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Biomedical subjects

L M Grimaldi

Publications and source records attributed to L M Grimaldi.

At least 73 records · Page 4Linked to original sources

The human-severe combined immunodeficiency myasthenic mouse model: a new approach for the study of myasthenia gravis.

We have established a new chimeric human-mouse model of myasthenia gravis in severe combined immunodeficiency mice, using human peripheral blood lymphocytes that survive in the mouse and produce specific antibodies that mediate pathological changes typical of human myasthenia gravis. Mice given peripheral blood lymphocytes from both anti-acetylcholine receptor (AChR) antibody-positive and -negative patients with myasthenia gravis showed circulating anti-acetylcholine receptor antibodies, deposition of human IgG at muscle end-plates, and simplification of the postsynaptic membrane, findings characteristic of human myasthenia gravis. Mice given human peripheral blood lymphocytes from healthy donors and simultaneously immunized with Torpedo acetylcholine receptor showed the same changes. This chimeric model, utilizing human cells to reproduce the immunopathological findings of human myasthenia gravis in a nonhuman environment, offers new opportunities to study immune regulation in autoimmunity.

Adult↗

Heterogeneity of autoantibodies in stiff-man syndrome.

Stiff-man syndrome is a rare neurological disorder characterized by skeletal muscle rigidity and spasms in which detection of circulating anti-glutamic acid decarboxylase antibodies has suggested an autoimmune pathogenesis. To further define the role of autoimmunity in the pathogenesis, we studied anti-glutamic acid decarboxylase antibodies, as well as organ- and non-organ-specific autoantibodies in 13 patients with stiff-man syndrome and 127 patients with other neurological disorders. Thyrogastric antibodies were more frequent in patients with stiff-man syndrome (46%) than in those with other neurological disorders (12%) (p < 0.05). Non-organ-specific antibodies were found at a similar frequency in the patients with stiff-man syndrome (61%) and those with other neurological disorders (65%). Islet-cell autoantibodies and anti-glutamic acid decarboxylase antibodies were more common in stiff-man syndrome patients (38% and 31%) compared to the patients with other neurological disorders (6% and 3%, respectively; p < 0.001). With the exception of 1 patient in the other neurological disorders group, anti-glutamic acid decarboxylase antibodies were always associated with islet-cell autoantibodies. Four patients with stiff-man syndrome had an associated solid tumor: 3 of them had antibodies recognizing a 125/130-kd protein and not glutamic acid decarboxylase.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

The fate of human peripheral blood lymphocytes after transplantation into SCID mice.

Human peripheral blood lymphocytes (hu-PBL) can be adoptively transferred by intraperitoneal injection into mice with severe combined immunodeficiency (SCID). The transplanted lymphocytes can produce immunoglobulin (Ig), respond to antigens, and survive for months in this chimeric model (hu-PBL SCID). However, whether the lymphocytes actually repopulate and reconstitute lymphoid structures and organs has been subject of some debate. To address this question and to characterize the hu-PBL SCID model better, we employed a novel technique for the identification of human cells in xenogeneic mice. We used fluorescence in situ hybridization (FISH) with a biotinylated DNA probe to all human centromeres. We demonstrated that FISH could be used to detect human cells when they accounted for less than 1% of human/mouse cell mixtures; it could also be employed for the identification and localization of individual human cells in tissue sections. By using FISH, we studied 31 SCID mice injected with 1.5 x 10(7)-4 x 10(7) hu-PBL via intravenous (i.v.) or intraperitoneal (i.p.) routes. In the 6 i.v.-injected mice, we found that the human cells were removed from the circulation into the lung within 1 h. In 22 of 25 i.p.-injected animals, 90-3716 micrograms/ml of human IgG was found in the sera at 3 to 13 weeks after transplantation (a.t.). Human cells colonized the peritoneal cavity and persisted for up to 13 weeks a.t. and, in the 12 mice studied, accounted for 4% to 57% of the cells in the peritoneal fluid. However, only rare, isolated human cells were found in the spleen, blood, bone marrow, lung or Peyer's patches. In 7 of 19 mice that received hu-PBL i.p. from Epstein-Barr virus-seropositive donors, we found masses of human cells usually beneath the peritoneal lining but sometimes infiltrating normal tissue. We conclude that FISH offers a simple means for accurate identification of human cells in the xenogeneic mouse. Although there is colonization of the peritoneal cavity in most mice, and development of lymphoid masses in some, there is no reconstitution of lymphoid structures and only minimal engraftment of lymphoid organs by human cells in conventionally-prepared hu-PBL SCID constructs.

Animals↗

Bilateral eighth cranial nerve neuropathy in human immunodeficiency virus infection.

