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J B Posner

Publications and source records attributed to J B Posner.

At least 55 records · Page 3Linked to original sources
PubMed1997

Anti-Hu antibodies in patients with small-cell lung cancer: association with complete response to therapy and improved survival.

PURPOSE: Anti-Hu antibodies (HuAb) recognize antigens expressed by neurons and small-cell lung cancer (SCLC). High titers of HuAb were initially reported in serum from patients with paraneoplastic encephalomyelitis/sensory neuropathy (PEM/SN) and SCLC. Preliminary studies have indicated that some SCLC patients without PEM/SN harbor low titer of HuAb in their serum, and that the SCLC of these patients may grow more indolently. Based on these observations, we conducted a multicenter prospective study of SCLC patients without PEM/SN to determine the incidence and prognostic implications of HuAb. METHODS: Serum samples were collected at diagnosis of SCLC in 196 patients without PEM/SN. HuAb were determined by immunoblot of purified recombinant HuD antigen. RESULTS: HuAb were detected in 32 (16%) of the 196 patients. Of the 170 patients who received treatment for the tumor, 27 (16%) were HuAb positive. HuAb was associated with limited disease stage (59.3% v 38.6%; P = .047), complete response to therapy (55.6% v 19.6%; P < .001), and longer survival (14.9 v 10.2 months; P = .018). In a logistic regression analysis, HuAb status was an independent predictor of complete response induction. The probability of achieving a complete response was more than five times higher in HuAb-positive than in HuAb-negative patients (odds ratio, 5.4; 95% confidence interval, 1.71 to 16.89; P = .004). Cox multivariate analysis indicated that HuAb status was not independently associated with survival. CONCLUSION: The presence of HuAb at diagnosis of SCLC is a strong and independent predictor of complete response to treatment. This feature accounts for the association between HuAb and longer survival.

Antibodies, Neoplasm↗
PubMed1997

Steroid myopathy in cancer patients.

We prospectively evaluated 15 adult cancer patients being treated with adrenocorticosteroids (steroids) to determine the frequency and time course of "steroid myopathy." Nine (60%) developed clinically detectable proximal muscle weakness that, in six, was severe enough to interfere with activities of daily living. Proximal muscle weakness developed within 15 days in eight of nine patients and was significantly related to the cumulative dose of steroid. Eight of nine patients with proximal muscle weakness, and two of six without such weakness, experienced a significant decline in respiratory function, leading to symptomatic dyspnea in four patients of the former group. In three patients who could be followed for more than 3 months off steroids, there was either improvement or resolution of the weakness and, when present, of the respiratory impairment. Steroid myopathy is a common complication among cancer patients receiving steroids. It can often affect respiratory function even when proximal limb muscles remain strong. Clinical recognition is important since steroid myopathy can lead to increased morbidity and may be reversible with reduction or discontinuation of steroids.

Adult↗
PubMed1997

Paraneoplastic syndromes affecting the nervous system.

Paraneoplastic syndromes can affect virtually any portion of the nervous system. Most paraneoplastic syndromes are believed to be caused by an autoimmune reaction to an "onconeural" antigen shared by the cancer and the nervous system. The immune reaction may retard growth of the cancer, but it also damages the nervous system. Specific autoantibodies found in some individual paraneoplastic syndromes are usually associated with specific tumors. Neurological disorders, clinically and pathologically identical to paraneoplastic syndromes, may occur in some patients without cancer, but paraneoplastic antibodies are not found in these patients. The diagnosis of a paraneoplastic syndrome is based on its increased incidence in patients with cancer, the occasional response of the neurological syndrome to treatment of the underlying cancer, or the presence of specific autoantibodies. Some paraneoplastic syndromes respond to treatment of the underlying cancer or to immunosuppression but, for most syndromes, no effective treatment exists.

Autoantibodies↗
PubMed1997

A controlled study of serum anti-locus ceruleus antibodies in REM sleep behavior disorder.

