Antibody induction of lymphocyte-mediated cytotoxicity against human transitional-cell carcinomas of the urinary tract

Mucinous (colloid) carcinoma of urinary bladder following long-term cyclophosphamide therapy for Waldenstrom's macroglobulinemia

Carcinoma of the urinary bladder is a known complication of cyclophosphamide therapy. Almost all such cases have been transitional cell carcinomas. We report here the second example of an adenocarcinoma of bladder and the first purely mucinous (colloid) carcinoma of urinary bladder developing after long-term cyclophosphamide therapy. The patient, a 77-year-old woman, had been treated for Waldenstrom's macroglobulinemia for at least 24 years, during which time treatment for this disease varied from 50 to 100 mg per day. The disease terminated in acute myelogenous leukemia, and she died of severe disseminated intravascular coagulopathy associated with hypermacroglobulinemia. The mucinous (colloid) carcinoma of the urinary bladder was an incidental finding at autopsy.

Severely atypical changes in renal epithelium in biopsy and graft nephrectomy specimens in two cases of cadaver renal transplantation

Severely atypical metaplastic and dysplastic changes were noted in the lining epithelium of collecting tubules and pelvis of the graft kidneys in two cases of cadaver renal transplants on immunosuppressive treatment with azathioprine and prednisolone. These changes were observed in case 1 in a needle biopsy and a nephrectomy specimen, 3 and 3.5 years after transplantation respectively. In a second case, the patient received two cadaver grafts, and both transplants showed similar changes 2 years after transplantation. The risk of malignant disease in kidney transplant recipients is now well recognized. The implications of the severe dysplastic changes noted in these two cases are discussed.

Antibody-dependent cell-mediated cytotoxicity in serum samples from patients with ulcerative colitis. Relationship to disease activity and response to total colectomy

A group of six medically treated patients with ulcerative colitis were followed for up to 30 months along with eight additional patients who underwent proctocolectomy. Patients were examined frequently, and serum samples were collected for antibody-dependent cell-mediated cytotoxicity studies. Clinically active disease was substantiated by history, physical examination, laboratory investigations, proctoscopy and, when feasible, by rectal and/or colonic biopsy specimens. During active clinical disease, serum samples from patients with ulcerative colitis showed antibody-dependent cell-mediated cytotoxicity of 16.5 +/- 1.6 percent (range 8.2 to 25.8 percent). During remission of the disease, serum samples from the same patients demonstrated a mean antibody-dependent cell-mediated cytotoxicity value of 5.9 +/- 1.3 percent (range 0.4 to 11.1 percent) (p less than 0.01). In the eight patients who underwent proctocolectomy, mean preoperative antibody-dependent cell-mediated cytotoxicity value was 19.5 +/- 2.3 percent (range 4.1 to 38.6 percent). One month after proctocolectomy, antibody-dependent cell-mediated cytotoxic activity decreased by 72 +/- 11 percent of the preoperative value (p less than 0.001). These findings reveal a positive correlation between the antibody-dependent cell-mediated cytotoxicity with RPMI-4788 and clinical activity of ulcerative colitis, and support the hypothesis that the antibody being studied has direct relation to the presence of the ulcerative colitis colon in situ.

Murine hybridoma antibodies against human transitional carcinoma-associated antigens

Spleen cells from mice immunized with the human urinary bladder transitional cell carcinoma cell line 647V have been fused with a syngeneic myeloma cell line to produce hybridomas. Screening of supernatants from 40 hybridomas which reacted with the immunizing cell line identified antibodies recognizing a variety of common, shared and tumor-associated antigens as well as newborn calf serum dependent antigens. Three hybridoma antibodies, 9A7 , 2E1 and 2A6 , recognize antigens found on all the human transitional cell carcinoma cell lines and tissue preparations tested, but the antigens were not found on normal human tissue (including urothelium), thus demonstrating the capability of the antibodies to distinguish normal from malignant bladder transitional epithelium. These antibodies, however, otherwise differ in their patterns of reactivity, with 1 recognizing an antigen which is also expressed on highly anaplastic malignant non-transitional cell carcinoma cell lines and tumors, while the other 2 demonstrate reactivities which are far more restricted to transitional cell carcinoma.

