Brain-Derived Neurotrophic Factor (BDNF) Is Associated with Platelet Activity and Bleeding Tendency in Patients with Gaucher Disease.

Bleeding tendency, a prominent feature of patients with Gaucher disease (GD), is associated with abnormal platelet function. Brain-derived neurotrophic factor (BDNF) is a protein with neuroprotective potential stored in alpha granules of circulating platelets. Here we studied BDNF levels in 50 patients with type I GD (GD1) and their correlation with platelet activity and bleeding tendency. Flow cytometry was used to test unstimulated and stimulated measurement of platelet surface-activated expression of αIIbß3 integrin, P-selectin and lysosomal-associated membrane protein (LAMP3/CD63). Serum and plasma BDNF levels were quantified using ELISA. The bleeding history was recorded by a bleeding questionnaire. Serum BDNF levels were positively correlated with platelet count and moderately correlated with unstimulated and stimulated platelet P-selectin expression. Patients with more than one bleeding manifestation were shown to have lower serum BDNF levels, albeit similar platelet count. Plasma BDNF levels were significantly elevated in splenectomized patients and showed a moderate positive correlation with stimulated platelet CD63 expression. These observations demonstrate the first association between BDNF levels in the peripheral blood with platelet dysfunction and increased bleeding manifestation. The role of measuring serum BDNF for assessing platelet alpha degranulation defects and bleeding risk in patients with GD and the general population needs further study.

Anti-CD20 monoclonal antibodies inhibit seropositive response to Covid-19 vaccination in non-Hodgkin lymphoma patients within 6 months after treatment.

The Covid-19 pandemic has caused millions of deaths worldwide. Although vaccines have been developed, patients on immunosuppressive therapy are less likely to respond. This study was aimed at investigating the efficacy of a Covid-19 vaccine (Pfizer-BioNTech) in patients with non-Hodgkin lymphoma treated with anti-CD20 monoclonal antibodies. Only 1 of 28 lymphoma patients (3.6%) developed a seropositive response, compared with 100% (28/28) of the healthy volunteers. The low levels of CD19+ lymphocytes among the lymphoma patients suggest that anti-CD20 treatment prevents the seropositive response to the vaccine. An additional vaccination might be indicated in these patients once B cells are repopulated.

Trauma and pregnancy: Is flow cytometry detection and quantification of fetal red blood cells useful?

OBJECTIVE: To assess whether positive flow cytometry quantification of fetal red blood cells is associated with adverse maternal and neonatal outcomes in cases of mild trauma during pregnancy. STUDY DESIGN: A retrospective database study was conducted at a single tertiary center between 2013 and 2019. All pregnant women with viable gestation involved in trauma who underwent flow cytometry quantification of fetal red blood cells were included in the study. Flow cytometry was considered positive (≥0.03/≥30 ml). Composite adverse maternal and neonatal outcome was defined as one or more of the following: intrauterine fetal death, placental abruption, pre-term birth <37 weeks of gestation, immediate premature rupture of the membranes, and immediate delivery following trauma. Univariate analysis was performed followed by multivariate logistic regression analysis controlling for potential confounders, to assess the role of flow cytometry in predicting adverse maternal and neonatal outcome. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated. RESULTS: During the study period 1023 women met inclusion and exclusion criteria. The mechanisms of injury were motor vehicle accident in 387 women (38%), falls in 367 (36%), direct abdominal injury in 353 (35%) and in 14 women (1%) other mechanism of injury. Flow cytometry was considered positive (≥0.03/≥30 ml) in 119 women (11.6%) with median result of 0.03 [0.03-0.04], and negative in 904 women (88.4%) ((≤0.03/≤30 ml) with median result of 0.01 [0.01-0.02]. Composite adverse outcome occurred in 8% of the women involved in trauma during pregnancy, with no difference between the groups with vs. without positive flow cytometry (4.2% vs. 8.5%; p = 0.1). Positive flow cytometry was not associated with any adverse maternal or neonatal outcome. This was confirmed on multivariate analysis controlling for potential confounders. CONCLUSION: Flow cytometry result is not related to adverse maternal and fetal/neonatal outcome of women involved in minor trauma during pregnancy. We suggest that flow cytometry should not be routinely assessed in pregnant women involved in minor trauma.

The cellular immunological responses of patients undergoing coronary artery bypass grafting compared with those of patients undergoing valve replacement.

