Relevance of quantitative assessment of bleeding in haemorrhagic disorders

Quantitation of bleeding symptoms in a national registry of patients with inherited platelet disorders

BACKGROUND

Inherited platelet deficiency and/or dysfunction may be more common in the general population than has previously been appreciated. In 2013 the Israeli Inherited Platelet Disorder (IPD) Registry was established.

METHODS

Clinical and laboratory data were collected to pre-specified registration forms. The study protocol was approved by the local hospital ethics committees.

RESULTS

To date we have included in the registry 89 patients (male 52%) from 79 families. Most patients (74%) have a not-yet specified inherited thrombocytopenia (n=39) or non-specific platelet function disorder (n=27). Full clinical data were available for 81 (91%) patients. The median (range) age at presentation and time of follow-up were 1.8years (1day-17.8years) and 4.7 (0-26) years, respectively. The Pediatric Bleeding Questionnaire was available for 78patients; abnormal bleeding score (≥2) was recorded in 47 (52.8%, 95% CI 42%-63.5%) patients and was less frequent in patients followed for isolated thrombocytopenia. Abnormal score was associated with a longer time of follow-up, OR 1.19 (95% CI 1.04-1.36).

CONCLUSION

Long term follow-up of patients with IPDs is important as bleeding risks may increase with time. We expect that clinical and laboratory information of patients/families with IPDs gathered in a systemic format will allow for better diagnosis and treatment of these patients.

Gingival bleeding and mild type 1 von Willebrand disease

Oral bleeding is a frequently reported symptom of von Willebrand disease (VWD) and evaluated by several VWD bleeding scores. Gingival bleeding is also known to be a leading symptom of plaque-induced gingivitis and untreated periodontal disease. This study evaluates whether mild type 1 VWD is associated with an increased susceptibility to gingival bleeding. In this case-control study, 50 patients and 40 matched controls were periodontally examined, answered a questionnaire, and underwent professional teeth cleaning. Compared with the controls, the VWD patients more frequently reported periodontal symptoms, such as bleeding (34 vs. 20%, P = 0.141) and swelling (54 vs. 32.5%, P = 0.538) of the gingiva, and these patients had their teeth professionally cleaned less often (58 vs. 77.5%, P = 0.051). However, there was less gingival bleeding, as determined by the gingival bleeding index, in the VWD patients compared with the controls (10 vs. 12.2%, P = 0.047); the amount of bleeding on probing was similar between the VWD patients and the controls (17 vs. 17.2%, P = 0.723). Gingival bleeding in VWD patients may be triggered by gingival inflammation, but it is not a genuine symptom of mild type 1 VWD.

How I treat type 2 variant forms of von Willebrand disease

Type 2 von Willebrand disease (VWD) includes a wide range of qualitative abnormalities of von Willebrand factor structure and function resulting in a variable bleeding tendency. According to the current classification, 4 different subtypes can be identified, each with distinctive phenotypic and therapeutic characteristics. Current available laboratory methods allow a straightforward approach to VWD subtyping, and although the precise molecular characterization remains complex, it is not required for appropriate treatment of the vast majority of cases. Desmopressin can be useful only in a few type 2 cases compared with patients with actual quantitative deficiency (type 1), most often in variants with a nearly normal multimeric pattern (type 2M). However, since no laboratory test accurately predicts response to desmopressin, a trial test should always be performed in all type 2 VWD patients, with the exception of type 2B ones. Replacement therapy with plasma-derived von Willebrand factor-factor VIII concentrates represents the safe mainstay of treatment of all patients, particularly those not responding to desmopressin or requiring a sustained hemostatic correction because of major surgery or bleeding. A significant patient bleeding history correlates with increased bleeding risk and should be considered in tailoring the optimal antihemorrhagic prophylaxis in the individual patient.

Predictors of von Willebrand disease in children

BACKGROUND

Bleeding and bruising are common symptoms for which children are referred to a pediatric hematologist. Although bleeding scores have been validated to quantify bleeding risk in adults, there are no similar definitive data in children. The aim was to describe presenting bleeding symptoms in children and evaluate if these bleeding symptoms were predictive of von Willebrand disease (VWD) or low von Willebrand factor (VWF).

PROCEDURE

We performed a retrospective chart review of consecutive pediatric patients referred for perceived bleeding symptoms to the coagulation clinic at The Children's Hospital of Pittsburgh of UPMC. All underwent a uniform bleeding symptom inventory and hemostatic testing. Single and multiple variable logistic regression models were created to predict either VWD, low VWF, or nonspecific defective platelet aggregation, using the predictor variables of family bleeding history, mucocutaneous bleeding, cutaneous bleeding, and surgical bleeding, based on The International Society on Thrombosis and Hemostasis (ISTH) bleeding definitions.

