430
Autoantibodies in Down’s syndrome SIR,-Mariotti and colleagues’ report (June 29, p 1506) prompts report a similar pattern of thyroid microsomal antibody (TMA) concentrations in the Down’s syndrome (DS) population. Life expectancy of the DS population is reduced; about 44-4% and
us to
13-6% of livebom babies with DS will survive 60 and 68 years, these
figures being 86-4% and 78-4%, respectively, for the general population.1 Alzheimer’s disease, and vascular, cardiological, and, especially, immunological changes have been held responsible for these high mortality rates. Although many individuals with DS are euthyroid, hypothyroidism and hyperthyroidism have been widely
Fig 2-Western blots of
recombinant human 21 -OH.
Extracts from yeast transformed with human 21 -OH gene and grown in galactose (lane 1) or in glucose (lane 2) containing medium or transformed with the human thyroid peroxidase gene and grown in galactose-containing medium (lane 3). Lane 4 = non-transformed yeast, lane 5= purified native human 21 -OH. Lanes 1-5 were reacted with an adrenal autoantibody positive serum (1 in 800) from a patient with adult onset Addison’s disease. No reaction when lanes 1-5 were incubated with normal pool human serum (1 in 800).
21-OH expressed in Saccharomyces cerevisiae (transformed with the 21 -OH gene in the pYES vector under the GAL 1 promoter) (fig 2). Thus four different approaches indicate that 21-OH is a major autoantigen in adult onset Addison’s disease. To develop an assay for 21-OH autoantibodies, we evaluated the use of Octyl-Sepharose purified 21-OH in a dot-blot system in combination with anti-human-IgG and a chemiluminescent substrate (ECL, Amersham). Out of 36 serum samples from patients with adult onset Addison’s disease, 26 (72%) reacted with dot blots of purified native adrenal autoantigen. In an analysis of 34 control sera from patients with various autoimmune diseases (10 Hashimoto’s disease, 10 Graves’ disease, 5 rheumatoid arthritis, 4 primary biliary cirrhosis, 5 lupus erythematosus), and 10 healthy individuals, only 1 (Graves’ disease) was positive by dot blot. This positive serum was confirmed to have antibodies reactive with the 55 kDa adrenal protein on western blot, and most studies with immunofluorescence report adrenal autoantibodies in a few Graves’ disease patients.2 The dot-blot assay results in Addison and control samples were in good agreement with analysis of the same sera for adrenal autoantibodies by other techniques.2,3 Our results and those of Winqvist et al can be compared with Dr Krohn and colleagues’ report (March 28, p 770) of autoantibodies to the non-adrenal specific enzyme 17a-hydroxylase in early onset Addison’s disease (type 1 polyendocrine autoimmunity syndrome). In adult onset Addison’s disease, however, the major autoantigen is the adrenal specific enzyme 21-OH.
Immunology Unit, University of Wales College of Medicine, Endocrine
Cardiff CF4 4XN, UK, and Renal Transplant Unit, Cardiff Royal Infirmary
A. BAUMANN-ANTCZAK N. WEDLOCK J. BEDNAREK Y. KISO H. KRISHNAN S. FOWLER B. REES SMITH J. FURMANIAK
1 Anderson JR, Goudie RB, Gray KG, Timbury GC Autoantibodies in Addison’s disease Lancet 1957; i: 1123-24. 2. Muir A, MacLaren NK. Autoimmune diseases of the adrenal glands, parathyroid glands, gonads and hypothalamic-pituitary axis. Endocrinol Metab Clin N Am
1991, 20: 619-44. J, Talbot D, Reinwein D, Benker G, Creagh FM, Rees Smith B. Immunoprecipitation of human adrenal microsomal antigen FEBS Lett 1988;
3. Furmaniak
231: 25-28. 4. Kominami S, Ochi H, Kobayashi Y, Takemori S Studies on the steroid hydroxylation system in adrenal cortex microsomes. J Biol Chem 1980; 255: 3386-94. 5. Bumpus JA, Dus KM Bovine adrenocortical microsomal hemeproteins P-450-17alpha and P-450-c-21 J Biol Chem 1982; 257: 12696-704. 6 Hu M, Chung B. Expression of human 21-hydroxylase (P450c21) m bacterial and mammalian cells a system to charactense normal and mutant enzymes. Mol
Endocrinol 1990; 4: 893-98.
