Positive Acetylcholinesterase Research Articles

A RARE CASE OF JUVENILE MYASTHENIA GRAVIS

Juvenile Myasthenia Gravis is arare auto immune disorder affecting children and adolescents, characterized by ptosis, muscle weakness and fatigability, untreated patients may progress to paralysis of the respiratory muscles and the risk of aspiration, particularly at times when they have an upper respiratory tract infection. Early recognition of this disease helps avoid unnecessary testing, prevent undue parental anxiety and stop the progression of symptoms. An 18 months old girl admitted with progressive dropping of eyelids, swallowing difficulty, loss of head control and generalized fatigability. She had positive acetyl cholinesterase test. Investigation releavedelectro decrementalresponsonse in electromyography. Patient treated with oral pyridostigmine bromide and steroid resulted in improvement in muscle strength and functional ability with regularly followed in OPD.JMG requires prompt recognition and management to prevent complications. This case highlights the importance of considering JMG in children with persistent weakness and fatigue.

Choline-acetyltransferase (ChAT) and acetylcholinesterase (AChE) in the human infant dorsal motor nucleus of the Vagus (DMNV), and alterations according to sudden infant death syndrome (SIDS) category

Amongst other molecules, the cholinergic system consists of choline-acetyltransferase (ChAT, − synthesis enzyme), acetylcholinesterase (AChE – primary hydrolysis enzyme), and butyrylcholinesterase (BuChE – secondary hydrolysis enzyme). In the brainstem, the Dorsal Motor Nucleus of The Vagus (DMNV) has high cholinergic expression and is a region of interest in the neuropathology of sudden infant death syndrome (SIDS). SIDS is the unexpected death of a seemingly healthy infant, but postmortem brainstem abnormalities suggesting altered cholinergic regulation have been found.This study aimed to determine the percentage of positive ChAT and AChE neurons within the infant DMNV through immunohistochemistry at the three levels of the brainstem medulla (caudal, intermediate, and rostral), to investigate whether the proportion of neurons positive for these enzymes differs amongst the diagnostic subgroups of SIDS compared to those with an explained cause of Sudden unexpected death in infancy (eSUDI), and whether there were any associations with SIDS risk factors (male gender, cigarette smoke exposure, co-sleeping/bed sharing, and prone sleeping). Results showed that ChAT-positive neurons were lower in the rostral DMNV in the SIDS II cohort, and within the caudal and intermediate DMNV of infants who were exposed to cigarette smoke. These findings suggest altered cholinergic regulation in the brainstem of SIDS infants, with potential contribution of cigarette smoke exposure, presumably via the nicotinic acetylcholinergic receptor system.

