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Xanthine oxidase inhibitor in duchenne muscular dystrophy
Xanthine Oxidase Inhibitor In Duchenne Muscular Dystrophy Hideo Tamari, MD, Yoshinobu Ohtani, MD, Akimasa Higashi, MD, Sanji Miyoshino, MD and rehiro Matsuda, MD
The treatment with xanthine oxidase inhibitor, allopurinol, was evaluated in 17 patients with Duchenne muscular dystrophy (aged 2 years 9 months to 13 years 9 months) using the double blind technique. The total observed period was 27 months. The results of 100-point scale of graded functional abilities revealed that an improvement, unchange and progression of dysfunction were found in 2, 2 and 6 patients, respectively, in allopurinol group and in 0, 2 and 5 patients, respectively in placebo group. The patients' age and stage of the disease seemed to be related to the effectiveness of allopurinol treatment. Tamari H, Ohtani Y, Higashi A, Miyoshino S, Matsuda I Xanthine oxidase inhibitor in Duchenne muscular dystrophy. Brain Dev 1982;4:137-43
Duchenne muscular dystrophy (DMD) is a disease of unknown etiology with X-linked inheritance, for which no effective therapy has been proposed, except for the xanthine oxidase, allopurinol. In 1976, Thomson and Smith [1, 2] reported that oral administration of allopurinol in patients with classical DMD resulted in the restoration of muscular ability, accompanied with the recovery of adenosine triphosphate (ATP) content in muscle. An evaluation of the therapy, however, is still under discussion. Castro-Gago et al [3] supported Thomson and Smith's report but Bakouche et al [4], Doriguzzi et al [5], and Stern et al [6] questioned their results. From the Department of Pediatrics, Kumamoto University, School of Medicine, Kumamoto (HT, YO, AH, 1M); Department of Pediatrics, Nishibeppu National Hospital, Beppu, Oita (SM). Received for publication: October 29, 1981. Accepted for publication: February 3, 1982.
Key words: Allopurinol, Duchenne muscular dystro· phy. Correspondence address: Dr. Hideo Ta.mari, Department of Pediatrics, Kumamoto University, School of Medicine, Honjo 2-2-1, Kumamoto 860, Japan.
The present report deals with our studies on 17 patients with classical DMD for 27 months, using a double blind technique. Materials and Methods Patients Seventeen male patients with DMD (aged 2 years 9 months to 13 years 9 months), including two male identical twins, were used in the present study. All had clinically classical DMD features, confirmed by serum enzymology and 6 of them by muscle biopsy. Their clinical stage and laboratory data are shown in Table 1. Analytical Methods Glutamic-oxaloacetic transaminase (GOT) and creatinine phosphokinase (CPK) in serum were measured as described elsewhere [7]. The ATP content in biopsied quadriceps muscle was measured enzymologically and expressed on the basis of wet weight and non-collagen protein [8] . Urate in serum and in urine were measured by Technicon Auto-Analyzer [9].
Assessment of Clinical Stage and Evaluation of Muscular Abilities The clinical stage of the disease was based on the classification of Zellwegar and Harson (Appendix 1, [10]). Muscular abilities were scored using 100-point scale developed by "Muscle dystrophy study group, sponsored by Ministry of Health and Welfare of Japan." This was designed to evaluate more detailed muscular abilities (Appendix 2). Dynamometric testing was not used in the present study due to difficulties encountered especially with small children [5] . Experimental Design The allopurinol (100 mg) tablet, commercial but unmarked, and identical inert placebo were supplied by the Tokyo Tanabe Pharmacy Co., Ltd. The daily dosage of allopurinol was as follows: at 4 to 6 years 150 mg, at 7 to 9 years 200 mg, at 10 to 13 years 250 mg, and at over 13 years 300 mg [11]. At the first study, each patient, irrespective of age and severity of the disease, took tablets daily from the allopurinol/placebo bottle allocated to him . After the first 6 months of observation, the contents were revealed. The two groups consisted of 10 patients treated with allopurinol and 7 patients treated with placebo. At the second study, the treatment was exchanged in some of the cases, to separate the twin boys into different groups. The total observed · period of the first and the second study was 27 months. Laboratory and clinical studies were performed monthly. The tests for muscle abilities were performed by a skillful physical therapist of a rehabilitation clinic which was not a member of the study group and did not know the purpose of present study. In the informed consent, which was obtained from all patients and/or parents, permission was obtained for a muscle biopsy for ATP measurement at a time when muscle functions improved satisfactorily. Results Laboratory Data Serum and urine urate: Results before the treatment and after the first and second studies (6 months and 27 months after the treatment) are listed in Table 2. Significant difference was found only in serum urate level between allo138 Brain & Development, Vol 4, No 2,1982
