Citations

Abstract Purpose: Determine muscle and neuronal autoantibody frequencies in patients with thymoma, with and without paraneoplastic neurological accompaniments. Experimental Design: Analysis of IgG autoantibodies in stored serum collected between 1985 and 2003 from 201 patients with histologically diagnosed thymoma (including six with thymic carcinoma). Contemporary assays quantitated antibodies reactive with muscle and neuronal cation channels, muscle sarcomeric proteins and neuronal cytoplasmic, and nuclear proteins. Results: Neurological diagnoses included myasthenia gravis (MG), myositis, encephalitis, neuromuscular hyperexcitability, autonomic neuropathy, and subacute hearing loss, a previously unrecognized accompaniment of thymoma. Muscle acetylcholine receptor (AChR) binding antibodies were found in all patients with a diagnosis of MG. Muscle autoantibodies (AChR-binding, AChR-modulating, or striational) were also found in 59% of patients without any neurological disorder. One or more neuronal autoantibodies were found in 41% of patients without any neurological disorder, 43% of patients with MG only, and 78% of patients with other neurological disorders. Neuronal autoantibody specificities were, in descending order of frequency, as follows: glutamic acid decarboxylase, voltage-gated potassium channel, collapsin response-mediator protein-5, ganglionic AChR, and antineuronal nuclear antibody-type 1 (ANNA-1). Conclusions: Neuronal autoantibodies complement skeletal muscle autoantibodies as serological markers of thymoma in patients with and without clinical evidence of a neurological disorder. The high prevalence of glutamic acid decarboxylase autoantibody, not previously considered a paraneoplastic marker, justifies its consideration as a marker of thymoma-related neurological autoimmunity. Serological evaluation of a patient’s profile of neuronal and muscle autoantibodies may aid in preoperative identification of an indeterminate mediastinal mass.

Abstract A naturally occurring human antibody potentiates dendritic cell function on cross-linking B7-DC (PD-L2), supporting robust T-cell responses in vitro. Moreover, treatment of dendritic cells with B7-DC cross-linking antibody resulted in secretion of interleukin-12, suggesting a TH1 polarization of this response. Here we show an in vivo immunotherapeutic effect of this B7-DC cross-linking antibody using a poorly immunogenic B16 melanoma tumor model. Treatment of mice systemically with antibody at the time of tumor cell engraftment prevented tumor growth in a CD4 and CD8 T-cell-dependent manner. The protective effect of B7-DC cross-linking antibody treatment was independent of endogenous antibody responses. Tumor-specific CTL precursors could be isolated from lymph nodes draining the tumor site in animals treated with B7-DC cross-linking antibody, but not from those treated with isotype control antibodies. The elicited antitumor responses in vivo were specific and long-lasting. More strikingly, treatment of mice with B7-DC cross-linking antibody after the tumors were established in the lungs resulted in protection in a CD8-, perforin-, and granzyme B-dependent fashion. Depletion of natural killer cells did not block the effects of treatment with B7-DC cross-linking antibody. Together, these findings demonstrate that cross-linking B7-DC with the human IgM antibody sHIgM12 can induce a protective immune response against a weakly antigenic experimental tumor and therefore has potential as a novel immunotherapeutic approach for treating cancer.

Purpose On the basis of reported activity of methotrexate, vinblastine, doxorubicin, and cisplatin (MVAC) or topotecan plus cisplatin in advanced cervix cancer, we undertook a randomized trial comparing these combinations versus cisplatin alone, to determine whether survival is improved with either combination compared with cisplatin alone, and to compare toxicities and quality of life (QOL) among the regimens. Patients and Methods Eligible patients were randomly allocated to receive cisplatin 50 mg/m2 every 3 weeks (CPT); cisplatin 50 mg/m2 day 1 plus topotecan 0.75 mg/m2 days 1 to 3 every 3 weeks (CT); or methotrexate 30 mg/m2 days 1, 15, and 22, vinblastine 3 mg/m2 days 2, 15, and 22, doxorubicin 30 mg/m2 day 2, and cisplatin 70 mg/m2 day 2 every 4 weeks (MVAC). Survival was the primary end point; response rate and progression-free survival (PFS) were secondary end points. QOL data are reported separately. Results The MVAC arm was closed by the Data Safety Monitoring Board after four treatment-related deaths occurred among 63 patients, and is not included in this analysis. Two hundred ninety-four patients enrolled onto the remaining regimens: 146 to CPT and 147 to CT. Grade 3 to 4 hematologic toxicity was more common with CT. Patients receiving CT had statistically superior outcomes to those receiving CPT, with median overall survival of 9.4 and 6.5 months (P = .017), median PFS of 4.6 and 2.9 months (P = .014), and response rates of 27% and 13%, respectively. Conclusion This is the first randomized phase III trial to demonstrate a survival advantage for combination chemotherapy over cisplatin alone in advanced cervix cancer.

Objective. 2-Methylbutyryl-CoA dehydrogenase deficiency, also known as short/branched-chain acyl-CoA dehydrogenase (SBCAD) deficiency, is a recently described autosomal recessive disorder of l-isoleucine metabolism. Only 4 affected individuals in 2 families have been described. One patient developed athetoid cerebral palsy, and another had severe motor developmental delay with muscle atrophy. A sibling of the first patient is asymptomatic after prenatal diagnosis and early treatment. Family investigations in the second family revealed that the patient’s mother was also affected but asymptomatic. Methods. We report 8 additional patients identified by prospective newborn screening using tandem mass spectrometry. Results. Molecular genetic analysis performed for 3 of these patients revealed that all are homozygous for an 1165A>G mutation that causes skipping of exon 10 of the SBCAD gene. Although there was no obvious consanguinity, all patients belong to the Hmong, an ancient ethnic group that originated in China and constitutes only 0.8% and 0.6% of the Minnesota and Wisconsin population, respectively. Dietary treatment was initiated in the neonatal period. Except for 1 patient who developed mild muscle hypotonia, all patients remain asymptomatic at ages ranging from 3 to 14 months of age. Conclusions. These cases suggest that SBCAD deficiency is another inborn error of metabolism detectable by newborn screening using tandem mass spectrometry. The continued efficacy of long-term dietary therapy instituted presymptomatically remains to be established.

AbstractT-cell anergy is a tolerance mechanism defined as a hyporesponsive status of antigen-specific T cells upon prior antigen encounter and is believed to play a critical role in the evasion of tumor immunity and the amelioration of allogeneic transplant rejection. Molecular mechanisms in controlling T-cell anergy are less known. We show here that administration of an agonistic monoclonal antibody (mAb) to CD137, a member of the tumor necrosis factor receptor superfamily, prevents the induction of CD8+ cytolytic T-lymphocyte (CTL) anergy by soluble antigens. More importantly, CD137 mAb restores the functions of established anergic CTLs upon reencountering their cognate antigen. As a result, infusion of CD137 mAb inhibits progressive tumor growth that is caused by soluble tumor antigen-induced tolerance in a P815R model. CD137 mAb also restores proliferation and effector functions of anergic alloreactive 2C T cells in a bone marrow transplantation model. Our results indicate that ligation of CD137 receptor delivers a regulatory signal for T-cell anergy and implicate manipulation of the CD137 pathway as a new approach to break T-cell tolerance.