Immunobiologic staging of patients with carcinoma of the head and neck

For decades immunologic deficiencies have been documented in patients with carcinoma, and many investigators have attempted to utilize this information in determining prognosis more accurately. Determining prognosis more accurately would be most helpful with Stage III patients, since at present there are no useful guidelines as to which Stage III patients would benefit from aggressive surgery and/or radiation therapy and which would not. Assays of cellular immunity--such as skin testing, determining peripheral T-lymphocyte counts, and assessing lymphocyte reactivity--have achieved extremely limited clinical application. These assays are too expensive and/or too difficult to perform in the routine clinical setting. Total lymphocyte counts, however, are readily available in the clinical setting and can be helpful in determining prognosis. Other readily available clinical information, such as age and pretreatment serum immunoglobulin levels, can also be of value in determining prognosis. In this study, logistic regression was utilized to determine the prognostic implications of stage, age, and pretreatment total lymphocyte counts in 132 patients with carcinoma of the head and neck. Although each variable determined prognosis accurately less than 70% of the time, the stage, age, lymphocyte prognostic index (SALPI) accurately predicted outcome at 3 year follow-up 80% of the time (Pr. less than .0001). Discriminant function analysis was utilized to determine the prognostic implications of pretreatment serum immunoglobulins in 243 patients with head and neck carcinoma. A serum immunoglobulin prognostic index (SIPI) was derived which was based on the observations that elevated levels of immunoglobulin A (IgA) indicated a poor prognosis, while elevated levels of immunoglobulin E (IgE) and immunoglobulin D (IgD) indicated a favorable prognosis (Pr. less than .009). The SIPI was not as accurate as the SALPI in determining prognosis; however, when the indices were used simultaneously, concurring indices predicted the outcome of Stage III patients correctly 86% of the time.

Antibody-dependent cellular cytotoxicity in bullous diseases

Antibody-dependent cellular cytotoxicity (ADCC) was studied in six patients with pemphigus vulgaris, six patients with bullous pemphigoid, and thirteen controls. All patients had extensive, severe disease. The target cell used was a human lymphoblastoid cell line (LA 237) coated with either heterologous (rabbit R3) or homologous (anti-HLA-A5) antiserum. The assay consisted of a 2-hour incubation of patient and control lymphocytes with target cells in a ratio of 50: 1 and measuring 51Cr release. Statistically significant changes were not observed between the patients and the controls. This study indicated that ADCC mechanisms are unaltered by the disease process in patients with pemphigus vulgaris and bullous pemphigoid.

Spontaneous regression of pulmonary metastases from transitional cell carcinoma

Spontaneous regression of metastatic cancers occurs rarely and has been reported only once for pulmonary metastases from transitional cell carcinoma. Two cases of spontaneous complete regression of lung metastases from transitional cell carcinoma are presented. In one case, regression occurred after a course of radiation to the primary bladder cancer, but in the other patient, lung lesions disappeared without treatment to the primary or metastatic cancers. The factors that alter the tumor-host relationship to allow spontaneous regression of cancers are unknown, but observation of these phenomena may help reveal parameters that influence tumor progression in the majority of cancer patients.

Antibody-dependent lymphocyte cytotoxicity against basic protein of myelin in multiple sclerosis

An antibody was demonstrated in the serum of 166 out of 200 patients with MS which enabled normal lymphocytes to develop a cytotoxic (ADLC) reaction against MBP. The ADLC correlated with the stage of the process and was positive in 94% of those with active and in 62% of those with inactive disease independent of the type--relapsing or chronic progressive--and of the severity of the disease. Control studies in 200 patients with other organic nervous complaints gave positive findings in patients with carcinoma (7.5%), in rheumatoid arthritis (10-15%) and in syphilis (30%). On the ground of its good specificity and the frequency of positive findings, the reaction may be of diagnostic significance. In 55 of 57 CSF samples investigated in MS, the ADLC was positive. The intensity of the cytotoxicity in serum and CSF is practically identical. This finding supports the pathogenetic significance of the ADLC against MBP although it has no validity as a primary aetiological factor.

