Clinical trial: colectomy after rescue therapy in ulcerative colitis - 3-year follow-up of the Swedish-Danish controlled infliximab study

BACKGROUND

The long-term efficacy of infliximab as rescue therapy in steroid-refractory ulcerative colitis is not well described.

AIM

To examine the long-term efficacy of infliximab as a rescue therapy through a 3-year follow-up of a previous placebo-controlled trial of infliximab in acute steroid-refractory ulcerative colitis.

METHOD

In the original study, 45 patients were randomized to a single infusion of infliximab 5 mg/kg or placebo, and at 3 months, 7/24 patients given infliximab were operated vs. 14/21 patients given placebo. Three years or later, patients were asked to participate in a clinical follow-up.

RESULTS

Another seven patients underwent colectomy during follow-up: five in the infliximab group and two in the placebo group. After 3 years, a total of 12/24 (50%) patients given infliximab and 16/21 (76%) given placebo (P = 0.012) had a colectomy. None of eight patients in endoscopic remission at 3 months later had a colectomy compared with 7/14 (50%) patients who were not in remission (P=0.02). There was no mortality.

CONCLUSION

The benefit of rescue therapy with infliximab in steroid-refractory acute ulcerative colitis remained after 3 years. The main advantage of infliximab treatment occurred during the first 3 months, whereas subsequent colectomy rates were similar in the two groups. Mucosal healing at 3 months influenced later risk of colectomy.

Randomized controlled azathioprine withdrawal after more than two years treatment in Crohn's disease: increased relapse rate the following year

INTRODUCTION

Azathioprine is effective for maintenance of remission in Crohn's disease, however, duration of efficacy and the dose response relationship has not been fully evaluated.

AIMS

To investigate whether patients kept in remission by azathioprine treatment for >2 years benefit from further treatment, and to explore dose-response relationship.

PATIENTS AND METHODS

In an open 12-month trial, patients with inactive Crohn's disease after >2 years (median 37 months) of azathioprine treatment were randomized to azathioprine withdrawal or continued treatment. Primary end point was relapse defined as: (i) Crohn's disease activity index rise >/= 75, and Crohn's disease activity index >150 or (ii) disease activity requiring intervention.

RESULTS

Of 29 patients, 28 completed the observation period or relapsed. Eleven of 13 patients (85%) continuing azathioprine remained in remission compared with seven of 15 (47%) observed without azathioprine (P = 0.043). In patients who had been treated with azathioprine >1.60 mg/kg/day the difference was even more pronounced, eight of nine (89%) vs. four of 12 (33%) respectively (P = 0.017).

CONCLUSIONS

Patients with Crohn's disease in remission after >2 years of continuous azathioprine treatment will benefit from further continued treatment. Further controlled studies with azathioprine doses <2.0 mg/kg/day are needed.

On-demand treatment in patients with oesophagitis and reflux symptoms: comparison of lansoprazole and omeprazole

BACKGROUND

There are few data on how patients on maintenance treatment of reflux oesophagitis take their medication. This study was designed to investigate the dosing patterns of patients on on-demand treatment and to compare lansoprazole with omeprazole in this regard.

METHODS

Patients with reflux oesophagitis, initially treated until absence of symptoms, took capsules of either lansoprazole (30 mg) or omeprazole (20 mg) for 6 months; they were instructed to take the medication only when reflux symptoms occurred. In order to document dosing patterns, the medication was dispensed in bottles supplied with a Medication Event Monitoring System recording date and time the bottles were opened. There were regular follow-up visits with assessment of symptoms.

RESULTS

Three-hundred patients were eligible for analysis according to 'all patients treated'. A dosing pattern was found of an increased intake mornings and evenings and constant intervals between intakes. Although there was no correlation between oesophagitis grade or initial symptoms and the amount of medication consumed, the patients had significantly fewer reflux symptoms the more medication they consumed. There was no difference in the number of capsules consumed between the lansoprazole (0.73 capsules/day) and omeprazole groups (0.71 capsules/day). Nor was there any difference between the groups in reflux symptoms during the course of the study.

