Recombinant interleukin-6 in the treatment of congenital thrombocytopenia associated with absent radii

PURPOSE

The role interleukin-6 (IL-6) in the treatment of congenital thrombocytopenias is unknown. The purpose of this case report is to describe the efficacy of IL-6 in a child with thrombocytopenia with absent radii (TAR) syndrome.

METHODS

A 23-month-old girl with TAR syndrome was treated with recombinant IL-6 (Sigosix; Serono Laboratories, Norwell, MA) at a dose of 7 micrograms/kg subcutaneously daily. Complete blood counts were monitored weekly. The child was closely monitored for any toxicity.

RESULTS

After 3 weeks of therapy, the patient had an increase in platelet count from a baseline of 5,000 to 8,000/microliter to a maximal level of 33,000/microliter. She was platelet transfusion-independent during IL-6 therapy. Fevers and chills, the main toxicities encountered, were controlled with acetaminophen and ibuprofen. An increase in the IL-6 dose caused anemia with no further increase in platelet count. After discontinuation of the drug, her hemoglobin rose to baseline and the platelet count returned to pretreatment levels.

CONCLUSIONS

We conclude that IL-6 may benefit some children with TAR syndrome. The role of IL-6 and other thrombopoietic agents in the treatment of TAR and other congenital thrombocytopenias deserves further clinical study.

Recombinant human interferon-beta (rHuIFN-beta) and radiation therapy for inoperable non-small cell lung cancer

Fifteen patients with stage II, IIIA, and IIIB non-small cell lung cancer (NSCLC) received subcutaneous (s.c.) recombinant, glycosylated, human interferon-beta 1a (Rebif; rHuIFN-beta 1a) on each day of conventionally fractionated radiation therapy (RT) given in 2.0 Gy fractions to 60 Gy in 6 weeks. The rHuIFN-beta 1a was generated in CHO cells by recombinant DNA technology and is identical to natural IFN-beta produced by fibroblasts in primary sequence and glycosylation. Cohorts of three patients each were treated with escalating doses of rHuIFN-beta 1a: 1.5, 3, 6, 12, and 24 MIU/m2 per treatment day. Acute toxicity was assessed according to modified WHO criteria; late toxicity was graded using RTOG late toxicity criteria. The maximum tolerated dose (MTD) of rHuIFN-beta 1a was defined as the dose level immediately below that in which dose-limiting toxicity occurred in > or = two of six patients. Immunomodulatory effects and antigenicity of rHuIFN-beta 1a were assessed by 2-5A synthetase, beta 2-microglobulin, and neopterin levels and by measurement of anti-rHuIFN-beta antibodies, respectively. Fourteen of fifteen patients experienced grades 1-3 acute (early) toxicity (< or = 90 days), which was primarily gastrointestinal: dysphagia/esophagitis (14/15), nausea/vomiting (12/15), anorexia (7/15), and liver transaminasemia (6/15). One of three patients treated with 24 MIU/m2 per treatment day (total rHuIFN-beta 1a dose 672 MIU) died of complications secondary to pneumonia, sepsis, adult respiratory distress syndrome (ARDS), and radiation pneumonitis. Twelve patients were evaluable for late toxicity (> 90 days). Maximum toxicity was grade 0 in five patients, grade 1 in four patients, and grade 5 in one patient (radiation pneumonitis). Clinical responses from the combination were 1/15 CR, 6/15 PR, 6/15 stable disease, and 1/15 progressive disease. The MTD of rHuIFN-beta 1a has been estimated at 12 MIU/m2 per treatment day when given daily during conventional RT to 60 Gy in 6 weeks. Biologic response by rHuIFN-beta 1a alone was reflected by significant and dose-related increases in 2-5A synthetase, beta 2-microglobulin, and neopterin. Radiation therapy alone had no effect on these immune response parameters and did not diminish their augmentation by rHuIFN-beta 1a. There was no association of biologic modulation with clinical response or survival.

