Israel Medical Association Journal

The histopathology of severe persistent asthma and chronic obstructive pulmonary disease is predominantly characterized by neutrophilic inflammation. It is posited that chronic hypoxia from hypoventilation in combination with hypoperfusion and hypercapnia are associated with induction of pulmonary tissue acidosis in SPA[1] and COPD[2], which in turn provide ideal conditions to induce danger-associated molecular patterns, i.e., crystallized and calcium pyrophosphate. These stimuli in combination with other danger-related biochemical signals are capable of stimulating an innate immune receptor (cryopyrin inflammasome, NALP3) and cause interleukin-1β secretion with subsequent neutrophilic inflammation. There is evidence to suggest that the mechanisms and pathobiology associated with chronic hypoxia, reduced perfusion and reoxygenation in SPA/COPD may exhibit similarities to the biphasic pathobiology involved in ischemia-reperfusion injury. A rationale is suggested for trials of IL-1β[3] targeted therapies as an adjunct strategy to control neutrophilic inflammation in these conditions.

Background: Crohn's disease and ulcerative colitis are inflammatory bowel diseases with an unknown etiology. Interleukin-18 is a pro-inflammatory cytokine that is up-regulated in Crohn’s disease. IL-18[1] binding protein neutralizes IL-18. The relationship of IL-18 and IL-18BP[2] and disease activity in these diseases is not fully understood.

Objectives: To investigate the correlation of IL-18 and IL-18BP with disease activity and other disease parameters in inflammatory bowel disease.

Methods: IL-18 and IL-18BP isoform α were measured in 129 patients and 10 healthy individuals. Patients' mean age was 40.5 (range 15–70 years) and 43 were women; 58 Crohn's and 28 colitis patients were in remission and 52 and 14, respectively, were in exacerbation. Twenty-three (19 and 4 respectively) were studied in both remission and exacerbation.

Results: The mean level of free IL-18 was significantly different between healthy individuals and Crohn's patients, and between Crohn's patients during exacerbation and remission (167 ± 32 vs. 471 ± 88 and 325 ± 24 pg/ml, respectively, P < 0.05). Mean level of IL-18BP was significantly different between healthy individuals and Crohn patients, and between Crohn patients during exacerbation and remission (2.1 ± 1.1, 7.5 ± 4 and 5.23 ± 2.8 ng/ml, respectively, P < 0.01). In the colitis patients, mean free IL-18 level and IL-18BP were significantly different between healthy individuals and patients, but not between disease remission and exacerbation (167 ± 32, 492 ± 247 and 451± 69 pg/ml for IL-18, and 2.1 ± 1.1, 7.69 ± 4 and 6.8 ± 7 ng/ml for IL-18BP, respectively, P = 0.05).

Conclusions: IL-18 and IL-18BP levels are higher in patients with inflammatory bowel disease compared to healthy individuals. In Crohn's disease, but not in ulcerative colitis, IL-18 (but not free IL-18) and IL-18BP levels are significantly higher during exacerbation compared to remission. This observation highlights the importance of IL-18 in the pathogenesis of inflammatory bowel diseases, especially in Crohn's disease.

Background: Advanced glycation end products, formed by the non-enzymatic glycation of proteins with reducing sugars, are thought to play a pathogenetic role in the vascular complications of diabetes, uremia and atherosclerosis. β2-microglobulin is a major constituent of amyloid fibrils in dialysis-related amyloidosis. AGE[1]-modified β2m[2] has been found in amyloid deposits of long-term hemodialysis patients. AGE-modified β2m has also been shown to enhance chemotaxis and increase tumor necrosis factor-alpha and interleukin-1 beta secretion by circulating and tissue monocytes/macrophages.

Objectives: To investigate the effect of AGE-modified β2m and AGE-human serum albumin on TNF-α[3] and IL-1β[4] secretion by human peritoneal macrophages derived from patients on continuous ambulatory peritoneal dialysis.

Methods: Human PMØ[5] were isolated from peritoneal dialysis effluent of stable CAPD[6] patients and were incubated for 24 hours with AGE-modified β2m, β2m, AGE-HSA[7], HSA or lipopolysaccharide. TNF-α or IL-1β secretion was measured by enzyme-linked immunosorbent assay in cell-free culture supernatants.