CONCLUSION

Despite rigorous instructions to take medication on demand, the results suggest that it is patient habits more so than symptoms that determine the frequency and interval of medication intake. Symptoms are not therefore decisive for the amount of medication consumed.

Eradication of Helicobacter pylori compared with long-term acid suppression in duodenal ulcer disease. A randomized trial with 2-year follow-up. The Danish Ulcer Study Group

BACKGROUND

Trials evaluating long-term management of duodenal ulcer disease have mainly been focused on recurrence of ulcers, disregarding effects on dyspeptic and reflux symptoms. Profound acid inhibition with a proton pump inhibitor is the gold standard therapy in acid-related diseases. We aimed to compare the symptomatic effects of eradication therapy with those of long-term omeprazole treatment in a design with periods both with and without acid inhibition.

METHODS

Patients with active duodenal ulcer were randomized either to omeprazole, 20 mg twice daily until healing, followed by omeprazole, 20 mg/ day for 1 year, or to eradication therapy (metronidazole, amoxicillin, and omeprazole for 2 weeks) followed by placebo for 1 year. All patients were followed up passively for an additional year. Clinical controls were performed every 2 months the 1st year (maintenance phase) and every 6 months during the passive follow-up phase. The study was multicentric and double-blind. The primary end-point was discontinuation of treatment, irrespective of reason.

RESULTS

Two hundred and seventy-six patients were randomized (139 in the eradication treatment group). In the maintenance phase there were no differences in the reporting of dyspeptic symptoms or in premature withdrawal. In the passive follow-up phase only five patients in the eradication therapy group discontinued owing to relapse of dyspeptic symptoms or ulcer, compared with 51 patients initially randomized to long-term omeprazole. There were no differences in reflux symptoms or in the development of reflux oesophagitis.

CONCLUSIONS

Eradication therapy and long-term omeprazole are equally effective in controlling dyspeptic symptoms and reflux in duodenal ulcer patients with healed ulcers. One-quarter of the duodenal ulcer patients who start eradication therapy continue to be symptomatic or fail therapy for other reasons over a 2-year period. Eradication therapy does not increase the risk of reflux in ulcer patients.

[Azathioprine treatment of Crohn disease]

Azathioprine/6MP (AZA/6MP) is effective in long-term treatment (> 3 months) of Crohn's disease and superior to other established medical treatments. The optimal dose remains to be defined. So far, effect has been demonstrated with 2-2.5 mg azathioprine/kg/day, but not with 1 mg/kg/day. A disease controlling effect has been demonstrated during up to four years of continuous treatment, after which data remains to be established. As part of remission-inducing combination therapy the effect of AZA/6MP can not be detected until two-three months after treatment start. High dose intravenous AZA/6MP administration does not shorten this interval. Reversible dose dependent side effects may require dose reduction or termination of treatment. Reversible dose independent side effects exclude further or repeated treatment. Some 10-15% stop treatment due to side effects. There is no increased death rate due to cancer in AZA/6MP treated Crohn patients. When giving the above full dose of AZA/6MP, monthly blood tests are recommended for the entire treatment period, more often during the first three months.

The effect of cisapride in maintaining symptomatic remission in patients with gastro-oesophageal reflux disease

BACKGROUND

Successful treatment of gastro-oesophageal reflux disease (GORD) has traditionally been assessed as healing of reflux oesophagitis, which may not be relevant in patients with moderate disease. In these patients symptom relief and patient satisfaction with therapy are of fundamental importance. Cisapride has well-documented prokinetic effects and may be well suited for long-term therapy of GORD, but its effectiveness in purely symptomatic treatment is unknown. We therefore compared two dosage regimens of cisapride with placebo over a period of 6 months in patients with evidence of gastrooesophageal reflux, initially treated with antisecretory medication, with regard to maintaining symptom relief and satisfaction with treatment.

