Immunological aspects of severe bacterial sepsis

Abstract

In spite of discovery of new antibiotics and regular progress in intensive care, mortality from severe bacterial sepsis remains high. In this review the importance of cellular and humoral immunity in the pathogenesis and the outcome of severe infection is delineated. Immunological evaluation of patients in Intensive Care Units should be performed almost routinely in order to detect "high risk" patients with acquired defect in host-defence mechanisms. For these patients in addition to nutritional care, passive or active immunotherapy will help to restore resistance to bacterial infection.

Persistent inflammation and immunosuppression

“…The early findings of Meakins and others from the 1970’s showed that critically ill patients could not mount a delayed type hypersensitivity response to common antigens 46 and that T cell proliferation was markedly suppressed 47 . CARS had become the moniker for all the shared defects in adaptive immunity that accompany severe trauma and sepsis, including decreased antigen presentation, macrophage paralysis, depressed T-cell proliferative responses, increased lymphocyte and dendritic cell apoptosis, and shift from T H1 to T H2 lymphocyte phenotype (Table 1).…”

Efficacy of immunoglobulins in gram-negative infections in experimentally induced peritonitis in the rat

“…Severe septicemias in man, especially the septic shock occurring in 25% and then resulting in death of up to 80% [4,16], result in an extended hospital stay for a large percentage of these patients with long expensive intensive treatment. In attempts to reduce the disastrous consequences of the endotoxemia, immunoglobulins of different production methods were and are employed in varying dosages.…”

“…The latest surgical therapeutic possibilities, such as the continuous peritoneal lavage or the planned revision (second look), have extended the field of surgical treatment. In consequence of the still very high lethality [1,4,14] of peritoneal complications, attention should be directed to adjuvant therapy, especially chemotherapy. Antibiotics are one of the indispensable therapeutics for severe abdominal infections since they are clinically available.…”

Management of Sepsis

“…In several studies carried out in ICUs, the mortality rate was 57%-58% in anergic patients, whereas when at least one response (e.g. induration greater than 5 mm) was recorded it was 16%-18% [11]. This relationship was initially shown in surgical patients, in whom the presence of anergy before surgery was associated with an increased incidence of postoperative septic complications [32].…”

“…Recent studies have indicated that the compromised host, who is highly susceptible to severe infection, may be recognized by delayed hypersensitivity to skin testing (DHST) [11]: in patients suffering from severe acute illness, a failure of the DHST response (anergy) is associated with high mortality, mainly from sepsis. In several studies carried out in ICUs, the mortality rate was 57%-58% in anergic patients, whereas when at least one response (e.g.…”