purinol group and placebo group at the end of the first and second studies. In cases I and 2, who were both found to be improved, serum urate concentrations decreased from 4.l to 3.3 mg/dl and 4.9 to 3.2 mg/dl respectively, at the end of the second study, whereas the urinary urate excretion remained unchanged. Muscle ATP: Muscle ATP content in DMD was 1.45 ± 1.3 pmol/g wet weight and 12.4 ± 11.3 pmol/g non-collagen protein. When compared to the result of other muscular diseases in our laboratory (3.6 ± 1.1 pmol/g wet weight, 24.0 ± 7.8 pmol/g non-collagen protein (N =6), floppy infants with unknown etiology, benign muscle hypotonia, Kugelberg-Welander disease) and with reported normal levels [12], the obtained value in DMD was found to be reduced. Repeated muscle biopsy was refused in cases 1 and 2. Clinical Assessment of Muscle Abilities The changes in clinical stages and the score of muscle abilities are shown in Table 1 and Fig 1. An improvement was shown in two patients, aged 3 and 4 years, belonging to the allopurinol group. In these two cases, in addition to an increased score, relief of Cowers sign was observed, but the muscular pseudohypertrophy persisted at the end. Unchanged clinical features were found in two patients in the allopurinol group, as well as in two patients in the placebo group . Each of the twin belonged separately to these groups. Six patients of the allopurinol group and five patients of the placebo group showed progressive muscular dysfunction. Data on any intolerance to the drug were not available. Discussion Thomson and Smith [2] postulated that an impaired muscle function in DMD may be attributed to efflux of purine metabolite from muscle, as they found a decreased content of ATP in the muscle and of urate in urine. They administered allopurinol for 6 months in the patients with classical DMD, intending to repair the purine metabolism. In 7 of 8 cases with classical DMD, this therapy resulted in an improvement of muscular ability, including disappearance of Cowes sign. In addition , ATP content in muscle increased at the rate of 1.5fold to 2.0-fold from the pretreatment levels
Table I
Case 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
Result of double-blind trial in 17 patients with Duchenne muscular dystrophy
Age at CPK GOT start (yrs:mos) (unit) (mll/ml) 2: 9 4: 4 5: 6 7:9 8: 4 8: 9 9: 0 9: It 9: It 9: 5 11: 2 11: 5 11:10 12: 4 13: 0 13 : 2 13: 9
300 1,700 1,000 1,210 725 1,470 905 2,300 3,000 790 575 500 1,042 300 260 530 605
159 235 194 120 120 170 140 160 150 120 95 100 100 102 70 70 120
Clinical status At the end of Atthe end of the Comment At start the first study * second study**
Treatment Allopurinol Allopurinol Allopurinol Allopurinol-Placebo *** Allopurinol Allopurinol Allopurinol-Placebo ** * Placebo Placebo-Allopurinol *** Allopurinol Allopurinol Placebo-Allopurinol * ** Allopurinol Placebo Placebo Placebo Placebo
II II II V II II I II VI VI II VI V II IV
II II I II V IV V I IV VI VI II VII VII III
IV
II II VI V VI
V VI VI III VIII VIII IV V
Improved Improved Worsened Unchanged Worsened Worsened Worsened Unchanged Unchanged Worsened Unchanged Unchanged Worsened Worsened Worsened Worsened Worsened
* 6 months after the treatment, ** 27 months after the treatment, ***treatment was exchanged at the end of the first study, tidentical twins.
in 6 and 12 months of therapy, respectively [2]. Castro-Gago et al [3] confirmed this result in 3 young patients (mean age 3 years 4 months) in whom Gowers sign and muscle pseudohypertrophy diminished after allopurinol treatment. They further reported that another 4 patients (mean age 9 years 4 months) were partially improved and 3 patients with contracture and deformity (mean age 10 years) were unresponsive . In Doriguzzi's 9 cases [5] with DMD, the youngest patient (aged 5 years) with stage I remained on the same stage with allopurinol treatment, whereas other 3 older patients on stage I progressed to stages II and III with allopurinol and placebo treatment respectively. The rest of the 6 cases with more advanced stages became worse, regardless of the treatment. In Stern's report [6] outcome of each case was not described and as a group, allopurinol as well as placebo did not alter the progress of the disease. Bakonche et al [4] failed to obtain any evidence of improvement in 20 adults patients with limb-girdle muscular dystrophy and late onset DMD. It is possible that the responsiveness to allopurinol may
depend on the patient's age and stage of the disease. Indeed, the ages of the two patients improved in the present study were 2 years 9 months and 4 years 4 months, respectively. However, on another aspect, it might be argued that muscular ability in these patients developed normally rather than improved, since normal children around these years of age are still on the developmental stage of muscular ability. Even so, it seemed possible to state that allopurinol treatment prevented the progress of muscular dysfunction in these two patients. Except for these two patients, the results of the allopurinol group was similar to the results of the placebo group. In a 5-year-6-month-old patient, partial improvement was found only for several months, and subsequently muscle ability declined gradually. Two 9-year-old identical twin patients, one of whom belonged to the allopurinol group and the other to the placebo group, showed unchanged muscular function during the observed period. Thus, it is suggested that the responsiveness for allopurinol treatment may not depend on the patient's age alone, but on some unknown
Tamari et al: Xanthine oxidase inhibitor in DMD 139
factor or factors. We confirmed the observation of decreased muscle ATP content reported by Thomson and Smith [2], but their further observation of restored ATP content after allopurinol treatment could not be evaluated in the present study, since repeated biopsy was refused. Allopurinol treatment in dystrophic mouse resulted in no increase but significant decrease of muscle ATP [12]. However, the type of the disease in the mouse is not identical with human DMD, and therefore, this result is not applicable to o
0
~-----~
100
human DMD. In an earlier report [2] , the restored muscle ATP content in DMD was accompanied with a further decrease of serum urate level and urinary urate excretion, whereas in the present study, when compared to the control level and with the level before the treatment, allopurinol treatment resulted in significant changes in serum urate levels but not urinary excretion. Thus, clinical improvement was not supported by biochemical evidence in the present study. Further careful studies will be required
Allopurinol Placebo
75
50
25
'-0-----------------------S
12 18 Months after treatment
140 Brain & Development, Vol 4, No 2,1982
24
Fig 1 A 1 OO:point scale of muscular ability of the patient.