METHODS

Five hundred and thirty-five patients with reflux oesophagitis grade 1 (n = 293) or 2 (n = 124) or with no reflux oesophagitis but pathologic 24-h pH-metry (n = 118) achieved satisfactory symptom relief with an H2-receptor antagonist or proton pump inhibitor within 4-8 weeks. In a double-blind randomized, parallel-group study, they were then treated with cisapride, 20 mg at night or 20 mg twice daily, or placebo and followed up for a maximum period of 6 months. Relapse was defined as dissatisfaction with therapy or an average consumption of more than two antacid tablets a day.

RESULTS

Median time to relapse was 63 days for cisapride, 20 mg twice daily; 59 days for cisapride, 20 mg at night; and 49 days for placebo. Time to relapse was not significantly different (P = 0.09). Presence and grade of oesophagitis at base line, type of therapy before randomization, and pattern of non-reflux symptoms at base line did not influence these findings significantly.

CONCLUSION

The study indicates that cisapride is of limited value in maintenance therapy of GORD in patients in whom symptom relief has been accomplished with potent antisecretory medication. This 'step-down' approach to therapy seems disadvantageous in the long-term therapy of GORD.

[Prevention of duodenal ulcer recurrence with penicillin]

The aim of this study was to test the hypothesis that infection with Helicobacter pylori is essential for recurrence of duodenal ulcer. We performed a randomized controlled trial of the relapse rate of duodenal ulcer during 12 weeks treatment with penicillin V or placebo in 170 out-patients from five centres. The relapse rate was 9% during treatment with penicillin and 50% with placebo, P < 0.0001. It is concluded that infection with penicillin-sensitive bacteria, i.e. H. pylori, plays an important role for recurrence of duodenal ulcer disease. Penicillin V suppresses this infection but does not eradicate it.

Prevention of duodenal ulcer recurrence with penicillin. A double-blind, placebo-controlled trial

Eradication of Helicobacter pylori is associated with a reduced recurrence of duodenal ulcer (DU). The relationship between H. pylori and DU has been interpreted as causal, but the evidence has been criticized for methodologic reasons. To ascertain whether an antibiotic with no effect on epithelial-cell integrity prevents DU recurrence, we conducted a randomized double-blind trial of phenoxymethylpenicillin (PEN), 2.4 twice daily, and placebo (PLA). Patients with an active DU and positive H. pylori culture from antral biopsy specimens were treated with 40 mg omeprazole daily for 4 weeks, but at week 2 they were allocated at random to PEN (85 patients) or PLA (85 patients) for up to 14 weeks. Those without recurrence during this treatment were followed up for another 6 months. Endoscopy and H. pylori culture were performed at the end of the treatment period and at the end of follow-up, and in between if ulcer symptoms recurred. During the treatment period the ulcer relapse rate was 5 of 58 (9%) in the PEN group and 34 of 68 (50%) in the PLA group (P < 0.0001, log-rank test), with 53% and 14%, respectively, of the patients in the two groups being H. pylori-negative. The relapse rate in the PEN group did not differ between H. pylori-negative and H. pylori-positive patients. The recurrence rate in the PEN group remained low for another 5 months but then approached the rate in the PLA group. The prevalence of H. pylori-negative patients at the end of follow-up was 20% in the PEN group and 10% in the PLA group. These data provide strong evidence that DU has a bacterial cause, with H. pylori as the likely agent.

