Substantial differences in specificity of HIV-specific cytotoxic T cells in acute and chronic HIV infection.

Cytotoxic T lymphocytes (CTLs) play a vital part in controlling viral replication during human viral infections. Most studies in human infections have focused on CTL specificities in chronic infection and few data exist regarding the specificity of the initial CTL response induced in acute infection. In this study, HIV-1 infection in persons expressing human histocompatibility leukocyte antigen (HLA)-A*0201 was used as a means of addressing this issue. In chronic infection, the dominant HLA-A*0201-restricted CTL response is directed towards the epitope SLYNTVATL ("SL9") in p17 Gag (residues 77-85). This epitope is targeted by 75% of HLA-A*0201-positive adults, and the magnitude of this A*0201-SL9 response shows a strong negative association with viral load in progressive infection. Despite using the highly sensitive peptide-major histocompatibility complex tetramer and intracellular cytokine assays, responses to the SL9 epitope were not detectable in any of 11 HLA-A*0201-positive subjects with acute HIV-1 infection (P = 2 x 10(-6)), even when assays were repeated using the SL9 peptide variant that was encoded by their autologous virus. In contrast, multiple responses (median 3) to other epitopes were evident in 7 of the 11 A*0201-positive subjects. Longitudinal study of two subjects confirmed that the A*0201-SL9 response emerged later than other CTL responses, and after viral set point had been reached. Together, these data show that the CTL responses that are present and that even may dominate in chronic infection may differ substantially from those that constitute the initial antiviral CTL response. This finding is an important consideration in vaccine design and in the evaluation of vaccine candidates.

Cellular immune responses and viral diversity in individuals treated during acute and early HIV-1 infection.

Immune responses induced during the early stages of chronic viral infections are thought to influence disease outcome. Using HIV as a model, we examined virus-specific cytotoxic T lymphocytes (CTLs), T helper cells, and viral genetic diversity in relation to duration of infection and subsequent response to antiviral therapy. Individuals with acute HIV-1 infection treated before seroconversion had weaker CTL responses directed at fewer epitopes than persons who were treated after seroconversion. However, treatment-induced control of viremia was associated with the development of strong T helper cell responses in both groups. After 1 yr of antiviral treatment initiated in acute or early infection, all epitope-specific CTL responses persisted despite undetectable viral loads. The breadth and magnitude of CTL responses remained significantly less in treated acute infection than in treated chronic infection, but viral diversity was also significantly less with immediate therapy. We conclude that early treatment of acute HIV infection leads to a more narrowly directed CTL response, stronger T helper cell responses, and a less diverse virus population. Given the need for T helper cells to maintain effective CTL responses and the ability of virus diversification to accommodate immune escape, we hypothesize that early therapy of primary infection may be beneficial despite induction of less robust CTL responses. These data also provide rationale for therapeutic immunization aimed at broadening CTL responses in treated primary HIV infection.

Von Hippel-Lindau disease: clinical and pathological manifestations in nine families with 50 affected members.

Fifty individuals in nine families had von Hippel-Lindau disease. Nearly all of the morbidity and mortality of the entity is associated with six of its manifestations, each of which can be successfully treated. Retinal angiomatosis, which occurs in more than half of those affected, can produce blindness if not treated. Cerebellar hemangioblastoma, which is observed in one third of patients, is the most common source of initial symptoms and caused more than half of the deaths in the series. Medullary and spinal hemangioblastomas occur infrequently. Pheochromocytoma is common in certain families and is usually bilateral. Renal cell carcinoma, which generally arises at a later age, may befall the patient who is successfully treated for the tumors that occurred earlier. However, this tumor can be treated also, if there is early detection.

Rabbit placental relaxin: ultrastructural localization in secretory granules of the syncytiotrophoblast using rabbit placental relaxin antiserum.

