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The severity of our patients' illness when first studied and the difficulty in obtaining adequate numbers of monocytes significantly limit the interpretation of our findings. Nonetheless, this case may represent a unique monocyte killing defect. ADDENDUM Since the submission of this paper, a case of fatal disseminated BCG infection in a 12-month-oldchild was reported by Nezelof and his group (Clin lmmunol Immunopathol 17:296, 1980). This child demonstrated defective monocyte function similar to our patient. We thank S. Froman, M.D., for assistance and I. Krasnow, M.D., G. Friedly, and those ~it National Jewish Hospital in Denver for mycobacteriol0gic identification. Also we are indebted to Drs. G. A. Granger and R. Lehrer for immunologic evaluation. REFERENCES 1. Lincoln EM, and Gilbert LA: Diseases in children due to mycobacteria other than Mycobacterium tuberculosis, Am Rev Respir Dis 105:683, 1972. 2. Jenkin DJM, and Dall G: Lesions of bone in disseminated infection due to Mycobacterium avium/intracellulare group, J Bone Joint Surg 57:373, 1975.

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3. Engbaek HC: Three cases in the same family of fatal ini'ecti0n with M. avium, Acta Tuberc Scand 45:105, 1964. 4. Cashman TM; Navin JJ, and Chandor SB: Thymic alymphoplasia, previously reported as dysgammaglobulinemia type 1, J PEmAXR76:722, 1970. 5. McCrackenGH, and Reynolds RC: Primary lymphopenic immunologic deficiency: Disseminated Mycobacterium kansasii lnfection, Am J Dis Child 120:143, 1970. 6. DiGeorgeAM: Congenital absence of the thymus and its immunologic consequences. Concurrence with congenital hypothyroidism, Birth Defects 4:116, 1968. 7. Johnston RB, and Newman SL. Chronic granulomatous disease. Pediatr Clin North Am 24:365, 1977. 8. Spofford BT, Doynes RA, and Granger GA. Cell mediaied immunity in vitro: a highly sensitive assay for human lymphotoxin, J Immunol 112:2111, 1974. 9. Lehrer RI: Metabolism and microbicidal function (pp 79-82), in Cline MJ (moderator): Monocytes and macrophages: function and disease, Ann Intern Med 88:78, 1978. 10. Mackaness GB: The immunology of antituberculous immunity, Am Rev Respir Dis 97:337, 1967. 11. Seth V, and Chandra RK: Opsonic activity, phagocytosis, and bactericidal capacity of polymorphs in undernutrition, Arch Dis Child 47:282, 1972.

Amino acid pattern in Reye syndrome." Comparison with clinically similar entities Carolyn A. Romshe, M.D.,* Milo D. Hilty, M.D., H. Juhling MeClung, M.D., Benny Kerzner, M.D., and Charles B. Reiner, M.D., Columbus, Ohio

THE METABOLIC DISTURBANCES of Reye syndrome are many and involve carbohydrates, amino,acids, free fatty acids, proteins (clotting abnormalities), ammonia, and acid-base balance. Of primary interest to us has been the abnormalities involving amino acids, as reported in a previous paper. 1 It has been emphasized repeatedly that the diagnosis of Reye syndrome should be confirmed by direct examination of liver tissue by light and, if possible, electron microscopy. 2 We have found that the quantitative serum From the Department of Pediatrics, College of Medicine, The Ohio State University and Children's Hospital Research Foundation. Supported by The John W. Champion Center, Children's Hospi'tal, Columbus, Ohio. ,Reprint address: Children's Hospital, Room C-403, 700 Children's Drive, Columbus, OH 43205.

amino acid pattern can also be used to confirm the diagnosis. Numerous other disease states may produce encephalopathy, elevation of serum transaminase values, and other signs of liver dysfunction resembling Reye syndrome. These include chickenpox, hepatic necrosis, drug intoxications (salicylism, chlordane), metabolic disease (primary urea cycle defects, fructose intolerance, primary lactic acidosis, and systemic carnitine deficiency), and hypovolemic shock. The microscopic abnormalities of the liver in these entities are distinctly different from those of Reye syndrome. The fatty infiltration is of large droplet type and nonuniform in distribution, and mitochondrial abnormalities are not present. 3.~ It is possible to distinguish Reye syndrome from these similar entities by iatilizing the quantitative serum amino acid pattern, as will be seen from the data in this study.

0022-3476/81/050788+03500.30/0 9 1981 The C. V. Mosby Co.