A CASE OF MYASTHENIA GRAVIS ASSOCIATED WITH APLASTIC ANEMIA

SESSION TITLE: Fellows Critical Care Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: October 18-21, 2020 INTRODUCTION: Aplastic anemia is an uncommon complication of thymoma. We report a rare case of Myasthenia Gravis with thymoma, concomitant aplastic anemia and primary hyperparathyroidism. CASE PRESENTATION: 68-year-old male presented with back pain and cough, was found to have pancytopenia and an anterior mediastinal mass. Work up was notable for leukopenia of 1.7 K/uL, absolute neutrophil count of 510 K/uL, platelets of 54 k/uL and hemoglobin of 7.6 g/dL. Chest imaging showed an anterior mediastinal soft tissue mass and left para-aortic lymph nodes (Figure 1). On day 2, he required intubation for acute respiratory failure. A bone marrow biopsy revealed hypoplastic bone marrow consistent with aplastic anemia (AA). He then underwent a percutaneous biopsy of the mediastinal mass which confirmed a thymoma. His hospital course was complicated by Staphylococcus aureus bacteremia, new onset atrial fibrillation and ischemic stroke as well as bilateral upper extremity venous thromboemboli. He was started on Filgrastim and Romiplostim His hematological clinical picture was most consistent with aplastic anemia with a component of bone marrow suppression from sepsis contributing to pancytopenia. He was transfusion dependent given refractory anemia and thrombocytopenia. Further work up revealed primary hyperparathyroidism. A positive acetylcholinesterase (5.30 nmol/L) was consistent with myasthenia gravis (MG). He was started on intravenous immunoglobulin for 5 days. He underwent tracheostomy placement on day 21. He was started on prednisone and pyridostigmine and was then evaluated for thymoma resection by cardiothoracic surgery. DISCUSSION: Myasthenia gravis (MG) is an autoimmune disorder characterized by weakness of skeletal muscles, caused by an antibody-mediated attack against the acetylcholine receptor antibody. AA usually precedes the diagnosis of thymoma which is associated with autoimmune disorders, including MG, polymyositis, hypogammaglobulinemia, agranulocytosis, pure red cell aplasia, and AA (1). Our patient was noted to have primary hyperparathyroidism in association with MG with thymoma with concomitant aplastic anemia which is extremely rare (2). MG appears in about 20–40% of patients with thymoma (3). AA is a result of bone marrow failure characterized by hypocellular marrow and peripheral pancytopenia; and is an uncommon complication of thymoma. AA is thought to be an autoimmune manifestation of thymoma as a result of bone marrow suppression in the setting of unbalanced T cell regulation represented by an inverted CD4+ /CD8+ ratio or an increase in cytotoxic and suppressive cells (4). CONCLUSIONS: To the best of our knowledge, this is the first report of a patient with concomitant primary hyperparathyroidism, myasthenia gravis (MG), and aplastic anemia (AA). This case raises awareness of this rare association in order to recognize patients who have this constellation of clinical presentations Reference #1: Mitsumune S, Manabe Y, Yunoki T, et al. Autologous Bone marrow Transplantation for Polymyositis Combined with Myasthenia gravis and aplastic anemia: a case report. Case Rep Neurol. 2018;10(1):108–111. Reference #2: Hong S, Hyeok Cho D, Kang HC, Chung DJ et al. A case of myasthenia gravis associated with primary hyperparathyroidism. Korean J Med 2006. 71:S1039-S1043 Reference #3: Mizobuchi S, Yamashiro T, Nonami Y et al. Pure red cell aplasia and myasthenia gravis with thymoma: A case report and review of the literature. Japanese Journal of Clinical Oncology, 1998, 28(11): 696–701 DISCLOSURES: No relevant relationships by Nasheena Jiwa, source=Web Response no disclosure on file for Asher Qureshi

Occurrence of Guillain-Barr\xe9 syndrome and Myasthenia Gravis in an elderly male

IntroductionThe occurrence of both Guillain-Barré syndrome(GBS) and myasthenia gravis (MG) in the same individual is rare. The underlying pathophysiology was assumed to be autoimmune humoral mechanisms and molecular mimicry with a cross-reaction between autoantibodies and myelin sheath of peripheral nerves and acetylcholine receptors of the neuromuscular junction (NMJ).Case descriptionA 68-year-old male known diabetic and hypertensive with good drug compliance presented with acute onset quadriparesis with bulbar involvement for 1 day. On examination, he had mild neck flexion weakness and bulbar weakness. He had flaccid quadriparesis with absent deep tendon reflexes and negative Babinski. The rest of the neurological examination was normal.Discussion and evaluationBlood and electrophysiological studies showed evidence of demyelinating polyradiculoneuropathy with temporal dispersion suggestive of Guillain-Barré syndrome. He was treated with intravenous immunoglobin and complete resolution of symptoms. Two months later, he presented with new-onset asymmetrical ptosis and bulbar symptoms for 3 days. On further evaluation, repetitive nerve stimulation showed postsynaptic neuromuscular disorder pattern typical of myasthenia gravis, which was further confirmed by positive acetylcholinesterase receptor antibodies (AChR). Thymoma was ruled out by imaging. He was treated with anticholinesterases, low dose steroids, and immunosuppressants (azathioprine) following which he had improvement of symptoms.ConclusionOur patient, who was initially diagnosed with Guillain-Barré syndrome and recovered, presented 2 months later with a new-onset illness suggestive of myasthenia gravis. This existence of two different neurological entities in the same individual is a rarity, and early recognition is essential for treatment decision and prognostic strategies.

