Masazumi Miyake

Anti-cytokine nature of natural human immunoglobulin : one possible mechanism of the clinical effect of intravenous immunoglobulin therapy

Natural human immunoglobulins are now widely used to treat many clinical diseases. Historically, this therapy began as a supplement for patients with agammaglobulinemia (Barandun et al. 1981/82). Pneumonia, bacterial meningitis and other infectious episodes often seen in patients with this disorder have been improved by intravenous administrations of natural immunoglobulin (Ersoy et al. 1992, Liese et al. 1992, Popescu et al. 1992). Rather than being just a supplement, immunoglobulin is now being used because of its therapeutic effects. One of its most prominent features is its antipyretic effects against infection (Iwata et al. 1987). Some specific antibody fractions against causative microorganisms may be present in natural immunoglobulin. However, it now appears that some unidentified mechanisms play important roles in the outcome of this therapy (Blanchette et al. 1992, Horiuchi et al. 1993, Ronda et al. 1993). Natural human immunoglobulin preparations have been widely used in cases of severe infection such as septic shock and bacterial meningitis {Ruiz et al. 1993, Saladino et al. 1992, Schedel et al. 1991, Wortel et al. 1993). Subsidence of an infection as evidenced by the alleviation of high-grade fever, and the improvement of survival rate have been noticed with the use of natural polyvalent immunoglobulin preparations from simple stock plasma, as well as IgM-enriched specific preparations (Ersoy et al. 1992, Iwata et al. 1987, Shimozato et al. 1990, Taylor et al. 1992). Another example ofthe clinically indicated disorders for this therapy is autoim-

Natural human IgG inhibits the production of tumor necrosis factor-α and interleukin-1α through the Fc portion

The overproduction of cytokines such as the tumor necrosis factor-α (TNF-α) and interleukin-1α (IL-1α) may cause further deterioration in the already critical condition of patients with shock, sepsis, and acute inflammation. The effectiveness of infusion therapy of natural human IgG to such patients is suggested to depend partly upon the inhibition of the productivity of these cytokines. In this study, we investigated the modulation effects of IgG and its fragments on the production of TNF-α and IL-1α, on human peripheral blood mononuclear cells (PBMC). The production of TNF-α and IL-1α was found to be dose-dependently inhibited by IgG when stimulated by lipopolysaccharide (LPS), phytohemagglutinin (PHA), concanavalin A (Con A), and interleukin-2 (IL-2). However, no inhibition was seen when stimulated by phorbormyristate acetate (PMA). The F(ab′)2 fragment showed enhancing effects on cytokine production by LPS, while the Fc fragment showed not as much inhibitory effect as whole intact IgG. IgG showed no direct cytotoxic effect on PBMC. These data suggest that natural human IgG inhibits TNF-α and IL-1α production by PBMC through the Fc portion. The results of this study led us to conclude that whole intact IgG may be the best form of therapeutic delivery.

Changes in the productivity of cytokines and active-oxygen in peripheral blood cells following surgery

An investigation was carried out on the productivity of cytokines and active-oxygen by peripheral blood cells during the pre- and post-operative periods. While the preoperative production of tumor necrosis factor (TNF) and interleukin-lα (IL-1α) was elevated, that of lymphotoxin (LT) and interferon-γ (IFN-γ) were slightly suppressed. In the postoperative period the peak TNF and IL-1α and active-oxygen productivity was elevated, while LT and IFN-γ productivity was suppressed in patients with an intraoperative bleeding volume of more than 1,000 ml compared to those with that of less than 1,000 ml. Thus, stress stimulates the TNF and IL-1α and active-oxygen producing system, that is, the macrophage-neutrophil system, and suppresses the LT and IFN-γ system, being, the inflammatory helper T cell system, in the early postoperative period.

Role of membrane-associated lymphotoxin (mLT) in the killing activity of lymphokine-activated killer (LAK) cells towards various tumour cell lines.

Human lymphokine‐activated killer (LAK) cells developed by an incubation of peripheral mononuclear cells with IL‐2 express the membrane‐associated lymphotoxin (LT)‐related molecule (mLT). By a further cultivation of mLT expressing (mLT‐positive) LAK ceils for 24 h without IL‐2. mLT disappears (mLT‐negative LAK cells). Cytotoxicities of various tumour cell lines by either mLT‐positive or ‐negative LAK cells were compared. Eight out of 12 tumour cell lines, less susceptible to mLT‐negative LAK cells than mLT‐positive LAK cells, were categorized as group A, Two tumour ceils (K562 and Moit‐4) had the same susceptibility to both kinds of LAK cells. The others (Daudi and Jurkat) had less susceptibilities only when they were assessed at E:T ratios of less than 5. The four tumour cell lines in the latter two cases, containing K562. Moit‐4. Daudi and Jurkat cells, were categorized as group B. The cytotoxicities of group A tumour cells, but not group B tumourceils, by LAK cells were significantly suppressed by the presence of anti‐LT antibody. Group A tumour ceils had higher LT‐binding ability (2‐82‐16‐44 fmol/106 cells) than group B tumour cells (less than 1 46 fmol/106 cells). Both mLT‐positive and ‐negative LAK cells had similar perform activities and tumour cell‐binding capacities. These results suggest that the mLT‐mediated killing mechanism is involved in tumour ceil killing by LAK cells. Further, various tumour cell lines can be classified into two large groups according to their susceptibilities to the mLT‐mediated killing by LAK cells.