Results: Both AGE-modified β2m and AGE-HSA significantly increased TNF-α and IL-1β secretion by human PMØ in a dose-dependent manner (50–200 μg/ml). In contrast, β2m or HSA had no such stimulatory effect on TNF-α secretion but had a small significant increase in IL-1β secretion.

Conclusions: AGE-modified β2m promotes in vitro TNF-α and IL-1β secretion by human PMØ of CAPD patients. Activation of these macrophages by AGE-modified β2m may be a contributory factor to the morphologic changes and altered permeability of the peritoneal membrane in long-term CAPD. 

Background: Chronic nicotine administration has a dual effect on inflammatory bowel disease: augmentation of jejunitis and amelioration of colitis. We previously showed that chronic nicotine administration has divergent regional effects on small bowel and colonic mucosal mediators and blood flow.

Objective: To examine the effects of nicotine administration on cytokine levels in normal rat small bowel mucosa, colonic mucosa, and blood.

Methods: Male Sprague-Dawley rats weighing 200–250 g were given nicotine (12.5 μg/ml) that was dissolved in tap water. Rats were sacrificed on days 1, 2, 7 and 14 after nicotine initiation; blood was withdrawn, and small bowel and colon were resected, washed and weighed. Mucosal scrapings were extracted in 2 ml Krebs-Hemselest buffer for determination of interleukins-2, 6 and 10 using the Biosource International Immunoassay Kit.

Results: Nicotine decreased IL-10[1] and increased IL-6 levels in small bowel mucosa (from 3.5 ±  0.5 to 0.4 ± 0.1 pg/ml and from 1.9±0.4 to 13.6±0.4 pg/ml respectively; P < 0.05). Nicotine decreased IL-2 levels in the colon (from 15.8±3.0 to 7.9±1.0 pg/ml; P < 0.05), having no effect on IL-10 or IL-6 levels. Rats treated with nicotine had lower IL-6 and IL-2 blood levels compared to control rats.

Conclusions: Nicotine has different regional effects on small bowel and colonic cytokine mucosal levels, which might explain some of its opposite effects on small bowel and colonic inflammation.

The future promises good news for the treatment of systemic lupus erythematosus, some of which can already be foreseen. Increased knowledge on genes that participate in the predis­position, pathogenesis, pharmacogenetics of, and protection against this disease may permit intervention at this level. Also, better understanding about the role of sex hormones has allowed trials of weak androgens or prolactin inhibitors. New immunomodulators or i mmunosuppresors may enable more precise treatment at the immunoregulatory level, and greater knowledge on the disturbance of circuits has already provided hints and even allowed trials of anti-interleukin-10 antibodies, an IL-10 decreasing agent, tolerance-induction strategies or intervention at the level of T cell co-stimulation, as well as immune ablation with subsequent stem cell transplantation. Autoantibodies can be removed, controlled by means of anti­idiotypes, which are blocked from reaching their target antigen or uncoupled from the tissues they have reached. All these treatment strategies will gradually become decanted in order to achieve the optimal treatment of SEE, which may turn out to be its cure.

Background: The pathogenesis of neurological symptoms, the most common extraintestinal complication ofchildhood shigellosis, is unclear. To elucidate the mechanisms involved, we developed an animal model and demonstrated that TNF alpha and IL-1 beta play a role.

Objectives: To determine whether TNF alpha and IL-1 beta genes are expressed in the brain following peripheral administration of Shigella dysenteriae 60R.

Methods: Expression of mRNA for TNF alpha and IL-1 beta was examined in the brain structures (hypothalamus and hippocampus) and peripheral organs by reverse transcriptase polymerase chain reaction, at different time points after intraperitoneal injection of S. dysenteriae sonicate.

Results: In our animal model of Shigella related seizures, TNF alpha and IL-1 beta mRNA were induced in the brain, spleen and liver already 1 hour after injection of S. dysenteriae sonicate. The expression of TNF alpha and IL-1 beta mRNA in spleen, hippocampus and hypothalamus decreased after 6 h and increased again at 18 h post-injection.

Conclusions: Local production of TNF alpha and IL-1 beta in the brain may be involved in the enhanced seizure response of mice after administration of S. dysenteriae. It is possible that intracerebral production of TNF alpha and IL-1 beta plays a role in neurological disturbances of human shigellosis.