A 21-year-old HIV-1 seropositive African man developed an acute febrile illness followed by a sudden sensorineural bilateral hearing loss. Neurophysiological studies demonstrated the bilateral involvement of both branches of the vestibulocochlear cranial nerves. Immunological studies revealed the presence of an ongoing central nervous system HIV-1 infection. A sural nerve biopsy showed the presence of inflammatory cells. We suggest HIV testing for all cases of sudden onset of bilateral hypoacusia.

Acquired Immunodeficiency Syndrome↗

Absence of oligoclonally restricted immunoglobulins in tears from multiple sclerosis patients.

To study the extent of systemic immunodysregulation in multiple sclerosis (MS) we measured immunoglobulin (Ig)G, A, and M levels and studied their migrational properties after agarose isoelectric focusing in serum, cerebrospinal fluid (CSF) and tear samples from 18 MS patients, 17 patients with other neurological diseases (OND), and tears and serum samples from ten normal controls (NC). A slight elevation of total IgG, IgM and IgA levels was detected in tears from patients with MS and OND compared to NC. Of the five patients (two MS, three OND) that showed IgG oligoclonal bands (OCB) in tears, only one MS patient showed unique bands in tears not seen in the paired CSF and serum. We never found IgA, and IgM OCB in serum, CSF or tear samples. Our results suggest that polyclonal Igs are systemically elevated during chronic neurological inflammatory diseases. Oligoclonal Ig in MS, although occasionally detectable in tears, is mainly confined to the central nervous system and appears restricted to class G.

Adolescent↗

Elevated alpha-tumor necrosis factor levels in spinal fluid from HIV-1-infected patients with central nervous system involvement.

To assess the role of alpha-tumor necrosis factor in the pathogenesis of central nervous system involvement during human immunodeficiency virus type 1 infection, we recorded clinical data and measured alpha-tumor necrosis factor levels in serum and cerebrospinal fluid samples from 45 patients infected with human immunodeficiency virus type 1, classified as group II/III (10), group IV A (5), group IV B (10), and group IV C-1 (20) of the Centers for Disease Control acquired immunodeficiency syndrome classification system and 42 controls. Alpha-tumor necrosis factor was above the limit of detection in only 3 of 15 sera and 3 of 15 cerebrospinal fluid samples from patients in group II/III and group IV A, whereas it was detected in 17 of 30 sera (p less than 0.05) and 22 of 30 cerebrospinal fluid (p less than 0.0002) samples from clinically more advanced patients (group IV B and group IV C-1). Alpha-tumor necrosis factor mean values were 21.5 pg/ml in sera and 50.0 pg/ml in cerebrospinal fluid from group IV B patients and 30.4 pg/ml in sera and 24 pg/ml in cerebrospinal fluid from group IV C-1 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS Dementia Complex↗

Cells producing antibodies specific for myelin basic protein region 70-89 are predominant in cerebrospinal fluid from patients with multiple sclerosis.

Cells secreting antibodies against guinea pig myelin and synthetic myelin basic protein (MBP) peptides were evaluated in cerebrospinal fluid (CSF) and blood from patients with multiple sclerosis (MS) and a variety of other neurological diseases (OND). The peptides used, reproducing amino acid sequences 1-20, 70-89, 108-126, or 157-166 of MBP, were selected on the basis of their hydrophilic and encephalitogenic properties. Low numbers of cells secreting IgG antibodies against myelin or each of the MBP peptides (about 1 per 50,000) were detected in peripheral blood, with no difference between MS and OND. In CSF, cells secreting IgG antibodies to MBP 70-89 were more frequently (p = 0.007) detected in patients with MS (1/380 IgG-secreting cells on average) than in patients with OND (1/2083 IgG-secreting cells on average). The frequencies of cells secreting antibodies against myelin or the three other MBP peptides were similar in MS and OND. Thus, evaluation of B cell immunity at the cellular level indicates that MBP 70-89 is an immunodominant B cell epitope in MS. It is not clear whether this intrathecal anti-MBP 70-89 IgG antibody response has any pathogenetic relevance in MS or is the result of myelin breakdown.

Adult↗

CSF oligoclonal banding pattern changes in a long-surviving SSPE patient treated with alpha-IFN.

Oligoclonal bands are a constant, non-modifiable feature of CSF examination in SSPE. We studied CSF oligoclonal IgG banding pattern in a long-surviving SSPE patient treated with serial courses of intrathecal alpha-IFN. alpha-IFN administration did not significantly modify the clinical status of the patient. Oligoclonal IgG banding pattern varied during the 58 month-long treatment. Oligoclonal bands disappeared at the end of the first course only to reappear during the third course, 2 years later, with a different electrophoretic pattern. We conclude that oligoclonal bands may transiently disappear from the CSF of long-surviving SSPE patients. Although alpha-IFN treatment induces no clinical improvement, it might affect the quality of Ig production.