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Table. Comparison of serum amino acid concentrations in Reye syndrome with those in similar conditions

Normal (/~m/dL) RS--died (14) RS-survived (17) Salicylism (4) Chickenpox (6) Hepatic necrosis (4) Fructose Intol (2) OTC deficiency (2) Carnitine deficiency (1)

Glutamine

A lanine

6-47 378 • 47 210 + 39 40 _+ 5 40 • 4 340 + 125 62 _+ 5 211 117

17-38 291 + 77 90 +_ 23 29 +_ 2 39 _+ 7 156 _+ 65 17 • 2 52 20

a-Amino [ N-butyrate Leucine 1-3 16 _+ 3 7 _+ 1 1• 1 1 _+ 0.3 2 _+ 2 1• 1 7 Tr

6-18 23 • 10.7 • 10 • 12 • 17 • 6 • 6 6

6 1 2 3 4 1

Methionine 1-4 8• 2 2.6 _+ 0.6 Tr 1 • 0.2 90 _+ 27 1 • 0.5 5 4

Tyrosine 3-9 25 + 7.5 • Tr Tr 39 • l + 4 8

8 2

5 1

Phenylalanine

Lysine

3-6 16 • 5 3.4 • 1 Tr Tr 41 • 12 1_+1 4 9

11-27 162 _+ 28 95 + 14 20 • 5 17 _+ 5 127+_32 6_+2 3O 16

Tr = trace; RS = Reye syndrome; ( ) = number of patients.

METHODS Thirty-one patients with suspected Reye syndrome are included. The following clinical criteria were present: (1) a history of a preceding viral illness; (2) vomiting one to two days prior to the onset of the encephalopathy; (3) rapid development of encephalopathy within 24 to 48 hours; and (4) impaired liver function as evidenced by increased SGOT, SGPT, or blood ammonia values. All patients had both light and electron microscopic examination of the liver to confirm the diagnosis of Reye syndrome. Blood specimens for amino acids were drawn initially at the time Reye -syndrome was suspected, usually when the patients were in late Stage I or in Stage II. Serum samples were deproteinized immediately by the addition of sulfosalicylic acid prior to quantitation, utilizing the Bio-Cal amino acid analyzer. In order to compare other disease entities with Reye syndrome, quantitative amino acids were determined on patients with clinically similar conditions. RESULTS All 31 patients had the characteristic amino acid pattern. In severe Reye syndrome the pattern is very obvious, with many amino acids elevated, most notably glutamine, proline, alanine, a-amino-N-butyrate, ornithine, and lysine. Notably absent are marked elevations of methionine and leucine, valine, and isoleucine. In the milder cases, a similar pattern is evident although with less elevation of individual amino acids; the abnormalities are confir]ed primarily to glutamine, alanine, lysine, and a-amino-N-butyrate. All 31 patients also had microscopic findings characteristic of Reye syndrome, including panlobular small droplet fatty changes on light microscopy and mitochondrial

enlargement with amoeboid shapes, decrease in matrix density, and loss of mitochondrial dense bodies, characteristic of the electron microscopic picture. The serum amino acid pattern found in Reye syndrome was then compared to that in several other disease entities in which the clinical presentation may mimic Reye syndrome (Table). As can be seen, none of the patterns is identical to the Reye pattern. Fulminant hepatic necrosis has many similarities, with elevation of many amino acids, but m o s t striking is the many-fold elevation of methionine; even in very severe Reye syndrome, methionine values are rarely more than two- to threefold increased. Additionally, branched chain amino acid concentrations are normal to slightly decreased in fulminant hepatic necrosis, and are normal to slightly elevated in Reye syndrome. Amino acid patterns in salicylism and in chickenpox hepatitis are essentially normal. Fructose intolerance and systemic carnitine deficiency are also associated with essentially normal values, except for elevation of glutamine. There was significant elevation of glutamine and mild elevation of alanine and lysine concentrations in two patients with ornithine transcarbamylase deficiency. DISCUSSION Most of the metabolic abnormalities in Reye syndrome, including those of the amino acids, can be explained on the basis of the mitochondrial disruption and subsequent decrease in many of the enzymes which are found in the mitochondria. Intramitochondrial enzyme activities which have been shown to be low include ornithine transcarbamylase, carbamyl phosphate synthetase, pyruvate dehydrogenase, and cytochrome oxidase? T All of :hese enzyme values return to normal when the patient recovers. The decrease in activity of carbamyl phosphate synthe-

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tase and ornithine transcarbamylase can explain the decrease in citrulline and increase in ornithine, glutamine, and ammonia concentrations in these patients, since these two enzymes are necessary in the conversion of ammonia tO u r e a .

