20 HEMOPHILIA TODAY PHYSICAL FITNESSSUMMER 2002AND BLEEDING DISORDERSHemophilia Today: How did you firstbecome interested in hemophilia?Kathy Mulder: It’s actually a long story,with three chapters. First, in our finalyear of training, we had to do a majorpaper. One of my classmates had done aclinical placement at the Children’sHospital where she worked withDr. Aggie Bishop and the hemophiliaprogram, so she wrote her paper on therole of physiotherapy in hemophilia.This was in the early 1970’s andcryoprecipitate had only just becomeavailable, so physiotherapy forhemophiliacs was a new concept. Weproofread each other’s papers, and Ithought it sounded interesting, but neverthought much more about it.Second chapter—my first job inSaskatoon. There, a boy was admitted tohospital to see what could be done tostraighten his knee. He had a terribleflexion contracture. There were also twobrothers who had bad knees as well. Theorthopedic doctor referred all three boysfor physiotherapy. Trouble was, no oneon staff had ever treated a hemophiliacbefore! Since I had a BIT of knowledgefrom reading my friend’s paper, Idecided to see what we could do.Third chapter— when I returned toWinnipeg, I worked at the HealthSciences Centre in the AdultPhysiotherapy Department. One of myfirst patients there was Stuart Johnson,whom the older people in thehemophilia community will remember.Again, my smattering of knowledge wasmore than my colleagues had, so Iworked with Stuart extensively. Hetaught me so much—about growing upwith hemophilia, about living as an adultwith hemophilia and with terrible jointdisease, and about keeping a positiveoutlook when he could have had all sortsof things to complain about. Every time Ilooked at Stuart’s crippled joints, Ithought, “Man, we have GOT to dobetter than this.” I soon met many otheradults with hemophilia: Ed and BarryKubin, and Jim Love were among “myboys”. All of them had grown up withlittle or no treatment, all of them hadbad joints, and all of them could tellsome pretty scary stories about physio-“terrorists” that they had encounteredalong the way. I learned TONS from eachof them, and I think they learned thatexercise didn’t have to be torture, andcould even be good for you!Hemophilia Today: Why are you still soinvolved with hemophilia?Kathy Mulder: Probably the biggestreason is that it has been so fascinating towatch the changes that have gone on overthe course of my career. When I began, itwas inevitable that hemophiliacs woulddevelop joint disease. The discovery ofcryoprecipitate in the mid-sixties meantthat joint surgery had just become apossibility. Next, I saw the excitement andthe hope of a better life that came withthe availability of concentrates. The guyscould keep their treatments at work andthey could travel freely becauseconcentrate didn’t have to stay frozen likecryo did. I saw the heartbreak thatfollowed as those same concentratesturned from a blessing to a curse. I lostmany friends during the AIDS years, andwatched as the hemophiliac populationwas decimated. But now withrecombinant products and prophylaxis, Isee healthy children with healthy jointsparticipating in sports and leadingnormal lives! To see so many hugechanges in the course of one career isamazing!There are only a few therapists stillaround who remember what those badjoints looked like. Now my job is toremind young therapists and newfamilies not to take healthy joints forgranted!Hemophilia Today: Were there anyparticular people who influenced youalong the way?Kathy Mulder: I have been fortunate tohave had many mentors and role modelsalong the way. In the hemophiliacommunity, I had many teachers. Ialready mentioned Stuart. He had theforesight and the vision to lay thegroundwork for the Manitoba Chapter(now Hemophilia Manitoba). Ed Kubinwas one of the architects of the “MillionDollar Club” which was developed tofund hemophilia research. Ed could be adifficult person, but his dream ofimproving things for Canadianhemophiliacs was very strong. Now Itreat his grandsons! I remember quitevividly meeting Frank Schnabel, founderof the World Federation of Hemophilia.He was a remarkable man. And my longtimefriend, Jim Love, has been myteacher and has also helped me teach thenext generation. I