EP01.21: A case of positive amniotic acetylcholinesterase in a normal fetus following one fetal demise in twin

EP01.21: A case of positive amniotic acetylcholinesterase in a normal fetus following one fetal demise in twin

Routine measurement of amniotic fluid alpha-fetoprotein and acetylcholinesterase: the need for a reevaluation

The objective of the study was to evaluate whether the current screening regimen of measuring amniotic fluid alpha-fetoprotein (AF-AFP) at the time of amniocentesis and reflex acetylcholinesterase testing vs ultrasound alone to detect neural tube and ventral wall defects offers improved diagnostic accuracy and cost benefit. A retrospective chart review on all patients who had amniocentesis performed at 1 center over the past 11 years was performed. Those with an elevated AF-AFP were compared with those whose AF-AFP was within normal limits. Ultrasound findings and outcomes were reviewed in all cases to assess whether neural tube defects (NTDs) or ventral wall defects (VWDs) were missed by AF-AFP or ultrasound screening. A cost-benefit analysis was then performed. Of 6232 women who underwent amniocentesis between January 2002 and December 2012, 81 had an elevated AF-AFP with or without a positive acetylcholinesterase (AChE). Of these 81 women, 13 had NTDs and 5 had VWDs. The sensitivity of the detailed ultrasound was 100% in detecting NTDs and VWDs, whereas that of the AF-AFP ranged from 22% to 77%, with the inclusion of AChE. The total expenditure for AF-AFP in our sample set (n = 6232 amniocentesis at $76.00 per AF-AFP) was $473,632, and all NTDs and VWDs were detected by ultrasound. Translated to a national laboratory (>42,447 samples/year), the cost savings in 2011 alone would be $3,225,972. Given the accuracy of high-resolution ultrasound in the detection of both NTDs and VWDs, measuring AF-AFP and AChE as a reflex-screening test is not a cost-effective approach.

Total Colonic Aganglionosis: Case Report, Practical Diagnostic Approach and Pitfalls

Hirschsprung disease remains a challenging diagnosis for many pathologists. The disease is characterized by a lack of ganglion cells in the myenteric and submucosal plexus, associated with increased numbers of acetylcholinesterase-positive nerve fibers. Hypertrophic nerve fibers are present in most but not all patients. Total colonic aganglionosis (TCA) is an uncommon form of Hirschsprung disease with clinical, histologic, and genetic differences and is even more difficult to diagnose and manage. This case illustrates some of the difficulties frequently faced by the pathologists dealing with total colonic aganglionosis. Suction rectal biopsy specimens often lack significant nerve hypertrophy and positive acetylcholinesterase staining, which aid in the diagnosis. Pathologists have to depend mainly on the lack of ganglion cells in adequate submucosa to establish the diagnosis. Transition zone is often long in total colonic aganglionosis and interpretation of frozen sections can be difficult. The presence of several uniformly distributed clusters of mature ganglion cells and lack of nerve hypertrophy are required to avoid connections at the transition zone.

Total colonic aganglionosis: case report, practical diagnostic approach and pitfalls.

Hirschsprung disease remains a challenging diagnosis for many pathologists. The disease is characterized by a lack of ganglion cells in the myenteric and submucosal plexus, associated with increased numbers of acetylcholinesterase-positive nerve fibers. Hypertrophic nerve fibers are present in most but not all patients. Total colonic aganglionosis (TCA) is an uncommon form of Hirschsprung disease with clinical, histologic, and genetic differences and is even more difficult to diagnose and manage. This case illustrates some of the difficulties frequently faced by the pathologists dealing with total colonic aganglionosis. Suction rectal biopsy specimens often lack significant nerve hypertrophy and positive acetylcholinesterase staining, which aid in the diagnosis. Pathologists have to depend mainly on the lack of ganglion cells in adequate submucosa to establish the diagnosis. Transition zone is often long in total colonic aganglionosis and interpretation of frozen sections can be difficult. The presence of several uniformly distributed clusters of mature ganglion cells and lack of nerve hypertrophy are required to avoid connections at the transition zone.

Cow’s milk allergy presenting Hirschsprung’s disease-mimicking symptoms

The authors present a neonatal case of allergic colitis, which manifested the difficulty of spontaneous defecation and irregular narrowing of distal rectum in contrast enema. Rectal suction biopsy showed positive acetylcholinesterase activity. These clinical, radiological and histological findings were indistinguishable from Hirschsprung's disease. Gastrointestinal symptoms were improved by the cessation of cow's milk formula. The present findings may impact on the less recognizable gastrointestinal manifestation of allergic colitis.

Autonomic innervation of the human cardiac conduction system: changes from infancy to senility--an immunohistochemical and histochemical analysis.

