Biomedical subjects

D R Vlock

Publications and source records attributed to D R Vlock.

27 records · Page 2Linked to original sources

PubMed1989

Incidence of serum antibody reactivity to autologous head and neck cancer cell lines and augmentation of antibody reactivity following acid dissociation and ultrafiltration.

Serum antibody reactivity to squamous cell carcinoma of the head and neck (SCCHN) was evaluated in 41 autologous serum-tumor cell line combinations using the protein A hemadsorption assay. Autologous antibody reactivity (median titer of 1:4) was detected in sera from 24 of the patients tested. In 10 cases autologous antibody reactivity could be detected only in undiluted serum precluding further analysis. Analysis of higher titer sera from one patient revealed antibodies that define an antigen expressed on autologous tumor cells cultured from both the primary tumor (UM-SCC-17A) and from a metastasis (UM-SCC-17B). Absorption analysis showed that this antigen was also expressed on 6 of 10 allogeneic SCCHN cell lines but not on autologous fibroblasts or on allogeneic melanoma cell lines. Due to the low titer of autologous antibody reactivity in most sera, we sought to determine if dissociation of immune complexes through acidification and ultrafiltration of serum might enhance detectable antibody reactivity as has been done in previous studies in melanoma. Twelve serum samples from eight patients were subjected to acid dissociation and ultrafiltration (AD-U). Only six of the untreated sera had detectable antibody reactivity against the autologous SCCHN cell line whereas following AD-U all 12 sera had enhanced IgG reactivity against autologous SCCHN. Specificity analysis of one serum sample after dissociation revealed that the antibody detected an antigen common to SCCHN cell lines as well as melanoma, glioma, renal, and colon carcinoma cell lines. Circulating immune complexes may provide a reservoir of antibody with potential diagnostic and therapeutic applications.

Antibodies, Neoplasm↗

PubMed1988

Isolation and partial characterization of melanoma-associated antigens identified by autologous antibody.

The study of the autologous immune response to cancer avoids the difficulties encountered in the use of xenoantisera and may identify antigens of physiological relevance. However, the low titer and incidence of autologous antibody to melanoma have hampered further evaluation. By utilizing acid dissociation and ultrafiltration of serum, we have been able to augment the detectable autologous immune response to melanoma in the majority of patients studied. In autologous system Y-Mel 84:420, serum S150 demonstrated a rise in titer from 1:32 in native sera to 1:262,044 after dissociation. The antigen detected by S150 was found to be broadly represented on melanoma, glioma, renal cell carcinoma, neuroblastoma, and head and neck carcinoma cell lines. It did not react with bladder or colon carcinoma, fetal fibroblasts, pooled platelets, lymphocytes and red blood cells, or autologous cultured lymphocytes. Using polyacrylamide gel electrophoresis, S150 detects a 66,000-mol wt antigen in spent tissue culture media and serum ultrafiltrate. In cell lysate two bands between 20,000 and 30,000 mol wt are detected by S150. The 66,000-mol wt antigen is sensitive to trypsin digestion and but is resistant to pepsin and heat inactivation. Exposure of spent media to trypsin results in the development of a 24,000-mol wt band that appears to correspond to the antigen detected in the cell lysate. The difference between the antigens detected in the cell lysate as compared with spent media and serum ultrafiltrate may be due to degradation during cell lysis. We conclude that melanoma-associated antigens are present in the serum of patients with melanoma and are shed or secreted by their tumor cells.

Antibodies, Neoplasm↗

PubMed1986

Prognostic role of antibody reactivity to melanoma.

