The diagnosis and management of common inherited bleeding disorders

Inherited bleeding disorders can be associated with significant morbidity and mortality. Bleeding episodes can be safely and effectively managed in the majority of patients provided the coagulation defect is identified and corrected with the appropriate replacement therapy. It is imperative that these patients are treated in centres that can provide full coagulation support, and a comprehensive care plan is formulated for each individual.

Successful use of recombinant factor VIIa in a patient with inhibitor secondary to severe factor XI deficiency

Factor XI (FXI) inhibitors are a rare complication of inherited FXI deficiency. We report the successful use of recombinant factor VIIa (FVIIa) in a patient with a high-responding inhibitor undergoing cataract extraction. At the time of surgery there were limited available data on the optimal management of patients with FXI deficiency. A 62-year-old Ashkenazi Jewish woman had a lifelong history of excessive bleeding secondary to severe FXI deficiency (2 U dL-1), and received FXI concentrate (FXI:C) when she underwent a colposuspension procedure. She was subsequently diagnosed with a FXI inhibitor of 16 Bethesda units (BU) when she developed a poor response to FXI:C at the time of total hip replacement. Two months later she was admitted for cataract extraction. The FXI level was < 1 U dL-1 with an inhibitor titre of 48 BU. She received 90 microg kg-1 of FVIIa immediately preoperatively followed by continuous infusion at a rate of 20 microg kg-1 h-1 for 24 h. The cataract extraction was successful and there was no excess bleeding during surgery or in the postoperative period. Mutation analysis of the FXI gene showed that the patient was homozygous for the type II genotype [exon 5, Glu117-->Ter]. The reason for the low prevalence of inhibitor formation in patients with FXI deficiency is unclear but may reflect a number of factors including reporting bias, the rarity of absent circulating FXI:C activity, and the infrequent use of FXI replacement therapy.

von Willebrand's disease: an important cause of dysfunctional uterine bleeding

We assessed the prevalence of von Willebrand's disease (VWD) in patients with objectively confirmed dysfunctional uterine bleeding. A case-control study was designed to include 38 patients with objectively confirmed dysfunctional uterine bleeding and 38 age-matched controls with normal menstrual blood loss (MBL). Menorrhagia was defined as a mean MBL of greater than 80 ml on three consecutive menses as measured by the alkali haematin method. von Willebrand factor antigen, von Willebrand factor activity (VWF:Ac) and factor VIII:C were measured on three serial venous blood samples 1 week apart. VWD was diagnosed in five of 38 (13%) patients with menorrhagia and one of 38 (2.6%) patients with normal menstrual blood loss. The mean VWF:Ac value was significantly reduced in patients with menorrhagia (mean +/- standard deviation, 84.5 +/- 26.7 IU/dl versus 103.9 +/- 34.5 IU/dl; P < 0.01) and this effect persisted after exclusion of patients diagnosed with VWD. Failure to investigate patients for VWD will limit the potential benefits of medical therapies such as tranexamic acid or nasal desmopressin [1-desamino-8-D-arginine vasopressin, (DDAVP)] and, in addition, will lead to an increased risk associated with surgical intervention in patients with undiagnosed VWD.

Thermolabile methylenetetrahydrofolate reductase (C677T): frequency in the Irish population

BACKGROUND

The genetic variation which underlies the thermolability and low enzyme activity of 5,10-methylenetetrahydrofolate reductase (MTHFR; C677T) has been extensively studied in many populations, including the Irish population.

AIM

To describe the examination of the C677T substitution in two new control samples drawn from the Irish population.

METHODS

A collection of 487 serum samples was obtained through the blood transfusion services of both the Republic of Ireland and Northern Ireland and a further 115 samples from volunteers.

RESULTS

In both samples, the frequency of the thermolabile/low enzyme activity allele (T) was higher than that previously reported for the Irish population.

CONCLUSION

This finding thus supports the need for a greater use of internal control/family-based association studies, as opposed to the classic case control study design, when assessing the contribution of the MTHFR T allele to disease processes.

Molecular genetic approaches to the targeted suppression of neuronal activity

Understanding how the diverse cells of the nervous system generate sensations, memories and behaviors is a profound challenge. This is because the activity of most neurons cannot easily be monitored or individually manipulated in vivo. As a result, it has been difficult to determine how different neurons contribute to nervous system function, even in simple organisms like Drosophila. Recent advances promise to change this situation by supplying molecular genetic tools for modulating neuronal activity that can be deployed in a spatially and temporally restricted fashion. In some cases, targeted groups of neurons can be 'switched off' and back 'on' at will in living, behaving animals.

Subjects with mild and moderate asthma respond to segmental allergen challenge with similar, reproducible, allergen-specific inflammation

BACKGROUND

The relationship between severity of asthma and bronchial inflammation is poorly understood.