Immune complexes in transitional cell carcinoma

Bladder cancer patients from 2 different medical centers were examined to establish whether such patients have circulating immune complexes. Four methods of analysis were used: 1) polyethylene glycol precipitation, 2) double crossed immunoelectrophoresis, 3) Raji cell and 4) Clq binding assays. In the first group of 24 patients 17 had positive results on cystoscopy for pathologically defined tumors at the time of the serum sample. Two tested positive for the presence of circulating immune complexes by all 4 techniques and an additional 1 tested positive by 3 of the 4 techniques. In the second group of 54 patients (41 of whom had pathologically definable tumors at sample date) 9 were judged possibly positive by the Raji cell assay, the polyethylene glycol and double crossed immunoelectrophoresis techniques. When tested by the Clq binding assay 8 of the 9 patients were positive, most being in the range of 260 to 320 microgram/ml. immune complex. Combining all data from the 78 patients with bladder cancer the results in 10 cases definitely were positive by all 4 techniques and an additional 2 were positive by 3 techniques. Our data indicate that a low percentage (13 to 15 per cent) of patients with bladder cancer has circulating immune complexes. Of interest is that the complexes, as judged by our assay procedures, bind Clq, contain aggregated IgG and can be dissociated into antigen and antibody. Thus, the immune complexes are similar to those found in immune complex diseases.

Does cyclophosphamide induce bladder cancer?

An increasing incidence of bladder neoplasms temporally associated with chemotherapy, usually cyclophosphamide, is being reported. These secondary primary bladder malignancies are characteristically found in two groups of patients: those with lymphoproliferative or myeloproliferative tumors, and those with immunosuppression after organ transplantation. A case of adenocarcinoma of the bladder associated with malignant lymphoma is reported, and the known cases of second primary bladder malignancies after cyclophosphamide therapy as reported in the literature are reviewed. Studies relating to the enhanced occurrence of second primary cancers in lymphoproliferative disorders are presented. The recognized urologic toxicities of cyclophosphamide, including cytopathologic changes in animals and humans, are discussed. The observed association between immunosuppression and second primary malignancies is explored, as supported by studies on congenital immunodeficiency in humans, viral oncogenesis in experimental animals, and neoplasia after organ transplantation. Possible mechanisms of carcinogenesis associated with cyclophosphamide are reviewed, including suppression of humoral and cell-mediated immune defense mechanisms, direct carcinogenesis, or cocarcinogenesis. A plea is made for the orderly reporting and careful documentation of bladder tumors in patients receiving cyclophosphamide. It is suggested that prospective studies in these patients and in patients receiving cyclophosphamide for nonmalignant disorders would be of value in assessing the culpability of cyclophosphamide as a carcinogen.

Differences in pathological characteristics and prognosis of clinical A2 prostatic cancer from A1 and B disease

A retrospective study was done of 53 cases of clinical stages A1 to B2 prostatic carcinomas staged by pelvic lymphadenectomy. The study compared the histologic differentiation, degree of lymphocytic infiltration, incidence of lymph node metastases and type of cellular response of clinical stage A2 to stages A1 and B disease. The available data pertaining to the incidence and survival of patients with stage A2 prostatic carcinoma were analyzed. Our study indicates that 1 of every 3 unsuspected carcinomas is of clinical stage A2. The stage A2 tumors are diffused, with a higher degree of undifferentiation and a higher incidence of lymph node metastases than tumors classified clinically as stages A1 and B1. Also the survival of patients with clinical stage A2 tumors is lower than the survival of patients with clinical stage B1 disease. Clinical stage A2 tumors are more advanced biologically than clinical stage B1 tumors.