Granulocyte-macrophage colony-stimulating factor as infection prophylaxis in high-risk oncologic surgery

BACKGROUND

A method of augmenting host defenses against bacterial pathogens could result in a decrease in postoperative infections. Given its effects on leukocyte proliferation and function, it is possible that prophylactic granulocyte-macrophage colony-stimulating factor (GM-CSF) could reduce the incidence and severity of infections in high-risk surgical patients. The current study was undertaken to determine the safety and hematologic effects of perioperative GM-CSF.

METHODS

Cancer patients undergoing operations with a high risk of postoperative infection were treated perioperatively for 10 days with subcutaneous GM-CSF. Cohorts were treated with GM-CSF at 125 micrograms/m2/day (12 patients) and 250 micrograms/m2/day (11 patients).

RESULTS

There were no severe or life-threatening toxicities associated with GM-CSF. Mean maximum neutrophil counts during the first 5 postoperative days were 16.3 +/- 9.14 and 24.5 +/- 7.60 at 125 and 250 micrograms/m2, respectively (P = 0.04). Only one wound infection was diagnosed during this study.

CONCLUSIONS

GM-CSF may be safely administered perioperatively at doses that augment neutrophil number and function. An ongoing randomized clinical trial will determine the impact of GM-CSF on postoperative infection.

Malignancy-related pericardial effusion. 127 cases from the Roswell Park Cancer Institute

BACKGROUND

Malignancy-related pericardial effusions may represent a terminal event in patients with therapeutically unresponsive disease. However, select patients with malignancies sensitive to available therapies may achieve significant improvement in palliation and long term survival with prompt recognition and appropriate intervention.

METHODS

From 1968 to 1994, 150 invasive procedures were performed for the treatment or diagnosis of pericardial effusion in 127 patients with underlying malignancies. These cases were reviewed retrospectively to best identify the clinical features, appropriate diagnostic workup, and optimal therapy for this complication of malignancy.

RESULTS

Dyspnea (81%) and an abnormal pulsus paradoxus (32%) were the most common symptoms. Echocardiography had a 96% diagnostic accuracy. Cytology and pericardial biopsy had sensitivities of 90% and 56%, respectively. Fifty-five percent of all effusions were malignant comprising 71% of adenocarcinomas of the lung, breast, esophagus, and unknown primary site. In 57 patients, a malignant effusion could not be determined, and no definitive etiology could be established for 74% of these effusions. Radiation-induced, infectious, and hemorrhagic pericarditis each were identified in fewer than 5% of cases.

CONCLUSIONS

Subxyphoid pericardiotomy proved to be a safe and effective intervention that successfully relieved pericardial effusions in 99% of cases with recurrence and reoperation rates of 9% and 7%, respectively. Survival most closely was related to the extent of disease and its inherent chemo-/radiosensitivity, with 72% of the patients who survived longer than 1 year having breast cancer, leukemia, or lymphoma.

Daily subcutaneous injection of low-dose interleukin 2 expands natural killer cells in vivo without significant toxicity

We aimed to determine the toxicity and immunological effects of daily s.c. administered low-dose interleukin (IL) 2. Adult cancer patients received a single daily s.c. injection of IL-2 as outpatients for 90 consecutive days. Cohorts of four to nine patients were treated at escalating IL-2 dose levels until the maximum tolerated dose (MTD) was defined. Peripheral blood mononuclear cell phenotyping, IL-2 serum levels, and the presence of anti-IL-2 antibodies were investigated. Thirty-eight patients were treated at seven IL-2 dose levels ranging from 0.4 to 1.75 million International Units (mIU)/m2 daily. The MTD was 1.25 mIU/m2, with constitutional side effects, vomiting, and hyperglycemia dose limiting. Severe toxicity did not occur at or below the MTD, although mild local skin reaction and mild constitutional side effects were common. Objective tumor regressions were not observed during this Phase I trial. Low-dose IL-2 resulted in natural killer (NK) cell (CD3(-) CD56(+)) expansion at all dose levels. This effect was dose dependent (P < 0.01), ranging from a 154 to 530% increase over baseline. Peak NK levels were achieved at 6-8 weeks and sustained through 12 weeks of therapy. As predicted by in vitro studies of IL-2 receptor structure-activity relationships, the subset of NK cells that constitutively express high-affinity IL-2 receptors (CD3(-)CD56(bright+)) showed more profound dose-dependent expansion, with increases ranging from 368 to 2763% (P = 0.015). NK expansion occurred at peak IL-2 levels <10 pM (2.3 IU/ml). Three patients developed nonneutralizing anti-IL-2 antibodies. Thus, we concluded that selective expansion of NK cells may be achieved in vivo with daily s.c. injections of low-dose IL-2 with minimal toxicity.