The endogenous induction of tumor necrosis factor serum (TNS) for the adjuvant postoperative immunotherapy of cancer —Changes in immunological markers of the blood—

The endogenous induction of tumor necrosis factor serum (TNS) for cancer immunotherapy was undertaken in the immediate postoperative period using Lentinan as the primer and OK-432 as the inducer. The changes in several immunological markers of the blood were assayed and compared with a control group to clarify the effects of this treatment. Plasma TNF-α levels were elevated two to three hours after eliciting treatment. The neutrophil count was elevated on the 7th post-operative day (POD) and the natural killer (NK) cell activity was transiently suppressed on the 1st POD, but NK cells possessing a high activity (Leu7-CD16+) were preserved until the 7th POD. Helper/inducer (CD4+) and killer cells (CD8+CD11−) tended to increase, and suppressor (CD8 bright+ CD11+) cells tended to decrease in the induction group. There was no difference in the levels of prostaglandin E2 (PGE2) between the groups, but a marked elevation of interferon-γ was evident on the 1st POD in the induction group. This treatment may be useful as postoperative adjuvant immunotherapy for cancer due to its ability to induce cytokines and activate host immune mechanisms.

Urine human epidermal growth factor (hEGF) levels following surgery

In order to investigate the contribution of growth factors in conditions of postoperative stress, we measured the blood and urine hEGF levels in patients with various surgical disorders. While the levels of serum and plasma hEGF did not change significantly after surgery, urine hEGF (u-hEGF) stayed at the base-level followed by a single peak within a postoperative period of two weeks. The peak day of u-hEGF in patients with more than 1000 ml of intraoperative bleeding was later than that in patients with bleeding of less than 1000 ml. In patients with postoperative renal failure or dysfunction, u-hEGF levels dropped and did not rise until the recovery of renal function. The changing pattern of u-hEGF levels was an indicator of operative bleeding volume and renal function.

Operative stress potentiates the inductivity of membrane associated lymphotoxin (mLT) on lymphokine activated killer (LAK) cells in vitro

Membrane-associated lymphotoxin (mLT) is induced in human peripheral blood mononuclear cells when cultured with interleukin 2, in the form of lymphokine-activated killer (LAK) cells. The inductivity of mLT is thought to be dependent upon the differentiation potential of LAK cell precursors, being T cells and natural killer cells. In this study, we investigated the inductivity of mLT on LAK cells from surgical patients. The preoperative values of mLT inductivity were found to be generally higher in malignant than benign cases, and the postoperative time course of mLT inductivity showed a transient decrease immediately after the operation followed by gradual increase over 2 weeks. Moreover, patients with an intraoperative bleeding volume of more than 1,000 ml showed a delay in the postoperative increase of mLT inductivity. These data suggest that operative stress potentiates the inductivity of mLT on LAK cells; however, excess stress may cause a delay in the restoration of mLT inductivity.

Thoracoabdominal aortic aneurysm associated with Marfan's syndrome —Report of a case—

A case of Marfans syndrome associated with thoracoabdominal aortic aneurysm and mitral regurgitation in a 29 year old male is reported herein. The aneurysm was replaced with a Y-shaped graft using Crawfords technique, while the major branches of the abdominal aorta were separately cannulated from inside the aneurysm and perfusedvia partial extracorporeal circulation using a left femoro-femoral bypass. We found this technique useful in the prevention of tissue ischemia during the operation. The patients postoperative course was uneventful and he has encountered no problems in the year and half since his operation.

Membrane‐associated Lymphotoxin Expression and Functional Analysis of Lymphokine‐activated Killer Cells Derived from Tumor‐infiltrating Lymphocytes

The expression of a membrane‐associated lymphotoxin molecule (mLT) on lymphokine‐activated killer (LAK) cells obtained from 18 patients with malignant tumors and its role in the tumor cell killing mechanisms were investigated. LAK cells from tumor‐infiltrating lymphocytes (TIL‐LAK cells) were mainly composed of CD3‐positive cells, whereas LAK cells from peripheral blood lymphocytes (PBL‐LAK cells) were mainly composed of CD16‐ and CD56‐positive cells. However, mLT was found to be expressed on TIL‐LAK cells as well as PBL‐LAK cells. The degree of mLT expression correlated with the killing activity of LAK cells towards L929 cells (r=0.806, P<0.01, n = 15), but not with that towards Daudi or K562 cells. Although the degree of mLT expression correlated with the amount of secreted lymphotoxin (LT) in the supernatant of LAK cell culture, the secreted LT itself could not account for the tumor cell killing activity of LAK cells. Polyclonal rabbit anti‐LT antibody partially inhibited the killing activities of LAK cells towards L929 cells and this inhibition was found in the combination of autologous tumor cells and PBL‐LAK cells. These findings suggest the possibility that the mLT‐related cytotoxicity is involved in the tumor cell killing mechanisms of TIL‐LAK cells as well as PBL‐LAK cells.

Decreased urinary epidermal growth factor levels in diabetic patients

Urinary human epidermal growth factor levels were assayed in diabetic patients and controls before and after surgery. The preoperative levels in the diabetic patients were decreased and postoperatively, did not show the trough and peak pattern which was seen in the controls.