June 09-41-2.indd - Kma.org.kw

June 2009KUWAIT MEDICAL JOURNAL 159with other autoimmune disorders [23] . There isclearly class I evidence for IVIg as standardtherapy for CIDP but most studies have only beenmade for induction therapy rather than at longterm therapy. Factors in favor of the use of IVIgover steroids includes safer long term profile andease of use (it can be given at home but not in thiscountry) while factors in favor of steroids includethe lower cost, availability worldwide and theease of administration whether intravenous ororal.The main drawbacks of IVIg are higher costand sometimes availability. Minor side effectssuch as rash, headache, fever and chills may beminimized by slowing infusion rate and using antiinflammatorypremedication. Serious side effectsincluding allergic reactions, aseptic meningitis andthromboembolic events occur in less than 5% ofinfusions [1] .There are different therapeutic regimens as todosage and duration of IVIg [24] . One gram/kg/day for two days may induce faster improvementthan 0.4 gram/kg/day for five consecutive days [3] .A dose of 0.4 g/kg body weight was superior to0.2 g/kg when given over five days. It can begiven as 2 g/kg over 2-5 days or 0.4 g/kg weeklyor every other week or every 28 days. The routinecycle of IVIg given over five days results in clinicalimprovement within 7-10 days in 56-79% of adultpatients. The mean half life of IVIg is 18 - 32 days.Therefore, periodic maintenance infusions atintervals of four weeks are needed [22,23,24] . Morethan 40% of patients need at least 1 g/kg every2-8 weeks to prevent further relapses. After 3-6months consider beginning gradual wean off bydecreasing frequency of treatment and loweringthe dose and later trail off the IVIG.Prednisolone is an effective alternative toIVIg as two thirds respond to either treatment.Family must be made aware of potential acuteand chronic risks of corticosteroids. The dose of1-2.5 mg /kg per day is usually used for at leastfour weeks followed by slow tapering. Relapseswere common when dose was lowered. There aremany potential adverse effects for corticosteroidstherapy (both acute and chronic) including weightgain, osteopenia, altered growth (occurred in our2 nd case), hypertension, susceptibity to infectionsand cataracts. These side effects may be minimizedby administering the medication on an alternateday basis or in pulse treatments.Children like adults demonstrate initialimprovement in two thirds of cases [1,7] afterinitiating treatment with prednisolone but childrenrequire continued high dose therapy as on taperingrelapses are frequent. This was evident in our2 nd case. If steroids are needed for more than oneyear, complete withdrawal is often very difficult.Attempts to reduce the dose without addition ofan immunosuppressive medication often lead tounnecessary relapses.The use of high dose pulse methylprednisolonehas been suggested with similar efficacy to IVIgand oral steroids [6,24] but physicians should beaware of possible significant clinical deteriorationafter high dose intravenous methylprednisoloneas reported by Rostasy et al [25,26] .PE is considered as a third option [22] andtrials comparing IVIg with PE did not findsignificant difference in short term effect of thesetwo treatments [1,17,23] . Although 60% of patientsrespond to PE, it is less often used in childrenbecause of technical difficulties with installationof central catheters which may account for itslimited use in young children [1] . In addition totechnical difficulties, there are potential infectious,thrombotic and hemodynamic complications ofthe treatment itself. The effect lasts only few weekswith over two thirds having a relapse or end ofdose effect after two weeks making it unsuitablefor long term treatment. It is usually administered2-3 times per week for 6-10 treatments and maybe tapered slowly. Improvement may beginwithin days but it is temporary and relapsesand even rebound phenomenon are commonwhen treatment is terminated. PE is an effectivetemporary or adjuvant therapy for CIDP butimmunosuppressive drug treatments are requiredfor long term management.The short term effects of initial treatment withIVIg and PE, in addition to the serious side effectsof prolonged use of steroids necessitates the use ofseveral immunosuppressive agents as adjunctivetherapy to reduce the dose of steroids or the frequencyof IVIg and PE courses [23,27] . In these treatment resistantcases, different immunosuppressant includingazathioprine, methotrexate [27] , cyclosporine A [28] ,cyclophosphamide [6] , mycophenolate [29] , interferon-αand β-Ia, can be used but the evidence is insufficientto recommend one over the other [1,14] .PrognosisThe prognosis in children is generally morefavorable than adults with complete remissionor minimal weakness in 70-100% cases [1,2,3,9] . Incomparison, adults exhibit moderate to severesequelae in 30-40% of cases. A small number ofchildren respond poorly to all treatment modalitiesor develop significant side effects to protractedimmunosuppression resulting in moderate tosevere neurological disability. Pain at onset andinfectious prodromal illness predicts a betteroutcome while axonal loss on electrodiagnosticstudies predicts a poor prognosis [2] .