Pentamidine for Prophylaxis against Pneumocystis jirovecii Pneumonia in Pediatric Oncology Patients Receiving Immunosuppressive Chemotherapy.

Pneumocystis jirovecii pneumonia is a life-threatening opportunistic infection in children receiving immunosuppressive chemotherapy. Without prophylaxis, up to 25% of pediatric oncology patients receiving chemotherapy will develop Pneumocystis jirovecii pneumonia. Trimethoprim-sulfamethoxazole is the preferred agent for prophylaxis against Pneumocystis jirovecii pneumonia. Pentamidine may be an acceptable alternative for pediatric patients unable to tolerate trimethoprim-sulfamethoxazole. A retrospective review was conducted of pediatric oncology patients who received ≥1 dose of pentamidine for Pneumocystis jirovecii pneumonia prophylaxis between January 2007 and August 2014. Electronic medical records were reviewed to determine the incidence of breakthrough Pneumocystis jirovecii pneumonia or discontinuation of pentamidine associated with adverse events. A total of 754 patients received pentamidine prophylaxis during the period. There were no cases of probable or proven Pneumocystis pneumonia, and 4 cases (0.5%) of possible Pneumocystis pneumonia. The incidence of possible breakthrough Pneumocystis pneumonia was not significantly different between subgroups based on age (<12 months [1.7%] versus ≥12 months [0.4%], P = 0.3), route of administration (aerosolized [0%] versus intravenous [1.0%], P = 0.2), or hematopoietic stem cell transplant status (transplant [0.4%] versus no transplant [0.8%], P = 0.6). Pentamidine was discontinued due to an adverse drug event in 23 children (3.1%), more frequently for aerosolized than for intravenous administration (7.6% versus 2.2%, respectively, P = 0.004). Intravenous or inhaled pentamidine may be a safe and effective second-line alternative for prophylaxis against Pneumocystis jirovecii pneumonia in children with cancer receiving immunosuppressive chemotherapy or hematopoietic stem cell transplantation.

Paraneoplastic Disorders.

PURPOSE OF REVIEW: Paraneoplastic neurologic syndromes target specific areas of the nervous system with pathogenic autoantibodies or T-cell responses. Each syndrome conveys a risk of particular tumors. Expanded paraneoplastic antibody testing has led to improved diagnosis but created challenges involving appropriate interpretation of test results. RECENT FINDINGS: Peripheral nervous system paraneoplastic disorders such as myasthenia gravis and Lambert-Eaton myasthenic syndrome involve pathogenic autoantibodies. Recently, the pathogenic mechanisms and antigens of these disorders have been further elucidated. Paraneoplastic syndromes associated with onconeuronal antibodies, such as anti-Hu, have strong cancer associations and limited response to treatment. Autoimmunity to central nervous system membrane proteins, such as the N-methyl-D-aspartate (NMDA) receptor or leucine-rich, glioma inactivated 1 (LGI1), defines an expanding group of disorders with better prognosis and more variable cancer associations. In these diseases, the autoantibodies are either proven to be or are potentially pathogenic. An animal model of anti-NMDA receptor encephalitis will allow novel treatments to be developed. Autoantibodies to intracellular synaptic antigens, such as glutamic acid decarboxylase 65 (GAD65), are associated with diverse disorders such as stiff person syndrome, and the pathophysiology of these diseases is unclear. SUMMARY: Paraneoplastic disorders have diverse clinical manifestations, including weakness, sensory neuronopathy, encephalitis, epilepsy, and psychosis. Proper use of antibody testing may assist with diagnosis. Treatment may require immunotherapy and tumor treatment.

The role of the immune system in neurofibromatosis type 1-associated nervous system tumors.

With the recent development of new anticancer therapies targeting the immune system, it is important to understand which immune cell types and cytokines play critical roles in suppressing or promoting tumorigenesis. The role of mast cells in promoting neurofibroma growth in neurofibromatosis type 1 (NF1) patients was hypothesized decades ago. More recent experiments in mouse models have demonstrated the causal role of mast cells in neurofibroma development and of microglia in optic pathway glioma development. We review here what is known about the role of NF1 mutation in immune cell function and the role of immune cells in promoting tumorigenesis in NF1. We also review the therapies targeting immune cell pathways and their promise in NF1 tumors.

Paraneoplastic and autoimmune encephalopathies.