Adult↗

Kappa light chain predominance in serum and cerebrospinal fluid from human immunodeficiency virus type 1 (HIV-1)-infected patients.

We measured kappa/lambda light chain ratios of Ig and IgG in 41 serum and 34 cerebrospinal fluid (CSF) samples from 47 patients at different clinical stages of human immunodeficiency virus type 1 (HIV-1) infection and in serum and CSF samples from control subjects. Both ratios were more elevated in HIV-1 seropositive subjects than controls. The elevation was more evident in samples from asymptomatic seropositive patients (ASP) than those from patients with acquired immunodeficiency syndrome (AIDS). In addition, there was a statistically significant elevation of Ig kappa/lambda ratios in ASP CSF compared to serum. We also delineated the light chain composition of oligoclonal IgG bands (OCB) by isoelectric focusing followed by immunofixation in CSF and serum samples from selected ASP and patients with AIDS who had neurological involvement. Five of six AIDS and all seven ASP samples had IgG OCB exclusively or predominantly of the kappa type. Four IgG OCB of the lambda type and one free lambda chain band were seen in CSF from a pediatric AIDS patient. The presence of an abnormally elevated kappa/lambda ratio correlated with the presence of IgG kappa OCB (p less than 0.02). We conclude that HIV-1 infection is associated with a kappa light chain predominance and with OCB mainly composed of kappa light chains.

Acquired Immunodeficiency Syndrome↗

Autoantibodies to glutamic acid decarboxylase (GAD) detected by an immuno-trapping enzyme activity assay: relation to insulin-dependent diabetes mellitus and islet cell antibodies.

It has recently been proposed that the islet 64,000 Mr protein autoantigen (64K) of insulin-dependent diabetes mellitus (IDDM) is glutamic acid decarboxylase (GAD). We evaluated, by means of a newly developed immunotrapping enzyme activity assay (ITEAA), the prevalence of circulating GAD-autoantibodies (Ab) in a large population of IDDM patients (n = 168), blood donors (n = 87) and non-diabetic autoimmune patients (n = 40). The latter two groups were used as controls. Overall, GAD-Ab were found in 22% of IDDM patients, but in none of the two control groups (P = 0.007). These specificities were invariably associated with islet cell antibodies (ICA) (31.6% in IDDM with ICA vs 0 in IDDM without ICA, P = 0.0001), and this prevalence was higher in sera with high titer ICA (54.5% in IDDM with ICA greater than 80 JDF-units vs 22.6% of IDDM with ICA 5-80 JDF units; P = 0.002). Moreover, GAD-Ab were associated with the female sex (P = 0.002) and the concomitant presence of thyroid and/or gastric antibodies (P = 0.002). No correlation was observed between GAD-Ab and age of the patients, duration of IDDM, or associated non-organ specific antibodies. Our study indicates that GAD-Ab measured by ITEAA are: (1) detected in a proportion of IDDM patients; (2) strongly associated with ICA; (3) preferentially found in IDDM female patients with autoimmune polyendocrine serology; and (4) detected with lower frequency than that reported for 64K-Ab in IDDM.

Adolescent↗

Discontinuous distribution of IgG oligoclonal bands in cerebrospinal fluid from multiple sclerosis patients.

To test the effect of sampling on the detection of immunoglobulin (Ig) cerebrospinal fluid (CSF) abnormalities, we analyzed the first and last 1 ml fraction of 10 ml obtained during a single CSF removal from 27 multiple sclerosis (MS) patients and six patients with other neurological diseases. IgG index, hyperbolic function, and IgG synthesis rate decreased between the first and the last CSF aliquot. Discordant results were found in 4/27 (15%) MS patients. In 2/27 (7.5%) clinically definite MS patients, the number of CSF oligoclonal bands (OCB) decreased between the first and the last fraction. In one of the two patients, the three OCB visualized in the first fraction were not found in the last. We conclude that fractionated sampling may partially account for the absence of OCB in the CSF of some definite MS patients.

Adult↗

Isoelectric focusing herpes simplex virus-gB overlay study in brainstem encephalitis.

We report a case of herpetic brainstem encephalitis (HBE) retrospectively diagnosed in adult patient. Conventional immunovirological studies failed to disclose the etiology of this patient's affection. An isoelectric focusing-antigen overlay (IEF-O) technique showed that the target of one of the four cerebrospinal fluid oligoclonal bands was herpes simplex virus (HSV)-1 glycoprotein B, indicating a specific anti-HSV immunoresponse restricted to the CNS. IEF-O may represent a useful support for in vivo diagnosis of HBE.