have a great photo ofhim taken at a family weekend that washeld last summer. I invited him to comeand talk to the 7-12 year-old boys abouthis experiences growing up in ‘the oldendays’. In the photo he is surrounded bywide-eyed speechless little boys lookingon as he shows them his damaged knees.That was worth WAY more than anytalking I could ever have done.Hemophilia Today: You were recentlyelected to a World Federation positionwhile in Seville. Could you tell usabout it?Kathy Mulder: Yes, I was elected asJunior Vice-President of the Musculo-Skeletal Committee. This committee ismade up of orthopedic surgeons andphysiotherapists. I’m the secondphysiotherapist to be elected to thiscommittee. I’m just learning what myjob is as I go along.Hemophilia Today: Is there anythingelse you would like to talk about?Kathy Mulder: Yes. I would like toremind all hemophiliacs and theirfamilies not to take anything for granted.We are so fortunate to live in Canadawhere medical care is accessible andfunded. I just came from the WorldFederation of Hemophilia Congress inSpain. Treatment is still available to only25% of the world’s hemophiliacs. Those25% are doing quite well. The other 75%still have terrible joint disease. In ourCanadian system, joint disease should becompletely preventable but I still see it,and I see it in young children. Factor isimportant but it is not the whole answer.Proper management and rehabilitationof EACH AND EVERY joint or musclebleed is just as important. We must neverlet down our guard.
lood factorHEMOPHILIA TODAY SUMMER 2002 21THEBLOODFACTORRecovery in Factor IXConcentratesWilma McClure, R.N.,Hemophilia B (Factor IX deficiencyhemophilia) is estimated to affect 1 in30,000 males. It is caused by a geneticdefect of the X chromosome resulting in low orabsent Factor IX coagulant activity.Clotting factor concentrates have beenavailable for 30 years for the effective control ofbleeding episodes in people with Hemophilia B.In the mid and late 1980s, viral inactivationtechniques were developed to eliminate bloodbornepathogens like HIV and Hepatitis C. Thenin the early 1990s, high-purity factor plasmaderivedIX (pdFIX) concentrates wereintroduced. They included Immunine®,manufactured by Baxter; Mononine®,manufactured by Aventis-Behring; andAlphaNine®, manufactured by Alpha. Theseproducts significantly lowered the risk offormation of unwanted blood clots. Then, fouryears ago, the first, and so far only, recombinantfactor IX product (rFIX), BeneFIX®,manufactured by Wyeth-Ayerst, was approved foruse in Canada.Inhibitor antibodies to any of the plasmaderivedor recombinant concentrates continue tobe uncommon in hemophilia B, affectingapproximately 3% of patients. There have beenno incidents of viral infection with HIV or HCVin pdFIX concentrates since the late 1980s;however, since rFIX was licensed in Canada in1998, most patients have changed to this productdue to its freedom of risk of blood-bornepathogens.Global experience suggests that both the rFIXand pdFIX formulations are associated with ahigh degree of safety and predictable benefits.The most important difference betweenpdFIX and rFIX is the variable pharmacokinetics.It now appears that recovery for all FIXconcentrates is influenced by patient age andbody weight. “Recovery” is often described as “theamount of clotting factor a person’s body canactually use compared to the amount infused.”David Page,CHS Blood Safety CoordinatorIn this issue, THE BLOOD FACTOR presents three articles. The first is by WilmaMcClure, Nurse Coordinator at the Northern Alberta Hemophilia Centre, onissues related to recovery in factor IX concentrates. On page 22, I report on theFifth Workshop on Gene Therapies, organized by the National HemophiliaFoundation in April. Finally, on page 23, James Kreppner, Chair of the CHS BloodSafety Committee, writes on a variety of subjects discussed at the CanadianBlood Services National Liaison Committee.Recovery is lower in children, especially youngchildren with low body weight, for all FIXconcentrates. However, in addition, averagerecovery with rFIX is approximately 25% lowerthan with pdFIX. Thus, the effect of lower overallFIX recovery in children combined with the loweraverage recovery of rFIX for the group as a