The newly identified association of human nonnarcoleptic rapid eye movement (REM) sleep behavior disorder (RBD) with human leukocyte antigen (HLA) DQw1 class II genes raises the possibility that RBD may arise from autoimmune mechanisms. Two recent case reports involving postmortem brain stem histochemical analyses in elderly males with RBD identified severe monoaminergic cell loss in the locus ceruleus (LC). Thus, we designed a study to detect anti-LC antibodies in RBD. Ten Caucasian males (mean age, 66 years) with polygraphically confirmed RBD (n = 5, idiopathic RBD: n = 5, RBD with Parkinson's disease), but without narcolepsy, idiopathic hypersomnia, or autoimmune disease, were recruited for this study, along with 10 Caucasian male controls (mean age, 63 years) without a history of sleep disorder or autoimmune disease. In a blinded design, sera from the RBD patients and their controls were tested against human LC and other brainstem neurons. Brainstem tissue was obtained from autopsies of neurologically normal individuals. The presence of anti-LC antibodies was examined using immunohistochemistry on brainstem sections. Sections incubated with sera from normal individuals and sera from patients with paraneoplastic antineuronal antibodies (anti-Hu and anti-Ri) were used as controls. No reactivity with LC or any other brainstem area was identified with sera from either RBD patients or their controls, or from the other group of normal individuals. In contrast, sera from patients with paraneoplastic anti-Hu and anti-Ri antibodies reacted strongly with nuclei of LC and other brainstem neurons, sparing the nucleoli, and reacted to a lesser extent with the cytoplasm of these neurons. Therefore, it is unlikely that human RBD is associated with anti-LC antibodies. However, an autoimmune process in RBD has not been excluded by this study.

Aged↗
PubMed1996

Inflammatory infiltrates and complete absence of Purkinje cells in anti-Yo-associated paraneoplastic cerebellar degeneration.

We studied the nervous systems and tumors of two patients with anti-Yo-associated paraneoplastic cerebellar degeneration (PCD). In both patients the underlying tumor was an ovarian adenocarcinoma that expressed Yo antigens and contained extensive infiltrates of lymphocytes and plasma cells. The major central nervous system findings were a complete loss of cerebellar Purkinje cells with Bergmann astrogliosis. One patient had inflammatory infiltrates in the medulla and pons, and moderate axonal loss and demyelination involving the spinal cord. No inflammatory infiltrates were identified in the cerebrum, cerebellum or brain-stem of the other patient. Using quantitative Western blot analysis, deposits of anti-Yo IgG could not be demonstrated in the nervous system, possibly as a result of the loss of cells expressing Yo antigens. The detection of the anti-Yo antibody as a common marker of PCD in one patient with inflammatory infiltrates and another without infiltrates suggests that some PCD pathologically classified as "non-inflammatory" may represent a final burn-out stage of a cellular immune-mediated disorder. Our findings indicate that Purkinje cells are the main, but not necessarily the exclusive, targets of this disorder.

Adenocarcinoma, Papillary↗
PubMed1996

Pitfalls in the diagnosis of autoantibodies associated with paraneoplastic neurologic disease.

We studied the sera of 15 patients with Sjögren's syndrome using the Western blot technique for the presence of anti-Ro and anti-Hu (type 1 antineuronal nuclear autoantibody [ANNA-1]). All sera reacted with Ro-52 protein. Two of the Sjögren sera reacted with 38-kd bands on Western blots of rat cerebellar homogenate, resembling anti-Hu immunoreactivity. However, when reacted with purified human Purkinje cells or purified recombinant HuD protein, none of the sera immunoreacted with the Hu antigens. We recommend the use of either a recombinant Hu protein or the combination of immunohistochemistry and Western blot of purified human neuronal preparations to identify paraneoplastic antibodies. This approach will prevent the unnecessary workup for suspected lung cancer.

Animals↗
PubMed1995

Major histocompatibility proteins, anti-Hu antibodies, and paraneoplastic encephalomyelitis in neuroblastoma and small cell lung cancer.

BACKGROUND: Patients with neuroendocrine-related tumors and paraneoplastic encephalomyelitis (PEM) or paraneoplastic sensory neuronopathy (PSN) develop high titers of antibodies, called anti-Hu, against neuronal proteins expressed in their tumors, usually small cell lung cancer (SCLC). These tumors appear to be more indolent than those not associated with anti-Hu antibodies. The aims of this study were to determine 1) if patients with neuroblastoma (NB) also have anti-Hu antibodies, 2) the correlation between antibody titer and survival, and 3) if coexpression of Hu antigens and major histocompatibility proteins (MHC) by the tumor correlates with the development of anti-Hu associated PEM/PSN: METHODS: Using immunohistochemistry and Western blot analysis, the sera of 109 patients with NB whose neurologic condition was concealed at the time of the study were examined for the presence of anti-Hu antibodies. The expression of Hu antigens and MHC proteins in 50 nonselected NB and 26 SCLC (16 known to be from seropositive and 10 from seronegative patients) was examined using immunohistochemistry. RESULTS: Four Stage 4 NB patients were seropositive and had longer survival (median 86 months) than 71 seronegative patients in the same age group and with the same tumor stage (median survival, 28.5 months). Seventy-eight percent of NB and all SCLC expressed Hu antigens. Overall, 17 of 20 tumors from seropositive patients expressed both Hu and MHC Class I proteins, but only 4 of 30 tumors from seronegative patients expressed both proteins (P < 0.0001). CONCLUSIONS: 1) Some patients with NB develop anti-Hu antibodies; a search for that type of tumor is indicated in seropositive children, 2) most NBs and SCLCs express Hu antigens but only a few are associated with anti-Hu antibodies, and 3) Class I MHC expressed by some Hu antigen-bearing tumors may play a role in the development of anti-Hu associated PEM/PSN:

Adult↗
PubMed1995

Hu antigens: reactivity with Hu antibodies, tumor expression, and major immunogenic sites.