RESULTS

Of 298 pediatric patients evaluated, 8% had VWD (VWF:RCo and VWF:Ag ≤ 30 IU/dl) and 34% had low VWF (VWF:RCo and VWF:Ag 30-50 IU/dl). Further, 16% had a nonspecific platelet aggregation disorder, 41% had normal hemostatic testing, and 1% had factor VIII or IX deficiency. In single and multiple variable logistic regression analysis, neither a personal or family bleeding history at presentation, nor the presence of two or more bleeding symptoms were predictive of VWD, low VWF, or nonspecific defective platelet aggregation.

CONCLUSIONS

These findings suggest that qualitative assessment of bleeding symptoms alone is not useful in children.

A cost-effectiveness analysis of coagulation testing prior to tonsillectomy and adenoidectomy in children

BACKGROUND

The American Society of Pediatric Otolaryngology recommends pre-operative coagulation testing only when indicated by history or physical exam. Nevertheless, many surgeons test all children scheduled for tonsillectomy and/or adenoidectomy (T&A). Studies of pre-operative screening have had conflicting results. A decision analysis model was constructed to address the costs and health outcome states of pre-operative screening strategies in children.

PROCEDURE

A 14-day Markov model evaluated three strategies: (1) test all children for coagulation disorders; (2) test only those children with a pertinent history; and (3) perform no pre-operative testing. A literature search and a review of national databases estimated probabilities, costs, and utility data. Parameters then were varied widely in sensitivity analyses. Using a societal perspective and a cycle length of 1 day, we compared the strategies based on total costs and quality-adjusted life years (QALYs).

RESULTS

Total costs for the strategies were $3,200 for testing all children, $3,083 for testing only those with a history finding, and $3,077 for not testing. Total utilities were 0.02579, 0.02654, and 0.02659 QALYs, respectively. Cost-effectiveness ratios were most sensitive to variation in the cost of post-operative care and the probability of post-operative bleeding. The strategy of not testing was dominant in all sensitivity analyses.

CONCLUSIONS

Our results demonstrate that not performing preoperative testing is the most cost-effective strategy. This was persistent in sensitivity analyses, indicating that the model was robust. These data may be helpful to institutions and organizations to formulate policies regarding pre-operative coagulation for children without previous diagnoses of bleeding disorders.

Comprehensive pediatric care of rare bleeding disorders

Although less common than hemophilia or von Willebrand disease, inherited rare bleeding disorders, comprising afibrinogenemia and deficiencies in factors II, V, VII, X, XI, XIII or V plus VIII combined, or in vitamin K-dependent coagulation factors, may lead to severe bleeding episodes such as recurrent hemarthroses and neonatal intracranial or gastrointestinal hemorrhage. Consanguinity significantly increases the risk of the occurrence of all rare bleeding disorders that are associated with an autosomal recessive pattern of inheritance. Each of the disorders is characterized by a wide interindividual variation in clinical phenotype and a large mutational spectrum with no clear correlation between the phenotype and genotype. Replacement therapy relies on specific molecules or concentrates (afibrinogenemia, factor VII, XI and XIII deficiencies), on a mixture of different concentrates that are otherwise known as a prothrombin complex, which contains factors II, VII, IX and X, or on fresh frozen plasma. International consensus guidelines for treatment modalities are progressing; however, guidelines for prophylaxis, especially in pediatric patients, are lacking.

Evaluation of children with a suspected bleeding disorder applying the Impact-R [Cone and Plate(let) Analyzer]

BACKGROUND

A convenient screening test for children with bleeding symptoms before more labor-intensive diagnostic steps are taken would be of value. The Impact-R was designed in an attempt to analyse platelet function under near physiological conditions. Results are presented as surface coverage (SC, %) and average size (AS, microm(2)).

OBJECTIVE

In this cross-sectional retrospective study, we assessed the use of the Impact-R in the evaluation of children with a suspected bleeding disorder (BD).

METHODS

The hospital charts of 110 children referred to the coagulation laboratory were reviewed for personal and family bleeding history (BH) as well as results of the laboratory evaluation.

RESULTS

A laboratory 'diagnosable' BD (LBD) was found in 23 children (21%, 95% CI 14-30%). A diagnosis of LBD was associated with the severity of bleeding but not with family BH. By receiver-operating characteristic (ROC) curve analysis, the SC was superior to the AS for diagnosis of a LBD. The Impact-R was abnormal in 43/97 children (44.3%, 95% CI 34-55%). The predictive values of a normal and abnormal Impact-R were 96% (95% CI 92-97%) and 42% (95% CI 28-56%), respectively. When considering the personal and family BH, the post-test probability for LBD after a normal Impact-R was reduced from 20% to 3.5% (95% CI 2.5-7%).

CONCLUSIONS

A normal Impact-R test is highly effective in excluding LBDs. Yet, in case of an abnormal Impact-R test, further testing is needed. An algorithm that includes the personal and family BH and the results of a screening test may improve the diagnostic process. Prospective studies are now needed to confirm these findings.