Treatment of Crohn's disease with fusidic acid: an antibiotic with immunosuppressive properties similar to cyclosporin

Fusidic acid is an antibiotic with T-cell specific immunosuppressive effects similar to those of cyclosporin. Because of the need for the development of new treatments for Crohn's disease, a pilot study was undertaken to estimate the pharmacodynamics and tolerability of fusidic acid treatment in chronic active, therapy-resistant patients. Eight Crohn's disease patients were included. Fusidic acid was administered orally in a dose of 500 mg t.d.s. and the treatment was planned to last 8 weeks. The disease activity was primarily measured by a modified individual grading score. Five of 8 patients (63%) improved during fusidic acid treatment: 3 at two weeks and 2 after four weeks. There were no serious clinical side effects, but dose reduction was required in two patients because of nausea. Biochemically, an increase in alkaline phosphatases was noted in 5 of 8 cases (63%), and the greatest increases were seen in those who had elevated levels prior to treatment. All reversed to pre-treatment levels after cessation of treatment. The results of this pilot study suggest that fusidic acid may be of benefit in selected chronic active Crohn's disease patients in whom conventional treatment is ineffective. Because there seems to exist a scientific rationale for the use of fusidic acid at the cytokine level in inflammatory bowel disease, we suggest that the role of this treatment should be further investigated.

Leucocyte scintigraphy to localize inflammatory activity in ulcerative colitis and Crohn's disease

The validity of using autologous leucocytes labelled with technetium -99m hexamethyl-propyleneamine-oxine (Tc-HMPAO) for scintigraphy in inflammatory bowel disease was evaluated in 12 patients with clinically active ulcerative colitis (UC) and 10 with Crohn's disease (CD). Colonoscopy and biopsy were used as reference. Scintigrams taken 1 h and 3 h after leucocyte reinjection were evaluated blindly by two independent observer groups. Full agreement was found in 11 of 12 UC patients when compared with colonoscopy but in only 3 of 10 CD patients. Segments with agreement in CD patients often showed neutrophilic granulocyte infiltration at biopsy. The judgements of clinicians and physiologists differed for only 2 of totally 70 UC segments but for 13 of 59 CD segments (kappa, 0.94 and 0.52). It is concluded that Tc-HMPAO scintigraphy might be an alternative to colonoscopy in the control of disease extent in UC. In CD patients the technique might warn about infections complications.

Increased concentrations of interleukin 1 beta, interleukin-2, and soluble interleukin-2 receptors in endoscopical mucosal biopsy specimens with active inflammatory bowel disease

Concentrations of interleukin-1 beta (IL-1 beta), interleukin-2 (IL-2), and soluble IL-2 receptors (sIL-2R) were determined by enzyme linked immunosorbent assays (ELISA) in supernatants of sonicated endoscopical mucosal biopsy specimens from 31 patients with inflammatory bowel disease and 19 controls. IL-1 beta was detected in 53% of the patient supernatants (p = 0.0001), IL-2 in 35% (p = 0.0031), compared with none of the controls. Soluble IL-2R was present in 55% and 26% of the specimens, respectively (p = 0.07). The concentrations of IL-1 beta (p = 0.00015), IL-2 (p = 0.0019), and sIL-2R (p = 0.0073) were highest in the most inflamed biopsy specimens, compared with less inflamed specimens and controls. There were no significant differences in IL-1 beta, IL-2, and sIL-2R concentrations between ulcerative colitis (16) and Crohn's disease patients (15). The results suggest that enhanced cellular immunity operates in vivo at the mucosal level in active inflammatory bowel disease.

Colonic epithelial dysplasia or carcinoma in a regional group of patients with ulcerative colitis of more than 15 years duration

Colonoscopic screening for neoplasia was performed in a regional group of ulcerative colitis patients with a disease duration of greater than or equal to 15 years. A total of 121 patients, aged less than 80 years, were invited to participate, of whom 100 (83%) accepted colonoscopy, including biopsies in 15 standard locations of the entire colon, plus additional biopsies from all visible lesions. Unequivocal dysplasia was found in one patient with extensive colitis and a disease duration of 31 years. A polyp with highly differentiated adenocarcinoma was found in the sigmoid colon of a patient with intermittent rectum involvement, 37 years after the ulcerative colitis diagnosis had been made. Biopsy specimens from the remaining 98 patients showed no signs of dysplasia or cancer. Thus the frequency of pre-malignant or malignant changes is very low compared with the results of similar studies, and the rationale for general colonoscopic surveillance programmes for such patients is open to question.