Suppressive effects of regional lymph node cells and extracts of antibody-dependent cellular cytotoxicity

Lymphocytes from regional lymph nodes that drain tumors and extracts of such lymphocytes suppress antibody-dependent cell-mediated target cell lysis by effector cells from cancer patients and controls. In contrast, lymph node cells from control patients are not suppressive. Control extracts from normal lymphocytes and 2 immunologically inert tissues, muscle and kidney, exhibit some suppressive activity but significantly less than extracts from lymph nodes that drain tumors.

In vitro morphological studies on antibody-dependent nonimmune lymphocyte-mediated cytotoxicity in chronic active liver disease

Using an in vitro system of antibody-dependent cellular cytotoxicity (ADCC), the killing effect of chronic liver disease sera on target Chang cells, mediated by effector nonimmune lymphocytes (NLy), was studied. NLy destroyed Chang cells in monolayers pretreated with sera of patients with chronic active liver disease (CALD). Sera from these patients with CALD, after receiving steroid therapy, demonstrated a significant decrease of the cytotoxic action of NLy. The target cells treated with sera of normal subjects or patients with chronic persistent hepatitis were only minimally affected. Morphological observations of the cytotoxic action in a CALD serum-treated group showed intimate contact between NLy and the target cells in the areas of the plaques, where large numbers of the target Chang cells were injured and were closely associated with effector NLy. The Chang cells developed cytoplasmic swelling. The surface became ruffled, and intracytoplasmic organelles displayed vesicular degeneration. Thereafter, cell rupture, and fragmentation occurred. The sera in patients with CALD appear to possess a membrane reactive factor, presumably antibody, against the surface membrane of Chang cells. This immunological mode of reaction between the effectors and target cells (ADCC) may be important in the perpetuation and pathogenesis of hepatocyte death in CALD.

In vitro antitumor reactivity of mononuclear leukocytes from cancer patients receiving immunotherapy with BCG

Mononuclear cell-mediated cytotoxicity (MCMC) against cultured tumor target cells was studied sequentially in melanoma and breast cancer patients before and during BGC administration. MCMC showed temporary fluctuations. In patients with locally advanced melanoma and carcinoma of the breast after tumor load reduction, the administration of BCG may increase the MCMC. This did not always correlate with a favorable clinical course. Potentiating serum factors appeared in 50% of these patients during BCG therapy, while blocking factors were rare. Neither correlated with prognosis. In patients with disseminated melanoma receiving chemoimmunotherapy, increases in MCMC may be related to clinical course. Blocking serum factors frequently developed in this group of patients and potentiating factors were rare. Neither correlated with the clinical course. Significant MCMC among normal donors and the apparent lack of specificity suggest a common nonspecific (? natural) cellular reactivity against cultured tumor target cells.

Commentary on the immunobiology of bladder cancer

This review is an attempt to integrate the conflicting studies that constitute the literature on immunobiology of bladder cancer and to indicate areas that need further investigation. It is clear that immune reactivity directed at antigens expressed on bladder cancer cells and general host immunologic competence decline with progressive tumor growth. This immunodepression correlates with patient prognosis, even within a given stage of disease. The mechanisms underlying this decline in host immune reactivity are poorly understood. A better understanding of these mechanisms may provide fundamental insight into the host-tumor relationship that possibly could be exploited for preventive, diagnostic and therapeutic purposes.