Immune-mediated encephalitis is an increasingly recognized cause of neurologic dysfunction including behavioral change, psychosis, movement disorders, seizures, autonomic instability, and coma. Associated antineuronal antibodies are of two main subtypes, those targeting neuronal cell surface antigens, which are pathogenic, and nonpathogenic antibodies targeting intracellular antigens. Antibody identification aids in screening for underlying cancers and prediction of outcome. Cancer is found most commonly with antibodies targeting intracellular neural components. Certain cancers, such as small-cell lung carcinoma, and breast and ovarian cancer are particularly immunogenic. When cancer is detected, oncologic treatment should be followed with immunotherapy. Nonpathogenic antibody disorders respond poorly to treatment, whereas pathogenic antibodies predict a favorable response to immune treatment. If no cancer is identified, then ongoing surveillance is recommended for 5 years after detection of most antineuronal antibodies.

Frequent abnormalities of the immune system in gliomas and correlation with the WHO grading system of malignancy.

AIM: To investigate the cellular and humoral immunity status of gliomas, and their association with the WHO grading system. MATERIAL AND METHODS: We have conducted a case-control study of 49 patients with gliomas and 30 healthy controls. We used ELISA assays, radial immunodiffusion, indirect immunofluorescence, latex test and flow cytometry assays to estimate preoperative in serum the immunological profile. RESULTS: Patients with glioma had significantly reduced amounts of IL2 (p=0.000), TNF-a (p=0.033), IgG (p=0.011), IgA (p=0.027),C4 (p=0.026) ,CD3+ (p=0.001), CD4+ (p=0.000), CD8+ (p=0.002), ratio CD4/CD8 (p=0.000), CD19+ (p=0.04) and elevated IL10 (p=0.05) compared with healthy controls. No statistically significant differences were observed concerning viral agents, total NK cells, IgM, IgE, IL16, granzyme-b, RF, ANA, ENA, anti-dsDNA and anti-cardiolipin antibodies. A higher WHO grade, after controlling for age and gender, was associated with decreased number of CD3+ (p=0.011), CD4+ (p=0.015), CD8+ (p=0.048) and ratio CD4/CD8 (p=0.027), as well as with decreased IL2 (p=0.018), C4 (p=0.02), and IgG (p=0.05). IL2 and CD4+ counts were significant predictors of grade. CONCLUSIONS: A shift from Th1 to Th2, a CD3+ and CD19+ lymphocytopenia, a diminished fraction CD4/CD8 and a reduced amount of immunoglobulins and complement were observed in the patients with gliomas. A higher WHO grade of the tumor was associated with greater impairments of immunity. Since defects of both humoral and cellular immunity were equally observed and significant predictors of grade were assessed, a preoperative evaluation of the immune system of patients with gliomas is being proposed.

Potential role of immunosenescence in cancer development.

The incidence and prevalence of most cancers increase with age. The reasons for this may include tumor escape mechanisms and decreased immunosurveillance, but most are caused by the time required for carcinogenesis, according to most scientists. The immune system is a unique mechanism of defense against pathogens and possibly cancers; however, there is a body of evidence that the immune system of the aged is eroded, a phenomenon termed immunosenescence. There is a growing interest in immunosenescence and how it may contribute to the increased number of cancers with aging. Each arm of the immune system, innate and adaptive, is altered with aging, contributing to increased tumorigenesis. Understanding the contribution of immunosenescence to cancer development and progression may lead to better interventions for the elderly.

Potential cancer gene therapy by baculoviral transduction.

Many different types of therapeutic genes, ranging from suicide genes, tumor suppressor genes, to genes encoding tumor-specific antigens, have been successfully delivered by insect baculoviral vectors to treat tumours in animal models. These encouraging results observed to date underscore the potential for using the non-human baculovirus to combat human cancer. The present review outlines the advances in this area and highlights the challenges behind translating the findings from research with baculoviral vectors into clinical practice.

Leucoencephalopathy, transverse myelopathy, and peripheral neuropathy in association with glutamic acid decarboxylase-65 (GAD) antibodies in children with cancer.

Neurologic toxicity may occur as a direct effect of cancer and its therapy or indirectly because of a dysfunctional immune system. The authors report the development of axonal neuropathy, myelopathy, and leucoencephalopathy associated with glutamic acid decarboxylase-65 (GAD) antibodies in 4 children with progressive cancer who were heavily pretreated. Three patients with refractory leukemia and 1 with Ewing sarcoma developed paraplegia with sensory level and dorsal column dysfunction. Three developed leucoencephalopathy and 1 died of neurologic disease. All had high serum titers of GAD antibodies during the progressive phase of the illness, and the antibody levels returned to normal with the stability of the neurologic disease. Three survivors are showing gradual recovery. This syndrome of central and peripheral nervous system toxicity may have resulted from chemotherapy toxicity or from immune dysfunction, as suggested by the high GAD antibody titers.

