A Comprehensive Overview of Coagulation Factor V and Congenital Factor V Deficiency.

Coagulation factor (F) V is a glycoprotein that plays an essential role in the formation of the prothrombinase complex, which is critical for progressing clot formation. FV deficiency is a rare bleeding disorder with an estimated incidence of one per 1 million in the general population. The disorder is manifested with a wide array of clinical bleeding events. The most common bleeding features of FV deficiency are mucosal bleedings. Life-threatening manifestations are rarely seen in this disorder. FV deficiency is diagnosed using routine coagulation tests and FV activity assay. A wide spectrum of mutations including missense, nonsense, and frameshift is observed throughout the F5 gene. Although fresh frozen plasma is the dominant therapeutic choice, a newly introduced plasma-derived FV concentrate was found effective in in vitro correction of prothrombin time, activated partial thromboplastin time, and thrombin generation parameters in severe FV deficiency and should provide more targeted treatment for patients with FV deficiency in the future.

Laboratory Diagnosis of Factor XIII Deficiency, Routine Coagulation Tests with Quantitative and Qualitative Methods.

BACKGROUND: Factor XIII (FXIII) deficiency is a severe bleeding disorder with normal routine coagulation tests that makes diagnosis of the disorder complicated. After normal results in routine coagulation tests, clot solubility test, and FXIII activity, antigen assays along with molecular methods can be used for precise diagnosis of disorder. In the present study, we described routine coagulation tests along with clot solubility test and FXIII activity and antigen assays. METHODS: Data were collected from all relevant publications until 2015. RESULTS: All routine coagulation tests including prothrombin time (PT), partial thromboplastin time (PTT), thrombin time (TT), and platelet count are normal in FXIII deficiency (FXIIID) but different conditions such as blood collection, transport, and storage can result in abnormal results in these first line screening tests. In addition to these tests, clot solubility tests as the most common screening tests of FXIIID can influenced by different factors including clotting and solubilizing agents. Different commercial kits are available for FXIII activity and antigen assays with different sensitivity and specificity which could affect diagnosis of FXIIID. CONCLUSIONS: Results of routine coagulation tests as well as clot solubility tests along with specific coagulation tests can affect diagnosis of FXIIID; therefore, all steps of these tests should be under control.

Hemostasis critical values among Iranian clinical laboratories "National Survey of 157 Clinical Laboratories".

BACKGROUND: Immediate reporting of critical values or test results significantly outside the normal range has a growing role in the management of patients, especially in life-threatening conditions. Due to the lack of international consensus, diverse approaches are used for determination of thresholds, reporting, documentation, and follow-up. In this study, we assessed how Iranian laboratories manage critical values for hemostasis. METHODS: We designed a standard questionnaire to assess different aspects of hemostasis critical values, including the number of coagulation tests with a defined critical value, critical values reporting, documentation, and follow-up policies. All results were self-reported and correctness of the data was not assessed by the authors. RESULTS: A total of 166 (66.4%) out of 250 laboratories completed the questionnaire; most (52.4%) were private. About 97% of responding laboratories had a critical values policy. These were defined for 64.3% (n: 27) of all coagulation tests (n: 42) performed in Iranian laboratories. Activated partial thromboplastin time (APTT), prothrombin time/international normalized ratio (PT/INR), platelet count, factor XI, and factor XIII assays had defined critical values among all laboratories performing these tests. Almost all laboratories reported critical values within 1 hour, after confirmation of the result on the same sample (70% of the laboratories) or a new one (13.4% of the laboratories). State and private laboratories had the same critical value reporting policy for in and outpatients, with laboratory technicians reporting critical results to nurses, for the most part. CONCLUSION: Although critical value policy is widely used among Iranian laboratories, there is no consensus policy for the reporting of hemostasis critical values, or documentation, threshold determination, and follow-up processes. It is impossible to determine whether non-responding laboratories had any critical values reporting policy. Results thus are biased toward laboratories that did.

Blood coagulation factor XIII and factor XIII deficiency.

Factor XIII (FXIII) is a multifunctional pro-γ-transglutaminase that, in addition to its well-known role in hemostasis, has a crucial role in angiogenesis, maintenance of pregnancy, wound healing, bone metabolism, and even cardio protection. FXIII deficiency (FXIIID) is a rare bleeding disorder (RBD) with an estimated incidence of one per two million that is accompanied by life-threatening bleeding such as umbilical cord bleeding, recurrent spontaneous miscarriage, and intracranial hemorrhage (ICH). Today, the disease is successfully managed by FXIII concentrate and recombinant FXIII for prophylaxis, management of minor and major bleeding, treatment of ICH, and successful delivery in women with recurrent pregnancy loss. Molecular analysis of patients with FXIIID revealed a wide spectrum of mutations, most frequently missense mutations in the FXIII-A subunit, with a few recurrent mutations observed worldwide. In vitro expression studies revealed that most of the missense mutations cause intracellular instability of the FXIII protein and, subsequently, FXIIID.