a very rare case where brain biopsies were performed in a patient with anti-GABA_A receptor antibody-positive encephalitis.