Plasma Corticotropin Levels in Patients withFamilial Amyloidotic Polyneuropathy During

Liver Transplantation

JULIAN DIAZ,1,2 FRANCISCO ACOSTA,1 TEODOMIRO FUENTE,1 JERONIMO MORENO,1

LUIS F. CARBONELL,2 and PASCUAL PARRILLA1

1Liver Transplant Unit, University Hospital “Virgen de la Arrixaca,” Murcia, Spain, and 2Department ofPhysiology, University of Murcia School of Medicine, Murcia, Spain

Introduction

Familial amyloidotic polyneuropathy type I (FAP)is an autosomal dominant inherited disorder and

hereditary amyloidosis. The disease is characterizedby a progressive polyneuropathy affecting both theperipheral and the autonomic nervous systems. Ner-vous system affection is typical of FAP and amyloiddeposits can also infiltrate and destroy other organs,such as kidneys, intestines, eyes, and adrenalglands. Progressive peripheral and autonomic neu-ropathy are associated with neural and visceraldeposition of amyloid (1,2). Currently, liver trans-plantation (LT) is an efficient treatment for thisdisease. FAP has previously been incurable, but LThalts the progression of the disease (3).

The role of the hypothalamic-pituitary-adrenalaxis in stress is well established. b-Endorphin andcorticotropin (ACTH) are released into the circula-tion from the pituitary gland in response to variousstressful stimuli, including pain, surgery, acutehemorragic, hypotension, hypoxia, and acidosis (4).Increased concentrations of plasma b-endorphin andACTH have been observed in non-premedicated pa-tients before and during surgery (4,5). These studiesdemonstrated a direct correlation between stressand b-endorphin and ACTH plasma concentrations(4,6). Because of the importance of ACTH measure-ments as a marker of response to various stressfulstimuli, we undertook the current study to describethe response of plasma ACTH levels in patients withFAP during LT.

Materials and methods

After Hospital Ethics Committee approval and pa-tient consent, we studied 28 LT patients divided intotwo groups: group A (n 5 12), patients diagnosedwith FAP; and group B (n 5 16), patients diagnosedwith alcoholic cirrhosis. The diagnosis of FAP wasalways based on the following:

1. compatible neurological symptoms and electro-myographic signs;

2. family history;3. location of amyloid in abdominal fat and sural

nerve; and4. finding of the biochemical marker in plasma with

the enzyme-linked immunosorbent assay method.

The marker was TTR-Met-30 in 10 patients andTTR-Ala-71 in 2 patients. The classification accord-ing to Sales-Luis et al. (5), which includes neurolog-ical and electromyographic parameters to evaluatethe severity of polyneuropathy, are expressed inTable 1.

The anesthetic technique was identical in the 2groups. Anesthesia was induced with sodium thio-pental, and succinylcholine; and maintained with anoxygen/air mixture (FiO2 5 0.5) and continous infu-sion of fentanyl, pancuronium bromide, and midazo-lam; there was no premedication.

Arterial blood samples were collected immediatelybefore (A1) and after anesthesia induction (A2); atthe beginning (A3) and the end of the preanhepaticphase (A4); at the beginning (B1) and the end of theanhepatic phase (B2); at 5 and 60 min after thebeginning of the reperfusion phase (C1 and C2,respectively); and at the end of the procedure (C3).Blood was collected into 5 mL evacuated tubescontaining ethylenediaminetetraacetic acid solutionas anticoagulant. After centrifugation (2500 3 g) for10 min in a centrifuge cooled to 4° C, the superna-tant plasma was removed carefully within 30 min

Correspondence: Julian Diaz, M.D., C/ Jose MariaMortes Lerma, 32 Dpl, Pta 14, 46014-Valencia, Spain.

Manuscript received March 3, 1998; accepted July 31,1998.

Clinical Biochemistry, Vol. 31, No. 8, 689–691, 1998Copyright © 1998 The Canadian Society of Clinical Chemists

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after sample collection. During the assay period,plasma samples were stored at 280° C until ana-lyzed with no freeze–thaw cycles, in trace-element-free tubes to mantain the stability of the plasmasamples.