Glycosphingolipid antigens in neural tumor cell lines and anti-glycosphingolipid antibodies in sera of patients with neural tumors.

To characterize biomarkers in neural tumors, we analyzed the acidic lipid fractions of 13 neural tumor cell lines using enzyme-linked immunoabsorbent assay (ELISA) and high-performance thin-layer chromatography (HPTLC) immunostaining. Sulfated glucuronosyl glycosphingolipids (SGGLs) are cell surface molecules that are endowed with the Human Natural Killer-1 (HNK-1) carbohydrate epitope. These glycosphingolipids (GSLs) were expressed in all cell lines with concentrations ranging from 210 to 330 ng per 2 x 10(6) cells. Sulfoglucuronosyl paragloboside (SGPG) was the prominent species with lesser amounts of sulfoglucuronosyl lactosaminyl paragloboside (SGLPG) in these tumor cell lines as assessed by quantitative HPTLC immunostaining. Among the gangliosides surveyed, GD3 and 9-O-acetylated GD3 (OAc-GD3) were expressed in all tumor cell lines. In contrast, fucosyl-GM1 was not found to restrict to small cell lung carcinoma cells. In addition, we have analyzed serum antibody titers against SGPG, GD3, and OAc-GD3 in patients with neural tumors by ELISA and HPTLC immunostaining. All sera had high titers of antibodies of the IgM isotype against SGPG (titers over 1:3,200), especially in tumors such as meningiomas, germinomas, orbital tumors, glioblastomas, medulloblastomas, and subependymomas. Serum in a patient with subependymomas also had a high anti-SGGL antibody titer of the IgG and IgA types (titers over 12,800). The titer of anti-GD3 antibody was also elevated in patients with subependymomas and medulloblastomas; the latter cases also had a high titer of antibody against OAc-GD3. Our data indicate that certain GSL antigens, especially SGGLs, GD3, and OAc-GD3, are expressed in neural tumor cells and may be considered as tumor-associated antigens that represent important biomarkers for neural tumors. Furthermore, antibody titers in sera of patients with these tumors may be of diagnostic value for monitoring the presence of tumor cells and tumor progression.

Increased glioma growth in mice depleted of macrophages.

Macrophages can promote the growth of some tumors, such as those of the breast and lung, but it is unknown whether this is true for all tumors, including those of the nervous system. On the contrary, we have previously shown that macrophages can slow the progression of malignant gliomas through a tumor necrosis factor-dependent mechanism. Here, we provide evidence suggesting that this antitumor effect could be mediated by T lymphocytes, as their number was drastically reduced in tumor necrosis factor-deficient mice and inversely correlated with glioma volume. However, this correlation was only observed in allogeneic recipients, prompting a reevaluation of the role of macrophages in a nonimmunogenic context. Using syngeneic mice expressing the herpes simplex virus thymidine kinase under the control of the CD11b promoter, we show that macrophages can exert an antitumor effect without the help of T lymphocytes. Macrophage depletion achieved by ganciclovir treatment resulted in a 33% increase in glioma volume. The antitumor effect of macrophages was not likely due to a tumoricidal activity because phagocytosis or apoptosis of glioma cells, transduced ex vivo with a lentiviral vector expressing green fluorescent protein, was rarely observed. Their antitumor effect was also not due to a destructive action on the tumor vasculature because macrophage depletion resulted in a modest reduction in vascular density. Therefore, this study suggests that macrophages can attenuate glioma growth by an unconventional mechanism. This study also validates a new transgenic model to explore the role of macrophages in cancer.

Neuroblastoma-induced inhibition of dendritic cell IL-12 production via abrogation of CD40 expression.

BACKGROUND/PURPOSE: CD40 expression by dendritic cells (DCs) critically regulates their maturation/antitumor activity. CD40-CD40 ligand (CD40L) signaling stimulates DC-mediated IL-12 production/cytotoxicity. Recent studies suggest that neuroblastoma (NB)-derived gangliosides impair DC maturation, IL-12 secretion, and NK/T-cell activity. Neuroblastoma ganglioside-mediated abrogation of CD40 expression by DC and tumor-induced tolerance has not been studied. The purpose of this study is to determine if NB inhibits DC IL-12 production via CD40. The contributory role of the NB-derived ganglioside GM3 in this process is also examined. METHODS: Dendritic cells were generated from bone marrow of mice injected with saline (control) or murine NB. Control DCs were matured with or without GM3. Dendritic cells were cocultured with NB cells treated with or without a ganglioside synthesis inhibitor. Dendritic cell groups were analyzed for maturation/costimulatory markers. Control and tumor-derived DC were stimulated with CD40L or Staphylococcus aureus and studied for IL-12 expression. RESULTS: CD40 expression on DC generated from NB bearing mice decreased by 64% (P < .001). GM3 down-regulated DC maturation and CD40 expression. Only CD40-dependent IL-12 production was abrogated (60%, P < .01) in DC derived from NB-bearing mice. Dendritic cell capacity to synthesize IL-12 remained intact. CONCLUSIONS: Neuroblastoma-induced inhibition of DC function may result from ganglioside-mediated CD40 signaling deficiency. Strategies to bypass/augment CD40-CD40L signaling may improve current NB immunotherapies.