The effect of the benzodiazepine antagonist flumazenil on the sequels of diazepam given before upper gastrointestinal endoscopy. A double-blind randomized trial

The prolonged sedation of benzodiazepines may be inconvenient for the patient. Reversal of sedation, therefore, would be desirable. Accordingly, we assessed the efficacy of the benzodiazepine antagonist flumazenil in a placebo-controlled randomized trial including 40 adults undergoing upper gastrointestinal endoscopy under diazepam (Diazemuls) sedation. We found no significant differences between groups with regard to either performance (two tests) or duration (within 240 min) of sedation. There were no noticeable side effects.

Golytely preparation for colonoscopy: 1.5 liters is enough for outpatients

In a prospective double-blind study of the effectiveness and patient acceptance of Golytely whole-gut preparation for colonoscopy, 50 consecutive patients were randomly allocated to drink either 1.5 l (Group I) or 3 l (Group II). The patients had some slight dietary restrictions, and received mild laxatives on the preceding day. The cleansing result did not differ significantly in the two groups. The result was assessed as "good" in 76% of cases in Group I (95% confidence limits 55-91%) and in 83% of cases in Group II (95% confidence limits 63-95%). In half of the remaining cases in both groups the result was "acceptable" and in the other half "poor". Patient acceptance did not differ significantly in the two groups. After completion of the randomized study, oral cleansing with 1.5 l Golytely has been our daily routine. In 42 patients so treated quality of cleansing was good in 81% (95% confidence limits 66-91%), acceptable in 12%, and poor in 7%.

Acyclovir in the prevention of duodenal ulcer recurrence

This study tests the hypothesis that reactivation of a latent herpes simplex virus infection may be a cause of recurrent duodenal ulceration. Patients with recently healed duodenal ulcer were entered into a double blind, randomised study of maintenance treatment with the antiviral drug acyclovir (400 mg bid) versus placebo, to determine if suppression of herpes virus infection would influence the natural history of the ulcer disease. One hundred and fifteen patients entered the trial and 76 patients completed it according to the protocol. Endoscopy was performed when ulcer symptoms recurred and at the end of the 25 week trial period. In the acyclovir group the cumulated relapse rate was 63% compared with 56% in the placebo group (NS). This result suggests that reactivation of herpes simplex virus is not a cause of recurrent duodenal ulcer.

99mTc-sucralfate scintigraphy in inflammatory bowel disease

Technetium-99m-labeled albumin-sucralfate was orally administered to 11 patients (Crohn's disease, 8; ulcerative colitis, 3) and 3 healthy volunteers. Serial scintigraphy was performed, and scintigraphic interpretations were compared with radiographic and endoscopic findings in an open study. We were not able in any patient to relate the scintigraphic findings to the localizations of inflammatory bowel disease, nor could we distinguish the scans in the patients from the scans of the healthy volunteers. We conclude that 99mTc-albumin-sucralfate scintigraphy is of no value in the detection of inflammatory bowel disease.

Supposed coeliac disease during childhood and its presentation 14-38 years later

Thirty-five subjects treated with a gluten-free diet for a chronic gastrointestinal disorder (no biopsy performed) in early childhood were re-examined 14-38 (median, 28) years later. Twenty-one accepted jejunal biopsy at re-examination. None of those studied were on a gluten-free diet at the time of the study. Ten of 21 biopsy specimens were abnormal--6 with flat mucosa and very low disaccharidase levels, indicating coeliac disease, and 4 with low disaccharidase activity but morphologically normal mucosa. Three of the six subjects with flat mucosa showed a slight fat and lactose malabsorption, but their clinical condition did not suggest serious intestinal disease. Ingestion of gluten throughout most of childhood did not appear to affect growth, as evaluated by final height. Jejunal biopsy is recommended in all patients with gastrointestinal symptoms that are not otherwise explainable if their medical history shows a period of gluten-free diet for a chronic gastrointestinal disorder in childhood.

