Antineuronal Nuclear Autoantibody Type 1/Anti-Hu-Associated Opsoclonus Myoclonus and Epilepsia Partialis Continua: Case Report and Literature Review.

BACKGROUND: Opsoclonus-myoclonus syndrome is a rare clinical condition that has been associated with neuroblastoma. There are few reported examples of ANNA-1/anti-Hu antibodies in children with neuroblastoma and opsoclonus-myoclonus, all in children aged less than three years of age. METHODS: We describe the new onset of focal seizures without alteration of consciousness and opsoclonus-myoclonus in an 11-year-old girl with ANNA-1/anti-Hu positivity and a paraspinal ganglioneuroblastoma. A systematic review of the literature of children with ANNA-1/anti-Hu positivity and malignancy was also performed. RESULTS: Fourteen patients were identified, eight of whom had opsoclonus-myoclonus. Although epilepsia partialis continua has been described in association with several neuronal autoantibodies, association with ANNA-1/anti-Hu has not been reported. CONCLUSIONS: We describe epilepsia partialis continua in a child with ANNA-1/anti-Hu antibodies and neuroblastoma. Testing for antineuronal antibodies should be considered in children presenting with either opsoclonus-myoclonus or epilepsia partialis continua.

Three sensitive assays do not provide evidence for circulating HuD-specific T cells in the blood of patients with paraneoplastic neurological syndromes with anti-Hu antibodies.

Anti-Hu antibody-associated paraneoplastic neurological syndromes (Hu-PNSs) are severe and often precede the detection of a malignancy, usually small-cell lung cancer. In Hu-PNS, it is hypothesized that neuronal cells are destroyed by T cells targeted against HuD, a protein expressed by small-cell lung cancer cells and neurons. There is only limited evidence for the existence of HuD-specific T cells. To detect these T cells in the blood of Hu-PNS patients, we employed 3 highly sensitive assays that included T cell stimulation with dendritic cells (DCs) to specifically expand the number of any HuD-specific T cells. A total of 17 Hu-PNS patients were tested with 1 or more of the following 3 assays: (1) tetramer staining after stimulation of T cells with conventionally generated DCs (n = 9), (2) interleukin (IL)-13 enzyme-linked immunosorbent spot (ELISpot; n = 3), IL-4 and IL-5 and interferon (IFN)-γ multiplex cytokine bead array (n = 2) to assay cytokine production by T cells after stimulation with conventionally generated DCs, and (iii) IFN-γ ELISpot and tetramer staining after T cell stimulation with accelerated co-cultured DCs (n = 11). No circulating HuD-specific T cells were found. We suggest that either autoaggressive T cells in Hu-PNS are not targeted against HuD or that their numbers in the blood are too low for detection by highly sensitive techniques.

Blood-based biomarkers can differentiate ulcerative colitis from Crohn's disease and noninflammatory diarrhea.

BACKGROUND: Blood gene expression profiling has been used in several studies to identify patients with a number of conditions and diseases. A blood test with the ability to differentiate Crohn's disease (CD) from ulcerative colitis (UC) and noninflammatory diarrhea would be useful in the clinical management of these diseases. METHODS: Affymetrix U133Plus 2.0 GeneChip oligonucleotide arrays were used to generate whole blood gene expression profiles for 21 patients with UC, 24 patients with CD, and 10 control patients with diarrhea, but without colonic pathology. RESULTS: A supervised learning method (logistic regression) was used to identify specific panels of probe sets which were able to discriminate between UC and CD and from controls. The UC panel consisted of the four genes, CD300A, KPNA4, IL1R2, and ELAVL1; the CD panel comprised the four genes CAP1, BID, NIT2, and NPL. These panels clearly differentiated between CD and UC. CONCLUSIONS: Gene expression profiles from blood can differentiate patients with CD from those with UC and from noninflammatory diarrheal disorders.

Successful diagnosis of a combined thymic epithelial tumor by endobronchial ultrasound-guided transbronchial needle aspiration.