OBJECTIVE

We examined acute and subacute inflammatory responses to allergen in subjects with mild and moderate persistent asthma to evaluate whether different cellular and mediator responses to endobronchial allergen challenge are associated with differences in disease severity.

METHODS

Segmental allergen challenge was performed in 8 subjects with mild and 10 subjects with moderate allergic asthma to compare baseline airways inflammation and allergen-induced inflammatory responses 24 hours later. This evaluation was repeated after 6 weeks in 9 subjects to investigate the reproducibility of these inflammatory responses.

RESULTS

Subjects with mild and moderate asthma had similar decreases in FEV(1) in response to segmental allergen challenge (9.1% +/- 4.2% vs 15.1% +/- 4.6%, P = .35). There was no difference in inflammatory cell counts or cytokine concentrations in the groups with mild and moderate asthma at baseline or after saline or allergen challenge. Repeat segmental allergen challenge 6 weeks later showed that these cellular and cytokine responses were reproducible.

CONCLUSION

Segmental allergen challenge in subjects with mild and moderate asthma produces similar allergen-specific physiologic and inflammatory responses that are reproducible 6 weeks later. In this model of allergic asthma, acute responses to allergen do not appear to be related to disease severity.

Three double-blind, randomized trials evaluating the safety and tolerance of different formulations of the saponin adjuvant QS-21

The effects of the adjuvant QS-21 in various formulations on immediate pain on injection after intramuscular injection were evaluated in three Phase I clinical trials in healthy adults. Each trial was designed as a double-blind, randomized, four-way or five-way cross-over study with each subject acting as his/her own control. In the first trial, four formulations designed to evaluate the effect of QS-21 or pH (over a range of 6--7.2) were evaluated: phosphate-buffered saline at pH 6.0 or 7.2, and 50 microg of QS-21 in phosphate-buffered saline at pH 6.0 or 7.2. Thirty-three volunteers received each of the four intramuscular injections in random order separated by approximately 1 week. The volunteers assessed the immediate injection pain from 0 to 10 (none to most pain). The data indicate that the presence of QS-21, but not pH, is associated with transient injection site pain. The second trial, which utilized the same design as the first trial, evaluated formulations of QS-21 in various excipients. Fifteen volunteers received phosphate-buffered saline, QS-21/PBS, QS-21/aluminum hydroxide, and QS-21/4 mg/ml of polysorbate 80. Polysorbate 80, but not aluminum hydroxide, reduced the mean pain score compared to QS-21/PBS. The third trial evaluated formulations of QS-21 in additional excipients. Fifteen volunteers received aluminum hydroxide (without QS-21), QS-21/PBS, QS-21/0.72% benzyl alcohol, QS-21/30 mg/ml of hydroxypropyl-beta-cyclodextrin, and QS-21/8-mg/ml of polysorbate 80. Benzyl alcohol, cyclodextrin, and the higher concentration of polysorbate 80 reduced the pain scores associated with QS-21. Hence, QS-21 is associated with injection pain in simple buffer formulations, but it is possible to improve the acceptability of QS-21-containing formulations through reformulation with certain excipients.

Effects of the American College of Rheumatology systemic sclerosis trial guidelines on the nature of systemic sclerosis patients entering a clinical trial

OBJECTIVES

To compare the systemic sclerosis (SSc) patients entered into the d-penicillamine trial with SSc patients entered into previous controlled SSc trials. It was hypothesized that the d-penicillamine trial patients, who conformed to the American College of Rheumatology (ACR) guidelines for clinical trials in SSc were different from patients entered into previous trials.

METHODS

Patients entering a double-blind, randomized trial of low- vs high-dose d-penicillamine were described carefully and completely. Their characteristics were then compared with previously published data on SSc and its treatment.

RESULTS

One hundred and thirty-four patients had early [mean duration 9.5 (s.d. 4.2) months], diffuse [skin score 21 (8)] disease. Organ involvement in the patients was as follows: pulmonary 54%, cardiac 20%, joints 38%, muscular 20%. Thirty-three per cent had mild proteinuria and 13% were hypertensive when first seen. Compared with patients in most previous studies, these SSc patients had earlier disease and uniformly had diffuse disease. They had less muscular involvement, less dyspnoea, less abnormal pulmonary function and less cardiac and less renal involvement than patients in earlier studies.

CONCLUSIONS

The use of the new ACR guidelines for SSc trials may change the nature of patient populations entering future studies.