Immune responses in patients with T-cell lymphoma treated with an anti-idiotype antibody mimicking a highly restricted T-cell antigen

We generated an IgG1 murine monoclonal anti-idiotype antibody (Ab2) to a highly restricted T-cell antigen designated glycoprotein (gp) 37 that is found on T-cell malignancies but not on normal cells. gp37 is identified by the murine monoclonal antibody SN2 (Ab1) against which the Ab2 was raised. Each of four patients with T-cell lymphoma predominantly confined to the skin received a minimum of four intracutaneous injections of aluminum hydroxide precipitated anti-idiotype murine monoclonal antibody (1 mg/injection) given every 2 weeks. For responding patients, injections were continued on a monthly basis. All tumors were measured along orthogonal major and minor axes, using a ruler and/or calipers, by the same observer. Tumor sizes were documented photographically. Three of the four patients developed specific idiotypic humoral immune responses, and two of the four patients also demonstrated idiotypic cell-mediated responses. Humoral responses included binding of the patients' sera to the anti-idiotype antibody as well as specific inhibition of binding of the SN2 antibody (Ab1) to the anti-idiotype antibody (Ab2). Anti-anti-idiotypic (Ab3) antibody from one patient's serum bound specifically to the gp37-positive cell line MOLT-4 and also to semipurified gp37 antigen. Cell-mediated responses were demonstrated by specific proliferative response to the aluminum hydroxide precipitated anti-idiotype antibody by patients' peripheral blood mononuclear cells. While three of the four patients had extensive disease and did not have clinical responses, one of the patients who had nine discrete skin tumors and peripheral blood involvement without other detectable disease had virtually complete disappearance of the tumors lasting over 11 months. Our results demonstrate that this particular anti-idiotype antibody can induce humoral and cellular immune responses, and at least in one patient led to a meaningful therapeutic response. Future trials should focus on immunocompetent patients with minimal disease.

Platelet transfusion and alternatives to transfusion in patients with malignancy

Platelet transfusions have long had an important role in the treatment of patients with thrombocytopenia due to disease or myelotoxic treatment or in patients with reduced platelet function. However, platelet transfusions are associated with numerous risks, both immunologic (e.g., transfusion reactions, alloimmunization, immunosuppression) and infectious (e.g., viral, bacterial). In addition, several laboratory and clinical factors can influence post-transfusion platelet recovery. Recent technological advances have introduced the potential for using alternatives to platelet transfusions, such as cytokines or platelet substitutes, which may avoid the risks of transfusion. Platelet development from megakaryocytes is a process that is highly regulated by cytokines and animal research suggests that selected cytokines involved in this process may be useful in the treatment of thrombocytopenia. Newer developments, including the utilization of recombinant cytokines with relatively selective stimulation of platelet production (e.g., interleukin 6 [IL-6]) and the recent discovery of a megakaryocyte colony stimulating factor (thrombopoietin), represent major therapeutic opportunities in the treatment of thrombocytopenia. Platelet substitutes, e.g., thromboerythrocytes, also show promise in the management of platelet deficiencies.

Malignancy-related pericardial effusion. 127 cases from the Roswell Park Cancer Institute

BACKGROUND

Malignancy-related pericardial effusions may represent a terminal event in patients with therapeutically unresponsive disease. However, select patients with malignancies sensitive to available therapies may achieve significant improvement in palliation and long term survival with prompt recognition and appropriate intervention.

