Discrepancies between the one-stage clotting assay and the chromogenic assay in haemophilia B
(2017) In Haemophilia 23(4). p.620-627- Abstract
Introduction: Assay discrepancy in factor VIII activity between the one-stage and the chromogenic assays has been described in approximately one third of patients with non-severe haemophilia A. Whether assay discrepancy may also occur in patients with haemophilia B remains unknown. Aim: This study compared the results from the one-stage and the chromogenic assays in patients with haemophilia B. Methods: Plasma samples from patients with haemophilia B attending the haemophilia centre in Malmö, Sweden, were collected after a wash-out period of more than 7 days and analysed with both assays. Results: Fifty samples from 36 patients were analysed. No discrepancy was found in patients with severe haemophilia B. Among the 44 plasma samples... (More)
Introduction: Assay discrepancy in factor VIII activity between the one-stage and the chromogenic assays has been described in approximately one third of patients with non-severe haemophilia A. Whether assay discrepancy may also occur in patients with haemophilia B remains unknown. Aim: This study compared the results from the one-stage and the chromogenic assays in patients with haemophilia B. Methods: Plasma samples from patients with haemophilia B attending the haemophilia centre in Malmö, Sweden, were collected after a wash-out period of more than 7 days and analysed with both assays. Results: Fifty samples from 36 patients were analysed. No discrepancy was found in patients with severe haemophilia B. Among the 44 plasma samples from patients with non-severe disease, 15 showed a twofold or greater difference between the results of the two methods, with the chromogenic method presenting the higher value (mean FIX:Cone-stage 0.02 vs. FIX:Cchromo 0.06 IU mL-1). Of these 15 samples, 14 were from seven individuals from five families with the same mutated amino acid at the N-terminal cleaving site of the activation peptide (FIX: c.572G>A; p.Arg191His or FIX: c.571C>T; p.Arg191Cys). These mutations were not observed in any patients with non-discrepant results. The reported bleeding frequency for these patients was low and indicative of a mild bleeding phenotype. Conclusion: Our findings imply that assay discrepancy occurs for factor IX activity and that both type of assays are needed for a correct diagnosis and classification of haemophilia B. The underlying mechanism by which the mutation influences the assays remains to be determined.
(Less)
- author
- Kihlberg, K. LU ; Strandberg, K. LU ; Rosén, S. ; Ljung, R. LU and Astermark, J. LU
- organization
- publishing date
- 2017-04-24
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Assay discrepancy, Chromogenic assay, Coagulation factor IX, Haemophilia B, Mutations, One-stage assay
- in
- Haemophilia
- volume
- 23
- issue
- 4
- pages
- 620 - 627
- publisher
- Wiley-Blackwell
- external identifiers
-
- scopus:85018672226
- pmid:28440032
- wos:000405873900046
- ISSN
- 1351-8216
- DOI
- 10.1111/hae.13219
- language
- English
- LU publication?
- yes
- id
- 0a58a3d9-8606-4e4c-9859-5bb29ba2c8b2
- date added to LUP
- 2017-06-01 11:34:35
- date last changed
- 2025-01-07 14:32:25
@article{0a58a3d9-8606-4e4c-9859-5bb29ba2c8b2, abstract = {{<p>Introduction: Assay discrepancy in factor VIII activity between the one-stage and the chromogenic assays has been described in approximately one third of patients with non-severe haemophilia A. Whether assay discrepancy may also occur in patients with haemophilia B remains unknown. Aim: This study compared the results from the one-stage and the chromogenic assays in patients with haemophilia B. Methods: Plasma samples from patients with haemophilia B attending the haemophilia centre in Malmö, Sweden, were collected after a wash-out period of more than 7 days and analysed with both assays. Results: Fifty samples from 36 patients were analysed. No discrepancy was found in patients with severe haemophilia B. Among the 44 plasma samples from patients with non-severe disease, 15 showed a twofold or greater difference between the results of the two methods, with the chromogenic method presenting the higher value (mean FIX:C<sub>one-stage</sub> 0.02 vs. FIX:C<sub>chromo</sub> 0.06 IU mL<sup>-1</sup>). Of these 15 samples, 14 were from seven individuals from five families with the same mutated amino acid at the N-terminal cleaving site of the activation peptide (FIX: c.572G>A; p.Arg191His or FIX: c.571C>T; p.Arg191Cys). These mutations were not observed in any patients with non-discrepant results. The reported bleeding frequency for these patients was low and indicative of a mild bleeding phenotype. Conclusion: Our findings imply that assay discrepancy occurs for factor IX activity and that both type of assays are needed for a correct diagnosis and classification of haemophilia B. The underlying mechanism by which the mutation influences the assays remains to be determined.</p>}}, author = {{Kihlberg, K. and Strandberg, K. and Rosén, S. and Ljung, R. and Astermark, J.}}, issn = {{1351-8216}}, keywords = {{Assay discrepancy; Chromogenic assay; Coagulation factor IX; Haemophilia B; Mutations; One-stage assay}}, language = {{eng}}, month = {{04}}, number = {{4}}, pages = {{620--627}}, publisher = {{Wiley-Blackwell}}, series = {{Haemophilia}}, title = {{Discrepancies between the one-stage clotting assay and the chromogenic assay in haemophilia B}}, url = {{http://dx.doi.org/10.1111/hae.13219}}, doi = {{10.1111/hae.13219}}, volume = {{23}}, year = {{2017}}, }