OBJECTIVE: Major surgical intervention such as cardiac surgery has been shown to have profound effects on the immune system. We conducted a prospective study comparing the effects of coronary artery bypass grafting (CABG) versus isolated valve surgery. METHODS: Blood samples were drawn from 59 patients undergoing either elective CABG or elective isolated valve replacement surgery. Samples were obtained preoperatively and on the first and third postoperative days. Total cell counts and differential counts were recorded. Several cellular immunity parameters were determined by flow cytometry. RESULTS: On all postoperative days, significant increases in white blood cell (WBC) and monocyte counts were observed. Significant decreases in all lymphocyte populations were also observed with similar decreases in both helper (CD4) and suppressor (CD8) T cells. An increase in activated T cells was noted on day 1, returning to normal on the third postoperative day. Despite the significant decrease in human leucocyte antigen-DR (HLA-DR) antigen expression on monocytes on both the first and third postoperative days, a significant increase in monocyte activation as represented by increased CD11b and CD64 expression was detected. No significant difference was found for any of the measured parameters between the CABG group and the valve replacement group. Eight patients developed early wound infections, with no correlation with any of the measured parameters, including magnitude and duration of decrease in HLA-DR antigen expression on monocytes. CONCLUSIONS: Cardiac surgery induces both a state of pro-inflammation and of immune suppression. The two major types of cardiac surgery induce similar effects to the immune system. None of the measured parameters was predictive for development of postoperative wound infection.

Prospective evaluation of colonization with extended-spectrum beta-lactamase (ESBL)-producing enterobacteriaceae among patients at hospital admission and of subsequent colonization with ESBL-producing enterobacteriaceae among patients during hospitalization.

OBJECTIVE: To determine the rates of and risk factors for carriage and acquisition of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae during hospitalization. DESIGN: Cohort study. SETTING: Shaare Zedek Medical Center, a 550-bed teaching hospital. METHODS: During a 5-month period (February 1-June 30, 2004), 167 (8%) of 1,985 newly admitted general medical patients were enrolled in our study. Nasal, oropharyngeal, and rectal swab specimens were obtained at admission and every 2-3 days until hospital discharge or death. Enterobacteriaceae isolates were tested for ESBL, and Staphylococcus aureus isolates were tested for methicillin resistance. RESULTS: Of the 167 patients enrolled in our study, 15 (9%) were identified as nasal carriers of methicillin-resistant S. aureus (MRSA) at admission, and 13 (8%) were rectal carriers of ESBL-producing Enterobacteriaceae at admission. Univariate risk factors for rectal carriage of ESBL-producing Enterobacteriaceae included female sex (odds ratio [OR], 11 [95% confidence interval {CI}, 1.4-238]; P < .05), nursing home residence (OR, 6.9 [95% CI, 1.8-27]; P < .01), recent antibiotic treatment (OR, 9.8 [95% CI, 1.7-74]; P < .05), and concomitant nasal carriage of MRSA and/or ESBL-producing Enterobacteriaceae (OR, 5.8 [95% CI, 1.2-26]; P < .01). Multivariate risk factors were female sex and recent antibiotic treatment. During hospitalization, 35 (21%) of 167 patients had acquired rectal carriage of ESBL-producing Enterobacteriaceae (P = .002, for trend analysis). Of the 12 patients who were still in the hospital 2 weeks after admission, 4 (33%) were carriers of ESBL-producing Enterobacteriaceae. Univariate risk factors for acquisition included an age of older than 65 years (P < .005), nursing home residence (OR 2.6, [95% CI, 0.98-2.6]), impaired cognition (OR, 4.8 [95% CI, 1.9-12]), recent antibiotic treatment (OR, 2.7 [95% CI, 0.9-8.3]), respiratory assistance (OR, 4.2 [95% CI, 1.2-14]), and prolonged hospitalization. Multivariate risk factors were an age of older than 65 years and broad-spectrum antibiotic therapy. CONCLUSIONS: Rectal carriage of ESBL-producing Enterobacteriaceae occurred in 13 (8%) of 167 patients at admission to the medical departments of our hospital and in 4 (33%) of 12 patients still remaining in our hospital after 2 weeks.

Direct fluconazole susceptibility testing of positive Candida blood cultures by flow cytometry.

The standard methods for yeast susceptibility testing require 24-48 h of incubation. As there has been an increase in incidence of non-albicans Candida species, the clinician is very often wary of initiating therapy with fluconazole until a final susceptibility report is generated, especially when treating very sick patients. A rapid reliable susceptibility testing method would enable the clinician to prescribe fluconazole, thus avoiding more toxic or expensive therapy. To determine the feasibility of direct susceptibility testing of Candida species to fluconazole by a rapid flow cytometric method, 50 Candida strains were seeded into blood culture bottles and were tested for susceptibility to fluconazole directly from the bottles after their being flagged as positive by the blood culture instrument. Minimal inhibitory concentration (MIC) determined by fluorescent flow cytometry (FACS) showed excellent agreement to that determined by macrodilution. Following the seeding experiments, 30 true patient specimens were tested directly from positive blood cultures, and MIC determined by both methods showed excellent agreement. Antifungal susceptibility testing by FACS directly from positive blood culture bottles is a reliable, rapid method for susceptibility testing of Candida to fluconazole. The method allows same-day results, does not require subculture to agar media, and can greatly assist in the selection of appropriate antifungal therapy.