In order to study the changes in the pattern of autonomic innervation of the human cardiac conduction system in relation to age, the innervation of the conduction system of 24 human hearts (the age of the individuals ranged from newborn to 80 years), freshly obtained at autopsy, was evaluated by a combination of immunofluorescence and histochemical techniques. The pattern of distribution and density of nerves exhibiting immunoreactivity against protein gene product 9.5 (PGP), a general neural marker, dopamine beta-hydroxylase (DBH) and tyrosine hydroxylase (TH), indicators for presumptive sympathetic neural tissue, and those demonstrating positive acetylcholinesterase (AChE) activity, were studied. All these nerves showed a similar pattern of distribution and developmental changes. The density of innervation, assessed semiquantitatively, was highest in the sinus node, and exhibited a decreasing gradient through the atrioventricular node, penetrating and branching bundle, to the bundle branches. Other than a paucity of those showing AChE activity, nerves were present in substantial quantities in infancy. They then increased in density to a maximum in childhood, at which time the adult pattern was achieved and then gradually decreased in density in the elders to a level similar to or slightly less than that in infancy. In contrast, only scattered AChE-positive nerves were found in the sinus and atrioventricular nodes, but were absent from the bundle branches of the infant heart, whereas these conduction tissues themselves possessing a substantial amount of pseudocholinesterase. During maturation into adulthood, however, the conduction tissues gradually lost their content of pseudocholinesterase but acquired a rich supply of AChE-positive nerves, comparable in density to those of DBH and TH nerves. The decline in density of AChE-positive nerves in the conduction tissues in the elders was also similar to those of DBH and TH nerves. Our findings of initial sympathetic dominance in the neural supply to the human cardiac conduction system in infancy, and its gradual transition into a sympathetic and parasympathetic codominance in adulthood, correlate well with the physiologic alterations known to occur in cardiac rate during postnatal development. The finding of reduction in density of innervation of the conduction tissue with ageing is also in agreement with clinical and electrophysiological findings such as age-associated reduction in cardiac response to parasympathetic stimulation. Finally, our findings also support the hypothesis that, in addition to the para-arterial route, the parafascicular route of extension along the conduction tissue constitutes another pathway for the innervation of the conduction system of the human heart during development.

Repeated intracerebroventricular administration of β-amyloid25–35 to rats decreases muscarinic receptors in cerebral cortex

The effects of repeated in vivo administration to rats of β-amyloid25–35 (βA25–35) on several cholinergic markers have been studied and compared with those of a peptide with a scrambled sequence. Rats received intracerebroventricular injections of βA25–35 (5 or 20 μg/day) for 7 days and they were sacrificed at 2 or 3 weeks survival. The density of total muscarinic receptors labeled with [3H]N-methyl-scopolamine was dose-dependently decreased by βA25–35 in the cerebral cortex at 3 weeks survival. No changes were observed at 2 weeks survival in cerebral cortex or in the hippocampus, at any time. βA25–35 administration did not modify choline acetyltranferase activity in cerebral cortex. However, in βA25–35-treated rats hypertrophic/hyperactive positive acetylcholinesterase nucleus basalis cholinergic neurons were observed at 2 weeks survival, while the density of acetylcholinesterase-positive fibers of cerebral cortex was increased along with the number of cortical positive neurons at 3 weeks survival. These results suggest that increased cholinergic function may be responsible of muscarinic receptor down-regulation. Given the involvement of cholinergic systems in memory and learning, repeated administration of βA25–35 may represent a good approach to explore the role of βA in Alzheimer's disease and to develop therapeutic strategies relevant to it.

Prenatal Diagnosis of dup(3q) syndrome

There are numerous reports on the duplication of the long arm of chromosome 3, ranging from 3ql2 to 3qter. Although the duplicated segments vary in size, a defined clinical phenotype, dup(3q) syndrome, has been investigated by us and others. A 22 year old G4P0030 (1SPAB, 2ELAB) Caucasian was referred at 31 weeks gestation for fetal anomalies on sonogram including hydrocephalus, bilateral polydactyly, and a possible CHD Amniocentesis was performed and showed an unbalanced chromosomal rearrangement: 46,XX,der(9)t(3;9) (q26.1;p24).ish. 46,XX,der(9)t(3;9)(q26.1;p24) (WCP3+WCP9+), and a positive acetylcholinesterase. Parental chromosomes showed that the father was a carrier of a balanced rearrangement: 46,XY,t(3;9) (q26.1;p24). The baby was bom at 42 weeks gestation following prostaglandin induction due to failure to progress. She weighed 4264 grains and cried spontaneously with APGAR scores of 8/8 at 1 and 5 minutes. The major dysmorphic features included: up-slanting palpebral fissures, synophyrs, prominent alveolar ridge, hypertelorism, down-turned corners of the mouth, short neck with redundant skin folds, bilateral postaxial polydactyly, a deep sacral dimple and an anteriorly displaced anus with low rectal stenosis. During the surgical correction of the rectal stenosis, a pre-sacral teratoma was excised. The telomeric DNA segment (9p24-pter) lost due to the translocation is generally associated with chromosomal capping rather than phenotypic expression. The clinical manifestations consistent with dup(3q) syndrome are being presented. To our knowledge, teratoma has not been described before as part of the dup3q phenotype.

