O. Eremin

Modulation in vitro of human natural cytotoxicity, lymphocyte proliferative response to mitogens and cytokine production by essential fatty acids

Essential fatty acids (EFA) have been shown in animal studies to have a differential effect on various aspects of immune reactivity. However, there have been few studies in humans. Therefore, we elected to investigate the effects of a variety of EFA [ gamma‐linolenic acid (GLA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] in vitro on human blood lymphocyte reactivity, cytokine secretion and natural cytotoxicity. The proliferative response to polyclonal mitogens (phytohaemagglutinin, pokeweed mitogen, concanavalin A), as measured by [3H]thymidine incorporation into newly synthesized lymphocytes, was inhibited (P<0·05) by all EFAs tested, in a dose‐dependent manner (3–15 &mgr;g/ml). The greatest inhibition of proliferation was caused by EPA and DHA. Similarly, EPA, DHA and GLA significantly reduced cytotoxic activity [expressed as lytic units, using 51 chromium‐release assays, natural killer (NK) (K562 cells) and lymphokine‐activated (LAK) (Daudi cells) cells] (P<0·05) in a concentration‐dependent manner (5–50 &mgr;g/ml), without affecting cell viability. EPA and DHA exhibited greater suppression than GLA. Furthermore, the inhibition of cell proliferation and suppression of natural cytotoxicity was associated with marked decrease in cytokine [interleukin‐1 (IL‐1), IL‐2, tumour necrosis factor‐&agr; (TNF‐&agr;) and interferon‐&ggr; (IFN‐&ggr;)] production in vitro. Our findings demonstrate that EFAs (GLA, EPA, DHA) have the potential to inhibit significantly various aspects of human lymphocyte cell‐mediated and humoral immune reactivities.

Stimulation of lymphocyte natural cytotoxicity by L-arginine

In vitro L-arginine enhanced natural-killer (NK) and lymphokine-activated-killer (LAK) cell activity; this cytotoxicity was mediated by CD56+ cells. In vivo arginine supplements (30 g/day for 3 days) increased the number of circulating CD56+ cells by a median of 32% in eight volunteers (p less than 0.01); this increase was associated with a mean rise of 91% in NK cell activity (p = 0.003) and of 58% in LAK cell activity (p = 0.001) in thirteen volunteers. These findings have potentially important implications for the modulation of natural cytotoxicity in a wide range of disease states.

Minimal modulation of lymphocyte and natural killer cell subsets following minimal access surgery

BACKGROUND Trauma, whether accidental or surgically induced, is known to cause significant modulation of the cell-mediated immune response. Minimal access surgery (MAS) has been shown to improve postoperative recovery and enhance rehabilitation. The degree of immunosuppression resulting from two MAS techniques was studied and compared by measuring the circulating T lymphocyte and natural killer (NK) cell subsets. METHOD This investigation was a randomized prospective study of patients admitted to the Professorial Surgical Unit, Aberdeen Royal Infirmary for elective cholecystectomy. Two methods of MAS were studied-laparoscopy and minilaparotomy. RESULTS Laparoscopy was found to cause significantly less reduction in the number of cells expressing T lymphocyte phenotypic surface markers (CD2, CD3, CD8, CD4:CD8 ratio), activation markers (CD71 and HLA-DR), and NK cell subsets (CD11b, CD16, CD56 and CD57), when compared with the minilaparotomy technique. CONCLUSIONS These data show that host defences are less suppressed after laparoscopic cholecystectomy, and this may have important implications for the use of laparoscopic techniques in major surgical resections, especially for malignant disease.

Distal procto-colitis, natural cytotoxicity, and essential fatty acids.

Objective:Recently, it has been postulated that patients with ulcerative colitis have altered natural cytotoxicity, in particular natural killer (NK) and lymphokine-activated killer (LAK) cell activities. These cellular mechanisms have been postulated to play an etiological role in the pathogenesis of the disease process. We have shown previously that the essential fatty acids (EFA) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) specifically inhibit natural cytotoxicity. Our aim was to evaluate the role of omega-3 EFA in the modulation of natural cytotoxicity and disease activity in patients with distal procto-colitis.Methods:In this pilot study patients were randomized into two groups. Each patient received either fish oil extract (EPA, 3.2 g, and DHA, 2.4 g) (n = 9) or sunflower oil (placebo) (n = 9) daily in a double-blind manner for 6 months. Monthly assessments of disease activity (clinical and sigmoidoscopic scores) and histological evaluation of mucosal biopsies were carried out. Also, the circulating levels and activities of NK and LAK cells, using flow cytometric analysis (CD16+ CD56+) and in vitro 51 chromium release assays (K562), respectively, were monitored.Results:After 6 months’ supplementation with EFA, there was improvement in the clinical activity compared with pretreatment evaluation. There was significant reduction in the sigmoidoscopic and histological scores in the EFA group compared with the placebo group. Essential fatty acid supplementation for 6 months also induced significant reduction in the circulating numbers of CD16+ and CD56+ cells and the cytotoxic activity of NK cells, compared with the placebo group.Conclusions:This pilot study has demonstrated that omega-3 fatty acids can suppress natural cytotoxicity and reduce disease activity in patients with distal procto-colitis. These findings suggest a therapeutic strategy for managing patients with inflammatory bowel disease.