Plasma ACTH levels were measured by a inmu-noradioimmunoassay with use of avidin-biotin sep-aration (Nichols Institute, San Juan de Capistrano,CA, USA). Sensitivity, concentration of the lowestcalibrator, interassay and intraassay coefficients ofvariation are 0.2 pmol/L, 0.0 pmol/L, 7.8%, and 3.0%,respectively) (7). To determine the range of refer-ence, the specimen used and the method were thesame. We measured plasma ACTH concentrationsin 100 adults subjects (54 men and 46 women)selected for absence of known organic disease andwere carefully screened for infectious, malignant,and other serious disorders. To additionally checktheir state of health, they were subjected to a con-

ventional biochemical screening and hematologicalanalysis (8).

The statistical study (mean, standard deviation,analysis of variance for repeated measures, Kolmog-orov-Smirnov and Student’s t-tests) was determinedwith the SPSS statistical package (SPSS Inc., Chi-cago, IL, USA). In Table 1, the Group A results arepresented as individual values, while Group B re-sults are expressed as the mean 6 SD, becauseACTH concentrations followed a normal frequencydistribution in the different times of the procedure,as showed by the Kolmogorov’s of fit test.

Results and discussion

Because of the importance of these parameters mea-surements, together with the investigation of rela-tionships between clinical outcome and laboratorytest requires reliable reference range, we undertookthe current study to provide reference intervals forhuman plasma. To determine the range of reference,the group choosed, was a representative sample asreference population, according to the InternationalFederation of Clinical Chemistry (IFCC) guidelines.From the initial 100 individuals, we discarded theresults of those who, in the diagnosis, had somedisease and more than one biochemical or hemato-logical measurement altered. The distribution ofplasma ACTH concentrations values followed agaussian frequency distribution. Aberrant valueswere excluded according to the IFCC guidelines. Ourparametric reference interval expressed as mean 62 SD was: 1.8–7.0 pmol/L. The plasma ACTH levelsin the two groups during LT are expressed in Table2.

The endogenous opiate system consists of a familyof opiate peptides located in the brain stem andhypotalamus near the cardiovascular centers, in thesympathetic ganglia and adrenal medulla (4). Cir-

TABLE 1Classification of Severity of Disease

Patient No. Gradea

1 IV2 III3 IV4 IV5 III6 III7 II8 III9 III10 III11 II12 IV

aAccording to the classification of Sales-Luis et al. (5):II, mild; III, severe; IV, very severe.

TABLE 2Plasma Corticotropin Levels (pmol/L) in the Two Groups During Liver Transplantation

Phases A1 A2 A3 A4 B1 B2 C1 C2 C3

Group APatient No.

1 ,0.2 ,0.2 ,0.2 0.4 0.6 0.5 0.6 ,0.2 ,0.22 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.23 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.24 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.25 ,0.2 ,0.2 0.4 0.6 0.4 0.6 0.8 0.6 ,0.26 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.27 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 0.4 ,0.2 ,0.28 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.29 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.210 ,0.2 ,0.2 0.4 0.4 0.6 0.8 1 0.6 ,0.211 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.212 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2 ,0.2

Group BMean 2.1 3.0 5.5a 6.8b 7.6c 6.9b 9.9c 4.2b 4.1a

SD 0.2 0.7 0.8 0.8 0.9 0.9 1.0 0.9 0.8

ap , 0.05, bp , 0.01 and cp , 0.001 compared with baseline value (A1). Reference interval is 1.8–7.0 pmol/L.

DIAZ et al.

690 CLINICAL BIOCHEMISTRY, VOLUME 31, NOVEMBER 1998

culating b-endorphin is released from the anteriorand intermediate lobes of the pituitary gland, orig-inates from the same precursor molecule calledproopiomelanocortin, and ussually is released inconjunction with ACTH. In acute hemorrhagicshock, plasma concentrations of b-endorphin andACTH are elevated, and these signs of circulatorydysfunction were accompanied by increased plasmaNE levels, consistent with a stress reaction (4,9,10).

The baseline ACTH levels, as well as those ob-tained immediately after anesthesia induction werenormal, and these results show that preoperativestress and anesthesia induction do not modify ACTHlevels. This demonstrates that the influence of emo-tional stress and anesthesia technique on the base-line ACTH levels was small. However, surgicalstress causes a significant increase in the cirrhoticpatients. In addition, the significant hemodynamicchanges caused by clamping and unclamping theinfrahepatic vena cava and portal vein at the begin-ning of the anhepatic and neohepatic phases, respec-tively.

