The immunocompromised host: immune alterations in splenectomized patients and clinical implications.

The spleen plays a paramount role in the host protection against invading microorganisms. In support of the above concept, in splenectomized patients there is increasing evidence of overwhelming postsplenectomy infections (OPSI). OPSI are caused by Streptococcus pneumoniae in about 80% of cases, but also Gram-negative bacteria are implicated in a certain number of cases. Therapeutically, penicillin and pneumococcal vaccines represent valid therapeutic approaches in Gram-positive OPSI. However, the effectiveness of polyvalent polysaccharide pneumococcal vaccines is still debated and, thus, other therapeutic strategies should be validated for combating OPSI. According to our personal data, a deficit of phagocytic activities and of T helper (h)-1 cells is very frequent in splenectomized patients. In sera, we found reduced levels of both Interferon-gamma and Interleukin (IL)-4. These data are in accordance with the recent observation on the protective role of T cells against S. pneumoniae. In fact, patients deficient in IL-12 develop severe pneumococcal infections and undergo apoptosis of Th(1) cells.

The uncertain primary diagnosis of inflammatory bowel diseases.

BACKGROUND: The purpose of this study is to re-evaluate our series of patients affected by a colonic non-neoplastic disease, in order to measure the percentage in whom we were unable to make a correct diagnosis after the first clinical and histological approach and to single-out the reasons for our inability to reach the correct diagnosis. METHODS: During the period 1985-1999 we observed 1228 patients affected by chronic inflammatory colonic diseases. RESULTS: In 859 patients (69.9%) an ulcerative colitis was diagnosed for the first time, and 248 patients (20.1%) were affected by Crohn's colitis. One hundred and twenty-one patients (9.8%) were defined as being affected by an undetermined colitis. Forty-three patients of these had a definite diagnosis, afterwards: 27 patients were affected by ulcerative colitis and 16 by Crohn's colitis. Differential diagnosis between inflammatory large bowel diseases (ILBD) and other forms of colitis was set out as follows: 62 cases out of 1228 were consequent on a bacterial infection or parasitosis; in 28 patients a colitis pseudomembranosus was diagnosed. Eighteen cases of ischemic colitis are reported and 14 patients were affected by NSAID-related colitis. In another 6 patients we diagnosed a postradiation colitis. In 22 cases mimicking a Crohn's colitis we ascertained 9 patients affected by intestinal lymphoma, 11 mycobacterium tuberculosis related intestinal infections and 2 cytomegalovirus related colitis. CONCLUSIONS: Despite progress in scientific acquisitions and in diagnostic methods, correct initial diagnosis of ILBD is still difficult, even though it will be defined with time.

[Cell-mediated immunity and delayed hypersensitivity study in splenectomy patients: a comparative evaluation between IFN-gamma and skin tests]. / Studio dell'immunità cellulo-mediata e dell'ipersensibilità ritardata negli splenectomizzati: valutazione comparativa fra IFN gamma e skin tests.

The authors of this paper attempt to indicate a feasible, easy-to-use and inexpensive instrument for daily assessing and monitoring of splenectomized subjects to see if they are immunocompromised. Skin tests which are considered easy and inexpensive, may be useful for immunological investigation if their effectiveness is considered equal to that of more difficult and expensive methods. They have also assessed the effectiveness of ST in the study of specific cell-mediated immunity in general and also in cases of delayed hypersensibility, comparatively to serum IFN gamma dosage. The latter is produced by Th1 lymphocytes and Natural Killer cells and is considered a reasonable indicator of cell-mediated immunity and Th1-related delayed hypersensibility. The results of this study confirm that ST is effective in 100% of all splenectomized patients compared to positivity of 60% for the compromise of the immunocompetent system revealed by serum IFN gamma dosage in the same sample of patients. In addition, the fundamental role of other cytokines was confirmed. These include IL-2 which is produced by Th1 lymphocytes and whose lack of results in splenectomized patients are immunocompromised. This is revealed not only by IFN gamma dosage but also by ST.

[Th1-Th2 cytokine correlates (INF-gamma and IL-4) in splenectomized patients]. / Studio delle citochine Th1-Th2 correlate (IFN gamma e IL-4) negli splenectomizzati.

This paper attempts to explain if immunodepression in patients who had undergone a splenectomy may be due to altered balance between Th1-Th2 lymphocyte subpopulations, as shown in several studies on phagocyte and lymphocyte cells. This was achieved by dosing serum levels of IFNg, produced by Th1 lymphocytes and IL-4, produced by Th2 lymphocytes. Final analysis showed immunodepression in splenectomized patients but also emphasized that in 70% of all cases, there is functional damage of T-lymphocytes that continues for several years after the surgery involving both cellular and humoral immunity. Immunoglobulin dosage allows the increase of IgE to be seen in 50% of the splenectomized patients studied, all with allergic symptoms that appeared after the operation. The production of IgE is stimulated by Th2 lymphocytes. This leaves one to believe that splenectomy may favour the persistence of allergens in the blood, the appearance of allergic symptoms and the increase of IgE serum levels in patients with normal Th2 functioning and consequently, with normal or increased IL-4 serum levels.

[Palliative treatments in obstructive jaundice due to periampullary neoplasms]. / I trattamenti palliativi dell'ittero ostruttivo da neoplasie periampollari.

OBJECTIVE: The evaluation of the palliative procedures, surgical and endoscopical or radiological, in the treatment of patients affected by obstructive jaundice resulting from periampullary tumors. SUBJECTS: Patients with jaundice by periampullary tumors undergoing to surgery or to endoscopical or radiological procedures from january 1987 to april 1998. RESULTS: Jaundice has come down in all patients after surgery. Mortality after surgery was 5.2% (5.9% in geriatric patients); morbidity 15.8% (17.6% in geriatric patients) survival 10.4 months after surgery (8.8 months in geriatric patients) versus 3.1 months after non surgical procedures. DISCUSSION: In all patients periampullary tumors are more frequent than hepatic hilum and common bile duct tumors. We have performed surgical and not surgical palliative procedures more frequently than curative resection (DCP), especially in geriatric patients (94.5% versus 79%). In geriatric patients we have chosen, between bile-digestive by-passes, the cholecysto-jejunal anastomosis because it is easier and faster to carry out than choledochojejunal anastomosis with the same results as well as from literature data. We have always performed a gastroenteric anastomosis in association with palliative surgical procedures to prevent or to solve a duodenal obstruction. This additional treatment didn't show an increasing of mortality and morbidity as well as from literature data. CONCLUSIONS: We have reserved the palliative non surgical procedures only to high surgical risk patients. In the other cases we have chosen palliative surgery for better long-term results and quality of life in the general series patients as well as in geriatric patients.

Splenectomy and sepsis: the role of the spleen in the immune-mediated bacterial clearance.

Over the past few years, many observations of overwhelming post splenectomy bacterial infections have been reported. Streptococcus pneumoniae is the aetiologic agent in about 80% of cases, but also gram-negative bacteria are involved in the development of fatal infections in splenectomized patients. Functionally, the spleen plays a fundamental role in bacterial clearance either by antibody response or macrophage bactericidal capacity. At the same time, there is evidence that the spleen also contributes to bacterial endotoxin detoxification. Finally, the mechanisms responsible for gram-positive and gram-negative sepsis in the splenectomized host and possible therapeutical approaches able to neutralize bacterial products endowed with noxious effects are discussed.