HuD, a human neuronal RNA-binding protein, was the first identified member of a family of antigens that also includes HuC and Hel-N1 (Hu antigens). The serum of all patients with anti-Hu-associated paraneoplastic encephalomyelitis and sensory neuronopathy react with HuD and Hel-N1, but the reactivity with HuC is unknown. In the current study we examined (1) the reactivity of anti-Hu sera with HuD, HuC, and Hel-N1; (2) the expression of HuD, HuC, and Hel-N1 messenger RNA in small-cell lung cancer of patients with and those without paraneoplastic encephalomyelitis/sensory neuronopathy; (3) the correlation between anti-Hu serum reactivity with these three Hu antigens and the type of neurological symptoms; and (4) the major immunogenic sites of HuD. Our findings indicate that all anti-Hu sera react with HuD, HuC, and Hel-N1. However, only HuD is expressed in the small-cell lung cancer tumors, indicating that among the three Hu antigens, HuD appears to play a central role in triggering the anti-Hu immune response. No differences were identified regarding the reactivity of the anti-Hu antibodies with HuD, HuC, and Hel-N1 and the spectrum of neurological symptoms presented by the patients. Study of the major immunogenic sites of HuD resulted in the identification of two major immunodominant regions with at least two distinct epitopes recognized by the serum of all patients with anti-Hu-associated paraneoplastic encephalomyelitis/sensory neuronopathy.

Adolescent↗
PubMed1995

Immunization with the paraneoplastic encephalomyelitis antigen HuD does not cause neurologic disease in mice.

Paraneoplastic encephalomyelitis/paraneoplastic sensory neuronopathy (PEM/PSN) associated with small cell lung cancer is characterized by high serum and CSF titers of anti-neuronal (anti-Hu) antibodies and by intrathecal synthesis of anti-Hu IgG. A pathologic role for the anti-Hu antibodies in PEM/PSN is further suggested by reported intraneuronal accumulation of the antibodies in the nervous system of PEM/PSN patients at autopsy. We immunized SJL/J mice, Lewis rats, and Hartley guinea pigs with purified recombinant HuD fusion protein. In spite of high-titer anti-HuD antibodies, neurologic and pathologic examination of the animals was normal. Apparent uptake of purified IgG by neurons in the brain proved to be artifactual.

Animals↗
PubMed1995

Paraneoplastic peripheral neuropathy.

Paraneoplastic peripheral neuropathies are not common. They are out-numbered by the far more common peripheral neuropathies that occur either as a direct result of the cancer (metastases) or its treatment (usually chemotherapy). Nevertheless, paraneoplastic peripheral neuropathies are important because they may be the first sign of an otherwise occult cancer and/or because they may substantially disable the patient even when the cancer itself is asymptomatic. Paraneoplastic disorders are sometimes marked by the presence of autoantibodies that react with proteins both in the underlying cancer and in the nervous system. Their discovery may lead to an early diagnosis and potential cure of the underlying cancer.

Autoantibodies↗
PubMed1994

Immunological and pathological study of anti-Ri-associated encephalopathy.

A patient with high titers of the anti-Ri antibody died 3 years after a progressive course with ataxia, opsoclonus, dementia, and peripheral neuropathy. At autopsy, no tumor was found. The nervous system exhibited severe Purkinje cell loss and contained perivascular and interstitial inflammatory infiltrates, particularly involving the brainstem. B and CD4 cells predominated in the perivascular spaces and CD8 cells in the interstitial infiltrates. Complement reactivity and natural killer cells were present and predominated in areas with more intense inflammatory infiltrates. Deposits of IgG were detected in the cytoplasm and nuclei of some neurons, particularly those in the brainstem tegmentum. The proportion of anti-Ri IgG in the total IgG extracted from various areas of the brain, serum, and cerebrospinal fluid was determined by quantitative western blot analysis. Anti-Ri reactivity was identified in immunoblots of all regions of the brain, but it predominated in basis pontis and dorsal mesencephalon. Our findings support the hypothesis of an autoimmune basis for the disorder and suggest that an antibody-mediated mechanism may play a role in its pathogenesis.

Aged↗