to settle the arguments discussed above. Due to a small number of patients involved in the present study, further experience with the allopurinol treatment is needed, especially
in patients with a very early stage of the disease. This type of the patients may be found in a family study or through neonatal screening for the disease .
Table 2 Serum urate and urinary urate excretion in Allopurinol and placebo group Before treatment Serum urate (mg/dl, mean Allopurinol (n = 10)
±
At the end of the first At the end of the second study (6 months after study (27 months after the treatment) the treatment)
=10)
SD) 4.2 ± 0.5
3.6 ± 0.5
4.1 ± 0.5 b
a Placebo (n = 7)
Control
(n
4.6 ± 0.8
5.5 ± 1.0
5.4 ± 0.8
0.27 ± 0.11
0.27 ± 0.09
c
4.0 ± 0.7
a
0.39 ± 0.09
Urinary urate excretion (g/day, mean ± SD) Allopurinol (n = 10)
0.35 ± 0.13
a
a Placebo (n = 7)
0.35 ± 0.09
0.35 ± 0.12
a, not significant; band c, these two means are significantly different (b: p
0.35
±
0.13
< 0.05, c: p < 0.01).
Appendix 1 Classification of clinical stage (Zellweger and Harson).
Performance
Stage
Withou t railings Can climb stairs
Ambulatory Cannot climb stairs without assistance
With railings with mild exertion Slowly and cumbrously with railings
III
Can stand up independently from chair
IV
Cannot stand up independently from chair
Predominantly in wheelchair but can walk a little, usually with braces or other assistive devices Independent in transfer activities (from wheelchair to bed, toilet, etc.) Can sit up independently Wheelchair existence
Dependent in transfer activities
(a) Cannot sit up independently (b) Cannot raise arms in off arm rests
Bed existence - cannot use wheelchair
II
V VI VII VIII
IX X
Cited from Dubowitz [10).
Tamari et al: Xanthine oxidase inhibitor in DMD 141
Appendix 2 A 100-point scale activity of daily life developed by "Muscle dystrophy study group, sponsored by Ministry of Health and Welfare of Japan." Head 4 3 2 1
control Normal Possible when lying face down but not up Not possible even lying face down Stable when sitting up straight only o No control
Sitting balance 4 Possible to establish self-balance 3 Establish partial balance 2 Fall on slight loss of balance 1 Can sit with assistance o No control without support From 4 3 2 1
o
sitting to reclining position Can recline on back slowly without using hands Can recline on back slowly using hands First lie on stomach then turn over Arm support insufficient and fall down Need assistance to recline
Rolling 4 Roll over easily 3 Roll over with little difficulty with assistance from hands and feet 2 Roll over but take time and difficulty 1 Half roll over only to side position o Cannot ever roll over on side Crawl 4 3 2 1
o
Crawl on hands quickly Crawl with hands facing in or out Crawl with elbows Attempt elbow crawl but no movement No crawl possible
Walk 4 3 2 1
up stairs Walk up stairs normally Walk up stairs with hands on thighs Walk up stairs by using hand rail Walk up stairs turning face sideways using handrail o Impossible without: assistance
Walk 4 3 2 1
down stairs Walk down stairs normally Walk down stairs with hands on thighs Walk down stairs by using hand rail Walk down stairs turning face sideways using handrail o Impossible without assistance
Run 4 3 2 1
o
Run Run Run Run Run
10 m at full speed within 5 seconds 10 m at full speed in 5-10 seconds 10 m at full speed in 10-15 seconds 10 m at full speed in 15-20 seconds 10 m at full speed more than 20 seconds
Sit in chair 4 Sit normally-retain position after removing chair 3 Sit normally but impossible to retain position after removing chair 2 Sit in chair gradually with hands on hips 1 F all in chair o Impossible to sit without assistance Rising from chair 4 Normal 3 Stand up using hands on knees 2 Stand up with support 1 Can rise out of chair but not stand (high chairpossible) o Impossible to rise from chair
Rising 4 Rise without using hands 3 Rise by using hands 2 First turn on stomach, then rise 1 First turn on stomach, then rise with difficulty o Impossible to rise
Squatting 4 Normal 3 Squat gradually with hands on knees 2 Fallon knees but maintain balance 1 Fall on hands and knees o Impossible without assistance
Maintain vocal sound 4 Say "ha" for more than 20 seconds 3 Say "ha" between 15 and 20 seconds 2 Say "ha" between 10 and 15 seconds 1 Say "ha" between 5 and 10 seconds o Say "ha" for less than 5 seconds
Putting on trousers 4 Can put on while standing 3 Step into trousers up to thigh while sitting or lying down, then stand to complete 2 Step into trousers up to thigh 1 Can reach toes, but not put on trousers o Impossible to reach toes