The decrease in gluconeogenic enzymes is also important. With the mitochondrial insult there is limited ability of a cell to oxidize fatty acids, ketone bodies, and pyruvate, with increased production of alanine, lactate, and pyruvate. Normally these increased substrates are efficiently handled by hepatic mechanisms, but with mitochondrial damage, the liver is also impaired in its ability to take up the substrates. The decrease in pyruvate carboxylase and in pyruvate dehydrogenase supports the concept that increased peripheral mobilization and decreased hepatic clearance lead to the increase in pyruvate, lactate, and alanine values? Many of the amino acids enter the cycle at this point. All of these are elevated in Reye syndrome. The final consideration is the specificity of the amino acid pattern for Reye syndrome. In several recent reports on quantitative amino acids in patients with liver disease, especially f u l m i n a n t hepatic failure,~. ' the branched chain amino acids (isoleucine, leucine, and valine) were normal to decreased; the most marked elevations were in methionine (27-fold), tyrosine (fivefold), and phenylalanine (fourfold). Other amino acid concentrations were elevated approximately twofold. We have seen a similar pattern in four patients with fulminant hepatic necrosis. In contrast to this, patients with severe Reye syndrome have a twofold increase in the branched chain amino acid values and only about a two- to threefold increase in methionine concentrations; phenylalanine and tyrosine values are similar to those in fulminant hepatic necrosis. Other amino acids such as proline, alanine, a-aminoN-butyrate are as much as sixfold elevated in severe Reye syndrome. In mild Reye syndrome, on the other hand, branched chain amino acid values are low, and there is essentially no elevation methionine, phenylalanine, or tyrosine concentrations. Other entities which may be confused clinically are much easier to differentiate from Reye syndrome by the amino acid pattern, although each specific entity cannot be diagnosed solely by the amino acid values. In primary urea cycle defects, including carbamylphosphate synthetase and ornithine transcarbamylase deficiency, the amino acid patterns are variable; they may be completely normal, there may be elevation of glutamine only or there maybe mild-to-moderate elevation of glutamine, alanine, proline, and lysine.1~ Systemic carnitine deficiency has been reported as "recurrent Reye syndrome" and is virtually identical

The Journal of Pediatrics May 1981

clinicatly~; amino acid values were low normal, similar to those in our patient with this disorder, the only exception being mild elevation of glutamine. In two patients with fructose-l-aldolase deficiency, there was mild elevation of glutamine; however, if severe acute liver disease is present, there may be generalized aminoacidemia?-' Ideally the confirmation of Reye syndrome concentrations should include a liver biopsy and quantitation of serum amino acid concentration, especially in unusual cases. However, if a liver biopsy is not possible, the pattern of serum amino acids can be a great help in confirming the diagnosis and is a simple and safe procedure. In addition, the quantitative serum amino acid pattern can be used to differentiate Reye syndrome patients from those with other syndromes clinically mimicking it. REFERENCES

1. Hilty MD, Romshe CA, and DeLameter PV: Reye's syndrome and hyperaminoacidemia, J PEOIATR84:362, 1974. 2. Partin JC, Schubert WK, and Partin JS: Mitochondrial ultrastructure in Reye's syndrome (encephalopathy and fatty degeneration of the viscera), N Engl J Med 285: 1339, 1971. 3. Partin JC, Partin JS, and Schubert WK: Fatty liver in Reye's syndrome: Is it a distinct morphologic entity? (abstracted)., Gastroenterology 65:563, 1973. 4. LaBrecque DR, Latham PS, Riely CA, Hsia E, and Klatskin G: Heritable urea cycle enzyme deficiency-liver disease in 16 patients, J PEDIATR94:580, 1979. 5. DeVivoDC: Reye's syndrome: A metabolic response to an acute mitc~cbondriatinsult? Ncurology 28:105, 1978. 6. Sinatra F, Yoshida T, Applebaum M, Mason W, Hoogenroad N, and Sunshine P: Abnormalities of earbamyl phosphate synthetase and orinthine transcarbamylase in liver of patients with Reye's syndrome, Pediatr Res 9:829, 1975. 7. Robinson BH, Gall DG, and Cutz E: Deficient activity of hepatic pyruvate dehydrogenase and pryuvate carboxylase in Reye's syndrome, Pediatr Res 11:279, 1977. 8. Rosen HM, Yoshimura N, Hodgman JM, and Fischer JE: Plasma amino acid patterns in hepatic encephalopathy of differing etiology, Gastroenterology 72:483, 1977. 9. CascinoA, Cangiano C, Calcaterra V, Rossi-FaneUiF, and Capoeaccia L: Plasma amino acids imbalance in patients with liver disease, Am J Dig Dis 23:591, 1978. 10. Delong Gr, Snodgrass PJ, Shih V, Glick TH, and Shannon OC: Urea cycle enzymes, amino acid patterns, and therapeutic trial of L-citrulline in Reye's syndrome, in Pollack JD, editor: Reye's Syndrome: Proceedings of the Reye's Syndrome Conference sponsored by the Children's Hospital Research Foundation, Columbus, Ohio, 1974, New York, 1975, Grune & Stratton, Inc. p 329. 11. Glasgow A, Eng G, and Engel A: Systemic carnitine deficiency simulating recurrent Reye syndrome, J PEDIATR 96: 889, 1980. 12. Lindemann R, Gjessing LR, Merton B, Asgot CL, and Halvorsen S: Amino acid metabolism in hereditary fructosemia, Acta Paediatr Scand 59:141, 1970.