THIRD INTERNATIONAL CONFERENCE ON ALZHEIMER’S DISEASE s21

diagnosis. We report the discovery of a possible ante mortem diagnostic te.st based on analysing lumbar spinal fluid in life.

Iso-electric focusing using gel electrophoresis can be used to demonstrate a number of different isoforms of the enzyme acetylcholinesterase (AChE). We have recently reported that in both post mortem and ante mortem samples of CSF there is an anomalous isoform present in patients with histopathological AD which we have cal e ACh -A is not present in those without AD creu, h s;reP.?Pl' ";f';r, conducting a longitudinal prospective study of more than 200 subjects referred with varying degrees of cognitive failure. So far 50 have died and all have come to post mortem.

Of the 27 subjects in whom we have a histological report to date, 21 had AD, 1 had PSP, 1 had NPH, 1 had MID, 1 had no pathology to account for profound dementia and 2 were controls with no CNS pathology. At a loading of 2.5 nMol/min activity, 18/21 with AD had the anomalous form of AChE in their CSF obtained in life. It was not found in any of the other subjects, ie. so far there have been no false positives.

References

1. Anomalous molecular form of acetylcholinesterase in cerebrospinal fluid in histologically diagnosed Alzheimer's disease. Navaratnam.D S, Pridd1e.J D et al. Lancet 1991, 337, 447-50.

2. Anomalous acetylcholinesterase in lumbar CSF in Alzheimer's disease. Smith,A D. Jobst,K A et al. Lancet 1991, 338, 1538

106 ABNORMALITIES OF TRANSKETOLASE IN ALZHEIMER'S DISEASE FIBROBLASTS. S. Sorbi, F. Lolli, P. Piersanti, * R-R Sheu, S. Piacentini, L. Amaducci. Department of Neurological and Psychiatric Sciences, University of Florence, Florence, Italy, and * Burke Medical Research Institute, White Plains, NY, USA Transketolase is a thiamine pyrophosphate dependent enzyme of the non-oxidative pentose cycle. We have studied the isoelectrophoretic (IEF) pattern of transketolase in human skin fibroblasts from Alzheimer's patients (AD), and neurological and normal controls using rabbit anti-liver transketolase. IEF was performed on 1 % agarose gel containing 5.4 % ampholine solution. IEF transketolase pattern was then revealed by policlonal anti-transketolase IgG preparations coupled with the avidin-biotin-peroxidase system. Cell extracts from normal individuals and from patients with other neurological diseases have a typical transketolase IEF profile consisting in fOUr major band migrating between pH 1.0 and pH 0.4. About 50 % of cell lines from either familial or sporadic AD have an abnormal transketolase pattern characterized by the appearance of two major alkaline bands and by decrease or missing of the typical transketolase bands observed in controls. The appearance of this shifting towtowards the cathode in AD fibroblast extracts may be the expression of a proteolytic degradation possibly caused by an imbalance of the protease/antiprotease system. In conclusion this study suggests that some but not all patients with AD have an alterations of IEF transketolase profile which may help in identifying a possible subtype and/or eventually help in the clarification of the pathogenic mechanisms of this disease. Further experiments are in progress to elucidate this abnormality of transketolase in Alzheimer disease.

107 ACUTE PHASE REAmANTS IN ALZHEIMER’S DISEASE L. Altstiel, B. Lawlor. D. Johannessen, R. Mohs, K. Davis. Department of Psychiatry, The Mount Sinai School of Medicine, 1 Gustave Levy Place, New NY 10029, USA. Department of Psychiatry, The Bronx Veterans’ Administration Medi- cal Center, Bronx NY, USA.