METHODS

From 1968 to 1994, 150 invasive procedures were performed for the treatment or diagnosis of pericardial effusion in 127 patients with underlying malignancies. These cases were reviewed retrospectively to best identify the clinical features, appropriate diagnostic workup, and optimal therapy for this complication of malignancy.

RESULTS

Dyspnea (81%) and an abnormal pulsus paradoxus (32%) were the most common symptoms. Echocardiography had a 96% diagnostic accuracy. Cytology and pericardial biopsy had sensitivities of 90% and 56%, respectively. Fifty-five percent of all effusions were malignant comprising 71% of adenocarcinomas of the lung, breast, esophagus, and unknown primary site. In 57 patients, a malignant effusion could not be determined, and no definitive etiology could be established for 74% of these effusions. Radiation-induced, infectious, and hemorrhagic pericarditis each were identified in fewer than 5% of cases.

CONCLUSIONS

Subxyphoid pericardiotomy proved to be a safe and effective intervention that successfully relieved pericardial effusions in 99% of cases with recurrence and reoperation rates of 9% and 7%, respectively. Survival most closely was related to the extent of disease and its inherent chemo-/radiosensitivity, with 72% of the patients who survived longer than 1 year having breast cancer, leukemia, or lymphoma.

Carboplatin for small cell lung cancer: progress toward greater efficacy and reduced toxicity

Small cell lung cancer, an aggressive malignancy characterized by early dissemination, is highly responsive to radiotherapy and cytotoxic chemotherapy. Since the introduction of combined-modality regimens that incorporate both radiotherapy and chemotherapy, the median survival time for patients with localized disease has increased to 12 to 15 months, but median length of survival of patients with extensive disease has remained at a plateau of only 6 to 8 months. New cytotoxic agents, such as ifosfamide, etoposide, and carboplatin, have contributed to a reduced toxicity profile and an increase in complete response rates to combination regimens of 40% to 50%, but they have not contributed to any major increase in long-term survival. Potential strategies for improving efficacy and reducing toxicity of the chemotherapy of small cell lung cancer are reviewed.

Renal cell carcinoma treated with continuous-infusion interleukin-2 with ex vivo-activated killer cells

High-dose recombinant interleukin-2 (rIL-2) results in tumor responses in patients with metastatic renal cell carcinoma ranging from 9 to 31%. Continuous infusion regimens of rIL-2 may be less toxic and may result in greater in vivo lymphokine-activated killer (LAK) cell production. The current trial used a continuous infusion of rIL-2 with ex vivo LAK cells. These cells were pretreated with phenylalanine methyl ester to remove monocytes to allow cell culture at higher concentrations. Twenty-three patients were entered into the trial. Two patients had complete responses (9%) lasting 15+ and 20+ months. Four patients had partial responses (17%) of 9+, 6+, 3, and 3 months, respectively. One partial responder at 9+ months had only minimal residual retroperitoneal disease that may represent scar tissue. All responders had prior nephrectomies. All but one of the responding patients completed a full cycle of rIL-2 at the highest (starting) dose, 6 x 10(6) U/m2. This rIL-2/LAK regimen appears to be an effective therapy for metastatic renal cell carcinoma.

Monoclonal antibodies and chemiluminescence immunoassay for detection of the surface protein of human T-cell lymphotropic virus

