Feasibility of a dietary intervention to modify gut microbial metabolism in patients with hematopoietic stem cell transplantation

Evaluation of the impact of dietary intervention on gastrointestinal microbiota and metabolites after allogeneic hematopoietic stem cell transplantation (HCT) is lacking. We conducted a feasibility study as the first of a two-phase trial. Ten adults received resistant potato starch (RPS) daily from day -7 to day 100. The primary objective was to test the feasibility of RPS and its effect on intestinal microbiome and metabolites, including the short-chain fatty acid butyrate. Feasibility met the preset goal of 60% or more, adhering to 70% or more doses; fecal butyrate levels were significantly higher when participants were on RPS than when they were not (P < 0.0001). An exploratory objective was to evaluate plasma metabolites. We observed longitudinal changes in plasma metabolites compared to baseline, which were independent of RPS (P < 0.0001). However, in recipients of RPS, the dominant plasma metabolites were more stable compared to historical controls with significant difference at engraftment (P < 0.05). These results indicate that RPS in recipients of allogeneic HCT is feasible; in this study, it was associated with significant alterations in intestinal and plasma metabolites. A phase 2 trial examining the effect of RPS on graft-versus-host disease in recipients of allogeneic HCT is underway. ClinicalTrials.gov registration: NCT02763033 .

Should PICCs be avoided in patients with certain solid organ cancers?

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Background: Peripherally inserted central catheters (PICCs) are widely utilized in oncology. Previous studies have shown a high risk of catheter-related thrombosis and bloodstream infection in the uniquely susceptible oncologic population; however, most studies are limited by single center, outpatient, retrospective designs. Therefore, we performed a multi-center study to further describe PICC use and complications in the solid tumor population within the inpatient setting. Methods: Data was collected on PICC lines inserted across 50 hospitals in Michigan from November 2013 to December 2019. Patients with a solid tumor diagnosis at time of PICC insertion were selected (n = 3,956). Indications for PICC placement, catheter characteristics, and associated complications were compared by metastatic (n = 1,488) and non-metastatic (n = 2,468) disease. Complications were also compared by cancer type. Major complications were defined as central line associated blood stream infection (CLABSI), catheter occlusion, deep vein thrombosis (DVT), and pulmonary embolism (PE). Paired t-test and Pearson Chi-square test were used for analyses. Results: PICCs were most commonly placed for antibiotics (n = 1232, 31%) and chemotherapy (n = 907, 23%). The majority of catheters were multi-lumen with 61% (n = 2362) double lumen and 8% (n = 326) triple lumen. Median dwell time was 13 days. Notably, 17% of patients had another central venous catheter (CVC) at time of placement. Metastatic patients were more likely to have a PICC placed for difficult venous access (24.7% vs 17.7%, p < 0.001) and total parenteral nutrition (20.2% vs 12.3%, p < 0.001) as well as to have a current CVC in place (22% vs 14%, p <.001). Non-metastatic patients were more likely to have a PICC placed for chemotherapy (24.1% vs 20.9%, p = 0.02) and have a longer median dwell time (13.0d vs 11.0d, p = 0.04). Of all solid tumor patients, 15.5% (n = 612) experienced a major complication. Catheter occlusion occurred most frequently (n = 402, 10.2%) followed by DVT (n = 138, 3.5%), CLABSI (n = 107, 2.7%), and PE (n = 22, 0.6%). Catheter occlusion was more likely to occur in non-metastatic patients (11% vs 8.8%, p = 0.03). Rates of CLABSI, DVT, and PE did not differ significantly by presence of metastases. Certain cancers had a higher frequency of major complications when compared to the average solid tumor cohort rate of 15.5%; these were malignant brain (17.2%), pancreatic (18.4%), uterine (18.5%), and ovarian tumors (24.2%). Conclusions: PICCs are associated with significant complications in 16% of patients with solid organ cancers. Alternate access such as an implanted port should be considered; alternatively, limiting PICC placement in the presence of concurrent CVC or minimizing use of multiple lumen PICCs may limit complications and resultant morbidity. Specifically, these considerations may apply preferentially to patients with certain solid organ cancers with higher rates of PICC associated morbidity.

Multicentre retrospective study of intravascular large B-cell lymphoma treated at academic institutions within the United States

Intravascular large B-cell lymphoma (IVLBCL) is a rare entity, with a generally aggressive course that may vary based on geographic presentation. While a United States (US) registry study showed relatively good outcomes with IVLBCL, clinicopathological and treatment data were unavailable. We performed a detailed retrospective review of cases identified at 8 US medical centres, to improve understanding of IVLBCL and inform management. We compiled data retrieved via an Institutional Review Board-approved review of IVLBCL cases identified from 1999 to 2015 at nine academic institutions across the US. We characterized the cohort's clinical status at time of diagnosis, presenting diagnostic and clinical features of the disease, treatment modalities used and overall prognostic data. Our cohort consisted of 54 patients with varying degrees of clinical features. Adjusting for age, better performance status at presentation was associated with increased survival time for the patients diagnosed in vivo (hazard ratio: 2·12, 95% confidence interval 1·28, 3·53). Based on the data we have collected, it would appear that the time interval to diagnosis is a significant contributor to outcomes of patients with IVLBCL.

Basal ganglia volumes and white matter hyperintensities in patients with bipolar disorder

OBJECTIVE

Accumulating evidence suggests an association between abnormalities of the basal ganglia and affective disorders. The authors hypothesized that patients with bipolar disorder would demonstrate smaller basal ganglia volumes and a greater number of hyperintensities on magnetic resonance imaging than comparison subjects who were matched on age, race, sex, and education.

METHOD

Volumes of the caudate, putamen, and globus pallidus were measured in 30 patients with bipolar disorder and 30 matched normal comparison subjects. The presence, number, and location of hyperintensities were also assessed.

RESULTS

Male patients with bipolar disorder demonstrated larger caudate volumes than male comparison subjects. Older, but not younger, patients with bipolar disorder demonstrated more hyperintensities than comparison subjects, primarily in frontal lobe white matter.

CONCLUSIONS

These results are not consistent with those of previous studies showing reduced basal ganglia volume in subjects with affective disorders, but they are consistent with previous findings of increased white matter hyperintensities, especially in older patients with bipolar disorder. Considered together with results from other studies, the findings suggest that the nature of basal ganglia/subcortical white matter involvement may differ according to the type of depression (unipolar versus bipolar) and the age and sex of the patient.