INTRODUCTION: Endobronchial ultrasound-guided tranbronchial needle aspiration (EBUS-TBNA) can be applied to not only the determination of the clinical stages of lung cancer, but also the diagnosis of lymphadenopathies such as lymphoma and sarcoidosis. CASE REPORT: We report the successful diagnosis of a combined thymic epithelial tumor in a 68-year-old female by EBUS-TBNA. The patient presented with a 6-month history of dysesthesia in bilateral legs. Chest computed tomography revealed a 5.5 cm-tumor with heterogeneous enhancement in the superior and anterior mediastinum. The serum levels of ProGRP and NSE were elevated and anti-Hu antibody was positive at the time of diagnosis. A biopsy by EBUS-TBNA revealed histological evidence of a combined thymic epithelial tumor consisting of small cell neuroendocrine carcinoma and thymic carcinoma. Chemo-radiotherapy reduced the tumor remarkably in size, but the patient's neurologic symptoms remained. CONCLUSION: This case suggests that EBUS-TBNA is a safe and useful technique for the diagnosis of paratracheal mediastinal tumors.

Small cell carcinoma with paraneoplastic polyneuropathy and tumor embolization: a case report and literature review.

Although small cell cancer of the lung may have protean manifestations, tumor embolization and inability to identify the primary sites are unusual features. We present a patient with anti-Hu antibody-associated paraneoplastic sensory polyneuropathy and tumor embolism diagnosed by endovascular biopsy to be due to small cell cancer, the primary site of which was not evident. To our knowledge, this patient represents only the second individual to be described with tumor embolization complicating small cell cancer and reminds clinicians of the extended spectrum of this disease.

Myasthenia gravis with presynaptic electrophysiologic abnormalities.

OBJECTIVES: To describe the clinical, serologic, and electrophysiologic features of 2 patients with myasthenia gravis (MG), who also had presynaptic electrophysiologic abnormalities. METHODS: Case reports. RESULTS: Two patients developed clinical symptoms consistent with MG. They lacked autonomic symptoms or signs, and their reflexes were not absent. Acetylcholine receptor antibody studies were positive, but assays for voltage-gated calcium channel antibodies were negative. Low-amplitude baseline compound muscle action potentials combined with large incremental responses immediately after exercise were consistent with a presynaptic disorder. Thymic pathology in 1 patient was characteristic of autoimmune MG showing lymphoid follicular hyperplasia. No underlying malignancy was found in either patient. CONCLUSIONS: Patients with MG may rarely have presynaptic electrophysiologic abnormalities. This may occur even in the absence of the typical clinical and serologic features of the Lambert-Eaton syndrome. It is possible that there is another antibody present that is modulating presynaptic acetylcholine release.

Low level anti-Hu reactivity: A risk marker for small cell lung cancer?

BACKGROUND: Previous experimental and laboratory studies have implicated antibodies against Hu proteins (anti-Hu) as a potential marker for small cell lung cancer (SCLC); there are no estimates of the association between anti-Hu and SCLC using a population-based design. METHODS: We used stored plasma specimens to evaluate anti-Hu reactivity in relationship to small cell lung cancer in a population-based case-control study. Using Western Blot analysis, we measured anti-Hu reactivity against recombinant Hu family member, HuD, in plasma samples from 41 SCLC cases and 79 controls individually matched for age, race, sex, and smoking status (never, past, current). We analyzed the association between anti-Hu reactivity and SCLC using conditional logistic regression. RESULTS: Anti-Hu reactivity was associated with SCLC, both before and after adjustment for amount of smoking. We observed a smoking-adjusted odds ratio of 3.2 (95% confidence interval from 0.98 to 13.4) comparing subjects above 1800 units (the lower limit of the second tertile of the distribution among antibody positive controls) to subjects with lower reactivity. We also found suggestive evidence in follow-up of our cases that anti-Hu above 1800 units was related to longer-term survival from SCLC. The present research is the first report of anti-Hu reactivity and SCLC in a population-based study. CONCLUSIONS: Given the suggestive evidence in this study, prospective analyses to examine whether anti-Hu reactivity might predict risk of developing SCLC, or whether anti-Hu reactivity could serve as an early marker for SCLC, may be warranted.

Paraneoplastic chronic demyelinating neuropathy and Lambert-Eaton myasthenic syndrome associated with multiple anti-neural antibodies and small-cell lung cancer.