Implications of atypical biochemical data in a case of presumed anencephaly

Anomaly scan on a 21 year old primigravida at 22 weeks showed absence of the superior portion of the calvarium with poorly defined cerebral tissue floating in the amniotic fluid. Maternal serum alphafetoprotein (MSAFP) at 18 weeks was 1.4 MOM. The patient was counseled for anencephaly and amniocentesis was performed. Biochemical data consisting of amniotic fluid alphafetoprotein (AFAFP) of 1.94 MOM with weak positive acetylcholinesterase (ACHE) was atypical of classic anencephaly; karyotype was 46, XX. Following termination, fetopsy showed a gaping cranial defect with protruding brain tissue, partially covered by attenuated translucent skin; meninges were torn and congested. Amniotic bands were identified explaining the cranial findings. Radial aplasia and imperforate anus further suggested VATER. While normal MSAFP can be seen with anencephaly, a normal AFAFP and weak positive ACHE are atypical. In the context of the post-mortem findings, it is presumed that without pregnancy termination, expansion of the cranial anomaly would have eventually lead to unequivocally abnormal biochemical results. This case suggests that alternative etiologies, in particular amniotic bands, be considered when atypical biochemical data is seen at midtrimester in the presence of apparent anencephaly.

Risks for Fetal Abnormalities after very and moderately elevated AF-AFPs

In the 2 years between 1993 and 1995, we assayed alpha-fetoprotein (AFP) in 48,412 amniotic fluids (AFs). One thousand and eighty-six (2.2 per cent) measured > or = 2.0 MOM and these were subdivided into three groups; mildly (2.0-4.9 MOM), moderately (5.0-9.9 MOM), and very elevated (> or = 10.0 MOM). Abnormalities occurred in 25 per cent of the mildly elevated compared with 88 per cent of the moderately and 98 per cent of the very elevated cases. Forty-five per cent of the neural tube defects (NTDs) had AF-AFPs in the 5.0-9.9 and 36 per cent in the > or = 10.0 MOM range. After a positive acetylcholinesterase (AChE) test, both the moderately and the very elevated groups had abnormalities in > or = 95 per cent of cases, compared with 85 per cent in the mildly elevated group. After a negative AChE test, abnormalities occurred in 79, 52 and 18 per cent in the very elevated, moderately, and mildly elevated groups, respectively. Excluding chromosome abnormalities, an abnormal twin, and bloody samples, the risk of a fetal abnormality after a normal ultrasound was less than 1 per cent if the AChE was positive in both the moderately and the very elevated groups. If the AChE was negative, the risk was 18 per cent for the moderately and 55 per cent for the very elevated groups, of which congenital nephrosis accounted for 75 per cent; AFP levels usually increased in a later AF sample. Repeat amniocentesis may be offered to women with AF-AFPs > or = 5.0 MOM if no abnormality is seen with high-resolution ultrasound.

Diagnostic dilemma with elevated level of α-fetoprotein in an undiagnosed twin pregnancy with a small discordant holoacardius acephalus

We report a case of a patient who had highly elevated levels of α-fetoprotein when she was first examined and a positive acetylcholinesterase test result in amniotic fluid. Despite repeated ultrasonographic screening, pathologic findings were not detected and the holoacardius acephalus twin was not identified. After termination of pregnancy the histopathologic findings demonstrated a twin pregnancy with a holoacardius acephalus. (Am J Obstet Gynecol 1997;177:466-8.)

Colocalization of acetylcholinesterase and vasoactive intestinal peptide (VIP) in nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) positive neurons in the intralingual ganglia and perivascular nerve fibers around lingual arteries in the porcine, monkey and canine tongue

Distribution of nitric oxide synthase in the intrinsic ganglia in the porcine, monkey and canine tongue was histologically investigated using the reduced nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) method, acetylcholinesterase histochemistry and vasoactive intestinal peptide (VIP) immunohistochemistry. The majority of intralingual ganglionic cells showed intense NADPH-d reactivity with positive acetylcholinesterase reaction or positive VIP immunohistochemistry. The NADPH-d positive, acetylcholinesterase-rich and the NADPH-d positive, VIP immunoreactive nerve fibers are particularly conspicuous around intralingual blood vessels. These fibers around the arteries in the tongue may be partly derived from the intralingual ganglion cells, because some bundles associated with these nerve cells were easily traced on the wall of blood vessels. The present study suggests the view that the three markers coexist in the axons and nerve terminals of these intralingual neurons.