5-Aminosalicylic acid in the treatment of Crohn's disease. A 16-week double-blind, placebo-controlled, multicentre study with Pentasa

The response to 5-aminosalicylic acid (5-ASA) in mild and moderately active Crohn's disease localized in the small bowel was studied in a randomized, double-blind, placebo-controlled trial in four centres. Sixty-seven patients were included, of whom 30 were treated with 1500 mg slow-release 5-ASA/day (Pentasa) for a scheduled period of 16 weeks. In the 5-ASA group 40% of the patients improved, versus 30% of the placebo-treated group ('intent to treat' basis; p greater than 0.1). Four of the patients treated with 5-ASA left the study owing to disease deterioration, versus 10 of the placebo-treated patients (p greater than 0.2). Seventeen patients were secondarily excluded, and the remaining 50 patients (23 receiving 5-ASA) were reevaluated in greater detail. No statistically significant differences in outcome were shown. Three patients (one given 5-ASA) were withdrawn from the study because of presumed side effects, but no serious adverse reactions were recorded. The present results indicate that 5-ASA, at least in the dosage used, is not superior to placebo. Nevertheless, trends towards a beneficial effect in Crohn's disease in the small bowel justify further clinical trials with a larger dosage of 5-ASA.

CEA and carbohydrate antigens in normal and neoplastic colon mucosa. An immunohistochemical study

Antibodies raised against tumour-associated antigens have been assessed for tumour selectivity using an indirect immunohistochemical peroxidase staining of formalin-fixed, paraffin-embedded tissue from colon carcinomas, colon polyps and normal mucosa. The following antibodies were used: 1) Unabsorbed polyclonal antibody to carcinoembryonic antigen (poly-CEA). 2) Monoclonal antibodies to CEA (mabs 3851 and 27). 3) Monoclonal antibodies to protein-bound carbohydrates (mabs C 216 and C 242) or to lipid- and protein-bound carbohydrates (C 50 and 19-9). These antibodies had been produced by hybridization of lymphocytes from mice, immunized with colon carcinoma cell lines or colon cancer tissue. All antibodies were used in one concentration only, preselected by initial titration experiments. No antibody was completely tumour-specific, but four antibodies, mabs 3851, 27, C 216 and C 242, showed statistically significant tumour selectivity. Using these antibodies, respectively 19, 19, 19, and 18 of 20 colon cancer were stained compared with 3, 4, 4, and 8 of 15 specimens of colon mucosa from normal controls. An increased frequency of staining was also noted in dysplastic polyps (statistically significant using mabs 3851 and C 216) and in dysplastic mucosa adjacent to a tumour (statistically significant using mabs 3851 and 27). The staining frequency of normal colon mucosa in cases of colon cancer did not differ from that in the normal controls. Poly-CEA and the anti-ganglioside mabs C 50 and 19-9 revealed no tumour selectivity. A pronounced goblet cell staining was seen using C 50, C 242 and 19-9.

A classification of human urothelial cells propagated in vitro

Human urothelial cell lines of non-malignant and malignant origin were classified into three grades of transformation, i.e. TGr I, TGr II, and TGr III, which differ from primary and early cultures of normal bladder mucosa (TGr 0) by growth in the absence of fibroblasts, prolonged survival, increasing chromosomal abnormalities, and antigenic modifications. Non-malignant pure epithelial cell lines with a prolonged, but finite life span (18-38 passager in vitro) were classified as TGr I. These cells were characterized by chromosomal counts showing a considerable variation but with a near-diploid mode and a smaller size but otherwise normal morphology. TGr II cells differed from TGr I by infinite growth transformation and wide morphological variability. TGr III cells were above all characterized by their ability to produce tumors in nude mice and to invade and destroy fragments of embryonic heart in vitro. These immortalized cells were small with a large nucleus and a uniform polygonal shape. Chromosomal counts showed pronounced aneuploidy with an increased number of chromosomes.

