Ri antibodies in patients with breast, ovarian or small cell lung cancer determined by a sensitive immunoprecipitation technique

Initial screening for neuronal autoantibodies and their putative impact on survival in patients with small-cell lung cancer

INTRODUCTION

Small-cell lung cancer (SCLC) may be associated with neuronal autoantibodies and paraneoplastic neurological syndromes. It has been suggested that neuronal autoantibodies, especially antineuronal nuclear antibody type 1 (Hu) autoantibodies, are associated with longer survival of patients with SCLC. The objective of this study was to determine the frequency and distribution of neuronal autoantibodies at the time of diagnosis of SCLC patients and assess survival rates in relation to autoimmunity.

METHODS

In this retrospective study, serum from 40 patients with biopsy-proven SCLC at the time of diagnosis was studied prior to treatment. The sera originated from a cancer registry at the Oncology Department, Vejle Hospital from 2007 to 2010. The sera were analyzed blindly to clinical status for the presence of neuronal autoantibodies. Medical records were reviewed for neurological symptoms.

RESULTS

Neuronal autoantibodies were detected in 22/40 (55%) of the SCLC patients. A broad range of neurological symptoms was recorded in 28/40 (70%) patients, of which 14/28 (50%) were positive for neuronal autoantibodies. The most frequently detected autoantibodies were Hu (7/40, 17.5%) followed by GAD65 (6/22, 15.0%). Striational and P/Q- or N-type voltage-gated calcium channel antibodies were less common, with each found in five patients (12.5%). Eight patients (20%) had coexisting autoantibodies. Autoantibody-positivity was not associated with survival.

CONCLUSION

Neuronal autoantibodies were at time of diagnosis found in approximately half of the treatment-naïve SCLC patients. Neither autoantibody positivity at diagnosis nor neurological manifestations correlated with survival and their clinical importance requires further studies in larger, prospective cohorts.

Evaluation of potential prevalence of onconeural antibodies in women with breast cancer

OBJECTIVE

Aim: To analyse onconeural antibodies in the blood serum of breast cancer patients without neurological symptoms..

PATIENTS AND METHODS

Materials and Methods: The study included 48 women with breast cancer. Paraneoplastic Neurologic Syndromes 12 Ag (IgG) Euroline by EUROIMMUN test was used to determine onconeural antibodies: anti-Hu, anti-Yo, anti-Ri, anti-CV2, anti-Ma/anti-Ta, anti-amphiphysin, anti-recoverin, anti-SOX1, anti-tytin, anti-zic4, anti-GAD65 and anti-Tr (DNER).

RESULTS

Results: The conducted analysis revealed the presence of onconeural antibodies such as: anti-recoverin, anti-CV2, anti-Zic4, anti-SOX1, anti-MA2/Ta and antititin in blood serum of women with breast cancer.

CONCLUSION

Conclusions: Further analysis may allow the assessment of the possible clinical usefulness of these determinations.

Changing landscape in the field of paraneoplastic neurology: Personal perspectives over a 35-year career

Paraneoplastic neurologic syndromes are a group of rare disorders that have fascinated neurologists for more than a century. The discovery in the 1980s that many of these disorders occurred in association with antibodies against neuronal proteins revived the interest for these diseases. This chapter first traces the history of the paraneoplastic neurologic syndromes during the era that preceded the discovery of immune mechanisms and then reviews the immunologic period during which many of these syndromes were found to be associated with antibodies against intracellular onconeuronal proteins and pathogenic cytotoxic T-cell mechanisms. Alongside these developments, investigations on the antibody-mediated disorders of the peripheral nervous system, such as the myasthenic syndromes or neuromyotonia, provided suggestions for the study of the central nervous system (CNS) syndromes. These converging areas of research culminated with the groundbreaking discovery of a new category of CNS disorders mediated by antibodies against neuronal surface proteins or receptors. These disorders are not always paraneoplastic, and the understanding of these syndromes and mechanisms has changed the landscape of neurology and neurosciences.