Raise hands over head 4 Raise hands over head from sitting position 3 Raise upper arms to shoulder level from sitting position 2 Raise upper arms 45° with hands on table from sitting position 1 Raise upper arms from reclining position o Impossible to move upper arms Walk 4 3 2 1
up incline Walk up 15° slope normally Walk up gradual slope normally Walk up gentle slope (5°) gradually Possible to walk on unpaved road (10 m) o Possible to walk on paved road
142 Brain & Development, Vol 4, No 2,1982
Handle rice bowl for eating 4 Eat with chopsticks from bowl in hand easily 3 Rest elbows on table and handle chopstick and bowl 2 Do No.3 but stop from exhaustion 1 Use chopsticks/spoon with difficulty but cannot handle bowl o Cannot handle chopsticks/spoon Washing face 4 Wash face with both hands in standing position 3 Support self with one hand and wash face with other in standing position 2 Wash face with both hands in sitting position
Appendix 2 Continued. 1 Hands reach face but cannot use to wash o Impossible to wash face
Using 4 3 2 1
o
o
towel Wring completely Wring, but incompletely Wring, but most water remains Hold towel but cannot wring Impossible to hold towel
Writing 4 Write big letters with brush with elbow up 3 Write middle sized letters by moving forearm with elbow support 2 Write with pen easily 1 Wirte with pen with difficulty o Impossible to write Standing 4 Stand at attention easily 3 Stand easily with feet apart (with equipment no problem) 2 Stand momentarily with feet apart (with equipment stand with difficulty) Holding thigh, can stand with much difficulty (with support, can raise oneself) o Impossible to stand without assistance Standing on one leg 4 Stand on one leg easily 3 Stand on one leg momentarily (one minute) 2 Stand on one leg (more than one minute) using one hand on a support
Acknowledgment This work was supported by grants from the Ministry of Health and Welfare, Japan. References 1. Thomson WHS, Smith I. X-linked recessive (Duchenne) muscular dystrophy and purine metabolism. Lancet 1976;2:805-6. 2. Thomson WHS, Smith I. X-linked recessive (Duchenne) muscular dystrophy (DMD) and purine metabolism: Effects or oral allopurinol and adenylate. Metabolism 1978;27:151-63 . 3. Castro-Gago M, Jimenez JF, Pombo M, Tojo R, Couselo JM, Peiia J. Allopurinol in Duchenne muscular dystrophy. Lancet 1980;1:1358-9. 4. Bakouche P, Chaouat D, Nick J. Allopurinol not effective in muscular dystrophy. N Engl J Med 1979;301:785. 5. Doriguzzi C, Bertolotto A, Ganzit GP, Mongini T, Palmucci L. Ineffectiveness of allopurinol in Duchenne muscular dystrophy. Muscle Nerve 1981;4:176-8. 6. Stern L, Fewings JD, Bretag AH, et al. The progression of Duchenne muscular dystrophy:
Stand on one leg using hands on a support but with difficulty Impossible to stand on one leg even with assistance
Stand by leaning on support 4 Stand without assistance (with equipment easily) 3 Stand with one hand as support (with equipment can barely stand) 2 Stand with both hands as support (with equipment and hands, can stand) 1 Can stand by leaning against support o Impossible to stand even while leaning on support Walk 4 Walk normaly 3 Unsteady walk (can walk with equipment) 2 Impossible to walk alone but can with support (walk more than 10 m with walker) Can walk with support for 10 m (with walker less than 10 m) o Impossible to walk without assistance Rise from floor 4 Normal 3 Leaning heavily forward can rise without using hands 2 Stand by using hands on knees 1 Get on all fours, place hands on knees and rise gradually o Impossible without assistance
7.
8.
9. 10. 11 . 12. 13.
clinical trial of allopurinol therapy. Neurology 1981;31:422-6. Matsuda I, Miyoshino S, Miike T, et al. Mitochondrial fraction of serum glutamic-oxaloacetic transaminase in Duchenne muscular dystrophy. CZin Chim Acta 1978;83:2314. Sugita H, Okumura Y, Ayai K. Application of a property of troponin to determination of tropomyosin content of a small piece of muscle. J Biochem 1969;65 :971 -2. Patel CP. Semimicro method for determination of serum uric acid using EDTA-hydrazine. Clin Chem 1968;14:764-75. Dubowitz V. Muscle disorders in childhood. London· Philadelphia· Toronto: WB Saunders, 1978:69. Thomson WHS, Smith I. Allopurinol in Duchenne muscular dystrophy. N Engl J Med 1978;299: 101. Griffiths J, Shuttlewood RJ. Allopurinol for muscular dystrophy. Lancet 1980;2:423-4. Lundberg A, Eriksson BO, Mellgren G. Metabolic substrate, muscle fiber composition and fiber size in late walking and normal children. Eur J Pediatr 1979; 130: 79-92.