Monoclonal antibodies (MAbs) raised against human T-cell lymphotropic virus type I (HTLV-I) recognized five distinct antigenic domains of viral env gene-encoded proteins. By using recombinant env proteins and synthetic peptides as mapping antigens, it was determined that the most immunogenic region represented a central portion of the retroviral surface protein (domain 2; amino acids 165 to 191). However, only a single MAb was able to react strongly with native viral proteins. This antibody (clone 6C2) was directed to an epitope within domain 4 (amino acids 210 to 306) of the retroviral env gene and reacted with envelope proteins in both HTLV-I and HTLV-II, as determined by immunoprecipitation, solid-phase binding, and immunoblotting. No reactivity against envelope components of other human retroviruses, including human immunodeficiency virus types 1 and 2, was present. Flow cytometry data demonstrated that MAb 6C2 reacted with cell lines chronically infected with HTLV-I or HTLV-II and also with surface antigens expressed on fresh adult T-cell leukemia cells, following up-regulation with interleukin-2. By a chemiluminescence immunoassay procedure, picogram amounts of viral surface protein could be detected in the unconcentrated supernatants of HTLV-infected cell lines and in diagnostic cultures. Levels of env and gag proteins released by cells into culture supernatants were not directly related to percent expression of cell surface viral-coat proteins. Further, the molar ratio of p19 to gp46 in conditioned media varied from strain to strain, possibly reflecting differences in viral assembly or packaging mechanisms. MAb 6C2 will be of value in characterizing the biochemical and immunological behavior of retroviral env gene proteins and in studying the interaction of HTLV-I and HTLV-II with their receptors.

Immune markers in hematologic malignancies

The precise delineation of biologic traits that distinguish normal hematopoietic cells from their malignant counterparts is of fundamental importance in understanding all aspects of hematologic malignancies. An increasingly sophisticated technologic battery has been utilized to dissect out these differences--primarily utilization of monoclonal antibodies, by immunoperoxidase, immunoalkaline phosphatase and flow cytometric techniques. An even more basic understanding of normal and malignant hematopoietic cells has begun to evolve as molecular biology begins to unravel gene misprogramming by Southern and Northern blot analysis and the polymerase chain reaction. These techniques not only help distinguish a normal cell from a malignant one, but characterize the malignant clone as B-lymphoid, T-lymphoid or myeloid and allow further subcategorization within these broad lineages. These distinctions are vital to the entire spectrum of basic and clinical research involving hematologic malignancies and are assuming an increasingly important role in their diagnosis, prognosis and treatment.

Interleukin-2 with ex vivo activated killer cells: therapy of advanced non-small-cell lung cancer

A phase II study was conducted to examine the efficacy of interleukin-2 (IL-2) with lymphokine-activated killer (LAK) cells as therapy for advanced non-small-cell lung carcinoma (NSCLC). IL-2 was administered at a fixed dose of 6 x 10(6) U/M2 per day as a 24 h continuous intravenous infusion (CIV) with LAK cells. Eleven patients were entered onto this study and six were evaluable. One patient had a near complete response of 18 months duration. Only two patients were able to complete the regimen without dose reduction. This regimen was poorly tolerated with pulmonary toxicity being the major problem. The partial responder was the only patient to undergo more than one course of therapy. IL-2/LAK therapy may have activity in NSCLC and further studies are warranted in this uniformly fatal disease. However, future studies will have to incorporate less toxic IL-2 regimens.

Cytokine influence on killing of fresh chronic lymphocytic leukemia cells by human leukocytes

The feasibility of combining the Lym-1 monoclonal antibody (MoAb) with interferon-gamma (IFN-gamma) in the treatment of chronic lymphocytic leukemia (CLL) was evaluated. We used an in vitro tumor lysis model that incorporated fresh CLL cells from 21 different patients as targets for two distinct normal human leukocyte effector subsets, neutrophils, and peripheral blood mononuclear cells (PBMCs). Lym-1 antigen (Lym-1-Ag) expression varied greatly and did not correlate with the expression of other CLL-associated antigens such as CD5, CD19, or HLA-DR. CLL cells were not lysed by neutrophils alone or with IFN-gamma in the absence of Lym-1. Neutrophil Lym-1-dependent cytotoxicity (ADCC) in the absence of IFN-gamma was weak and inconsistent. IFN-gamma exposure induced MoAb-dependent lysis of 80% of 21 CLL targets and resulted in an eightfold augmentation of neutrophil ADCC against the remainder. Cytotoxicity correlated directly and positively with Lym-1-Ag expression. Confirmation of the need for interaction between neutrophil IgG Fc receptors (Fc gamma Rs) and the Fc portion of the Lym-1 MoAb was obtained by demonstrating that purified Staphylococcus aureus Protein A (SpA) inhibited ADCC. IFN-gamma exposure caused no consistent alternations in Lym-1-Ag expression on CLL cells so that target antigen upregulation was unlikely to account for augmentation of neutrophil ADCC. PBMCs alone, exposed to interkeukin-2 (IL-2) or IFN-gamma, or with Lym-1 in the presence or absence of IL-2 or IFN-gamma were unable to lyse CLL targets. PBMCs were able to kill Raji Burkitt lymphoma cells in conjunction with Lym-1, so their ability to interact with Lym-1-coated targets and their lytic functions appeared intact. These results emphasize the importance of examining fresh tumor cells with different leukocyte effector subsets before designing a clinical trial that combines a therapeutic MoAb with a cytokine.