wholecan dramatically affect the amount of rFIX that iseffectively infused.As a condition for making rFIX available inCanada in 1998, the Canadian Blood Agencyrequired that hemophilia clinics conduct a postlicensure surveillance study. This was coordinatedby the Factor IX Subcommittee of the Associationof Hemophilia Clinic Directors of Canada(AHCDC). They investigated the recovery of rFIXcompared to that of the last dose of pdFIX givenbefore switching to rFIX.As stated above, the recovery of rFIX followinginfusion is significantly lower than that withpdFIX and, for all products, recovery issignificantly lower in people less than 15 years ofage compared to people more than 15 years of age.Based on this data, the mean multiplicationfactor for rFIX dose calculation to compensate forlower recovery is:• 1.29 (1.24 – 1.35) for all age groups• 1.57 (1.48 – 1.66) for patients less than 15years of age and• 1.19 (1.13 – 1.26) for patients greater than 15years of age.This means that an average person less than 15years of age would have to infuse 1.57 times thenormal dose of rFIX to recover the same amountas indicated on the box.According to Dr. Man-Chiu Poon of theAHCDC, the individual variation in recovery thatwas documented following the infusion of pdFIXand rFIX suggests that an in vivo recovery studyshould be performed on all patients receiving anew factor IX concentrate to allow more accuratedosage calculation and achieve desired clottingfactor levels. According to Dr. Poon, these shouldbe performed periodically to allow dosageadjustment, particularly in young children. Thenew BeneFIX label reinforces this.In late 2001, as a result of this new data onrecovery, Health Canada approved Wyeth-Ayerst’sproposed changes to the label for BeneFIX.The dosage calculation for pdFIX is:• Number of pdFIX units required = bodyweight(kg) x % (desired level of FIX) x 1• Example:1,800 units = 60 kg x 30% (desiredlevel of FIX) x 1The dosage calculation for rFIX as nowrecommended by Wyeth-Ayerst Canada Inc. is asfollows:Adult patients (more than 15 years of age):• Number of rFIX units required = bodyweight(kg) x % (desired level of FIX ) x 1.2• Example: 2,160 units = 60 kg x 30% (desiredlevel of FIX) x 1.2Pediatric patients (less than 15 years of age):• Number of rFIX units required = bodyweight(kg) x % (desired level of FIX ) x 1.4• Example: 840 units = 20 kilo x 30% (desiredlevel of FIX) x 1.4In summary of the data provided by theproduct manufacturer of BeneFIX, Wyeth-AyerstCanada, there have been 25 reports of allergicreactions since the product was released. Twenty ofthese were mild to moderate, involvingdermatologic or respiratory reactions. The otherfive were anaphylactic type reactions reinforcingthe need for ANA kits or Epipens for patients onhome infusion; some of the five were associatedwith formation of inhibitor antibodies. In the fouryears that rFIX has been available, there have beensix new reports of inhibitor antibodies. Thisincidence is similar to that reported with pdFIX.There were 17 case reports of red blood cellagglutination observed in approximately 4,500patients exposed to rFIX. This has been associatedwith the practice of drawing blood back into thetubing or syringe containing rFIX. A warningagainst this practice is now included in thelabeling.Over the last decade, there have been majoradvances in the treatment of Hemophilia B. BothpdFIX and rFIX are highly effective if proper doseadjustments are used. rFIX has become thestandard of care at most institutions; however, anumber of patients have preferred to remain onpdFIX, stating that they felt comfortable with theproduct they had been using for many years.Others, after using rFIX, and even though doseadjustments to rFIX were made, did not feel thatbleed resolution was as effective, and switchedback to pdFIX.Further studies will have to be undertaken todetermine whether these anecdotal reports oflesser efficacy with rFIX have a basis in fact. In themeantime, it is essential that Hemophilia Bpatients, especially children, undergo recoverystudies when starting use of a new clotting factorproduct.Wilma McClure is Nurse Coordinator at theNorthern Alberta Hemophilia Centre in Edmontonand is a member of the CHS Blood SafetyCommittee.