Tamari et al: Xanthine oxidase inhibitor in DMD 143
The treatment with xanthine oxidase inhibitor, allopurinol, was evaluated in 17 patients with Duchenne muscular dystrophy (aged 2 years 9 months to 13 years 9 months) using the double blind technique. The total observed period was 27 months. The results of 100-point scale of graded functional abilities revealed that an improvement, unchange and progression of dysfunction were found in 2, 2 and 6 patients, respectively, in allopurinol group and in 0, 2 and 5 patients, respectively in placebo group. The patients' age and stage of the disease seemed to be related to the effectiveness of allopurinol treatment. Tamari H, Ohtani Y, Higashi A, Miyoshino S, Matsuda I Xanthine oxidase inhibitor in Duchenne muscular dystrophy. Brain Dev 1982;4:137-43
Duchenne muscular dystrophy (DMD) is a disease of unknown etiology with X-linked inheritance, for which no effective therapy has been proposed, except for the xanthine oxidase, allopurinol. In 1976, Thomson and Smith [1, 2] reported that oral administration of allopurinol in patients with classical DMD resulted in the restoration of muscular ability, accompanied with the recovery of adenosine triphosphate (ATP) content in muscle. An evaluation of the therapy, however, is still under discussion. Castro-Gago et al [3] supported Thomson and Smith's report but Bakouche et al [4], Doriguzzi et al [5], and Stern et al [6] questioned their results. From the Department of Pediatrics, Kumamoto University, School of Medicine, Kumamoto (HT, YO, AH, 1M); Department of Pediatrics, Nishibeppu National Hospital, Beppu, Oita (SM). Received for publication: October 29, 1981. Accepted for publication: February 3, 1982.
Key words: Allopurinol, Duchenne muscular dystro· phy. Correspondence address: Dr. Hideo Ta.mari, Department of Pediatrics, Kumamoto University, School of Medicine, Honjo 2-2-1, Kumamoto 860, Japan.
The present report deals with our studies on 17 patients with classical DMD for 27 months, using a double blind technique. Materials and Methods Patients Seventeen male patients with DMD (aged 2 years 9 months to 13 years 9 months), including two male identical twins, were used in the present study. All had clinically classical DMD features, confirmed by serum enzymology and 6 of them by muscle biopsy. Their clinical stage and laboratory data are shown in Table 1. Analytical Methods Glutamic-oxaloacetic transaminase (GOT) and creatinine phosphokinase (CPK) in serum were measured as described elsewhere [7]. The ATP content in biopsied quadriceps muscle was measured enzymologically and expressed on the basis of wet weight and non-collagen protein [8] . Urate in serum and in urine were measured by Technicon Auto-Analyzer [9].
Assessment of Clinical Stage and Evaluation of Muscular Abilities The clinical stage of the disease was based on the classification of Zellwegar and Harson (Appendix 1, [10]). Muscular abilities were scored using 100-point scale developed by "Muscle dystrophy study group, sponsored by Ministry of Health and Welfare of Japan." This was designed to evaluate more detailed muscular abilities (Appendix 2). Dynamometric testing was not used in the present study due to difficulties encountered especially with small children [5] . Experimental Design The allopurinol (100 mg) tablet, commercial but unmarked, and identical inert placebo were supplied by the Tokyo Tanabe Pharmacy Co., Ltd. The daily dosage of allopurinol was as follows: at 4 to 6 years 150 mg, at 7 to 9 years 200 mg, at 10 to 13 years 250 mg, and at over 13 years 300 mg [11]. At the first study, each patient, irrespective of age and severity of the disease, took tablets daily from the allopurinol/placebo bottle allocated to him . After the first 6 months of observation, the contents were revealed. The two groups consisted of 10 patients treated with allopurinol and 7 patients treated with placebo. At the second study, the treatment was exchanged in some of the cases, to separate the twin boys into different groups. The total observed · period of the first and the second study was 27 months. Laboratory and clinical studies were performed monthly. The tests for muscle abilities were performed by a skillful physical therapist of a rehabilitation clinic which was not a member of the study group and did not know the purpose of present study. In the informed consent, which was obtained from all patients and/or parents, permission was obtained for a muscle biopsy for ATP measurement at a time when muscle functions improved satisfactorily. Results Laboratory Data Serum and urine urate: Results before the treatment and after the first and second studies (6 months and 27 months after the treatment) are listed in Table 2. Significant difference was found only in serum urate level between allo138 Brain & Development, Vol 4, No 2,1982
purinol group and placebo group at the end of the first and second studies. In cases I and 2, who were both found to be improved, serum urate concentrations decreased from 4.l to 3.3 mg/dl and 4.9 to 3.2 mg/dl respectively, at the end of the second study, whereas the urinary urate excretion remained unchanged. Muscle ATP: Muscle ATP content in DMD was 1.45 ± 1.3 pmol/g wet weight and 12.4 ± 11.3 pmol/g non-collagen protein. When compared to the result of other muscular diseases in our laboratory (3.6 ± 1.1 pmol/g wet weight, 24.0 ± 7.8 pmol/g non-collagen protein (N =6), floppy infants with unknown etiology, benign muscle hypotonia, Kugelberg-Welander disease) and with reported normal levels [12], the obtained value in DMD was found to be reduced. Repeated muscle biopsy was refused in cases 1 and 2. Clinical Assessment of Muscle Abilities The changes in clinical stages and the score of muscle abilities are shown in Table 1 and Fig 1. An improvement was shown in two patients, aged 3 and 4 