Influence of alcohol on antimicrobial immunity.

Prolonged consumption of excessive amounts of alcohol by itself, as well as possibly leading to a state of alcoholism, has been a long-standing biological/social problem. As a major public health concern, there is an estimated expenditure of about 20% of total health care costs for medical/hospital care related to alcohol-induced illness. In addition, a significant proportion of both men and women who are hospitalized can be classified as alcoholics. This review focuses primarily on one of the many biomedical problems attributed to alcohol abuse--its adverse effects on our immune-defense system. A considerable body of evidence has mounted, over the past several decades, indicating that those who abuse alcohol are more susceptible to certain infectious disorders and are more prone to bacteremia. Such infections tend to be continuous and are often associated with a high rate of mortality. Also, along these lines, various and suitable animal models have been developed to further elucidate what the causes are for the greater frequency and severity of infectious illnesses, and this review deals primarily with those studies linking alcohol abuse to disruption in the normal functioning of the host's immune surveillance system. Based on the results from both clinical and experimental studies, it would seem that exposure to high levels of alcohol causes decreased humoral and cellular immune responses, thereby seriously limiting our ability to be protected from certain infectious agents.

Impaired bactericidal activity and host resistance to Listeria monocytogenes and Borrelia burgdorferi in rats administered an acute oral regimen of ethanol.

A rat model was used to examine how ethanol ingestion may interfere with antimicrobial immunity both in vitro and in vivo. Nonimmune Long-Evans rats were given a short-course treatment orally with excessive amounts of ethanol. Their spleens were removed at the time of sacrifice, and separate spleen cell suspensions were prepared and tested in vitro for their ability to kill two bacterial pathogens, Listeria monocytogenes and Borrelia burgdorferi. After the bacteria were mixed separately with various concentrations of spleen cells, it was found that spleen cells from the ethanol-treated rats killed fewer bacteria than matching pair-fed controls, based on counts of the number of cultured CFU (for Listeria) or based on microscopic examination (for Borrelia). For the in vivo studies, ethanol-treated and control rats were infected intraperitoneally with Listeria, and then, 1 to 3 days later, they were assessed for systemic infection based on the numbers of organisms present in their livers and spleens. Numbers of bacterial CFU for both organs were significantly higher in the group fed ethanol for the first 2 days after listerial challenge. These results support the concept that acute exposure to high levels of ethanol can impair host defense mechanisms, especially those expressed at the cellular level, which could lead to increased susceptibility to certain types of infections.

Comparative development of SIRC rabbit corneal cells grown on polycarbonate- and polyester-based filters.

Statens Seruminstitut Rabbit Cornea (SIRC) cells were grown on sterile polycarbonate- and polyester-based filter inserts to evaluate the feasibility of substituting the polyester-based filter inserts for use in a previously developed permeability model. The two filter types were compared for differences in cellular growth rate and morphological changes following days 3, 7 and 10 in culture. There were no significant differences in the number of cell layers formed on any day examined. The numbers of cell layers formed with the polycarbonate-based filter inserts were 1.75 +/- 0.09, 2.53 +/- 0.14 and 2.93 +/- 0.16, for days 3, 7 and 10, respectively. The numbers of cell layers formed with the polyester-based filter inserts were 1.79 +/- 0.07, 2.23 +/- 0.11 and 2.90 +/- 0.13, for days 3, 7 and 10, respectively. The SIRC cells had a similar comparative morphology on each of the above days. Active cell growth was seen on each day with signs of maturation evident by day 7 in culture. The polyester-based filter inserts can be substituted in the previously established permeability assay without alteration of morphology or rate of growth, thus allowing confirmation of cell confluency prior to use in the permeability assay. It will also allow for photographic documentation of cell injury prior to recovery studies, without necessitating the preparation of extra samples for fixation at the time of initial injury. Future studies will be required to determine if there will be any alteration in the rate of permeability with a previously tested standard, before adoption of the new filter.