In addition, hypotension, acute hemorrhaging andacidosis, could be stimulus for ACTH and b-endor-phin release, as it is at these times that the highestlevels are attained (5,9). The stressful stimuli pro-duced in LT patients by surgery we must add thesignificant hemodynamic alterations occurring as aresult of the clamping and unclamping of the infe-rior vena cava and portal vein at the beginning ofthe anhepatic and neohepatic phases. This wouldexplain why ACTH and b-endorphin levels aregreater in LT and specially at these times, becasusethese peptides are also involved in modifying endo-crine response to stress and water balance, and mayplay a role in the regulation of immune system(4,5,9). This did not occur in the FAP patientsassessed here, as in most of them the ACTH levelsduring the procedure were lower than the radioim-munoassay sensitivity (0.2 pmol/L).

Pathologically, amyloid deposition is present inthe peripheral and autonomic nerves and otherorgans (1). In addition, to sensory dominant poly-neuropathy, the serious complains experienced byFAP patients reflect disordered autonomic nervefunctions. Widespread deposition of amyloid in theautonomic nerves and glands has been frequentlynoted (1). Rapid enlargement of the thyroid glandfrom deposition of amyloid has been seen, as haspanhypopituitarism from destruction of the pitu-itary gland by amyloid deposits (1,2), which could beverify the lower release of ACTH and b-endorphin asresponse to surgical stress in patients with FAPundergoing LT. Consequently, the absence of b-en-dorphin and ACTH, and lower NE release as aresponse to the stress stimuli produced by LT sug-gests a possible central nervous system (CNS) dis-order and destruction of the pituitary gland, eitherbecause the amyloid substance is also deposited here

or, simply, because the nerve paths afferent to thebrain are affected.

Until now, amyloid deposition in the CNS in FAPhas been negligible compared to that in the periph-eral somatic and autonomic nerves, and no patientwith FAP has been reported to have CNS. Ourfindings confirm that these patients may present agreater clinical heterogeneity than previously recog-nized (2). Finally, the present investigation supportsthe suggestion that sympathetic neuropathy andamyloid deposition in pituitary gland are implicatedin the absence response of plasma ACTH in patientswith FAP during LT.

Acknowledgement

This work was supported in part by Fondo de Investi-gaciones Sanitarias, Madrid, Spain, Grants: FIS 96/1631and FIS 97/5249), plus a grant from Fundacion para elDesarrollo del Trasplante Hepatico and Novartis Farma-ceutica S.A., Madrid, Spain.

References

1. Kyle RA, Greipp PR. Amyloidosis. Clinical and labo-ratory features in 229 cases. Mayo Clin Proc 1983; 58:665–683.

2. Ikeda S, Hanyu N, Hongo M, et al. Hereditary gener-alized amyloidosis with polyneuropathy. Clinicopath-ological study of 65 japanese patients. Brain 1987;110: 315–337.

3. Parrilla P, Lopez-Andreu F, Ramirez P, et al. Familialamyloidotic polyneuropathy type I (Andrade’s dis-ease): a new indication for liver transplant. Trans-plantation 1994; 57: 473–474.

4. Young EA, Akil H. Corticotropin-releasing factorstimulation of adrenocorticotropin and b-endorphinrelease: effects of acute and chronic stress. Endocri-nology 1985; 117: 23–30.

5. Sales-Luis ML, Galvao M, Carvalho M, Sousa G, AlvesMM, Serrao R. Treatment of familial amyloidoticpolyneuropathy (Portuguese type) by plasma ex-change. Muscle Nerve 1991; 14: 377–378.

6. Acosta F, Diaz J, Moreno J, et al. Relationship be-tween b-endorphin release and surgical stress in or-thotopic liver transplantation. Transplant Proc 1995;27: 2303.

7. Raff H, Findling JW. A new immunorradiometricassay for corticotropin evaluated in normal subjectsand patients with Cushing’s Syndrome. Clin Chem1989; 35: 596–600.

8. Diaz J, Tornel PL, Martinez P. Reference intervals forblood ammonia in healthy subjects determined bymicrodiffusion. Clin Chem 1995; 7: 1048.

9. Acosta F, Diaz J, Fuente T, et al. Plasma b-endorphinlevels during liver transplantation in patients withfamilial amyloidotic polyneuropathy. Clin Biochem1996; 29: 393–395.

10. Diaz J, Acosta F, Tovar I, et al. Sympathetic nervoussystem response to surgical stress in patients withfamilial amyloidotic polyneuropathy undergoing or-thotopic liver transplantation. Transplant Proc 1995;27: 2295.

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