years, belonging to the allopurinol group. In these two cases, in addition to an increased score, relief of Cowers sign was observed, but the muscular pseudohypertrophy persisted at the end. Unchanged clinical features were found in two patients in the allopurinol group, as well as in two patients in the placebo group . Each of the twin belonged separately to these groups. Six patients of the allopurinol group and five patients of the placebo group showed progressive muscular dysfunction. Data on any intolerance to the drug were not available. Discussion Thomson and Smith [2] postulated that an impaired muscle function in DMD may be attributed to efflux of purine metabolite from muscle, as they found a decreased content of ATP in the muscle and of urate in urine. They administered allopurinol for 6 months in the patients with classical DMD, intending to repair the purine metabolism. In 7 of 8 cases with classical DMD, this therapy resulted in an improvement of muscular ability, including disappearance of Cowes sign. In addition , ATP content in muscle increased at the rate of 1.5fold to 2.0-fold from the pretreatment levels
Table I
Case 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
Result of double-blind trial in 17 patients with Duchenne muscular dystrophy
Age at CPK GOT start (yrs:mos) (unit) (mll/ml) 2: 9 4: 4 5: 6 7:9 8: 4 8: 9 9: 0 9: It 9: It 9: 5 11: 2 11: 5 11:10 12: 4 13: 0 13 : 2 13: 9
300 1,700 1,000 1,210 725 1,470 905 2,300 3,000 790 575 500 1,042 300 260 530 605
159 235 194 120 120 170 140 160 150 120 95 100 100 102 70 70 120
Clinical status At the end of Atthe end of the Comment At start the first study * second study**
Treatment Allopurinol Allopurinol Allopurinol Allopurinol-Placebo *** Allopurinol Allopurinol Allopurinol-Placebo ** * Placebo Placebo-Allopurinol *** Allopurinol Allopurinol Placebo-Allopurinol * ** Allopurinol Placebo Placebo Placebo Placebo
II II II V II II I II VI VI II VI V II IV
II II I II V IV V I IV VI VI II VII VII III
IV
II II VI V VI
V VI VI III VIII VIII IV V
Improved Improved Worsened Unchanged Worsened Worsened Worsened Unchanged Unchanged Worsened Unchanged Unchanged Worsened Worsened Worsened Worsened Worsened
* 6 months after the treatment, ** 27 months after the treatment, ***treatment was exchanged at the end of the first study, tidentical twins.
in 6 and 12 months of therapy, respectively [2]. Castro-Gago et al [3] confirmed this result in 3 young patients (mean age 3 years 4 months) in whom Gowers sign and muscle pseudohypertrophy diminished after allopurinol treatment. They further reported that another 4 patients (mean age 9 years 4 months) were partially improved and 3 patients with contracture and deformity (mean age 10 years) were unresponsive . In Doriguzzi's 9 cases [5] with DMD, the youngest patient (aged 5 years) with stage I remained on the same stage with allopurinol treatment, whereas other 3 older patients on stage I progressed to stages II and III with allopurinol and placebo treatment respectively. The rest of the 6 cases with more advanced stages became worse, regardless of the treatment. In Stern's report [6] outcome of each case was not described and as a group, allopurinol as well as placebo did not alter the progress of the disease. Bakonche et al [4] failed to obtain any evidence of improvement in 20 adults patients with limb-girdle muscular dystrophy and late onset DMD. It is possible that the responsiveness to allopurinol may
depend on the patient's age and stage of the disease. Indeed, the ages of the two patients improved in the present study were 2 years 9 months and 4 years 4 months, respectively. However, on another aspect, it might be argued that muscular ability in these patients developed normally rather than improved, since normal children around these years of age are still on the developmental stage of muscular ability. Even so, it seemed possible to state that allopurinol treatment prevented the progress of muscular dysfunction in these two patients. Except for these two patients, the results of the allopurinol group was similar to the results of the placebo group. In a 5-year-6-month-old patient, partial improvement was found only for several months, and subsequently muscle ability declined gradually. Two 9-year-old identical twin patients, one of whom belonged to the allopurinol group and the other to the placebo group, showed unchanged muscular function during the observed period. Thus, it is suggested that the responsiveness for allopurinol treatment may not depend on the patient's age alone, but on some unknown
Tamari et al: Xanthine oxidase inhibitor in DMD 139
factor or factors. We confirmed the observation of decreased muscle ATP content reported by Thomson and Smith [2], but their further observation of restored ATP content after allopurinol treatment could not be evaluated in the present study, since repeated biopsy was refused. Allopurinol treatment in dystrophic mouse resulted in no increase but significant decrease of muscle ATP [12]. However, the type of the disease in the mouse is not identical with human DMD, and therefore, this result is not applicable to o
0
~-----~
100
human DMD. In an earlier report [2] , the restored muscle ATP content in DMD was accompanied with a further decrease of serum urate level and urinary urate excretion, whereas in the present study, when compared to the control level and with the level before the treatment, allopurinol treatment resulted in significant changes in serum urate levels but not urinary excretion. Thus, clinical improvement was not supported by biochemical evidence in the present study. Further careful studies will be required
Allopurinol Placebo
75
50
25
'-0-----------------------S
12 18 Months after treatment
140 Brain & Development, Vol 4, No 2,1982
24
Fig 1 A 1 OO:point scale of muscular ability of the patient.