Antigens on melanoma cells detected by leukocyte dependent antibody assays of human melanoma antisera

Antibody-dependent cell-mediated cytotoxic assays have been used to examine antigens on human melanoma cells obtained either directly from patients or from long-term melanoma cell lines. A panel of melanoma antisera was selected from human subjects which could be shown not to have significant reactivity to histocompatibility antigens. With these antisera extensive cross-reactions between melanoma cells were found. However, the cross-reactivity was incomplete and the pattern of reactivity was different for each antiserum tested. These results were not consistent with a common melanoma antigen on human melanoma cells but rather indicated heterogeneity of melanoma antigens and multiple antibody specificities in the sera tested. This appeared to be confirmed by extensive cross-absorption studies which indicated limited cross-reactivity of antigens on melanoma cells from either long-term or short-term cultures. Several changes in the antigenic profile of melanoma cells in vitro from both long-term and short-term cultures were documented which resulted from contamination of the melanoma cell lines with non-melanoma cells and fibroblasts. Melanoma antisera may therefore be useful to mintor changes in long-term cultures which would otherwise give spurious results in in vitro tests. These results appear to have considerable significance for understanding tumour/host relationships and for the establishment of rational immunotherapeutic procedures and diagnostic tests in melanoma.

Production of tumor-specific inducer of cellular cytotoxicity by lethally irradiated mice

Antisera taken 1 or 2 days after inoculation of BALB/c mice with transplantable sarcoma cells or Moloney sarcoma virus (MSV) induce tumor-specific cell-dependent cytotoxicity in vitro. In the present experiments, lethally irradiated ("immunosuppressed") mice were tested for the early appearance of the serum factor responsible for this anti-serum-dependent cell-mediated cytotoxicity (E-ADC). BALB/c mice were infected with MSV, syngeneic sarcoma cells or sheep red blood cells 24 h following irradiation with 900 R. Sera were obtained from MSV and tumor cell recipients 48 or 72 h later and tested for E-ADC activity. Spleen cells from SRBC recipients were tested at day 4 or 5 for ability to form direct plaques in a modified Jerne plague assay. Although the anti-SRBC response was obliterated in the irradiated mice, the E-ADC response appeared to be unimpaired. These studies indicate that newly synthesized immunoglobulin is not required for the formation of the E-ADC factor.

Characterization of an early cytotoxicity-inducing factor in sera of Japanese quails after inoculation with Rous sarcoma virus

By pre-treatment with serum of normal spleen cells used in the microcytotoxicity assay, a humoral factor which induces cytotoxic activity in normal spleen cells was demonstrated in about 40% of sera of Japanese quails as early as 3 days after inoculation with Rous sarcoma virus (RSV). This cytotoxicity-inducing activity was not present either in the IgM or the IgG fraction obtained by Sephadex gel filtration. In sera of quails with experimentally induced agammaglobulinemia, the cytotoxicity-inducing activity was demonstrated at the same frequency as in normal animals. Thus, it seems unlikely that the early cytotoxicity-inducing factor is an immunoglobulin. On the other hand, membrane fractions extracted with 3 M potassium chloride from the RSV-induced quail tumor (QT) cells used as target cells in the microcytotoxicity assay exhibited cytotoxicity-inducing activity. After spontaneous regression of an RSV-induced tumor the serum of the regressor quail contained antibodies specific to the QT cell extract. This serum removed the cytotoxicity-inducing activity of both QT cell extract and serum sampled 3 days after RSV inoculation. In contrast, serum without antibody to the QT cell extract failed to absorb the cytotoxicity-inducing activity of the extract. It is therefore suggested that soluble tumor antigens can act as an early cytotoxicity-inducing factor.

Prognostic significance of regional lymph node histology in cancer of the bladder