Although relaxin has been isolated from the placenta of the human, rabbit, horse, and cat, this study represents the first ultrastructural localization of the hormone in placental tissue. Placentas were removed from rabbits on days 15, 23, and 30 of pregnancy, and the tissues were prepared for light and electron microscopies. The cytoplasm of the syncytiotrophoblast from all stages of pregnancy studied showed positive staining for the hormone at the light level using guinea pig antirabbit relaxin serum and the avidin-biotin technique. Ultrastructurally, the syncytiotrophoblast was found to contain membrane-bounded granules (150-400 nm in diameter) which formed at the Golgi and were seen in close association with the cell membrane. Exocytosis involving the incorporation of the granule membrane into the cell membrane was observed. These granules labeled positively for relaxin after treatment with guinea pig antirabbit relaxin serum and goat antiguinea pig immunoglobulin G-colloidal gold. Control sections in which the relaxin antiserum was absorbed with purified rabbit relaxin or substituted with normal guinea pig serum contained no gold-labeled granules. Cross-reactivity of the rabbit relaxin antiserum with porcine relaxin was demonstrated by labeling of the relaxin-containing granules in the pregnant pig corpus luteum with the rabbit relaxin antiserum and by inhibiting the labeling of rabbit placental and pig corpora luteal granules by absorbing the rabbit relaxin antiserum with porcine relaxin. We have previously described the labeling of rabbit placental relaxin with porcine relaxin antiserum. This study suggests that relaxin is synthesized and secreted from the syncytiotrophoblast of the rabbit placenta, with the subcellular site of storage being membrane-bounded granules.

Rabbit placental relaxin: purification and immunohistochemical localization.

Rabbit placentas were extracted with 0.7 N HCl-acetone (3:5, vol/vol) containing protease inhibitors. Gel filtration (Sephadex G-50) followed by ion exchange chromatography (carboxymethyl cellulose) separated a bioactive relaxin-like fraction with a specific activity of 8.5 U/mg protein as determined by the in vitro mouse uterus bioassay. Column chromatography using Sepharose CL-4B in 6 M guanidine HCl was employed to purify the bioactive sample. The yield of the purified relaxin-like protein was 12 micrograms/g placenta and the specific activity was 23 U/mg protein. The bioactive sample was also immunoreactive after being electrophoretically transferred to nitrocellulose paper and stained using rabbit antiporcine relaxin serum and peroxidase-antiperoxidase immunochemistry. Isoelectrofocusing of the purified relaxin-like protein revealed one band with an isoelectric point of approximately 6.5. The apparent molecular weight of the rabbit relaxin was approximately 7200 as determined by sodium dodecyl sulfate-urea slab gel electrophoresis. Upon reduction with 5.0% mercaptoethanol and electrophoresis on sodium dodecyl sulfate-urea polyacrylamide gels, both the 7200 dalton rabbit immunoreactive relaxin-like polypeptide and porcine relaxin migrated as a lower molecular weight protein. These results suggest that rabbit relaxin, like pig, rat, shark, and human relaxin, consists of two chains linked by disulfide bonds. At the light microscopy level, immunohistochemical staining with guinea pig antiporcine relaxin serum indicated that relaxin was located in the syncytiotrophoblast cells of the placental labyrinth of day-23 and day-30 pregnant rabbits. The syncytiotrophoblast cells from day 16 of pregnancy did not stain for relaxin.

Catecholamine metabolism in Gilles de la Tourette's syndrome.

Abnormal central catecholamine neurotransmission has been suggested in Gilles de la Tourette's syndrome. The authors evaluated the sympathetic nervous system in both the basal state and in its responsivity to postural and exercise stress. Plasma norepinephrine and the activities of its synthetic and degradative enzymes were not different in 33 Tourette patients, a control group of unaffected relatives, and another control group of unrelated healthy volunteers. This finding suggests that these patients have neither a generalized dysfunction of norepinephrine metabolism nor a defect in the central control of sympathetic function.

Possible risk factors in multiple sclerosis as found in a national twin study.

Fifty-one twin pairs, one or both members of each with multiple sclerosis (MS), were analyzed for extraneous events occurring prior to onset. Six patient groupings allowed comparison of events with and without the genetic factor. Comparison of monozygotic, discordant (one involved), and dizygotic discordant twins showed a difference. The affected members of the monozygotic pairs encountered prior to onset more birth anoxia, unusual infantile and childhood infections, major operations, and childbirth than did their unaffected twins, a difference not found when comparing dizygotic twins. The difference was most evident in the monozygotic discordant twins interviewed 30 years after onset of MS. If concordant (both involved) twins are analyzed by early vs late age of onset, these events occur at an older age in the late- and at younger age in the early-onset patients, suggesting that they may determine the age of onset of symptoms; they are suspected to be important in the causation of MS in genetically susceptible individuals, although the mechanism of their action is unknown.

Computed tomography and magnetic resonance imaging in adult-onset leukodystrophy.

Five clinically affected and nine at-risk members of a kindred with an autosomal dominant adult-onset leukodystrophy simulating chronic progressive multiple sclerosis were studied with computed tomography (CT) and magnetic resonance imaging (MRI). Computed tomographic scans showed white matter lucencies occurring earliest and most prominently in the frontoparietal region. The lesions were nondiscrete, diffuse, and bilaterally symmetric. These changes were more clearly visualized as areas of increased signal intensity with T2-weighted MRI. Magnetic resonance imaging also showed increased signal intensity in the brain stem, cerebellar white matter, or both of four patients. Both MRI and CT differentiated this entity from multiple sclerosis, but MRI was superior to CT in detailing the extent of white matter involvement.