Susceptibilities of ESBL-producing Enterobacteriaceae to ertapenem, meropenem and piperacillin-tazobactam with and without clavulanic acid.

BACKGROUND: Faced with the extended-spectrum beta-lactamase (ESBL) pandemic, we compared the susceptibilities of ESBL-producing Enterobacteriaceae to ertapenem, meropenem and piperacillin-tazobactam with and without clavulanate. METHODS: 121 strains of Escherichia coli and Klebsiella were studied. 70 strains were originally reported as resistant to ceftazidime based upon disk diffusion; 51 strains were originally reported as sensitive to ceftazidime based upon previous guidelines of the National Committee for Clinical Laboratory Standards, but subsequently shown to be ESBL producers. Minimal inhibitory concentrations (MICs) of the strains towards ertapenem, meropenem and piperacillin-tazobactam were determined by Etest. The effect of adding clavulanate on the MICs was determined by performing the Etest, using plates containing 2 microg/ml of clavulanate. RESULTS: The MIC90 of all isolates was 0.094 and 0.25 microg/ml for ertapenem, 0.032 and 0.064 microg/ml for meropenem, and 16 and 256 microg/ml for piperacillin-tazobactam with and without clavulanate, respectively. CONCLUSIONS: ESBL-producing organisms were more susceptible to meropenem than to ertapenem, although the MICs to ertapenem were well within clinically achievable levels. Piperacillin-tazobactam was ineffective in a large percentage of isolates. The presence of clavulanate resulted in a 5-fold decrease in the MIC of ertapenem and in a drastic reduction in the MIC of piperacillin-tazobactam. The decrease observed with ertapenem is unlikely to be of clinical significance. Thus, in our hospital, ertapenem could be a good meropenem-sparing agent for infections due to ESBL-producing organisms. Piperacillin-tazobactam appeared to be a poor choice, as our isolates produce ESBLs which are not successfully inhibited by tazobactam.

Acquisition of multidrug-resistant organisms among hospital patients hospitalized in beds adjacent to critically ill patients.

OBJECTIVE: To assess whether patients hospitalized in beds physically adjacent to critically ill patients are at increased risk to acquire multidrug-resistant pathogens. DESIGN: Cohort study.Setting. Shaare Zedek Medical Center, a 550-bed medical referral center. PATIENTS: From April to September 2004, we enrolled consecutive newly admitted patients who were hospitalized in beds adjacent to either mechanically ventilated patients or patients designated as "do not resuscitate" (DNR). For each of these patients, we also enrolled a control patient who was not hospitalized in a bed adjacent to a critically ill patient. We collected specimens from the anterior nares, the oral cavity, and the perianal zone at the time of admission and subsequently at 3-day intervals until discharge or death. Specimens were cultured on selective media to detect growth of antibiotic-resistant pathogens, including Acinetobacter baumannii, methicillin-resistant Staphylococcus aureus (MRSA), extended-spectrum beta lactamase (ESBL)-producing Enterobacteriaceae, and vancomycin-resistant enterococci (VRE). RESULTS: We enrolled 46 neighbor-control pairs. Among neighbors and controls, respectively, the incidence rates for isolation of A. baumannii was 8.3 and 4 isolations per 100 patient-days (relative risk [RR], 2.1 [95% confidence interval {CI}, 0.8-5.2]; P=.12), the incidence rates for MRSA were 1.4 and 2.6 isolations per 100 patient-days (RR, 0.6 [95% CI, 0.1-2.3]; P=.45), the incidence rates for ESBL-producing Enterobacteriaceae were 10.5 and 9 isolations per 100 patient-days (RR, 1.2 [95% CI, 0.6-2.4]; P=.84), the incidence rates for VRE were 4.3 and 4.8 isolations per 100 patient-days (RR, 0.9 [95% CI, 0.3-2.4]; P=1), and the composite incidence rate was 21.7 and 16.2 isolations per 100 patient-days (RR, 1.3 [95% CI, 0.8-2.3]; P=0.3). CONCLUSIONS: In this pilot study, we did not detect an increased incidence rate of isolation of multidrug-resistant pathogens among patients hospitalized in beds adjacent to critically ill patients. Further studies with larger samples should be conducted in order to generate valid data and provide patients, physicians, and policy makers with a sufficient knowledge base from which decisions can be made.