Prenatal diagnosis using interphase fluorescence in situ hybridization (FISH): 2-year multi-center retrospective study and review of the literature

Since 1993, the position of the American College of Medical Genetics (ACMG) has been that prenatal interphase fluorescence in situ hybridization (FISH) is investigational. In 1997, the FDA cleared the AneuVysion assay (Vysis, Inc.) to enumerate chromosomes 13, 18, 21, X and Y for prenatal diagnosis. Data is presented from the clinical trial that led to regulatory clearance (1379 pregnancies) and from retrospective case review on 5197 new pregnancies. These studies demonstrated an extremely high concordance rate between FISH and standard cytogenetics (99.8%) for specific abnormalities that the AneuVysion assay is designed to detect. In 29 039 informative testing events (6576 new and 22 463 cases in the literature) only one false positive (false positive rate = 0.003%) and seven false negative results (false negative rate = 0.024%) occurred. A historical review of all known accounts of specimens tested is presented (29 039 using AneuVysion and 18 275 specimens tested with other probes). These performance characteristics support a prenatal management strategy that includes utilization of FISH for prenatal testing when a diagnosis of aneuploidy of chromosome 13, 18, 21, X or Y is highly suspected by virtue of maternal age, positive maternal serum biochemical screening or abnormal ultrasound findings.

Lung transplantation and systemic sclerosis

We performed lung transplantation in nine patients with Scleroderma related lung disease. Patient characteristics included: 7 (78%) females, 6 (67%) with limited and 3 (33%) with diffuse Scleroderma. Pulmonary fibrosis was present in 7 (78%) and pulmonary hypertension in 4 (44%). All patients were carefully screened by the Johns Hopkins and University of Maryland Scleroderma Center and only referred for transplantation when concomitant renal insufficiency (creatinine clearance < or = 50 ml/min), aspiration, and skin brakdown were excluded. When compared to a similar group of transplant patients with nonscleroderma lung disease (primary pulmonary fibrosis), there was no significant difference in post-transplant survival at four years (76.2 +/- 0.15% vs. 69.2% +/- 0.12%), mean annual incidence rate for acute rejection (0.14 +/- 0.14 vs. 0.47 +/- 0.13) and infection (viral 0.17 +/- 0.17 vs. 0.29 +/- 0.11) (bacterial 0.17 +/- 0.17 vs. 1.4 +/- 0.4) (fungal 0.99 +/- 0.69 vs. 0.36 +/- 0.16) or serum creatinine (1.55 +/- 0.34 mg/dl vs. 1.15 +/- 0.09 mg/dl). We conclude that lung transplantation is viable option for carefully selected patients with scleroderma related lung disease.

The Disability Index of the Health Assessment Questionnaire is a predictor and correlate of outcome in the high-dose versus low-dose penicillamine in systemic sclerosis trial

OBJECTIVE

To explore the clinical implications of a score of > or =1.0 on the Disability Index of the Health Assessment Questionnaire (HAQ DI) at the first patient visit, and to examine the implications of improvement in HAQ DI score over 2 years in a cohort of systemic sclerosis (SSc) patients with diffuse cutaneous scleroderma.

METHODS

SSc skin and visceral involvement was assessed in 134 SSc patients with diffuse scleroderma (mean +/- SD disease duration of 10 +/- 4 months) when they entered a multicenter drug trial and again 2 years later. Mortality and the occurrence of scleroderma renal crisis were assessed for a mean +/- SD of 4.0 +/- 1.1 years. Logistic and linear regression analyses were used to examine the relationship of the baseline HAQ DI score to morbidity, mortality, and visceral involvement, as well as the relationship of changes in the HAQ DI score to changes in physical examination, laboratory, and functional variables over 2 years.

RESULTS

A baseline HAQ DI score of > or =1.0 was predictive of mortality (odds ratio 3.22, 95% confidence interval 1.097-9.468) over 4 years. Multivariate linear regression demonstrated that a model which included the erythrocyte sedimentation rate at baseline (P = 0.005) and changes at 2 years in the swollen joint count (P = 0.002), total skin score (P = 0.005), and white blood cell count (P = 0.005) best explained the change in HAQ DI score over 2 years (R2 = 0.528). The HAQ DI score and total skin score at baseline were highly correlated (correlation coefficient 0.368), as were changes in the HAQ DI score and the total skin score over 2 years (correlation coefficient 0.492). Although the HAQ DI score was heavily influenced by hand dysfunction at baseline and at 2 years, improvement (reduction) in the HAQ DI score over 2 years was related to factors other than hand dysfunction.

CONCLUSION

A baseline HAQ DI score of > or =1.0 predicted mortality over 4 years. Improvement in the HAQ DI score in these patients with diffuse scleroderma was associated with improvement in skin thickening, hand function, oral aperture, lung function, signs of arthritis, serum creatinine level, and the investigator's global assessment of improvement. The HAQ DI is a self-administered questionnaire that SSc patients can complete easily and rapidly and that gives the practicing physician important information about prognosis, patient status, and changes in disease course over time.