The regional lymph nodes from 47 patients with carcinoma of the bladder who had undergone radical cystectomy and bilateral pelvic lymphadenectomy were classified into 3 histologic patterns that correlated with immunologic function. Lymph nodes were designated as stimulated if they exhibited prominent germinal centers (B cell proliferation) and expansion of the deep cortex (T cell proliferation), depleted if they appeared markedly hypocellular and fibrotic, and unstimulated if they resembled a normal resting lymph node. Correlation of the histologic pattern with the extent of disease revealed that patients whose nodes appeared stimulated had fewer metastases (p less than 0.05) than those with either unstimulated or unstimulated combined with a depleted pattern. A markedly improved 5-year survival rate was seen in patients with a stimulated pattern (p less than 0.0001) compared to those patients who exhibited a depleted and/or unstimulated lymph node pattern. The survival advantage related to the stimulated pattern was observed primarily among patients with advanced disease. It is suggested that stimulated nodes reflect proliferation of T and B lymphocytes engaged in cell-mediated and humoral immune responses to the bladder tumor and that this favorably influenced survival in those patients. Patients whose lymph nodes showed a depleted pattern fared poorly despite the extent of the disease and those with an unstimulated pattern were intermediate in survival. A depleted pattern may represent a state of local immune paralysis, exhaustion of the draining lymph nodes as a result of exposure to excess tumor-derived products such as antigen or toxic substances or simply an atrophic node incapable of response. In the absence of a local immune response such patients might be expected to do poorly. These results suggest that morphologic evaluation of the lymph nodes regional to bladder cancer may provide a clue to their immunologic function and a more accurate guide to prognosis of patients with this neoplasm.

Immunobiology of human bladder cancer

The immune destruction of bladder cancer most likely results from an interaction of specific and non-specific cellular and humoral responses evoked by tumor-associated antigens. We are just beginning to comprehend the complex immune mechanisms operating to retard or facilitate tumor growth in patients with this disease. This understanding has led to renewed hope that the immune system may be manipulated for the benefit of the tumor-bearing patient. However, only a thorough understanding of the basic functions of the immune system in man will permit a rational approach to immunotherapy in patients with bladder cancer.

Neuraminidase immunotherapy: serum potentiation of lymphocyte cytotoxicity related to immunoglobulin levels

Seven patients completed couses of immunotherapy using neuraminidase-altered autochthonous cells. Their response to therapy was monitored by a cytotoxicity assay using 3H-proline-tagged tumor cells from the patient's own cultured tumor in a strictly autologous system. Serum effects were measured by exposing the tumor target cells to serum to see whether this impeded (blocked) or augmented (potentiated) lymphocyte cytotoxicity. Three of the seven patients developed increasing degrees of serum blocking effect and all died within six months of completing therapy. Four of the seven showed rapidly decreasing blocking and three eventual potentiation. Three patients are living, improved, and free of evidence of tumor. There was an increase in average serum immunoglobulins in patients developing potentiation, and a decrease in those showing blocking. In any immunotherapy program attention must be given to in vitro monitoring studies, and such studies should include attention to the serum factors influencing host response.

Histological and Immunological Study of Patients with Lung and Digestive Tract Tumors. Analysis of T and B Lymphocytes from the Peripheral Blood and from the Lymph Nodes Draining the Tumor

The nature of the immune response to the tumor cell is complex and has yet to be clearly defined. Although past research has focused on the cytotoxic effect of T lymphocytes versus tumor cells, it has been shown in animal studies that B lymphocytes may also be implicated. Lymphocytes from patients with respiratory and digestive tract tumors were studied. B and T lymphocytes of peripheral blood and of draining lymph node tumors were studied using the following techniques: E rosettes (marker for T cells); membrane Ig, EAC rosettes, aggregated-Ig (marker for B lymphocytes); PHA and PKW in vitro response of lymphocytes using tritiated thymidine incorporation. It was observed that both groups of patients had normal or depressed B and T populations. PHA response was depressed in the majority of the cases with lung tumor. No difference was observed between lymphocytes from peripheral blood and from lymph node suspensions. As in normal lymph nodes the EAC rosettes were constantly observed in the cortical area of lymph node draining tumors. The immune defect observed in part of these cases is discussed in relation to the local and general immunological factors probably responsible for this defect.

