Laboratory diagnostic approach of the parents–children relationship in differentiating low-level von Willebrand factor from mild type 1 von Willebrand disease

Low von Willebrand Factor in Children and Adolescents: A Review

IMPORTANCE

Recent studies have documented increased bleeding symptoms and related complications in patients with low von Willebrand factor (VWF), highlighting the clinical significance of this entity. Because children and adolescents with VWF deficiencies often present to primary care physicians with bleeding symptoms, physicians need to be aware of this condition for early detection.

OBSERVATIONS

Studies have found that children and adolescents with low VWF (VWF levels of 30-50 IU/dL) can present with clinically significant bleeding, including mucosal, menstrual, postsurgical, and posttraumatic bleeding, leading to complications such as anemia, iron deficiency, transfusion, hospitalization, and poor quality of life. Detecting and promptly managing low VWF in children and adolescents with bleeding are essential because failure to do so can lead to significant morbidity in adulthood, especially among female patients, including continued heavy menstrual bleeding; postpartum hemorrhage; related gynecologic complications, such as hemorrhagic ovarian cysts; and surgical interventions for heavy menstrual bleeding, including hysterectomy. This narrative review summarizes the observations of several studies that have shed light on the pathophysiologic mechanisms of low VWF and bleeding in these patients and the available diagnostic modalities and treatment options.

CONCLUSIONS AND RELEVANCE

Studies in children and adolescents have provided important insights into the clinical phenotype, complications, pathophysiologic mechanisms, evaluation, and management of low VWF, now recognized as an important clinicopathologic entity, as presented in this review. As gatekeepers, primary care physicians play an important role in guiding patients with this recently recognized clinicopathologic entity toward appropriate specialty care and providing continued comanagement to prevent future complications as the patients enter adulthood.

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.

Response to low-dose desmopressin by a subcutaneous route in children with type 1 von Willebrand disease

OBJECTIVE

The primary objective of this study was to determine responses to low-dose desmopressin (DDAVP) by a subcutaneous route in children with type 1 VWD.

METHODS

This study analyzed responses to low doses of DDAVP administered by a subcutaneous route to 14 children between the ages of 3 and 16 with type 1 VWD and a personal and familial history of bleeding. At 0 (baseline) and 1 hour (initial response) after the subcutaneous injection of DDAVP, the vital signs were assessed and blood samples were obtained for VWD panel determinations (VWF:Ag, VWF:RCo, FVIII:C levels, and Col/Epi, Col/ADP). At 4 hours (sustained response), only Col/Epi and Col/ADP were assessed.

RESULTS

The DDAVP mean (min-max range, μg/kg) based on the patient's weight was 0.15 (0.12-0.18). Laboratory values mean (min-max range in U/dl) baseline for VWF:RCo, VWF:Ag, and FVIII:C were 28 (20-36), 34 (25-42), and 40 (29-48), respectively. After a subcutaneous administration, the laboratory values mean (min-max range in U/dl(-1)) achieved for 1 hour for VWF:RCo, VWF:Ag, and FVIII:C were 109 (72-144), 132 (88-166), and 151 (96-198), respectively. PFA 100(®) CT (Col/Epi <134 seconds and Col/ADP <110 seconds) returned to normal values at 1 and 4 hours after a subcutaneous administration.

CONCLUSION

Subcutaneous low-dose DDAVP therapy is at least effective as 0.3 µg/kg intravenous therapy for children with type 1 VWD. This study shows that a wider use of DDAVP should be promoted, especially in developing countries.