Genetic pathways and histogenetic models of AIDS-related lymphomas.

Acquired immunodeficiency syndrome (AIDS)-related lymphomas consistently display a B-cell phenotype and are histogenetically related to germinal centre or post-germinal centre B cells in the overwhelming majority of cases. The pathogenesis of AIDS-related lymphoma is a multistep process involving factors provided by the host as well as alterations intrinsic to the tumour clone. The molecular pathways of viral infection and lesions of cancer-related genes associated with AIDS-related lymphomas vary substantially in different clinicopathological categories of the disease and highlight the marked degree of biological heterogeneity of these lymphomas.

Antiamphiphysin antibodies are associated with various paraneoplastic neurological syndromes and tumors.

BACKGROUND: Antiamphiphysin antibodies react with a 128-kd protein found in synaptic vesicles. They were first described in patients with paraneoplastic stiff-man syndrome and breast cancer, but studies suggest that they can also occur in patients with other tumors and neurological disorders. OBJECTIVE: To determine if antiamphiphysin antibodies are associated with various paraneoplastic neurological syndromes and tumors. PATIENTS AND METHODS: Of 2800 serum samples tested by routine immunohistochemical procedures on sections of paraformaldehyde-fixed rat brain for the detection of autoantibodies associated with paraneoplastic neurological syndromes, 5 were selected because of labeling suggestive of antiamphiphysin antibodies and subsequently confirmed by the results of Western blot analysis using recombinant amphiphysin protein. Controls consisted of 40 patients with various nonparaneoplastic neurological diseases; 101 patients with cancer but without paraneoplastic neurological syndrome; 9 patients with small cell lung cancer, anti-Hu antibodies, and paraneoplastic neurological syndrome; 3 patients with M2-type antimitochondrial antibodies but no neurological disorder; and 30 normal subjects. RESULTS: Of the 5 patients with antiamphiphysin antibodies, patient 1 had sensory neuronopathy, encephalomyelitis, and breast cancer; patient 2 had limbic encephalitis, and small cell lung cancer was detected in the mediastinum after 24 months of follow-up; patient 3 had encephalomyelitis and ovarian carcinoma; and patients 4 and 5 had Lambert-Eaton myasthenic syndrome and small cell lung cancer (patient 4 subsequently developed cerebellar degeneration). None of the 5 had stiffness. Two patients (Nos. 2 and 4) had antimitochondrial antibodies. The two patients (Nos. 4 and 5) with Lambert-Eaton myasthenic syndrome had antibodies directed against the voltage-gated calcium channel, and patient 2 subsequently developed anti-Hu antibodies. In the controls, antiamphiphysin antibodies were detected by Western blot analysis in 3 of 8 patients with anti-Hu antibodies, but in none of the other groups. CONCLUSIONS: These data indicate that antiamphiphysin antibodies are not specific for one type of tumor or one neurological syndrome and can be associated with other neural and nonneural antibodies. The simultaneous association of several antibodies in some patients suggests multimodal autoantibody production.

Paraneoplastic syndromes.

Most nervous system paraneoplastic syndromes probably result from an immune attack against antigens normally expressed only in the nervous system but aberrantly expressed in a cancer. Specific antibodies in serum and cerebrospinal fluid that react with the nervous system and the cancer can be used to characterize proteins usually restricted to the nervous system and to identify neurologic disorders as paraneoplastic caused by a specific tumor type.

Characterization of rat NCA/CD9 cell surface antigen and its expression by normal and malignant neural cells.