Clinical and pathological features of an autosomal dominant, adult-onset leukodystrophy simulating chronic progressive multiple sclerosis.

OBJECTIVE: To study the clinical and pathological features of a kindred with an adult-onset autosomal dominant leukodystrophy. PATIENTS: Five symptomatic and nine asymptomatic at-risk members of the kindred. INTERVENTIONS: Subjects underwent detailed histories and general and neurologic examinations. Further evaluation included electroencephalography, evoked potentials, electromyography, autonomic testing, and analysis of serum, urine, and cerebrospinal fluid. One patient underwent sural nerve biopsy and analysis. Another, previously studied patient, underwent a limited autopsy. RESULTS: Cerebellar and pyramidal dysfunction began in the fourth and fifth decades of life; subtle autonomic symptoms were often present years earlier. Frontal lobe dysfunction and abnormalities of the central visual pathways were mild and of late onset. Sensorineural hearing loss was common. The peripheral nervous system was spared. Autopsy results of one patient revealed severe degeneration of the white matter at all levels of the neuraxis, but most prominent in the frontoparietal and cerebellar regions, with sparing of the subcortical U fibers. Histological and ultrastructural examinations failed to show evidence of a specific pathogenetic mechanism or etiology. CONCLUSION: This disorder seems to be a distinct type of hereditary leukodystrophy, but its exact nature remains unknown.

A family with histologically confirmed Alzheimer's disease.

A Canadian family comprising 51 members affected with Alzheimer's disease was evaluated clinically, histologically, and genetically. Ancestors were traced through eight generations, and 51 members were examined at the National Institute of Mental Health, Bethesda, Md. The pedigree is consistent with autosomal dominant inheritance. The effect of interrelatedness among some parents of affected individuals is unknown. In contrast to other studies, there was not an increased incidence of Down's syndrome, hematologic malignancy, or preponderance of affected females.

Familial motor neuron disease. Evidence for at least three different types.

Based on a clinical, pathologic, and genetic study of 14 families, at least three types of familial motor neuron disease can be distinguished, all apparently of autosomal dominant transmission. The first is characterized by rapid, progressive loss of motor function with predominantly lower motor neuron manifestations and a course lasting less than 5 years. Pathologic changes are limited to the anterior horn cells and pyramidal tracts. The second type is clinically identical to the first, but at autopsy additional changes are found in the posterior columns, Clarke's column, and spinocerebellar tracts. The third type is characterized by a much longer survival usually beyond 10 and after more than 20 years in affected family members but is otherwise similar to the second type.

Gilles de la Tourette syndrome: clinical and genetic studies in a midwestern city.

Clinical and genetic observations of Gilles de la Tourette syndrome were carried out on members of 14 families from the Minneapolis area. An unusual number of the families were of Jewish and other Eastern European ancestry, and in all but one of these families multiple members were affected. These observations parallel our earlier findings based on 21 families from the New York City area. Together with recent evidence indicating relative instability of a specific enzyme in some patients, these observations suggest that there is a genetically determined form of Gilles de la Tourette syndrome.

Twin study of Parkinson disease.

Zero concordance for Parkinson disease was found in the first 12 monozygotic twin pairs examined in an ongoing twin study. One co-twin (subject without Parkinson disease) had essential tremor, another had cerebral vascular disease, and a third was an alcoholic. Cigarette smoking appeared to be less frequent in the probands than in the co-twins (11.9 versus 16.1 pack-years). There was also evidence of premorbid personality differences between probands and co-twins dating back to late adolescence or early adult years. These preliminary findings suggest that genetic factors do not play a major role in the etiology of Parkinson disease and point to a prodromal onset of the disease as early as late adolescence or early adult life.

Gilles de la Tourette's syndrome: clinical, genetic, psychologic, and biochemical aspects in 21 selected families.

Eighty-one patients and relatives with Tourette's syndrome, members of 21 selected families, participated in a 1-day clinic. In 12 of the 13 Jewish families and six of the eight non-Jewish families, there were multiple members with motor and vocal tics by observation or history. Males predominated among those with persistent symptoms, but among those with spontaneous clearing, females predominated. Twelve propositi had troublesome sexual and aggressive impulses, differing only quantitatively from normal. No evidence of abnormality was found in plasma dopamine beta hydroxylase, or norepinephrine levels.