The role of the laboratory in the expanding field of neuroimmunology: Autoantibodies to neural targets

Accelerated identification of autoantibodies associated with previously idiopathic neurological disease has provided insights into disease mechanisms, enhanced understanding of neurological function, and opportunities for improved therapeutic interventions. The role of the laboratory in the expanding field of neuroimmunology is critical as specific autoantibody identification provides guidance to clinicians in diagnosis, prognosis, tumor search strategies, and therapeutic interventions. The number of specific autoantibodies identified continues to increase and newer testing strategies increase efficiencies in the laboratory and availability to clinicians. The need for broadly targeted efficient testing is underscored by the variability in clinical presentation and tumor associations attributable to a specific autoantibody, and conversely the various autoantibody specificities that can be the cause of a given clinical presentation. While many of the antineural antibodies were first recognized in the setting of neoplastic disease, idiopathic autoimmune neurological disease in the absence of underlying tumor is increasingly recognized. Appropriation of therapeutic modalities used to treat autoimmune disease to treat these autoantibody mediated neurological diseases has improved patient outcomes. Interaction between clinicians and laboratorians is critical to our understanding of these diseases and optimization of the clinical benefits of our increasing knowledge in neuroimmunology.

NOVA1 regulates hTERT splicing and cell growth in non-small cell lung cancer

Alternative splicing is dysregulated in cancer and the reactivation of telomerase involves the splicing of TERT transcripts to produce full-length (FL) TERT. Knowledge about the splicing factors that enhance or silence FL hTERT is lacking. We identified splicing factors that reduced telomerase activity and shortened telomeres using a siRNA minigene reporter screen and a lung cancer cell bioinformatics approach. A lead candidate, NOVA1, when knocked down resulted in a shift in hTERT splicing to non-catalytic isoforms, reduced telomerase activity, and progressive telomere shortening. NOVA1 knockdown also significantly altered cancer cell growth in vitro and in xenografts. Genome engineering experiments reveal that NOVA1 promotes the inclusion of exons in the reverse transcriptase domain of hTERT resulting in the production of FL hTERT transcripts. Utilizing hTERT splicing as a model splicing event in cancer may provide new insights into potentially targetable dysregulated splicing factors in cancer.

Expression of the onconeural protein CDR1 in cerebellum and ovarian cancer

Cerebellar degeneration related protein 1 (CDR1) is expressed in the cerebellum, and CDR1 antibodies have been associated with paraneoplastic cerebellar degeneration (PCD). In this study, we examined CDR1 expression in cerebellum and in ovarian and breast tumors, as well as the intracellular localization of CDR1 in cancer cells in culture. CDR1 was strongly expressed in the cytosol and dendrites of Purkinje cells and in interneurons of the molecular layer in cerebellum. CDR1 was also present in ovarian and breast tumors, as well as in ovarian and breast cancer cell lines, but was not present in normal breast or ovarian tissue. In cells overexpressing CDR1, CDR1 localized close to the plasma membrane in a polarized pattern at one edge. CDR1 was strongly expressed on the outer surface, apparently in filopodias or lamellipodias, in cells endogenously expressing CDR1. Overexpression of CDR1 showed a 37 and a 45 kDa band in western blot. The 37-kDa isoform was present in 16 ovarian cancer lysates, while the 45-kDa isoform was only found in three ovarian cancer patients. The presence of CDR1 in ovarian cancer was not associated with PCD. CDR1 antibodies were only found in serum from one patient with PCD and ovarian tumor with metastases. Therefore, CDR1 is probably not a marker for PCD. However, CDR1 may be associated with cell migration and differentiation.

Derivation of a bronchial genomic classifier for lung cancer in a prospective study of patients undergoing diagnostic bronchoscopy

BACKGROUND

The gene expression profile of cytologically-normal bronchial airway epithelial cells has previously been shown to be altered in patients with lung cancer. Although bronchoscopy is often used for the diagnosis of lung cancer, its sensitivity is imperfect, especially for small and peripheral suspicious lesions. In this study, we derived a gene expression classifier from airway epithelial cells that detects the presence of cancer in current and former smokers undergoing bronchoscopy for suspect lung cancer and evaluated its sensitivity to detect lung cancer among patients from an independent cohort.

METHODS

We collected bronchial epithelial cells (BECs) from the mainstem bronchus of 299 current or former smokers (223 cancer-positive and 76 cancer-free subjects) undergoing bronchoscopy for suspected lung cancer in a prospective, multi-center study. RNA from these samples was run on gene expression microarrays for training a gene-expression classifier. A logistic regression model was built to predict cancer status, and the finalized classifier was validated in an independent cohort from a previous study.