to settle the arguments discussed above. Due to a small number of patients involved in the present study, further experience with the allopurinol treatment is needed, especially
in patients with a very early stage of the disease. This type of the patients may be found in a family study or through neonatal screening for the disease .
Table 2 Serum urate and urinary urate excretion in Allopurinol and placebo group Before treatment Serum urate (mg/dl, mean Allopurinol (n = 10)
±
At the end of the first At the end of the second study (6 months after study (27 months after the treatment) the treatment)
=10)
SD) 4.2 ± 0.5
3.6 ± 0.5
4.1 ± 0.5 b
a Placebo (n = 7)
Control
(n
4.6 ± 0.8
5.5 ± 1.0
5.4 ± 0.8
0.27 ± 0.11
0.27 ± 0.09
c
4.0 ± 0.7
a
0.39 ± 0.09
Urinary urate excretion (g/day, mean ± SD) Allopurinol (n = 10)
0.35 ± 0.13
a
a Placebo (n = 7)
0.35 ± 0.09
0.35 ± 0.12
a, not significant; band c, these two means are significantly different (b: p
0.35
±
0.13
< 0.05, c: p < 0.01).
Appendix 1 Classification of clinical stage (Zellweger and Harson).
Performance
Stage
Withou t railings Can climb stairs
Ambulatory Cannot climb stairs without assistance
With railings with mild exertion Slowly and cumbrously with railings
III
Can stand up independently from chair
IV
Cannot stand up independently from chair
Predominantly in wheelchair but can walk a little, usually with braces or other assistive devices Independent in transfer activities (from wheelchair to bed, toilet, etc.) Can sit up independently Wheelchair existence
Dependent in transfer activities
(a) Cannot sit up independently (b) Cannot raise arms in off arm rests
Bed existence - cannot use wheelchair
II
V VI VII VIII
IX X
Cited from Dubowitz [10).
Tamari et al: Xanthine oxidase inhibitor in DMD 141
Appendix 2 A 100-point scale activity of daily life developed by "Muscle dystrophy study group, sponsored by Ministry of Health and Welfare of Japan." Head 4 3 2 1
control Normal Possible when lying face down but not up Not possible even lying face down Stable when sitting up straight only o No control
Sitting balance 4 Possible to establish self-balance 3 Establish partial balance 2 Fall on slight loss of balance 1 Can sit with assistance o No control without support From 4 3 2 1
o
sitting to reclining position Can recline on back slowly without using hands Can recline on back slowly using hands First lie on stomach then turn over Arm support insufficient and fall down Need assistance to recline
Rolling 4 Roll over easily 3 Roll over with little difficulty with assistance from hands and feet 2 Roll over but take time and difficulty 1 Half roll over only to side position o Cannot ever roll over on side Crawl 4 3 2 1
o
Crawl on hands quickly Crawl with hands facing in or out Crawl with elbows Attempt elbow crawl but no movement No crawl possible
Walk 4 3 2 1
up stairs Walk up stairs normally Walk up stairs with hands on thighs Walk up stairs by using hand rail Walk up stairs turning face sideways using handrail o Impossible without: assistance
Walk 4 3 2 1
down stairs Walk down stairs normally Walk down stairs with hands on thighs Walk down stairs by using hand rail Walk down stairs turning face sideways using handrail o Impossible without assistance
Run 4 3 2 1
o
Run Run Run Run Run
10 m at full speed within 5 seconds 10 m at full speed in 5-10 seconds 10 m at full speed in 10-15 seconds 10 m at full speed in 15-20 seconds 10 m at full speed more than 20 seconds
Sit in chair 4 Sit normally-retain position after removing chair 3 Sit normally but impossible to retain position after removing chair 2 Sit in chair gradually with hands on hips 1 F all in chair o Impossible to sit without assistance Rising from chair 4 Normal 3 Stand up using hands on knees 2 Stand up with support 1 Can rise out of chair but not stand (high chairpossible) o Impossible to rise from chair
Rising 4 Rise without using hands 3 Rise by using hands 2 First turn on stomach, then rise 1 First turn on stomach, then rise with difficulty o Impossible to rise
Squatting 4 Normal 3 Squat gradually with hands on knees 2 Fallon knees but maintain balance 1 Fall on hands and knees o Impossible without assistance
Maintain vocal sound 4 Say "ha" for more than 20 seconds 3 Say "ha" between 15 and 20 seconds 2 Say "ha" between 10 and 15 seconds 1 Say "ha" between 5 and 10 seconds o Say "ha" for less than 5 seconds
Putting on trousers 4 Can put on while standing 3 Step into trousers up to thigh while sitting or lying down, then stand to complete 2 Step into trousers up to thigh 1 Can reach toes, but not put on trousers o Impossible to reach toes