Multiple sclerosis in twins.

We studied 30 sets of twins in whom one or both was suspected of having multiple sclerosis (MS). In 24 pairs, a firm clinical diagnosis was made on each twin. Among these 24 pairs, 6 of 12 monozygotic twins were concordant for clinical MS, compared with 2 of 12 dizygotic twins. Of those over the age of 50, two of three monozygotic pairs were concordant, but neither of the two dizygotic twin pairs were concordant. Because ascertainment was primarily through public announcement, this series may be biased in favor of twins concordant for MS. The individuals within monozygotic concordant twin pairs exhibited wide differences in severity and age at onset of disease; the more recently affected twin tended to have a lower cerebrospinal fluid (CSF) IgG and a higher IgM level. Although the frequency of HLA-B7 and Dw2 in this twin population was high, the HLA makeup did not differ appreciably between concordant and discordant MS twins. Furthermore, the two DZ-concordant twins were HLA-nonidentical. Unexplained neurologic signs were found in three asymptomatic twins, and a high proportion of clinically normal twins had abnormalities of CSF immunoglobulins. These latter findings suggest a high incidence of subclinical MS in this population.

Progressive myoclonus epilepsy of Unverricht-Lundborg type: a clinical and molecular genetic study of a family from the United States with four affected sibs.

We describe clinical and molecular genetic data on a family from the United States in which four of five sibs are affected with progressive myoclonus epilepsy of Unverricht-Lundborg type. The gene for this disorder (EPM1) has previously been mapped to the distal region of chromosome 21. Molecular genetic results suggest that the disease gene in this family is linked to the same region of chromosome 21. Crossover events in the family help refine the gene localization by placing EPM1 between loci CBS and D21S112.

Central neurofibromatosis with bilateral acoustic neuroma: genetic, clinical and biochemical distinctions from peripheral neurofibromatosis.

Neurofibromatosis includes the common "peripheral" form and a recently documented "central" form. We describe the central form in 130 cases from 9 kindreds personally studied and 15 reported kindreds. Central neurofibromatosis with bilateral acoustic neuroma is an autosomal dominant disorder beginning about 20 years of age, accompanied by mild skin changes. In three kindreds with central neurofibromatosis, we measured nerve growth factor in serum by radioimmunoassay and radioreceptor assay. Only the antigenic activity of nerve growth factor was increased. In contrast, in peripheral neurofibromatosis, only the functional activity of nerve growth factor has been reported increased. Central and peripheral forms of neurofibromatosis are closely related but discrete diseases which appear to have separate alterations in nerve growth factor activity.

Dementia of the Alzheimer type: clinical and family study of 22 twin pairs.

We studied 22 twin pairs in which one or both twins had dementia of the Alzheimer type (DAT). In four twins, diagnosis was confirmed by autopsy. Seven monozygotic (MZ) pairs were concordant for DAT; 10 MZ pairs were discordant. Two dizygotic (DZ) pairs were concordant for DAT, and 3 DZ pairs were discordant. The current concordance rate was 41% for MZ twins and 40% for DZ twins. The study supports the belief that, etiologically, DAT cannot be entirely accounted for by a single autosomal dominant gene. The data also suggest that in certain genetic circumstances, disease expression may be delayed in females.

Parkinson's disease in 65 pairs of twins and in a set of quadruplets.

Among 43 monozygotic (MZ) and 19 dizygotic (DZ) pairs in which an index case had definite Parkinson's disease (PD), only one MZ pair was definitely concordant for PD. When pairs with questionable clinical features were included, 4 of 48 MZ and 1 of 19 DZ pairs were concordant. The frequency of PD in MZ cotwins of index cases with PD was similar to that expected in an unrelated control group matched for age and sex. Although we were unable to identify a single environmental agent, we conclude that the major factors in the etiology of PD are nongenetic.

Adrenergic dysfunction in hereditary adult-onset leukodystrophy.

We studied the pressor response to norepinephrine infusion in patients with an autosomal dominant adult-onset leukodystrophy. We also examined cardiovascular and catecholamine responses to insulin-induced hypoglycemia. A parallel shift to the left of the norepinephrine dose response curve, in conjunction with low baseline plasma norepinephrine levels, was consistent with denervation supersensitivity, suggesting a distal lesion of sympathetic noradrenergic neurons. Absence of the epinephrine response to insulin-induced hypoglycemia indicated that autonomic neuropathy was attended by severe adrenal medullary dysfunction.