Comparative studies of normal, 'spontaneously' transformed and malignant human urothelium cells in vitro

In numerous in vitro studies of cell-mediated cytotoxicity directed against transitional cell carcinomas (TCC) urothelial cells of normal origin have served as control material. In the present work, which includes 13 human bladder cell lines of non-malignant or malignant origin, a comparison was made of morphology, chromosomal mode, growth fraction and tumorigenicity in nude mice. Signs of apparently spontaneous transformation were seen in two cell lines of non-malignant origin. The possibilities for cross-contamination as an explanation of these signs of 'spontaneous' transformation are discussed. During these studies radiation-dependent cytotoxicity of disposable microtissue culture plates was revealed as another important source of error.

Human spontaneous lymphocyte-mediated cytotoxicity (SLMC) against malignant and normal tissue-derived target cell lines tested in autologous and allogeneic combinations by the microcytotoxicity assay

Effector cell types and effector mechanisms of human spontaneous lymphocyte-mediated cytotoxicity (SLMC) were studied in a 44-h microcytotoxicity titration assay. Peripheral blood lymphocytes from cancer patients and controls were used as effector cells either unfractionated or after fractionation by rosetting techniques or affinity chromatography. The possible immunoglobulin dependency of the reactions was studied by incorporation of specific Fab fragments of rabbit anti-human IgG antibodies in the incubation mixtures. Twelve different target cell lines of either high or low sensitivity to SLMC and with or without easily detectable HLA antigens were used. Most of the target cells were cell lines derived from transitional cell carcinoma of the urinary bladder (TCC). Both allogeneic and autologous lymphocyte target cell combinations were tested. Although high- and low-sensitivity target cells differed significantly in susceptibility to lysis, the predominating SLMC was displayed by Fc-receptor-positive lymphocytes in both allogeneic and autologous combinations. Addition of the Fab anti-immunoglobulin reagent to the incubation mixtures resulted in strong inhibition of cytotoxicity regardless of the type of target cells used and in allogeneic as well as in autologous lymphocyte target cell mixtures. However, in some combinations no inhibition was seen and inhibition was usually not complete, suggesting that both immunoglobulin-dependent (i.e., ADCC-like) and immunoglobulin-independent mechanisms were involved in the cytotoxicity reactions. The results of the microcytotoxicity assay were compared with those obtained with aliquots of the same lymphocytes and target cells in an 18-h 51Cr-release assay. While similar results were obtained with high-sensitivity target cells, with low-sensitivity targets and in some autologous combinations the two assay systems registered lymphocyte/target cell interactions which differed with regard to specificity, effector cell type, and immunoglobulin dependency.

Lymphocyte-dose response relationship in spontaneous lymphocyte mediated cytotoxicity (SLMC) measured by microcytotoxicity assay

Titrations of spontaneous lymphocyte-mediated cytotoxicity (SLMC) in a 44-hour microcytotoxicity assay (MA) by serial dilutions of effector lymphocytes were performed to characterize the lymphocyte-dose response relationship, and to investigate the methodological basis for comparative cytotoxicity studies. The following lymphocyte fractions were used: unseparated, E rosetting, non-E rosetting, EA rosetting, and non-EA rosetting. Assays were performed against target cell lines from normal and malignant urothelium with high or low sensitivity to SLMC in allogeneic and autologous combinations, and against an osteosarcoma cell line. Analysis of SLMC titration curves showed that two different mathematical models could be used to describe the relationship between lymphocyte concentration and SLMC, I: linear relationship (log lymphocytes, CI) with exclusion of both high and low CI values, and II: sigmoid relationship (log lymphocytes, CI) which was transformed to linear relationship (log lymphocytes, log CI/100 - CI), including also high and low values. It is pointed out that perfect quantitative comparisons of SLMC in different combinations were complicated by statistically significant differences between the curve slopes. However, estimations based on experimental results in a range close to 50% cytotoxicity index (CI) may be acceptable, as the differences between slopes were small.