Antibody reactivity against cultured allogeneic melanoma Y-Mel 81:180 was studied in 43 patients who participated in an adjuvant trial for stage I and II melanoma. Serum samples were obtained at trial entry within 2 mo of definitive surgery. At the time of serum acquisition, all patients were free of disease by physical examination and routine radiologic and laboratory parameters. Serum antibody reactivity was tested for by protein A hemadsorption before and after acid dissociation and ultrafiltration of serum. We have previously shown that this technique for immune complex dissociation augments autologous antibody reactivity. Results of serum antibody reactivity were scored by an investigator blinded to the patient's clinical status. Of the 43 patients studied, 15 relapsed and 28 remained disease-free. At study entry, there were 25 stage I patients and 18 stage II patients. Breslow depth was 3.25 +/- 2.5 mm in relapse patients and 1.67 +/- 1.1 mm in disease-free patients. The presence and titer of antibody directed against melanoma in either native serum or serum dissociated from immune complexes was found to be associated with eventual relapse (P = 0.0001). When results were subgrouped by stage of disease, Breslow depth, and hypopigmentation, antibody reactivity was still correlated with eventual relapse. The incidence and titer of antibody reactivity against melanoma appears to be a new prognostic factor in predicting eventual disease recurrence.

Adult↗

PubMed1985

Serial studies of autologous antibody reactivity to melanoma. Relationship to clinical course and circulating immune complexes.

The low titer and incidence of autologous antibody to melanoma has hampered its evaluation. Through acid dissociation and ultrafiltration of serum, we have been able to augment the autologous immune response in 9 of 10 patients studied. This result suggests that autologous antibody is present in most patients with melanoma, but is obscured by circulating antigen and the formation of immune complexes. Because native antibody and antibody derived from circulating immune complexes are produced by the host against physiologically relevant antigens, correlations can be made to clinical course. Serological studies of three patients with melanoma were performed with serum samples obtained over many months; these studies demonstrated correlations with tumor progression and clinical course. Serial serologic studies may yet provide one of the better ways to evaluate these relationships. They have the advantage of detecting transient events that may occur with the inception of metastatic disease or autoimmune phenomena, and of avoiding the difficulties encountered in comparing antibody responses between different individuals.

Animals↗

PubMed1984

Augmentation of autologous antibody to human melanoma following acid dissociation and ultrafiltration of serum.

Sera of 22 individuals were examined for immunoglobulin M (IgM) and immunoglobulin G (IgG) antibody to autologous cultured tumor cells. Reactive native IgM was detected by immune adherence in four, and IgG by Protein A hemadsorption in five, sera. Direct and absorption testing of these reactive sera against a range of normal and neoplastic cells revealed one each with specificity for a highly restricted melanoma cell surface antigen and common tumor-associated antigen of melanoma. Given this low prevalence of antibody, we then tested whether IgG antibody might be retrieved from circulating immune complexes in melanoma patients' sera. Acidification and ultrafiltration of sera from seven patients have enhanced detectable IgG binding to autologous cultured melanoma in six. Characterization of one reactive autologous antibody has detected a common antigen in eight of nine melanoma lines tested. This antibody also detected two neuroblastomas, one of two glioblastomas, one of two sarcomas, and one of two breast carcinomas. The common melanoma antigen detected in these tests may be related to the neuroectodermal, oncofetal differentiation antigens described by others with autologous or allogeneic IgM. Autologous antitumor antibody in circulating immune complexes may provide a source of antibody for serodiagnostic and therapeutic applications relevant to treatment modalities, such as plasmapheresis and plasma perfusion over Protein A in melanoma and other cancers.

Antibodies, Neoplasm↗

PubMed1983

Tomographic gallium-67 citrate scanning. Useful new surveillance for metastatic melanoma.

Conventional gallium scans are not useful to evaluate patients with metastatic melanoma. We evaluated a new method of tomographic gallium imaging. One hundred fourteen tomographic scans were obtained in a prospective surveillance study of 67 patients over a 3-year period. Scans were evaluated and compared to findings of independent clinical evaluations. Sensitivity of gallium identification of tumor involving peripheral lymph nodes and soft tissues, abdomen, mediastinum, and osseous sites was 68% to 100%; overall sensitivity of this technique is 82% with specificity of 99% in 570 organ system assessments. Analysis of discordant findings when a site was clinically occult but gallium-positive showed gallium uptake to be true-positive in six of seven lymphatic sites, three of three lung and mediastinal sites, six of six abdominal sites, but in no brain or bone sites. Gallium lesions identified by computed tomographic scans proved to be false-positive at one lymphatic and one bone site, and false-negative at four otherwise clinically evident lymph node and soft tissue sites, seven pulmonary sites, and four brain sites. Gallium tomographic scanning provides a composite assessment of melanoma and may eliminate the need for other studies.