described, and TMA is present in about 30% of individuals?3 We evaluated 30 randomly selected clinically euthyroid DS subjects (aged 33-68 years, 15 under 50 and 15 aged 50 or over) for thyroid dysfunction. 12 (40%) had positive TMA (titre >40), which is close to reported data. Of the cases positive for TMA, 9 (75%) were under age 50 and 3 (25%) were 50 or older. Of the 18 individuals who were negative for TMA, 5 (28%) were under 50 and 13 (72%) were 50 or older (xz=47, df= 1, p = 0-03).
Although an age-dependent increase in the prevalence of TMA is apparent from existing studies in DS populations, the absence of circulating TMA in most subjects aged 50 or older reported here may result from selective mortality from coronary heart disease or other vascular disorders, such as proposed by Mariotti and Robuschi and their colleagues.4 not
Departments of Psychiatry and Endocrinology, Charing Cross Hospital,
DORA KOHEN PETER H. WISE
London W6 8RF, UK
1
Baird AP, Sadovnick AD. Life expectancy in Down’s syndrome adults. Lancet 1988, i, 354-56
S, Carpenter S. Down’s syndrome and thyroid disorder. J Mental Def Res 1990; 34: 187-93. 3. Kinnell HG, Gibbs N, Teale JD, Smith J. Thyroid dysfunction m institutionalised Down’s syndrome adults. Psychol Med 1987; 17: 387-92. 4. Robuschi G, Safran M, Braverman LE, Grudi A, Roti E. Hypothyroidism in the elderly. Endocrinol Rev 1987; 8: 142-53. 2. Dinani
Vigabatrin for startle-disease with altered cerebrospinal-fluid free gammaaminobutyric acid SIR,-Dr Dubowitz and colleagues (July 11, p 80) report low cerebrospinal fluid (CSF) concentrations of gamma-aminobutyric acid (GABA) in an infant with startle disease (hyperekplexia). I would like to add my experience of an infant with sporadic
hyperekplexia and a teenager with familial hyperekplexia. Patient 1-A first-born baby boy (weight 1 98 kg, apgar score 9) was delivered by emergency caesarean section at 36 weeks because of fetal distress. The first seizure was at 40 hours. The descriptions by nursing staff and the direct observations of paediatricians (tonic convulsion, generalised twitching, eyes flickering, four limbs twitching and cyanosed and mottled, proper generalised clonic convulsions, and going blue) suggested an epileptic origin. Investigations included electroencephalography (EEG), brain imaging by ultrasound and computed tomography, CSF examination, chromosome karyotyping, and detailed biochemical studies, including organic acids. He was treated without effect by phenobarbitone, pyridoxine, clonazepam (48 hours only), biotin, and sodium valproate. The mother’s account of the sequence of events-put in his bath, became "on edge", developed a fast tremble, became stiff as a board and blue, then white and like a rag
doll-suggested that these episodes were anoxic seizures. The suggestion that having a bath was a precipitant supported an anoxic or syncopal mechanism. Video-recording showed that a pain cry was followed by fast pseudo-myoclonic sobs before a tonic anoxic seizure with spasms. Cassette EEG and electrocardiographic monitoring confirmed pure syncope, with non-epileptic pseudospikes, EEG flattening, and bradycardia. Although the baby was not stiff to handle, his video-taped seizures
were
identical in appearance
to
those
seen
in Dubowitz’s
patient. Further, tapping the tip of the nose consistently induced the strikingly exaggerated startle response typical of hyperekplexia.’