Treatment of large and locally advanced breast cancers using neoadjuvant chemotherapy

BACKGROUND Neoadjuvant (primary) chemotherapy is being used increasingly in the treatment of patients with large and locally advanced breast cancer with the aim of reducing the size of the primary tumor and eliminating micrometastatic disease. Response rates to, compliance with, and survival of patients following neoadjuvant chemotherapy have been variable. We report the results of a consecutive series of 77 patients with breast cancer who received neoadjuvant chemotherapy. METHODS Seventy-seven patients with locally advanced breast cancers were treated with multimodality therapy comprising up to six cycles of chemotherapy (cyclophosphamide, vincristine, doxorubicin, and prednisolone), radiotherapy, and then surgery. The median follow-up was 54 months. Clinical response rates to therapy and overall survival have been documented. In addition, prognostic factors for survival were identified using the Cox proportional hazards model. RESULTS The overall objective response rate of the primary tumor to chemotherapy alone was 87% (25% complete and 62% partial responses, UICC criteria). Following radiotherapy the response rate was 90% (52% complete and 38% partial responses). The overall 5-year survival for all patients was 0.48. However, the probability of survival at 5 years was 0.74 in those with a complete response, and 0.36 if there was a partial clinical response, but no patients who had either stasis of disease or progression survived for 5 years. Independent predictors of better survival that were identified were a complete histopathological response after chemotherapy and radiotherapy, a complete clinical response to chemotherapy, and five or six cycles of chemotherapy versus four or less. CONCLUSIONS Neoadjuvant chemotherapy in patients with large and locally advanced breast cancers can result in satisfactory local control and overall survival rates, especially in patients with a complete clinical or histopathological response after treatment.

The psychological and psychiatric effects of rIL-2 therapy: a controlled clinical trial

It has been suggested that recombinant interleukin‐2 (rIL‐2) may cause pyschological and psychiatric problems, although the effects of rIL‐2 on its own have not been well documented. To evaluate these effects, 17 patients with advanced colorectal cancer took part in a randomised, parallel group study of rIL‐2 with chemotherapy (5‐fluorouracil and leucovorin) versus chemotherapy alone.

Apoptosis in colorectal carcinoma occurring in patients aged 45 years and under : Relationship to prognosis, mitosis, and immunohistochemical demonstration of p53, c-myc and bcl-2 protein products

The aim of this study was to ascertain whether apoptotic counts have prognostic significance in colorectal cancer and if such counts are related to the expression of proteins implicated in cell cycle regulation. Material from a cohort of patients aged 45 years or less with colorectal carcinoma was re‐examined to determine apoptotic and mitotic counts by light microscopy, in addition to assessing p53, c‐myc, and bcl‐2 protein status by immunohistochemistry. The apoptotic index in the 74 patients who were alive or who had died of colorectal carcinoma ranged from 1·2 per cent to 12·3 per cent and exhibited independent prognostic significance, with high counts predicting better survival (P=0·02). Mitotic counts were not related to survival, despite a close correlation with apoptosis (r=0·85). Tumours regarded as not staining with the CM1 antibody for p53 protein demonstrated higher apoptotic counts, compared with those that stained (medians 5·2 and 4·0 per cent, respectively; P=0·03), but p53 expression was found not to be related to survival. The 68 tumours which stained for c‐myc appeared to exhibit higher mitotic counts than those that did not. bcl‐2 was detected in only four tumours. The latter two proteins exhibited no apparent relationship to the apoptotic index or survival. Although these results indicate a potential role for apoptotic counting in prognostic prediction in colorectal tumours, this is an uncommon group of patients who exhibited some atypical features. The likelihood of a proportion of cases arising within hereditary non‐polyposis colorectal cancer syndrome may limit the application of the findings to a more general population with cancer of the colon and rectum. Further work is required, including critical measurement of reproducibility and assessment of the relative impact of this parameter compared with ‘traditional’ prognostic markers.