RESULTS

We found 232 genes whose expression levels in the bronchial airway are associated with lung cancer. We then built a classifier based on the combination of 17 cancer genes, gene expression predictors of smoking status, smoking history, and gender, plus patient age. This classifier had a ROC curve AUC of 0.78 (95% CI, 0.70-0.86) in patients whose bronchoscopy did not lead to a diagnosis of lung cancer (n = 134). In the validation cohort, the classifier had a similar AUC of 0.81 (95% CI, 0.73-0.88) in this same subgroup (n = 118). The classifier performed similarly across a range of mass sizes, cancer histologies and stages. The negative predictive value was 94% (95% CI, 83-99%) in subjects with a non-diagnostic bronchoscopy.

CONCLUSION

We developed a gene expression classifier measured in bronchial airway epithelial cells that is able to detect lung cancer in current and former smokers who have undergone bronchoscopy for suspicion of lung cancer. Due to the high NPV of the classifier, it could potentially inform clinical decisions regarding the need for further invasive testing in patients whose bronchoscopy is non diagnostic.

Electroencephalography of autoimmune limbic encephalopathy

There is an increasing recognition of autoimmune limbic encephalopathy with the hope for earlier diagnosis and expedited and improved treatment. Although antibody testing remains the definitive clinical diagnostic feature, the presentation of a rapid dementia, behavioral changes, and seizures leads to investigation using cerebral imaging, electroencephalography, and cerebrospinal fluid to confirm the diagnosis and also to exclude similar disorders. The electroencephalographer may be asked to comment on the types of electroencephalography abnormality and provide input toward the diagnosis of limbic encephalopathy. This article reviews the literature on limbic paraneoplastic and nonparaneoplastic encephalopathies, providing descriptions and examples of the electroencephalography findings. Typically, there are patterns of slow theta and delta activity and different patterns of temporal and frontal epileptic activity.

Clinical and organizational factors in the initial evaluation of patients with lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

This guideline is intended to provide an evidence-based approach to the initial evaluation of patients with known or suspected lung cancer. It also includes an assessment of the impact of timeliness of care and multidisciplinary teams on outcome.

METHODS

The applicable current medical literature was identified by a computerized search and evaluated using standardized methods. Recommendations were framed using the approach described by the Guidelines Oversight Committee of the American College of Chest Physicians. Data sources included MEDLINE and the Cochrane Database of Systematic Reviews.

RESULTS

Initial evaluation should include a thorough history and physical examination; CT imaging; pulmonary function tests; and hemoglobin, electrolyte, liver function, and calcium levels. Additional testing for distant metastases and paraneoplastic syndromes should be determined on the basis of these results. Paraneoplastic syndromes may have an adverse impact on cancer treatment, so they should be controlled rapidly with the goal of proceeding with definitive cancer treatment in a timely manner. Although the relationship between timeliness of care and survival is difficult to quantify, efforts to deliver timely care are reasonable and should be balanced with the need to attend to other dimensions of health-care quality (eg, safety, effectiveness, efficiency, equality, consistency with patient values and preferences). Quality care will require multiple disciplines. Although it is difficult to assess the impact, we suggest that a multidisciplinary team approach to care be used, particularly for patients requiring multimodality therapy.

CONCLUSIONS

The initial evaluation of patients with lung cancer should include a thorough history and physical examination, pulmonary function tests, CT imaging, basic laboratory tests, and selective testing for distant metastases and paraneoplastic syndromes.

Neurological paraneoplastic syndromes in lung cancer patients

Lung cancer is recognized among the most frequent causes of paraneoplastic neurological syndromes (PNS). Neurological syndromes in subjects with systemic malignancy remain a clinical and diagnostic challenge. The aim of the study was to evaluate the frequency of NPS, their clinical manifestation and association with onconeural antibodies in patients with lung cancer. Fifty patients hospitalized with the diagnosis of PNS participated in the study. Neurological evaluation consisted of the Rankin scale (mRS), the Barthel index (BI), and testing for the presence of onconeural antibodies by means of indirect immunofluorescence, as screening, and Western blotting as confirmation. The majority of lung cancer patients (64%) aged 62 ± 10 had NPS symptoms. Their neurological condition and daily living activities were reasonable: mRS (1.0; 0.0-4.0) and BI (100; 7.4-100) scores. Classical PNS were found in 30% of cases and included sensory neuropathy (16%), paraneoplastic cerebellar degeneration (12%) as the most frequent symptoms. Autoimmune reaction was observed in 42% of lung cancer patients and in 20% was represented by well-characterized onconeural antibodies. Anti-Hu antibody was identified as the most frequent. In conclusion, PNS signs in lung cancer patients have both classical and non-classical features. In the course of SCLC only well-characterized onconeural antibodies were identified. The presence of well-characterized onconeural antibodies is strongly associated with classical features of PNS.