Raise hands over head 4 Raise hands over head from sitting position 3 Raise upper arms to shoulder level from sitting position 2 Raise upper arms 45° with hands on table from sitting position 1 Raise upper arms from reclining position o Impossible to move upper arms Walk 4 3 2 1
up incline Walk up 15° slope normally Walk up gradual slope normally Walk up gentle slope (5°) gradually Possible to walk on unpaved road (10 m) o Possible to walk on paved road
142 Brain & Development, Vol 4, No 2,1982
Handle rice bowl for eating 4 Eat with chopsticks from bowl in hand easily 3 Rest elbows on table and handle chopstick and bowl 2 Do No.3 but stop from exhaustion 1 Use chopsticks/spoon with difficulty but cannot handle bowl o Cannot handle chopsticks/spoon Washing face 4 Wash face with both hands in standing position 3 Support self with one hand and wash face with other in standing position 2 Wash face with both hands in sitting position
Appendix 2 Continued. 1 Hands reach face but cannot use to wash o Impossible to wash face
Using 4 3 2 1
o
o
towel Wring completely Wring, but incompletely Wring, but most water remains Hold towel but cannot wring Impossible to hold towel
Writing 4 Write big letters with brush with elbow up 3 Write middle sized letters by moving forearm with elbow support 2 Write with pen easily 1 Wirte with pen with difficulty o Impossible to write Standing 4 Stand at attention easily 3 Stand easily with feet apart (with equipment no problem) 2 Stand momentarily with feet apart (with equipment stand with difficulty) Holding thigh, can stand with much difficulty (with support, can raise oneself) o Impossible to stand without assistance Standing on one leg 4 Stand on one leg easily 3 Stand on one leg momentarily (one minute) 2 Stand on one leg (more than one minute) using one hand on a support
Acknowledgment This work was supported by grants from the Ministry of Health and Welfare, Japan. References 1. Thomson WHS, Smith I. X-linked recessive (Duchenne) muscular dystrophy and purine metabolism. Lancet 1976;2:805-6. 2. Thomson WHS, Smith I. X-linked recessive (Duchenne) muscular dystrophy (DMD) and purine metabolism: Effects or oral allopurinol and adenylate. Metabolism 1978;27:151-63 . 3. Castro-Gago M, Jimenez JF, Pombo M, Tojo R, Couselo JM, Peiia J. Allopurinol in Duchenne muscular dystrophy. Lancet 1980;1:1358-9. 4. Bakouche P, Chaouat D, Nick J. Allopurinol not effective in muscular dystrophy. N Engl J Med 1979;301:785. 5. Doriguzzi C, Bertolotto A, Ganzit GP, Mongini T, Palmucci L. Ineffectiveness of allopurinol in Duchenne muscular dystrophy. Muscle Nerve 1981;4:176-8. 6. Stern L, Fewings JD, Bretag AH, et al. The progression of Duchenne muscular dystrophy:
Stand on one leg using hands on a support but with difficulty Impossible to stand on one leg even with assistance
Stand by leaning on support 4 Stand without assistance (with equipment easily) 3 Stand with one hand as support (with equipment can barely stand) 2 Stand with both hands as support (with equipment and hands, can stand) 1 Can stand by leaning against support o Impossible to stand even while leaning on support Walk 4 Walk normaly 3 Unsteady walk (can walk with equipment) 2 Impossible to walk alone but can with support (walk more than 10 m with walker) Can walk with support for 10 m (with walker less than 10 m) o Impossible to walk without assistance Rise from floor 4 Normal 3 Leaning heavily forward can rise without using hands 2 Stand by using hands on knees 1 Get on all fours, place hands on knees and rise gradually o Impossible without assistance
7.
8.
9. 10. 11 . 12. 13.
clinical trial of allopurinol therapy. Neurology 1981;31:422-6. Matsuda I, Miyoshino S, Miike T, et al. Mitochondrial fraction of serum glutamic-oxaloacetic transaminase in Duchenne muscular dystrophy. CZin Chim Acta 1978;83:2314. Sugita H, Okumura Y, Ayai K. Application of a property of troponin to determination of tropomyosin content of a small piece of muscle. J Biochem 1969;65 :971 -2. Patel CP. Semimicro method for determination of serum uric acid using EDTA-hydrazine. Clin Chem 1968;14:764-75. Dubowitz V. Muscle disorders in childhood. London· Philadelphia· Toronto: WB Saunders, 1978:69. Thomson WHS, Smith I. Allopurinol in Duchenne muscular dystrophy. N Engl J Med 1978;299: 101. Griffiths J, Shuttlewood RJ. Allopurinol for muscular dystrophy. Lancet 1980;2:423-4. Lundberg A, Eriksson BO, Mellgren G. Metabolic substrate, muscle fiber composition and fiber size in late walking and normal children. Eur J Pediatr 1979; 130: 79-92.
Tamari et al: Xanthine oxidase inhibitor in DMD 143