Adult↗

PubMed1982

High-dose fraction radiation therapy for intracranial metastases of malignant melanoma: a comparison with low-dose fraction therapy.

Malignant melanoma is considered unresponsive to conventional radiation therapy when it is delivered at a daily dose rate of 130--300 rad/fraction. Previous studies have suggested that this is in part due to a large shoulder on the radiation survival curve and that higher dose fractions might be beneficial. High-dose fraction therapy is effective for local control of cutaneous, lymph node, and soft-tissue metastases. Results in 46 patients treated with high- or low-dose fractions for intracranial metastases over the last decade in the Melanoma Unit and Department of Radiotherapy at Yale have been examined. Twenty-six patients received high-dose fraction therapy, generally 600 rad/fraction/week to 2400--3600 rad; 20 patients received low-dose fraction radiotherapy with 125--400 rad/fraction daily. All patients were given steroids, and most received chemotherapy. Results in both groups were similar. Comparison of high- and low-dose fraction patients revealed: improvement in 38 and 35%, respectively, stability in 23 and 25%, and deterioration in 38 and 40%. Median survival was three months in the high-dose fraction group and 2 1/2 months in the low-dose fraction group. Presence of hepatic metastases had no significant influence upon median survival in patients who received high-dose fraction radiotherapy. In patients receiving low-dose fraction, survival was 2 1/4 months with and three months without hepatic metastases. Death in most patients resulted from progression of central nervous system disease. Side effects, especially headache, were more prominent in the high-dose fraction group. However, in no instance did side effects require discontinuation of therapy. The greater ease of delivery for weekly high-dose fraction radiotherapy outweighed any other difference between the regimens.

Adult↗

PubMed1982

Tomographic gallium-67 citrate scanning: useful new surveillance for metastatic melanoma.

Adult↗

PubMedDate not supplied

Preliminary trial of nonrecombinant interferon alpha in recurrent squamous cell carcinoma of the head and neck.

Fourteen patients with recurrent squamous cell carcinoma of the head and neck (SCCHN) were treated with 10 x 10(6) U of nonrecombinant interferon alpha (IFN) intramuscularly (IM) daily for 3 days every 28 days. There were 11 men and 3 women, with ages ranging from 48 to 74 years. Patients had previously been treated with surgery (9 patients), radiotherapy (13 patients), or chemotherapy (8 patients). All patients had measurable disease by physical exam and radiologic evaluation and a performance status of less than or equal to 2 (ECOG). Patients were treated for a minimum of 3 months and continued on therapy until disease progression. The dose and treatment schedule of IFN was well-tolerated. Toxicities included low-grade fever, mild anorexia, and malaise. Treatment was stopped in 1 patient due to the development of atrial fibrillation. One death occurred as a complication of aspiration pneumonia 2 weeks following the onset of therapy and was not felt to be related to IFN therapy. Of the 14 patients treated, there was 1 complete response (30+ months) of a base of tongue primary. Two patients had stabilization of disease (SD, 8 and 12 months). One patient had a mixed response with resolution of subcutaneous nodules. The remaining 10 patients died of progressive disease. Immunological assessment was performed on 8 patients. The 1 patient who had a complete response was noted to have markedly low pretreatment natural killer (NK) cell activity and a subsequent sharp rise in activity after initial treatment. We conclude that low-dose cyclic IFN is well-tolerated in patients with recurrent SCCHN and has potential antitumor activity.

Aged↗