Adult↗

Immunological study in newborns at risk for HIV-1 infection.

We have performed an isoelectric focusing study (IEF) to detect the presence of oligoclonal bands (OB) in serum and in 5 of the correspondent cerebrospinal fluid (CSF) from 14 HIV-seropositive mothers and their newborns. CB were also searched in serum from 4 newborns every 3 months over a period of 12 months. OB were present in 8/14 sera and in 3/3 CSF obtained from the mothers; CSF OB were different from the correspondent serum indicating an intrathecal synthesis. OB were also visualized in serum, but not in CSF, from 3 newborns studied at birth: two of them died respectively at 4 and 5 months of age. One of the 4 newborns that were serially studied showed the appearance of OB at 12 months of age. A comparative study between sera obtained at the moment of delivery from the mother and her newborn showed that oligoclonal banding patterns were superimposable. Our data indicated that: 1) the IgG forming OB in the newborn's serum derive from a passive filtration from mother's serum; 2) the presence of OB seems to be an unfavourable prognostic feature in infants at risk for HIV-1 infection.

Acquired Immunodeficiency Syndrome↗

Antibody against EBV in CSF from HIV-1 and HTLV-I infected patients.

We have measured the levels of antibody (ab) against different Epstein-Barr virus (EBV) antigens in 10 AIDS patients, 7 HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients and 20 control subjects. We found comparable serum levels of anti-EBV ab between AIDS patients, HAM/TSP patients and control subjects. By contrast, anti-EBV ab were present in the large majority of CSF from AIDS patients (70%) and HAM/TSP patients (60%) but only in 15% of control group. Our results support a synergistic role of EBV in retroviral infections of the central nervous system.

Acquired Immunodeficiency Syndrome↗

Isoelectric focusing studies of serum and cerebrospinal fluid in patients with antecedent poliomyelitis.

The post-poliomyelitis syndrome (PPS) refers to symptoms of new weakness, fatigue, and pain years after recovery from acute poliomyelitis. Oligoclonal IgG bands have been reported in the cerebrospinal fluid (CSF) from PPS patients, suggesting that the syndrome is immune mediated or caused by persistent viral infection. We studied 15 paired serum and CSF samples and 6 unpaired CSF samples from a total of 21 patients with a prior history of poliomyelitis. Quantitative immune studies failed to show evidence for increased intrathecal IgG production relative to patients with noninflammatory central nervous system (CNS) disease. We found definite oligoclonal IgG bands in the CSF from only 1 patient, who also carried a diagnosis of multiple sclerosis. An isoelectric focusing poliovirus antigen overlay study showed evidence that suggested a CNS-specific antipoliovirus immune response in only 1 patient. Our results fail to support a dysimmune or persistent viral cause for post-poliomyelitis progressive muscular atrophy or PPS.

Adult↗

Tumor necrosis factor in serum and cerebrospinal fluid of patients with multiple sclerosis.

We measured levels of alpha-tumor necrosis factor (alpha-TNF) in cerebrospinal fluid and serum samples from 50 drug-free patients with multiple sclerosis, 25 patients with other neurological diseases, 27 patients with non-neurological diseases, and 10 normal subjects. The most elevated levels of alpha-TNF were found in patients with inflammatory or autoimmune diseases. Comparable serum levels of alpha-TNF were detected in normal control subjects, patients with multiple sclerosis, and patients with degenerative neurological diseases. In patients with multiple sclerosis, alpha-TNF levels were also unrelated to time elapsed between the occurrence of clinical exacerbation and the time of sample collection. Only 3 patients with chronic progressive multiple sclerosis had detectable alpha-TNF in the cerebrospinal fluid. Our data do not support a role for elevated levels of circulating alpha-TNF in the maintenance of the disease. However, we cannot rule out the possibility that a transient elevation of alpha-TNF triggers the cellular events leading to demyelination in multiple sclerosis.

Adolescent↗

Restricted heterogeneity of antibody to gp120 and p24 in AIDS.

Neurologic complications and cerebrospinal fluid (CSF) abnormalities are common in AIDS. We found that a substantial number of AIDS patients with neurologic involvement had oligoclonal IgG bands in CSF and sera by IEF. Using an IEF-Ag overlay technique, anti-gp120 antibody activity was demonstrated more frequently than anti-p24 antibody activity. These antibody activities exhibited restricted heterogeneity of their IEF pattern; this restriction may contribute to the relatively low titers of neutralizing antibody found in AIDS sera. None of the CSF and serum oligoclonal bands showed anti-HIV antibody activity, suggesting that they are directed against opportunistic agents or result from immunodysregulation.

Acquired Immunodeficiency Syndrome↗