Lambert-Eaton myasthenic syndrome (LEMS) developed in a patient with presumed chronic inflammatory demyelinating polyneuropathy (CIDP) and negative chest CT. Since antibodies against both Hu and voltage-gated calcium channel (VGCC) were detected, repeated chest CT was performed, which eventually showed a pulmonary mass lesion. Biopsy revealed small cell lung cancer (SCLC) indicating the importance of repeated chest CT in LEMS even when an existing autoimmune-like disease and negative CT may suggest an autoimmune origin. This is the first report of paraneoplastic CIDP and LEMS associated with anti-Hu, anti-VGCC and SCLC.

Molecular detection of neuron-specific ELAV-like-positive cells in the peripheral blood of patients with small-cell lung cancer.

BACKGROUND: n-ELAV (neuronal-Embryonic Lethal, Abnormal Vision)-like genes belong to a family codifying for onconeural RNA-binding proteins. Anti-Hu-antibodies (anti-Hu-Ab) are typically associated with paraneoplastic encephalomyelitis/sensory neuropathy (PEM/PSN), and low titres of anti-Hu-Ab, were found in newly diagnosed Small Cell Lung Cancer (SCLC). The aim of this study is to develop a sensitive and quantitative molecular real-time PCR assay to detect SCLC cells in peripheral blood (PB) through nELAV-like transcripts quantification. METHODS: Peripheral blood samples from 25 SCLC untreated patients and 12 healthy blood donors were investigated by real-time PCR. mRNA levels for HuB (ELAV2), HuC (ELAV3) and HuD (ELAV4) were measured in peripheral blood samples with an absolute quantification method using plasmid dilutions as calibration curves. RESULTS: A statistically significant increase in mRNA expression level was detected for HuB and HuD in SCLC patients as compared with samples from healthy blood donors. After establishing cut off values based on the level of expression in control samples, 28% of the SCLC samples were positive for HuD expression. Overall 60% of the SCLC displayed increased level of HuD or HuB transcripts. CONCLUSION: Our preliminary results suggest that neuron-ELAV mRNA are detectable in peripheral blood of SCLC patients using real-time quantitative PCR.

Paraneoplastic opsoclonus-myoclonus ataxia associated with non-small-cell lung carcinoma.

We report a case of the paraneoplastic opsoclonus-myoclonus ataxia syndrome in a patient with non-small cell lung carcinoma, which represents a highly unusual association. The patient simultaneously manifested both severe neurologic symptoms and widely metastatic disease, complicating her treatment.

Central hypoventilation as the presenting symptom in Hu associated paraneoplastic encephalomyelitis.

Central hypoventilation is usually caused by ischaemic or neoplastic lesions of the medulla and upper cervical spinal cord. An autoimmune disorder is not usually considered in the differential diagnosis of this syndrome. We retrospectively identified 14 patients from our database of 202 patients with Hu antibodies who presented with brainstem symptoms. Three were admitted to hospital because of central hypoventilation. All underwent intubation and mechanical ventilation. They could breathe properly while they were awake but suffered deep apnoeas during sleep. Two died, but one is still alive requiring ventilatory assistance during sleep. Autopsy was performed in one of the patients which showed severe inflammatory infiltrates and neuronal loss in the medulla. All patients had normal brain imaging studies and the cause of central hypoventilation was an unsolved problem until Hu antibodies were determined.

No evidence for circulating HuD-specific CD8+ T cells in patients with paraneoplastic neurological syndromes and Hu antibodies.

