T he clotting factor nowknown as factor V(FV)was first described in 1908(1), and adeficiencyofthis factor wasfirst described by Owren as parahaemophiliain1947 (2).FVis predominantlyproduced in the liverand to alesserdegree by the megakaryocytes. Circa80% of FV circulates in the plasma while 20% is stored in platelets. Following α -granule releaseupon platelet activation, plateletFVcan presumably bind immediatelyto surface receptorso ptimising prothrombinase complexa ctivity (3). Ther elationship between plasma FV and platelet FV and their relativesignificance is to date not fully understood,but FV expression in either platelets or plasma wasproventobesufficient forbasal haemostasis in mice(4).FV deficiencyisarare diseasewith an incidenceof1.10 -6 (5, 6, 20-24).I ti sa na utosomal recessively inheritedd isorderi n whicht he lacko ff actor Va ctivity impairsc lotting.H eterozygous patients showav ariable expression with am ild bleeding tendencyin10% of the cases (7),whereashomozygous patients usuallyp resentw ith moderate clinical manifestations of epistaxis, menorrhagiaa nd haemorrhages after trauma (8).T here seemst ob eap oor correlation betweenp lasma factor Vl evels and clinical phenotype (8), and differentopinions exist as to the necessary levelofcirculating FV for adequate haemostasis. Target FV activity levels during treatment are mainlybased on clinical experience(9). Relatively fewreportsonthe subjectoffactor Vd eficiencya nd pregnancyc an be foundi nt he medicall iterature, and these are mainlys poradic case reports (10-18) and threereviews (3,20,21).Case report A19-year-old Moroccanw oman, bornofconsanguineous parents, presented with complaintso ff atigue,e xcessive bleeding after dentalprocedures, frequent nose bleeds,severe menorrhagiaand large haematomas of the skin after minor trauma. Laboratorytests showedamicrocytic anaemia throughiron deficiency withhaemoglobin of 8.1 g/dl (nl 12-15g/dl),anMCV of 61.2 fl (nl 76-96fl) and ferritin of 5ng/ml (nl 13.0-150.0 ng/ml). The APTT wasclearlyprolonged at 110.4sec (nl25-39 sec)with a PT of 12%(nl 70-100%).F actor Vantigen levelw as 3% with factor Vactivity at 1%.All otherclotting factorswere present in normalamounts. No inhibitor againstFVcould be found.Molecular analysis showedt he presenceo fah omozygous factor V(Casablanca) nonsensemutation Q773Terminexon 13.The patient wasput on oralcontraceptivestodecreasemenstrualblood loss, tranexaminic acidand iron supplements. Both the patient and her husband expressed as trong wisht oh ave children on cultural and religiousgrounds, and even after full explanation of the possible complications,t he couple decided to accept the potential risks this entailed. Theyw ere advisedt o avoid ap regnancyu ntil ah aemoglobin levelo f1 2g /dl was reached,and this came about after 18 months of treatment during whicht herew ere only af ew minor bleeding episodes. After reaching the target haemoglobin and stopping of the oral contraceptives the patient becamep regnant after only three months. Thepregnancyitself wasuneventful and...
There was no shift in frequency of TPE or level of indication in our center. Controversial indications should be carefully evaluated on an individual basis and a trial of TPE cannot be solely ruled out because of lack of evidence.
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