Considerable recent evidence supports the presence of inflammatory reac- tions in Alzheimer’s disease (AD). Components of the complement system and reactive mlcroglia surround senile plaques; the acute phase reactants al- antichymotrypsin (ACT) and al-microglobulin, and the inflammatory cyrok- ine, interleukin-6 (IL-6). are components of the senile plaque; tissue levels of the inflammatory cytokine interleukin-1 (IL-l) are elevated in AD brain; both IL-6 and IL-l promote P-amyloid precursor protein synthesis and glial cell proliferation; and semm levels of ACT and tumor necrosis factor are elevated in a subset of AD patients.

We measured serum levels of the acute phase reactants, ACT and C- reac- tive protein (CRP) with an enzyme-linked immunosorption assay (ELISA) in patients with AD diagnosed by NINCDS/ADRDA criteria, non- demenred, age-matched control subjects, and first-degree relatives of patients with AD. Serum concentrations of Am were 119.3 * 54.3 mg/dL in AD patients ar,d 50.3 + 37.6 mg/dL in non-affected subjects, (p<O.oooOl). Serum concentra- tions of CRP were 155.2 i 117.3 pg/dL for AD patients and 52.8 + 60.7 kg/dL for non- affected subjects (p<o.O004). High serum levels of both ACT and CRP are highly associated with diagnosis of clinical AD in the population sk- died. Approximately 95% of patients with either ACT or CRP serum levels two standard deviations above the mean for non-affected subjects had a diag- nosis of clinical AD. In addition 31.3% (10/32) of non- demented first-degree relatives had levels of ACT two standard deviations above the mean for non- affected subjects. Because only 5% of the non-affected population (2/40) had elevated ACT levels, the relatively high proponion of first degree relatives with high serum concentrations of ACT is unlikely to have occurred by chance alone (X*=6.096, p<O.O05). There is no correlation between age and serum levels of either ACT or CRP.

These results suggest that measurement of serum ACI and CRP levels may be useful in both monitoring the inflammatory components of AD in patients who have the disease and as a pre-morbid marker in first- degree relatives who are at high risk for developing AD.

108 CSF AMINO-ACIDS PATTERN IN DIFFERENT NEURO- DEGENERATIVE DISORDERS. F. Dagani, L. Canevari, R. Masemtil G. Bono* and I’. Tosca*. Inst. of Pharmacology, Univ. of Pavia, pna Botta 11, *“C. Mondino” Fnd, and I Infect. Dis. Clin, Univ. of Pavia, 27100 Pavia-Italy. Amino-acids (AA) in blain play a role in neumtransmission acting either as neurohansmitter precursors, or neurotransmitter themselves, or as modulators of NMDA recepton for excitatov amineacid (F.AQ neurotransmitter. Several neurological disotdet5 have been correlated with modifications in amino-acid neurotransmission and/or metabolism. In neumpsychiatric patients these modifications have been studied evaluating the aminoacidic pattern in the CSF but several discrepancies exist among the different studies also due to technical problems in the analytical detection. In this investigation we wanted to analyse the pattern of CSF amino acid utilizing a technique showing these advantages: detection of both high concenhated (glutamine) and low concentrated (GABA) AA, short runs, resolution of most AA present in CSF. The pracolumn OPAderivation is followed ty reverse phase HPLC separation and electrochemical detection. This detection technique is much more sensitive and repetitive than fluorometric detection (at least 100x). Preliminary data obtained on CSF of asintomatic HIV-positive patients show a decreased giutamine/glutamate ratio, decreased isoleucine in comparison with data present in literature. GABA levels (20960 pmol/ml, n=4) were in the normal tange. Other neuropsychiattic diseases have also been studied. Utilizing the same method of detection we also analyzed three patients with suffered of head tmuma. We found that the amino acid pattern in the CSF was changing in the period after the trauma; in particular ghatamate was decxeas e 6 hours after txaurna and aspartate was higher than 24 hours after the bauma. These patients which often show after the survival from the acute traumatic insult hemiballismus, are compared with another group of patients suffering of Alzheimer’s disease. The data we found are potentially useful in determining a pattern of modifications which can be used as a temptative marker of neutudegenerative disorden possessing several clinical hallmark similar to Alzheimer’s disease.