Autoantibodies in Down’s syndrome SIR,-Mariotti and colleagues’ report (June 29, p 1506) prompts report a similar pattern of thyroid microsomal antibody (TMA) concentrations in the Down’s syndrome (DS) population. Life expectancy of the DS population is reduced; about 44-4% and
us to
13-6% of livebom babies with DS will survive 60 and 68 years, these
figures being 86-4% and 78-4%, respectively, for the general population.1 Alzheimer’s disease, and vascular, cardiological, and, especially, immunological changes have been held responsible for these high mortality rates. Although many individuals with DS are euthyroid, hypothyroidism and hyperthyroidism have been widely
Fig 2-Western blots of
recombinant human 21 -OH.
Extracts from yeast transformed with human 21 -OH gene and grown in galactose (lane 1) or in glucose (lane 2) containing medium or transformed with the human thyroid peroxidase gene and grown in galactose-containing medium (lane 3). Lane 4 = non-transformed yeast, lane 5= purified native human 21 -OH. Lanes 1-5 were reacted with an adrenal autoantibody positive serum (1 in 800) from a patient with adult onset Addison’s disease. No reaction when lanes 1-5 were incubated with normal pool human serum (1 in 800).
21-OH expressed in Saccharomyces cerevisiae (transformed with the 21 -OH gene in the pYES vector under the GAL 1 promoter) (fig 2). Thus four different approaches indicate that 21-OH is a major autoantigen in adult onset Addison’s disease. To develop an assay for 21-OH autoantibodies, we evaluated the use of Octyl-Sepharose purified 21-OH in a dot-blot system in combination with anti-human-IgG and a chemiluminescent substrate (ECL, Amersham). Out of 36 serum samples from patients with adult onset Addison’s disease, 26 (72%) reacted with dot blots of purified native adrenal autoantigen. In an analysis of 34 control sera from patients with various autoimmune diseases (10 Hashimoto’s disease, 10 Graves’ disease, 5 rheumatoid arthritis, 4 primary biliary cirrhosis, 5 lupus erythematosus), and 10 healthy individuals, only 1 (Graves’ disease) was positive by dot blot. This positive serum was confirmed to have antibodies reactive with the 55 kDa adrenal protein on western blot, and most studies with immunofluorescence report adrenal autoantibodies in a few Graves’ disease patients.2 The dot-blot assay results in Addison and control samples were in good agreement with analysis of the same sera for adrenal autoantibodies by other techniques.2,3 Our results and those of Winqvist et al can be compared with Dr Krohn and colleagues’ report (March 28, p 770) of autoantibodies to the non-adrenal specific enzyme 17a-hydroxylase in early onset Addison’s disease (type 1 polyendocrine autoimmunity syndrome). In adult onset Addison’s disease, however, the major autoantigen is the adrenal specific enzyme 21-OH.
Immunology Unit, University of Wales College of Medicine, Endocrine
Cardiff CF4 4XN, UK, and Renal Transplant Unit, Cardiff Royal Infirmary
A. BAUMANN-ANTCZAK N. WEDLOCK J. BEDNAREK Y. KISO H. KRISHNAN S. FOWLER B. REES SMITH J. FURMANIAK
1 Anderson JR, Goudie RB, Gray KG, Timbury GC Autoantibodies in Addison’s disease Lancet 1957; i: 1123-24. 2. Muir A, MacLaren NK. Autoimmune diseases of the adrenal glands, parathyroid glands, gonads and hypothalamic-pituitary axis. Endocrinol Metab Clin N Am
1991, 20: 619-44. J, Talbot D, Reinwein D, Benker G, Creagh FM, Rees Smith B. Immunoprecipitation of human adrenal microsomal antigen FEBS Lett 1988;
3. Furmaniak
231: 25-28. 4. Kominami S, Ochi H, Kobayashi Y, Takemori S Studies on the steroid hydroxylation system in adrenal cortex microsomes. J Biol Chem 1980; 255: 3386-94. 5. Bumpus JA, Dus KM Bovine adrenocortical microsomal hemeproteins P-450-17alpha and P-450-c-21 J Biol Chem 1982; 257: 12696-704. 6 Hu M, Chung B. Expression of human 21-hydroxylase (P450c21) m bacterial and mammalian cells a system to charactense normal and mutant enzymes. Mol
Endocrinol 1990; 4: 893-98.