Unusual gastrointestinal complications of interleukin-2 therapy

Minor and reversible gastrointestinal side effects are common when patients receive interleukin-2 (IL-2) with or without lymphokine-activated killer (LAK) cells. We treated 42 cancer patients with IL-2 therapy and 3 patients developed serious gastrointestinal problems during treatment. Complications included sigmoid colon perforation, ischemic necrosis of the small and large intestine, and diffuse bowel ulceration. These were not associated with tumor implants or hypotension. Two patients died as a direct result of these problems despite aggressive surgical and medical management. The incidence of major gastrointestinal complications with IL-2 therapy may be greater than previously reported and a heightened awareness of potential gastrointestinal problems may circumvent considerable morbidity and mortality.

Interleukin-2 lymphokine-activated killer cell therapy of non-Hodgkin's lymphoma and Hodgkin's disease

We conducted a phase II study utilizing interleukin-2 (IL-2) with lymphokine-activated killer (LAK) cells as therapy for non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD). IL-2 was given at a fixed dose of 3 x 10(6) U/m2/day administered as a 24-h continuous intravenous infusion with LAK cells. Nineteen extensively treated patients were entered and 15 were evaluable. In general, this regimen was reasonably well tolerated with mild toxicities that were rapidly reversible. Patients who completed therapy did so without dose attenuations. However, discontinuation of therapy was necessary in four patients due to atypical toxicities that were not clearly dose related. Two patients (one NHL and one HD) had partial remissions of brief duration, four had disease stabilization, and seven had progressive disease. While there were not sufficient numbers to evaluate critically any NHL or HD subtype, this regimen does not appear to have significant activity for either disease.

Overview of monoclonal antibodies in the diagnosis and therapy of cancer

Monoclonal antibodies initially offered the promise of a cure for cancer as "magic bullets" but this hope was quickly diminished as the complexities of the host-tumor relationship were realized. We have acquired a tremendous amount of practical experience since the first cancer patient was treated with a MAb nearly 10 years ago. This experience, combined with recent advances in recombinant DNA technology, has endowed us with a rich variety of opportunities to exploit in the diagnosis and treatment of malignancies. If recent preclinical research studies are clinically applicable and the antitumor responses seen in initial clinical trials can be optimized and confirmed, the next decade will likely be host to remarkable advances in the diagnosis and treatment of cancer with MAbs.

