Case records of the Massachusetts General Hospital. Weekly clinicopathological exercises. Case 20-2003. A nine-year-old girl with hepatosplenomegaly and pain in the thigh

Physicians' pharmacogenomics information needs and seeking behavior: a study with case vignettes

Background

Genetic testing, especially in pharmacogenomics, can have a major impact on patient care. However, most physicians do not feel that they have sufficient knowledge to apply pharmacogenomics to patient care. Online information resources can help address this gap. We investigated physicians’ pharmacogenomics information needs and information-seeking behavior, in order to guide the design of pharmacogenomics information resources that effectively meet clinical information needs.

Methods

We performed a formative, mixed-method assessment of physicians’ information-seeking process in three pharmacogenomics case vignettes. Interactions of 6 physicians’ with online pharmacogenomics resources were recorded, transcribed, and analyzed for prominent themes. Quantitative data included information-seeking duration, page navigations, and number of searches entered.

Results

We found that participants searched an average of 8 min per case vignette, spent less than 30 s reviewing specific content, and rarely refined search terms. Participants’ information needs included a need for clinically meaningful descriptions of test interpretations, a molecular basis for the clinical effect of drug variation, information on the logistics of carrying out a genetic test (including questions related to cost, availability, test turn-around time, insurance coverage, and accessibility of expert support).Also, participants sought alternative therapies that would not require genetic testing.

Conclusion

This study of pharmacogenomics information-seeking behavior indicates that content to support their information needs is dispersed and hard to find. Our results reveal a set of themes that information resources can use to help physicians find and apply pharmacogenomics information to the care of their patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12911-017-0510-9) contains supplementary material, which is available to authorized users.

A case of adult type 1 Gaucher disease complicated by temporal intestinal hemorrhage

A 21-year-old man with a history of sudden rectal hemorrhage was referred to our hospital. Examination disclosed thrombocytopenia and hepatosplenomegaly. A liver biopsy specimen demonstrated Gaucher cells in Glisson's capsule. Additional investigations revealed a low level of leukocyte β-glucosidase activity and common mutations of the glucocerebrosidase gene, L444P/D409H. We diagnosed the patient with Gaucher disease type 1. He underwent enzyme replacement therapy. Thrombocytopenia and hepatosplenomegaly improved at a rate of approximately 50 and 20%, respectively, within 6 months. This case suggests that we must pay attention to adult Gaucher disease as a differential diagnosis for cryptogenic thrombocytopenia.

Platelet adhesion defect in type I Gaucher Disease is associated with a risk of mucosal bleeding

Patients with type I Gaucher Disease (GD) may have a clinically significant bleeding tendency that is disproportionate to their platelet count. We hypothesized that impaired platelet adhesion might contribute to bleeding tendency. Adult patients with type I GD with platelet counts ≥130×10(9) /l and haematocrit ≥30% (n=48), obligatory carriers (n=52), and healthy controls (n=19) were studied. Platelet adhesion, using the IMPACT-R (Cone and Plate(let) Analyser), and platelet aggregation were determined. Type I GD patients had significantly lower platelet adhesion [surface coverage %, median (interquartile range)] 4·6 (3·2-7·5), compared to controls, 8·7 (7·6-10·3), or carriers, 8·1 (6·5-9·4; P=0·001). Platelet adhesion was not affected by the use of disease-specific enzyme replacement therapy but was improved in patients after splenectomy, 7·2 (5·8-9·3). Mixing tests showed that the reduced adhesion was an intrinsic platelet defect. Mucosal bleeding was reported in 17 (35·4%) patients and was associated with abnormal adhesion [P=0·037, with an Odds Ratio (95% confidence interval) of 5·73 (1·1-29·6)]. Five patients (22%) had reduced platelet aggregation, all of whom had reduced platelet adhesion. Platelet aggregation defect was not associated with mucosal bleeding. In conclusion, platelet adhesion defect is a major thrombocytopathy in type I GD patients and can explain part of the increased tendency to bleeding.

Biphasic threat to femoral head perfusion in abduction: arterial hypoperfusion and venous congestion

BACKGROUND

Hip abduction can cause avascular necrosis (AVN) of the femoral head in infants.

OBJECTIVE

To compare the US perfusion pattern of femoral head cartilage in neutral position with that in different degrees and duration of abduction, testing the venous congestion theory of post-abduction ischemia.

MATERIALS AND METHODS

In 20 neonates, the Doppler flow characteristics of the posterosuperior (PS) branch of the femoral head cartilage feeding vessels were evaluated in neutral and at 30 degrees, 45 degrees, and 60 degrees abduction. In three neonates the leg was held in 45-degree abduction and flow was assessed at 5, 10, and 15 min.

RESULTS

Male/female ratio was 11/9 with a mean age of 1.86 +/- 0.7 weeks. The peak systolic velocities (PSV) declined in all three degrees of abduction. After 15 min of 45-degree abduction, the mean PSV declined and showed an absent or reversed diastolic component and undetectable venous return. No perfusion was detected at 60-degree abduction.

CONCLUSION

Abduction-induced femoral head ischemia is biphasic and degree- and duration-dependent. In phase I there is arterial hypoperfusion and in phase II there is venous congestion. A new pathogeneses for femoral head ischemia is offered.

Outcome analysis in clinical trial design for acute stroke: physicians' attitudes and choices

BACKGROUND

Thrombolysis remains the only proven therapy to benefit acute ischemic stroke (AIS) patients. Recent studies have introduced more sensitive outcome measures such as the shift analysis to detect a treatment effect in AIS trials and are also including imaging as a surrogate of injury.

METHODS

We conducted a cross-sectional, internet-based survey of academic neurologists regarding their attitudes, choices and understanding of various outcome measures in clinical trial design for AIS. The survey population consisted of neurologists who specialize in the care of stroke patients and are on faculty at university-affiliated hospitals in the USA.

RESULTS

152 of 300 neurologists completed the survey. There were 79% men and 21% women. Among commonly used outcome scales in acute stroke, the most frequent ones selected for use as trial primary endpoints were the global statistic (59%), modified Rankin scale (mRS) (52%), and NIHSS (30%). When given choices about which outcome on the mRS would justify a therapeutic intervention, 54% chose a shift analysis of change in the distribution of outcomes and 39% chose a dichotomized outcome (mRS <or=2). A majority of respondents favored health transition states of 4-3, 3-2 and 2-1 on the mRS as clinically worthwhile. Only 2% of the respondents thought that a single transition point on the mRS was clinically meaningful. However, 20% of the respondents did not understand the shift analysis. In addition, nearly two thirds of the respondents believed that the presence of a mismatch on brain imaging is relevant to the success of neuroprotective agents.

CONCLUSION

The majority of respondents accepted an analysis of the entire distribution of the mRS scores as an appropriate endpoint analytic technique in AIS trials and did not require the traditional dichotomized outcome to demonstrate a treatment effect; however, a better understanding of the shift strategy is needed. Our data also support the importance of incorporating mismatch imaging into future neuroprotection trials.