Monolayer cultures of cells originating from ultrasonically guided fine needle aspiration biopsies

Explantation of small samples of tissue obtained by ultrasonically guided fine needle aspiration biopsy (0.6 mm outer diameter) from intraabdominal solid masses was performed in 25 patients. In 7 cases, the material was taken from nonmalignant tissue and in 18 from malignant lesions. Growth during 30 days or more obtained in 1 of the 7 nonmalignant cases and in 7 of the 18 malignant cases. The morphological appearance of three cultures in monolayer is demonstrated.

Cytotoxicity in vitro of blood lymphocytes from bladder cancer patients and controls to allogeneic or autologous tumor cells derived from established cell lines or short-term cultures

Blood lymphocytes from small groups of patients with transitional-cell carcinoma of the urinary bladder (TCC), clinical controls (CC) or healthy donors (HD) were tested for cytotoxicity in vitro by a 51Cr-release assay. The target cells were either from TCC or control tissue (long-term cultures) or were from short-term TCC cultures, kept in vitro for 10-20 transfer generations. When tested with allogeneic target cells from long-term cultures, TCC patients' lymphocytes tended to be more cytotoxic to TCC targets than to control targets. For the control lymphocytes this was not seen. A large proportion but not all of the cytotoxicity to these target cells was due to immunoglobulin-dependent cellular reactions, probably mediated by natural and disease-related antibodies of the lymphocyte donors, since it was significantly inhibited by Fab-fragments of rabbit antibodies to human immunoglobulin. Moreover, it was, to a large extent, mediated by lymphocytes with Fc-receptors for IgG. For seven of the TCC target cell cultures (two long-term and five short-term) autologous lymphocytes were also available for testing. While two patients were non-reactive to their own tumor cells, five reacted strongly in the autologous combinations. These autologous reactions were immunoglobulin-independent and were mediated by Fc-receptor-negative effector cells. In some instances, autologous cytotoxicity was accompanied by similar reactions to some of the allogeneic TCC targets but not to the allogeneic non-TCC control targets. On the basis of available information on HLA antigens in this material, the pattern of cross-reactions suggests that the cytotoxicity encountered in the autologous and in some of the allogeneic TCC-combinations may be the expression of antibody-independnet but specific CTL-mediated reactions, regulated by HLA. However, at the present stage of the investigation, other mechanisms must also be considered since the target cells from short-term TCC cultures were sometimes lysed by control lymphocytes in immunoglobulin-independent reactions. Whatever the explanation, the results show that the cytotoxicity observed in the in vitro systems is usually the net result of several different types of reaction. Which effector cell types and which mechanism of recognition will predominate in a given lymphocyte/target cell combination is greatly influenced by the nature and origin of the target cells used.

The specificity of the microcytotoxicity assay for cell-mediated immunity in human bladder cancer

Cytotoxicity of lymphocytes from T1 or T2 bladder cancer patients and patients with other diseases was tested in 44-hour microcytotoxicity assay against 3 different target cell lines: 1) HU 456, derived from human bladder carcinoma and established in our laboratory, 2) HU 609, a line derived from normal human bladder tissue and established in our laboratory and 3) SAOS-2, a human osteosarcoma cell line from the Memorial Sloan-Kettering Cancer Institute. Lymphocyte concentrations ranging from 7.8 time 10(4) to 2.5 times 10(6) lymphocytes per ml. were tested against each cell line. Lymphocytes from both groups of patients demonstrated a cytotoxicity against all 3 target cell lines, proportional to the lymphocyte concentration used. There was no difference in reactivity to HU 609 or to SAOS-2 between bladder cancer and control patients but the lymphocytes of bladder cancer patients showed a statistically greater cytotoxicity for HU 456, demonstrating a tumor type-specific cellular immune reaction superimposed on a background of non-specific cytotoxicity.