described, and TMA is present in about 30% of individuals?3 We evaluated 30 randomly selected clinically euthyroid DS subjects (aged 33-68 years, 15 under 50 and 15 aged 50 or over) for thyroid dysfunction. 12 (40%) had positive TMA (titre >40), which is close to reported data. Of the cases positive for TMA, 9 (75%) were under age 50 and 3 (25%) were 50 or older. Of the 18 individuals who were negative for TMA, 5 (28%) were under 50 and 13 (72%) were 50 or older (xz=47, df= 1, p = 0-03).
Although an age-dependent increase in the prevalence of TMA is apparent from existing studies in DS populations, the absence of circulating TMA in most subjects aged 50 or older reported here may result from selective mortality from coronary heart disease or other vascular disorders, such as proposed by Mariotti and Robuschi and their colleagues.4 not
Departments of Psychiatry and Endocrinology, Charing Cross Hospital,
DORA KOHEN PETER H. WISE
London W6 8RF, UK
1
Baird AP, Sadovnick AD. Life expectancy in Down’s syndrome adults. Lancet 1988, i, 354-56
S, Carpenter S. Down’s syndrome and thyroid disorder. J Mental Def Res 1990; 34: 187-93. 3. Kinnell HG, Gibbs N, Teale JD, Smith J. Thyroid dysfunction m institutionalised Down’s syndrome adults. Psychol Med 1987; 17: 387-92. 4. Robuschi G, Safran M, Braverman LE, Grudi A, Roti E. Hypothyroidism in the elderly. Endocrinol Rev 1987; 8: 142-53. 2. Dinani
Vigabatrin for startle-disease with altered cerebrospinal-fluid free gammaaminobutyric acid SIR,-Dr Dubowitz and colleagues (July 11, p 80) report low cerebrospinal fluid (CSF) concentrations of gamma-aminobutyric acid (GABA) in an infant with startle disease (hyperekplexia). I would like to add my experience of an infant with sporadic
hyperekplexia and a teenager with familial hyperekplexia. Patient 1-A first-born baby boy (weight 1 98 kg, apgar score 9) was delivered by emergency caesarean section at 36 weeks because of fetal distress. The first seizure was at 40 hours. The descriptions by nursing staff and the direct observations of paediatricians (tonic convulsion, generalised twitching, eyes flickering, four limbs twitching and cyanosed and mottled, proper generalised clonic convulsions, and going blue) suggested an epileptic origin. Investigations included electroencephalography (EEG), brain imaging by ultrasound and computed tomography, CSF examination, chromosome karyotyping, and detailed biochemical studies, including organic acids. He was treated without effect by phenobarbitone, pyridoxine, clonazepam (48 hours only), biotin, and sodium valproate. The mother’s account of the sequence of events-put in his bath, became "on edge", developed a fast tremble, became stiff as a board and blue, then white and like a rag
doll-suggested that these episodes were anoxic seizures. The suggestion that having a bath was a precipitant supported an anoxic or syncopal mechanism. Video-recording showed that a pain cry was followed by fast pseudo-myoclonic sobs before a tonic anoxic seizure with spasms. Cassette EEG and electrocardiographic monitoring confirmed pure syncope, with non-epileptic pseudospikes, EEG flattening, and bradycardia. Although the baby was not stiff to handle, his video-taped seizures
were
identical in appearance
to
those
seen
in Dubowitz’s
patient. Further, tapping the tip of the nose consistently induced the strikingly exaggerated startle response typical of hyperekplexia.’