Positron emission tomography: 2-deoxy-2-Z18F]-fluoro-d-glucose uptake in locally advanced breast cancers

Fifteen patients with locally advanced breast cancers were studied using the radiopharmaceutical 2-deoxy-2-[18F]-fluoro-D-glucose (FDG) with positron emission tomography (PET). Five patients were sequentially imaged before and after two pulses of chemotherapy. In 14 of 15 tumours increased uptake of FDG was observed which correlated with the clinical site of the tumour. The PET images were compared with the mammographic and ultrasonomammographic appearances of the tumours in selected patients. In two patients with normal mammograms PET imaging detected the tumour and in a further four patients, with suspicious but not conclusively malignant mammographic changes, a well-defined area of increased FDG uptake was demonstrated by PET. In all five sequentially imaged tumours, following chemotherapy, there was a decrease of the FDG tumour: normal breast uptake ratio. In four patients who completed a full chemotherapeutic course this change preceded a pathological response of their tumours. These findings suggest that this technique may be of benefit in imaging carcinomas in the breasts of pre-menopausal women which may appear dense on mammography and moreover, that sequential imaging may have a role in the prediction, at an early stage, of the response of locally advanced carcinomas to chemotherapy.

Distal proctocolitis and n-3 polyunsaturated fatty acids (n-3 PUFAs) : The mucosal effect in situ

It has been postulated that patients with ulcerative colitis (UC) have altered reactivity of gut-associated lymphoid tissue. In such cases there is intense infiltration of the mucosa with immune competent cells and associated tissue damage. We have shown previously that the dietary supplementation with the n-3 polyunsaturated fatty acids (n-3 PUFAs), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) results in significant systemic immune suppression. The aim of this study, therefore, was to evaluate the in situ effect of n-3 PUFAs on distal proctocolitis. Each patient received either fish oil extract (EPA 3.2 g, DHA 2.4 g) (n = 9) or sunflower oil (n = 9) daily in a double blind manner for six months. Monthly assessment included: (1) disease activity using clinical, sigmoidoscopic, and histological scores and (2) immunohistochemical analysis (immunoglobulins, CD profiles) of rectal biopsy specimens (before and after six months supplementation) using monoclonal antibodies and quantitative computer-assisted video image analysis. Prior to receiving supplementation, patients with proctocolitis (n = 18) showed significantly higher numbers of cells expressing CD3 (pan T cells) and HLA-DR and IgM containing cells compared with non-colitic controls (n = 8). Six months supplementation with n-3 PUFAs resulted in significant reduction in the number of cells expressing CD3 and HLA and the percentage of cells containing IgM. There was no significant change in the CD20 nor the percentage of IgG or IgA containing cells in either group of patients with procto-colitis. In patients receiving n-3 PUFA supplementation, there was improvement in the disease activity and histological scores, compared with pretreatment evaluation. This study has demonstrated both evidence of suppression of in situ immune reactivity and concurrent reduction in disease activity in patients with proctocolitis receiving n-3 PUFA supplementation. This may have important implication for therapy in patients with ulcerative colitis.

Minimal access surgery for cholelithiasis induces an attenuated acute phase response

BACKGROUND Some benefits of laparoscopic (LC) and minilaparotomy (MC) cholecystectomy may reflect attenuation of the acute phase response. The authors examined components of this response. METHODS Patients were randomized to LC (n = 11) or MC (n = 11). C-reactive protein (CRP), alpha-1-antitrypsin (AAT), retinol-binding protein (RBP), transferrin, and albumin were measured preoperatively and on postoperative days 1, 2, 4, and 7. Interleukin-1 receptor antagonist (IL-1ra), IL-6, and tumor necrosis factor (TNF-alpha) were measured more frequently perioperatively. Peak expiratory flow rate, forced expiratory volume in 1 second, and forced vital capacity were measured daily. RESULTS The IL-6 increase was more persistent and marked in the MC patients from hour 8 to day 7 postoperatively (P < 0.05). Alterations in CRP, AAT, and albumin were similar. Postoperative deficits of respiratory function correlated with the magnitude of acute phase protein alteration. CONCLUSIONS Minimal access surgery induces an acute phase response that is less prominent after a laparoscopic technique.