AIM: In paraneoplastic neurological syndromes (PNS) associated with small cell lung cancer (SCLC) and Hu antibodies (Hu-PNS), Hu antigens expressed by the tumour hypothetically trigger an immune response that also reacts with Hu antigens in the nervous system, resulting in tumour suppression and neuronal damage. To gain more insight into the hypothesized CD8(+ )T cell-mediated immune pathogenesis of these syndromes, we searched for circulating HuD-specific CD8(+) T cells in a large cohort of Hu-PNS patients and controls. PATIENTS AND METHODS: Blood was tested from 43 Hu-PNS patients, 31 Hu antibody negative SCLC patients without PNS and 54 healthy controls. Peripheral blood mononuclear cells (PBMC) were stimulated with HuD protein-spanning peptide pools (15-mers) and individual HuD-derived peptides (9-mers) and analysed by cytokine flow cytometry and interferon-gamma ELISPOT-assays. Additionally, HuD-based Class I HLA multimers were used to visualize HuD-specific CD8(+) T cells. RESULTS: No HuD-specific CD8(+ )T cells could be detected in the blood of Hu-PNS patients or controls. CONCLUSIONS: Our results do not support a role for HuD-specific CD8(+) T cells in Hu-PNS. Further studies should focus on the detection of circulating HuD-specific CD4(+ )T cells and examine the antigen specificity of T cells in affected tissues.

Hu and Yo antibodies have heterogeneous avidity.

Onconeural antibodies such as anti-Hu and anti-Yo may be important in the pathogenesis of paraneoplastic neurological syndromes. The avidity of these antibodies is not known. In this study, we compared the avidity of Hu and Yo antibodies both at single time points and over a time range of 2 months to 6 years. The avidity of Yo and Hu antibodies differed among the patients, but anti-Yo generally had higher avidity than anti-Hu. Whether Yo antibodies are more pathogenic than Hu antibodies are presently unknown.

Acute motor and sensory neuronopathy associated with small-cell lung cancer: a clinicopathological study.

A 48-year-old Chinese woman developed ascending motor paralysis while visiting Japan, leading to tetraplegia and respiratory failure over 2 weeks. The patient's course was complicated by anoxic encephalopathy. Nerve conduction studies revealed a severely decreased amplitude of compound muscle action potentials and a sural nerve biopsy specimen showed findings consistent with axonal-form Guillain-Barr6 syndrome. An autopsy, excluding the brain, demonstrated small-cell lung cancer that was not detected clinically, axonal-dominant degeneration in the nerve roots and distal peripheral nerves, and the loss of both myelin and axons in the dorsal spinal column. The spinal anterior horn cells were severely decreased and were accompanied by astrocytic reaction in all spinal segments with lymphocytic infiltration. A limited examination of the dorsal root ganglia did not show Nageotte nodules, but the infiltration of T cells was observed. Although the clinical course mimicked axonal-form Guillain-Barré syndrome, the autopsy demonstrated both sensory and motor neuronal involvement, as well as small-cell lung cancer. Although anti-Hu and antiganglioside antibodies were negative in the patient's serum, the para-neoplastic mechanism might have damaged the anterior horn and dorsal root ganglia cells, which subsequently led to secondary axonal degeneration. There has been a report on a case of paraneoplastic subacute motor neuronopathy, but the acute course described here has not been reported before.

BR serine/threonine kinase 2: a new autoantigen in paraneoplastic limbic encephalitis.

We describe a new antigen, BR serine/threonine kinase 2 (BRSK2), identified by an antibody present in the serum of a patient with limbic encephalitis and small-cell lung cancer (SCLC). Patient's serum immunolabeled the neuronal cytoplasm and, less intense, the neuropil of rat brain but did not immunoreact with other rat tissues with the exception of testis. Immunoblots of rat brain homogenate identified several immunoreactive bands in the range of 88-82 kDa and a weaker broad band of 47-43 kDa. Probing a rat hippocampus expression library with the patient's serum resulted in the isolation of BR serine/threonine kinase 2 (BRSK2), a protein (also know as SAD1B kinase) preferentially expressed in the brain and testis and implicated in neuronal polarization as well as synaptic development. Eluted IgG from the BRSK2 clone gave a similar immunolabeling than the patient's serum by immunohistochemistry and immunoblot of rat brain and testis. BRSK2 antibodies reacted with two SCLC from patients without paraneoplastic neurological syndromes. No anti-BRSK2 antibodies were found in the serum of 50 patients with SCLC without PNS, 19 with limbic encephalitis without onconeural antibodies, 50 with anti-Hu antibodies and several paraneoplastic neurological syndromes, including 14 with limbic encephalitis, and 160 with a variety of non-paraneoplastic neurological syndromes. Our study suggests BRSK2 may be an autoantigen involved in the pathogenesis of SCLC-associated limbic encephalitis.