A multidirectional sonographic approach to elevated amniotic alpha-fetoprotein or positive acetylcholinesterase

To evaluate the combined transvaginal and transumbilical ultrasonographic approach in cases of elevated amniotic fluid (AF) alpha-fetoprotein (AFP) and/or acetylcholinesterase in the second trimester. Nine pregnant women with normal sonographic results were referred because of elevated AF AFP and/or acetylcholinesterase and screened using a transvaginal and transumbilical 6.5-MHz ultrasound transducer. All women were at 17–21 weeks' gestation. The fetal skull and the vertebral column were scanned in both perpendicular and tangential planes for maximal exploitation of the axial resolution of the transducer, in both directions and in two to three planes. Despite increased AF AFP and/or present acetylcholinesterase, no fetal malformation was detected in any of the nine cases. Open neural tube defects were not detected by the diagnostic technique. All nine women were delivered of term healthy neonates without malformations. Our preliminary data suggest that targeted sonographic screening combining transvaginal and transumbilical approaches may reliably rule out an open neural tube defect larger than 0.3 mm. This may influence the decision-making process when termination of pregnancy is considered in cases of high AF AFP and/or positive acetylcholinesterase.

Aplasia cutis congenita: A rare cause of elevated α-fetoprotein levels

We present a catastropic case of aplasia cutis congenita from a pregnancy complicated by elevated maternal serum and amniotic fluid α-fetoprotein levels and a positive acetylcholinesterase. Delivery occurred at 27 weeks 1 day after premature rupture of membranes with chorioamnionitis. The neonate lacked >90% of its skin and died.

Scanning Gel Densitometry of Amniotic Fluid Acetylcholinesterase and Butyrylcholinesterase: Quantification of ‘Faint-Positive’ Bands in Fetal Malformations

The quantification of 'faint-positive' cholinesterases in amniotic fluid was performed in 40 patients with positive acetylcholinesterase (AchE) tests. Fetuses with anencephaly and open spina bifida presented an AchE/butyrylcholinesterase (A/B) ratio of more than 0.3 with clearly dense bands. Fetuses with gastroschisis showed a 'faint-positive' AchE band (A/B < 0.3). In 5 fetuses (1 teratoma, 3 open spina bifida, 1 unaffected) we found faint AchE and butyrylcholinesterase bands.

Are routine alpha-fetoprotein and acetylcholinesterase determinations still necessary at second-trimester amniocentesis? Impact of high-resolution ultrasonography

To audit routine measurement of alpha-fetoprotein (AFP) and acetylcholinesterase in amniotic fluid (AF) samples obtained at second-trimester amniocentesis. We reviewed retrospectively 1737 consecutive AF specimens obtained for cytogenetic evaluation over a 4-year period and routinely assayed for AFP and acetylcholinesterase. In all instances, high-resolution ultrasonography was performed before amniocentesis. Details of pregnancy outcome of all cases with AF AFP levels greater than 2.0 multiples of the median and a positive or faint acetylcholinesterase band were obtained. There were 31 abnormal results (1.8%, 1 of 56). Of these, 25 cases had elevated AF AFP and/or positive acetylcholinesterase. Ultrasonography correctly identified all 18 fetuses with anomalies associated with abnormal levels of these biochemical markers, including open neural tube defects and/or anterior abdominal wall defects (17 cases) and fetal hydrops (one). In the remaining seven, no fetal anomalies were detected, and all neonates were structurally normal after birth. In addition, six pregnancies with faint acetylcholinesterase and normal AF AFP showed no fetal abnormalities at ultrasonographic examination and post-delivery. High-resolution ultrasonography was more accurate than AF biochemistry in the detection of congenital anomalies associated with elevated AFP levels and acetylcholinesterase in the AF. Routine measurement of these biochemical markers in AF samples obtained for cytogenetic analysis appears to have a very low yield and would therefore not be cost-effective in practices where high-resolution ultrasonography is performed before amniocentesis.