Interferon gamma augments Lym-1-dependent, granulocyte-mediated tumor cell lysis

Lym-1 is a therapeutically promising IgG2a monoclonal antibody (MoAb) that reacts with variant class II molecules expressed on B-lineage malignancies. To optimize antitumor immunotherapy with Lym-1, we determined whether granulocytes could participate in tumor lysis mediated by Lym-1 and whether recombinant interferon gamma (IFN-gamma) could influence this reaction. Granulocytes had minimal activity in mediating Lym-1 antibody-dependent cellular cytotoxicity (ADCC) compared with peripheral blood mononuclear cells (PBMC). However, IFN-gamma markedly augmented and occasionally induced granulocyte Lym-1 ADCC in a dose-dependent fashion (optimal 100 U/mL). Granulocytes primed with IFN-gamma for 24 hours displayed greatly increased ADCC in the absence of further IFN-gamma exposure. In most individuals, IFN-gamma also enhanced PBMC Lym-1 ADCC. Interferon alfa (IFN-alpha), although able to enhance PBMC-mediated Lym-1 ADCC and non-ADCC lysis, had no effect on granulocyte activity. Lym-1 ADCC involved an interaction between Fc receptor-bearing granulocytes and Lym-1 antigen positive targets based on the following: (1) The reaction was Lym-1 dose-dependent with cytotoxicity detectable at concentrations as low as 0.5 microgram/mL. (2) An irrelevant, isotype-matched MoAb (UPC-10) was unable to mediate ADCC. (3) In the absence of Lym-1, granulocytes--with or without IFN-gamma--displayed no intrinsic tumor lytic ability. Conversely, without granulocytes, Lym-1 or Lym-1 plus IFN-gamma had no effect. (4) Protein A, which binds avidly to Lym-1, inhibited the reaction 95%. (5) IFN-gamma induced granulocyte expression of CD64, the IgG Fc receptor that binds murine IgG2a MoAbs. (6) Of nine malignant human cell lines, only the three that moderately or strongly expressed the Lym-1 antigen were consistently lysed. Preclinical studies such as these may provide a rational basis for designing clinical trials with Lym-1 in combination with IFN-gamma.

Antibody-dependent, cell-mediated cytotoxicity by an anti-class II murine monoclonal antibody: effects of recombinant interleukin 2 on human effector cell lysis of human B-cell tumors

Lym-1 is an IgG2a murine monoclonal antibody that reacts with variant Class II molecules expressed on B-cell malignancies. Lym-1 was shown to mediate antibody-dependent cellular cytotoxicity (ADCC) of human effector cells against a variety of malignant B-cell lines. Tumor cell lysis was Lym-1 specific because (a) the reaction was dose dependent with significant ADCC detectable at Lym-1 concentrations as low as 1 microgram/ml; (b) tumor targets not expressing the Lym-1 antigen were unaffected; (c) an isotype-matched irrelevant monoclonal antibody and an IgG1 anti-Class II monoclonal antibody failed to mediate ADCC; and (d) addition of Protein A (which binds avidly to Lym-1) blocked ADCC by 90 to 100%. Peripheral blood mononuclear cells obtained from normal donors as well as from cancer patients were able to interact with Lym-1 to elicit ADCC. Recombinant interleukin 2 (rIL-2) enhanced non-antibody-mediated tumor lysis and Lym-1 ADCC with an optimal concentration of 100 units/ml. Pulse treatment of normal peripheral blood mononuclear cells with rIL-2 was able to augment Lym-1 ADCC but was less effective than having the rIL-2 present through the assay. Peripheral blood mononuclear cells obtained from patients being treated with high doses of rIL-2 administered by continuous i.v. infusion demonstrated Lym-1 ADCC levels which were higher than normal individuals and which were further augmented by in vitro incubation with rIL-2.

Nuclear magnetic resonance spectroscopy of plasma for the detection of head and neck cancer

The plasma of 15 normal volunteers, four patients with benign head and neck disease, and 12 patients with biopsy proven head and neck malignancies were evaluated using water-suppressed nuclear magnetic resonance (NMR) spectroscopy. While the mean full width at half height (HHLW) of the NMR spectra showed a significant difference between groups (P less than .05), the predictive value of a positive test was only 57% the sensitivity was only 33%, and individual values in all groups demonstrated considerable overlap. The mean HHLW of the control group was 38.5 Hz +/- 3.5 compared with 35.2 Hz +/- 4.7 for the cancer group and 35.0 Hz +/- 10 for the benign disease group. This method was not able to distinguish patients with malignancy from those with benign disease or controls. Its use as a specific screening method for head and neck malignancy cannot be recommended.