Lung cancer-induced paraneoplastic syndromes

PURPOSE OF REVIEW

Paraneoplastic syndromes occur commonly in patients with lung cancer, especially cancers of neuroendocrine origin. The syndromes can be the first clinical manifestation of malignant disease or a harbinger of cancer recurrence. To update the knowledge that would facilitate the care of lung cancer patients with paraneoplastic syndromes, this review focuses on the epidemiology, pathogenesis, clinical features, and current management of the more common and clinically relevant syndromes.

RECENT FINDINGS

Certain combinations of clinical signs and symptoms (endocrine, neurologic, immunologic, dermatologic, metabolic, constitutional, and hematologic) are associated with lung carcinoma as a manifestation of the secretion of cytokines and hormones by these cells or as an associated immunologic response. These syndromes can be categorized by common causative mechanisms: hormonal syndromes, autoimmune syndromes, and other syndromes of less clear cause. Recent advances in medical technology have allowed better understanding of these syndromes and the development of novel diagnostic and therapeutic tools.

SUMMARY

Increased awareness of paraneoplastic syndromes associated with lung cancer should lead to the earlier recognition and diagnosis of malignancies, thereby improving the overall prognosis of patients and alleviating associated comorbidities. Despite the recent advances in recognizing and treating paraneoplastic syndromes, many questions remain to be answered.

Small-cell lung cancer-associated autoantibodies: potential applications to cancer diagnosis, early detection, and therapy

Small-cell lung cancer (SCLC) is the most aggressive lung cancer subtype and lacks effective early detection methods and therapies. A number of rare paraneoplastic neurologic autoimmune diseases are strongly associated with SCLC. Most patients with such paraneoplastic syndromes harbor high titers of antibodies against neuronal proteins that are abnormally expressed in SCLC tumors. These autoantibodies may cross-react with the nervous system, possibly contributing to autoimmune disease development. Importantly, similar antibodies are present in many SCLC patients without autoimmune disease, albeit at lower titers. The timing of autoantibody development relative to cancer and the nature of the immune trigger remain to be elucidated. Here we review what is currently known about SCLC-associated autoantibodies, and describe a recently developed mouse model system of SCLC that appears to lend itself well to the study of the SCLC-associated immune response. We also discuss potential clinical applications for these autoantibodies, such as SCLC diagnosis, early detection, and therapy.

Antibody to CCDC104 is associated with a paraneoplastic antibody to CDR2 (anti-Yo)

Patients with cancer may develop paraneoplastic neurological syndromes (PNS) in which onconeural antibodies are important diagnostic findings. As the functional role of onconeural antibodies is largely unknown, insight gained by identifying associated antibodies may help to clarify the pathogenesis of the PNS. In this study, we identified patients with Yo antibodies who also had antibodies to an uncharacterized protein called coiled-coil domain-containing protein 104 (CCDC104). We found a significant association between CCDC104 and Yo antibodies (4 of 38, 10.5%), but not other onconeural antibodies (0 of 158) (P = 0.007, Fisher's exact test). The prevalence of CCDC104 antibodies was approximately similar in patients with cancer (8 of 756, 1.1%) and in healthy blood donors (2 of 300, 0.7%). CCDC104 antibodies were not associated with PNS, as this was found in only two of the ten CCDC104-positive patients. The CCDC104 protein, whose function is unknown, is expressed in various human tissues, including the brain, and is localized mainly to the nucleus, but is also found in the cytoplasm. The association between Yo and CCDC104 antibodies may indicate functional similarities.

Onconeural antibodies in sera from patients with various types of tumours

PURPOSE

We assessed the frequency and levels of onconeural antibodies in 974 patients with various types of tumours, but without apparent paraneoplastic neurological syndromes (PNS).

PATIENTS AND METHODS

We included patients with the following tumours: 200 small-cell lung cancer (SCLC) patients, 253 breast cancer patients, 182 ovarian cancer patients, 266 uterine cancer patients and 73 thymoma patients, as well as 52 patients with PNS and cancer and 300 healthy blood donors. Sera were screened for amphiphysin, CRMP5, Hu, Ma2, Ri and Yo antibodies using a multi-well immunoprecipitation technique.