As part of investigations on ethylnitrosourea (EtNU)-induced neuro-oncogenesis in the rat, we have produced monoclonal antibodies (Mabs) specific for neural cell surface antigens (NCAs) by immunization with cells of the clonal tumorigenic neural rat cell line BT4Ca. Mabs designated as anti-NCA (alpha NCA1, alpha NCA2, alpha NCA3, alpha NCA4, and alpha NCA5) recognize proteins of 25 kDa and 23 kDa, as shown by immunoprecipitation and Western blot. The predominant 25-kDa protein was purified from BT4Ca cells by immunoaffinity chromatography with immobilized Mab alpha NCA1 and identified by N-terminal sequencing as the rat homologue of the CD9 antigen. Identification of proline as N-terminal amino acid of the purified protein suggests post-translational modification of CD9 in the rat central nervous system. The NCA/CD9 protein was localized in distinct regions of fetal and adult rat brain by immunofluorescence staining of frozen sections. Flow cytometric analyses of isolated fetal rat brain cells (FBC) showed that the proportion and number of NCA/CD9-expressing cells increased during prenatal development. Immunoreactivity of approximately 40% of brain cells isolated 13 days post conception (p.c.) indicated that NCA/CD9 is expressed by neuronal precursors at this stage of development. In primary cultures of rat FBC isolated 18 days p.c., the NCA/CD9 antigen was expressed by all premature and mature astrocytes, oligodendrocytes, ependymal cells, and microglial cells, but not by E-N-CAM-expressing neuronal progenitor cells and neurons. Furthermore, eight out of ten EtNU-induced malignant neural rat cell lines as well as EtNU-induced tumors of the central and peripheral nervous system exhibited intermediate or strong immunoreactivity with Mab alpha NCA1. Expression of the NCA/CD9 protein is, therefore, characteristic of both normal glial precursor cells and their malignant counterparts in the rat.

[Intrathecal IgG synthesis: when is determination of oligoclonal bands necessary?]. / Intrathekale IgG-Synthese: Wann ist eine Bestimmung der oligoklonalen Banden erforderlich?

Two quantitative methods of determining the intrathecal synthesis of IgG were tested for their usefulness in deciding about the necessity of further investigations of oligoclonal bands (OCB) in the CSF. For this purpose, in 2003 patients with various neurological diseases the intrathecal synthesis of IgG was determined by Reiber's formula and by the IgG index, as well as by the demonstration of OCB by isoelectric focusing (IEF). While OCB could be detected in no patient with an IgG index < 0.45, these bands were always demonstrated in patients with an index > 0.80. Even though arrange of 0.45-0.8 OCB was only detected in 268/1316 patients (20.4%), in 190/268 samples (70.8%) OCB were the only criterion for intrathecal synthesis of IgG. Calculation of intrathecal synthesis of IgG by Reiber's formula was less helpful in deciding about the necessity for IEF. Even though they had no intrathecal synthesis of IgG, as calculated by Reiber's formula, 189/1472 patients (12.8%) had OCB in the CSF. OCB were always detected if local production of IgG was > 12%. In patients with a severe damage of the blood-CSF barrier, calculation of the IgG index gave more false-positive results than calculations using Reiber's formula.

Immunoassays for measurement of chromogranin A and pancreastatin-like immunoreactivity in humans: correspondence in patients with neuroendocrine neoplasia.

Chromogranin A (CgA) is a useful marker of neuroendocrine tumors in humans. Here we describe and compare two immunoassay methods for determination of CgA, a radioimmunoassay (RIA) and an enzyme linked immunoassay (ELISA). The detection limit of the ELISA was lower than that of the RIA method (2 ng/ml versus 10 ng/ml, respectively), though the CgA RIA method covered a wider range than the CgA ELISA (10-920 ng/ml versus 2-500 ng/ml, respectively). There was no cross-reactivity with synthetic human and porcine pancreastatin (PST) in the two assays. There was a significant positive correlation between levels of CgA in sera from patients with carcinoid disease, measured by the two methods (r = 0.9, p < 0.0001), and the values were in the same range. Similarly, serum CgA levels in normal controls were also in the same range when assayed by the two methods. A commercially available porcine PST RIA method was evaluated, especially with respect to the influence of Sep-Pak extraction of serum on the levels of pancreastatin-like immunoreactivity (PST-LI). Ten sera from carcinoid patients were treated with Sep-Pak extraction, and levels of PST-LI were determined in non-extracted and extracted sera. There was a significant positive correlation between the concentrations of PST-LI measured in extracted and non-extracted carcinoid sera (r = 0.9, p < 0.002), and the levels were in the same range. There was also a significant positive correlation between levels of CgA and PST-LI in 49 carcinoid sera (r = 0.8, p < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Ri-associated paraneoplastic neurologic disorder without opsoclonus in a patient with breast cancer.

A 59-year-old woman with breast cancer and anti-Ri antibodies developed a neurologic paraneoplastic disorder characterized by nausea, vomiting, vertigo, paresis of upward gaze, and gait ataxia, without opsoclonus. The absence of opsoclonus does not rule out the possibility of an anti-Ri-associated paraneoplastic neurologic disorder.