Antibody-dependent cell-mediated cytotoxicity for human monolayer target cells bearing blood group and transplantation antigens and for melanoma cells

A sensitive assay for antibody-dependent cell-mediated cytotoxicity (ADCMC) was developed utilizing serum from a patient with gestational choriocarcinoma and the 3H-proline microcytotoxicity test for detection fo destruction of monolayer target cells. Conditions for optimal expression of ADCMC were investigated using serum from this patient and skin fibroblasts from her husband and daugther as target cells with semi-purified blood leukocytes from normal donors as effector cells. Factors critical for optimal expression of ADCMC in this assay are the selection of effector cell donors possessing high levels of activity in the presence of serum with known lymphocyte-dependent antibody. (LDA), the effector cell preparative technique, and incubation for up to 40 h. Tris-NH4Cl lysis of red blood cells was found significantly to reduce effector cell activity. Under optimal conditions, the LDA titer of this patient's serum was greater than 10(-4). The sensitivity of the assay was confirmed by the detection of LDA activity of an anti-blood-group antibody at dilutions not demonstrating hemagglutination, and by the induction of ADCMC for blood group A antigen-bearing target cells by normal sera of B and O blood groups. In a preliminary study of sera from 16 melanoma patients on the corresponding antologous tumor target cells, four had significant LDA. Further studies are under way to determine specificty, incidence, and relationship of LDA-positive autologous sera to course of disease.

Evidence for two factors in sera of tumor-immunized mice which induce specific lymphoid cell-dependent cytotoxicity: IgG2 and a rapidly appearing factor not associated with IgG or IgM

As previously shown, sera from tumor-bearing mice can induce specific antiserum-dependent lymphoid cell-mediated cytotoxicity (ADC) to syngeneic tumor cells in vitro. The ADC activity in such sera is now shown to be removed by adsorption of the sera to Sepharose-linked rabbit anti-mouse immunoglobulin or to goat anti-mouse IgG2. Immunoglobulins recovered by elution from the affinity columns mediated ADC to the specific tumor cells. In addition, the eluted immunoglobulin passively "armed" normal lymph-node cells in vivo so they were specifically cytotoxic when tested in vitro. Sera taken 48 h after inoculation of tumor or syngeneic tumor cells (before the appearance of palpable tumor) were also shown previously to induce lymphoid cell-mediated cytotoxicity in vitro. This cytotoxic activity was not removed by adsorption of the sera to either anti-IgG or anti-IgM-linked Sepharose. Thus both IgG and an early-appearing serum component which is apparently neither IgG nor IgM can induce specific cell-mediated cytotoxicity by non-immune lymphoid cells in vitro.

Specific anti-tumor responses by cultured immune spleen cells. II. Culture supernatants induce specific anti-tumor cytotoxicity by non-immune lymphoid cells in vitro

Sera from tumor-bearing mice induce specific cytotoxicity to tumor cells by non-immune lymphoid cells (antiserum-dependent cytotoxicity or ADC). When spleen cells from BALB/c mice bearing autochthonous or syngeneic sarcomas were cultured in vitro, culture supernatants were obtained which specifically sensitized sarcoma cells to injury in vitro by normal lymph-node cells (LNC). Culture supernatants of spleen cells from mice whose transplanted sarcomas had been excised also induced ADC. The ADC activity resided in the mouse immunoglobulin fraction of the culture supernatants and its synthesis did not depend on the presence of theta-positive cells. Following a brief in vivo exposure to culture supernatant with known ADC activity, LNC from non-immune mice specifically destroyed tumor cells in an in vitro assay.

Carcinoma of the urinary bladder in patients receiving cyclophosphamide

Hemorrhagic cystitis is a common side effect of cyclophosphamide therapy not observed with other alkylating agents. In five patients receiving cyclophosphamide by mouth for prolonged periods with large cumulative dosage urinary-bladder tumors fatal to four and requiring cystectomy in the lone survivor developed. These observations strongly suggest chemical carcinogenicity of this drug in the production of these tumors. Increasingly, cyclophosphamide is being used for non-neoplastic disease. These circumstances suggest careful follow-up observation of patients in whom hemorrhagic cystitis from this drug develops for evidence of bladder cancer, as well as restraint in use of cyclophosphamide for non-neoplastic diseases if alternative therapy is available.