RESULTS

The most frequently detected antibodies were Hu followed by CRMP5. Ma2, Yo, amphiphysin and Ri antibodies were less common, but each was found at similar frequencies. Onconeural antibodies were present at similar levels in sera from the PNS control group and from cancer patients. Hu antibodies were rare in cancers other than SCLC. CRMP5 was the only antibody found in patients with thymoma and this antibody was more common among patients with thymoma than in other tumour patients. With one exception, coexisting antibodies were only found in patients with SCLC. The presence of onconeural antibodies in SCLC patients was not associated with prolonged survival.

CONCLUSION

Onconeural antibodies are associated with various types of tumours suggesting that all antibodies should be included in the serological screening for possible PNS. The levels of onconeural antibody are not sufficiently sensitive to discriminate between cancer patients with PNS and those without.

Proteasome antibodies in patients with cancer or multiple sclerosis

Proteasome antibodies were detected by enzyme-linked immunosorbent assay in two of the 45 (4.4%) patients with lung cancer, 0 of the 39 patients with breast cancer and six of the 51 (11.8%) patients with ovarian cancer. Six of the 47 (12.8%) patients with relapsing remitting multiple sclerosis had proteasome antibodies, as well as two of the 100 (2%) blood donors. Significant higher odds ratios compared to the blood donors were found for the patients with ovarian cancer (OR: 6.4; 95% CI: 1.1-68) and multiple sclerosis (OR: 7.1; 95% CI: 1.2-74). There was no association between proteasome antibodies and metastases or onconeural antibodies. The antibodies showed reactivity to 23, 25 and 27 kD proteins of the 20S proteasome using Western blot. The increased prevalence of proteasome antibodies in patients with ovarian cancer or multiple sclerosis may reflect cellular damage and release of intracellular antigens. Whether the antibodies take part in the clearance of released proteasomes and thus participate in the pathogenesis of cancer or autoimmune disease is not known.

CRMP5 antibodies in patients with small-cell lung cancer or thymoma

The collapsin response mediator protein 5 (CRMP5) antibody is usually associated with paraneoplastic neurological syndrome (PNS) and small-cell lung cancer (SCLC) or thymoma. The objective of this study was to assess the frequency of CRMP5 antibodies in patients with such tumours and to see if the presence of antibodies was associated with prognosis in these cancers. A multi-well adapted immunoprecipitation assay using radiolabelled recombinant CRMP5 protein, produced by coupled in vitro transcription/translation, was used for the detection of CRMP5 antibodies. Sera from 200 patients with SCLC, 73 patients with thymoma and myasthenia gravis (MG) and from 300 healthy blood donors were examined for CRMP5 antibodies. Positive sera were also examined by immunofluorescence and immune blots. The serological results were compared with disease severity of the patients with thymoma or SCLC. CRMP5 antibodies were detected in 10/200 (5%) of the SCLC, 9/73 (12%) of the thymomas and in 2/300 (0.6%) of the healthy controls by immunoprecipitation. The antibodies were less frequently detected by immunofluorescence or immune blots. There was no significant correlation between CRMP5 antibodies and disease severity. CRMP5 antibodies are more than twice as frequent, and the antibody levels are higher in patients with thymoma and MG than in patients with SCLC. The antibodies are correlated to these tumours, but not to disease severity.

Paraneoplastic neurological syndromes and onconeural antibodies: clinical and immunological aspects

Paraneoplastic neurological syndromes (PNS) are infrequent disorders that are associated with cancer. The syndromes are highly heterogeneous and often affect several areas of the nervous system. Among the most well-known syndromes are paraneoplastic encephalomyelitis, cerebellar degeneration, sensory neuronopathy, and Lambert-Eaton myastenic syndrome. There are various associated tumors, in particular small cell lung cancer, cancer of the breast and ovary, and thymoma. The onset of neurological symptoms often precedes the cancer diagnosis, and the recognition of a paraneoplastic syndrome should lead to immediate search for cancer. The etiology of the paraneoplastic syndromes is believed to be autoimmune. Antibodies to onconeural antigens, expressed in the tumor of the affected individual and in normal neurons, are found in many of the patients. These antibodies are useful markers for paraneoplastic etiology. The pathogenesis of the PNS is uncertain, but cellular immune responses are thought to be the main effector mechanism. The cornerstone of therapy is the identification and treatment of the underlying malignancy. In some of the disorders, immunosuppressive therapy is of additional benefit. The prognosis of the different PNS varies depending on the level of affection and the degree of neuronal death.