Clarithromycin attenuates the inflammatory response induced by surgical trauma in a guinea pig model

Lung perfusion with clarithromycin ameliorates lung function after cardiopulmonary bypass

BACKGROUND

Macrolides antibiotics may affect neutrophil functions that correlate with the inflammation induced by cardiopulmonary bypass. Our study observed the protective effect of clarithromycin on inflammatory lung injury after cardiopulmonary bypass.

METHODS

Twelve adult sheep were randomly divided into two groups. After cardiopulmonary bypass was established, the lung was perfused through the pulmonary artery with either dextran solution (30 mL/kg) in the control group (n = 6) or dextran solution added to clarithromycin (10 mg/kg) in the experimental group (n = 6). Bypass was withdrawn after 90 minutes. Pulmonary function was determined and inflammatory factors were analyzed. Apoptotic neutrophils in the lung were assayed and lung biopsies were also performed.

RESULTS

Pulmonary vascular resistance (102.2 +/- 14.0 dyne.s.cm(-5)) was lower in the experimental group compared with the control group (202.6 +/- 47.3 dyne.s.cm(-5), p < 0.01) whereas the oxygen index was higher in the experimental group (p < 0.05). Plasma myeloperoxidase in the experimental group (0.015 +/- 0.006 U/L) was lower than that in the control group (0.029 +/- 0.007 U/L, p < 0.01). Plasma interlukin-8 (0.18 +/- 0.04 ug/L) and tumor necrosis factor (1.00 +/- 0.13 ug/L) in the experimental group were lower than in the control group (0.39 +/- 0.09 ug/L, 1.55 +/- 0.35 ug/L, p < 0.01). Histologic analyses showed intra-alveolar hemorrhage and neutrophil accumulation in the control group, whereas there were no significant changes in the experimental group. The apoptosis rate of accumulated neutrophils was significantly lower in the control group (p < 0.01).

CONCLUSIONS

Lung perfusion with hypothermic protective solution containing clarithromycin distinctly inhibits inflammatory responses caused by cardiopulmonary bypass and ameliorates lung function.

Effects of a short-course of amoxicillin/clavulanic acid on systemic and mucosal immunity in healthy adult humans

Although amoxicillin/clavulanic acid (AMC) is the most frequently administered antibiotic in France, its in vivo effects on immunity in healthy adults have never, to our knowledge, been described. Eighteen healthy adult male volunteers, 25+/-6 years old, were treated for 5 days with oral amoxicillin (1 g) /clavulanate potassium (125 mg), two times daily. Systemic and local intestinal immunity parameters were sequentially explored before, during and after the antibiotic treatment. No significant differences were obtained for transudation markers (albumin and alpha1-antitrypsin) in sera, feces and saliva, showing that AMC did not induce inflammatory reaction. Phagocytosis, peripheral blood cell subsets, intracellular interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha production by natural killer (NK) cells and cytotoxic T lymphocytes, intracellular TNF-alpha production by monocytes showed no significant differences throughout the trial. In fecal outputs, no significant differences were found in secretory immunoglobulin A (S-IgA), lactoferrin (Lf), lysozyme (Lz) and transforming growth factor (TGF)-beta1. In sera, concentrations of total IgA (T-IgA), S-IgA, IgM, Lf and Lz did not show any significant variations throughout the study, whereas concentrations of IgG were slightly but significantly reduced 15 days after AMC treatment. In saliva, concentrations of T-IgA were slightly but significantly higher, whereas S-IgA concentrations were unchanged. Our results showed that oral AMC intake did not induce any significant adverse effects on immunity in adult humans.

Immunomodulatory clarithromycin treatment of experimental sepsis and acute pyelonephritis caused by multidrug-resistant Pseudomonas aeruginosa

Clarithromycin was administered intravenously to 55 rabbits to evaluate its effect on experimental sepsis caused by multidrug-resistant Pseudomonas aeruginosa. Acute pyelonephritis was induced after ligation of the right ureter and injection of 10(8) CFU of the test isolate per kg of body weight into the renal pelvis. The animals were divided into six groups: group A, controls; group B, rabbits that received one intravenous dose of 80 mg of clarithromycin per kg concomitantly with bacterial challenge; group C, rabbits that received two doses of clarithromycin, the second one of which was given 2 h after the first one; group D, rabbits that received 15 mg of amikacin per kg; group E, rabbits that received one dose of clarithromycin and amikacin; and group F, rabbits that received two doses of clarithromycin and amikacin. Serum endotoxin levels were estimated by the QCL-1000 Limulus amoebocyte lysate assay, tumor necrosis factor alpha (TNF-alpha) levels were measured by a bioassay, and malondialdehyde (MDA) levels were measured by the thiobarbiturate assay. Viable bacterial counts in various tissue samples were also assessed. The mean survival times of the animals in groups A, B, C, D, E, and F were 4.50, 7.69, 4.07, 4.55, 11.55, and 11.60 days, respectively (P = 0.033 for group D versus group F, P = 0.006 for group D versus group E, P = not significant for group B versus group E, P = 0.042 for group C versus group F). Serum endotoxin levels were similar between groups at all sampling times; TNF-alpha and MDA levels in groups B, C, E, and F decreased significantly over follow-up. The numbers of viable bacterial cells in the infected kidney were similar among the groups; those in the liver, spleen, lungs, and mesenteral lymph nodes were significantly decreased in groups B, E, and F compared to those in groups A and D. It is concluded that a prolongation of survival in animals with experimental sepsis caused by multidrug-resistant P. aeruginosa was achieved after coadministration of clarithromycin and amikacin and that the increased survival was probably attributable to the immunomodulatory properties of clarithromycin.

Clinical and molecular epidemiology of erythromycin-resistant beta-hemolytic lancefield group G streptococci causing bacteremia

Among 100 patients with group G beta-hemolytic streptococcal bacteremia in a 6-year period (1997 to 2002), seven had bacteremia caused by erythromycin-resistant strains. Five of the seven patients had cellulitis and/or abscesses. The two isolates resistant to erythromycin and clindamycin possessed erm genes, one ermTR and the other ermB. The five isolates resistant to erythromycin but sensitive to clindamycin and one of those resistant to both erythromycin and clindamycin possessed mef genes.

The effects of fusidic acid on the inflammatory response in rats

In the present study the antiinflammatory activity of fusidic acid was investigated in a model of formalin-induced edema formation in rats. Fusidic acid at doses of 50 and 100 mg kg (-1) was administered p.o. to rats for ten days. It was observed that fusidic acid inhibited edema formation significantly (P< 0.05). After this period, gastric mucus secretions were evaluated by the Alcian blue dye binding method. Mucus secretion decreased significantly in the control group. Fusidic acid increased the amount of gastric mucus. Moreover, in all of the animals with paw edema, platelet count was also increased. Red blood cell count, haemoglobin concentration and haematocrit were all higher in the control group than those of the fusidic acid groups. The present observations suggest that fusidic acid suppressed the inflammatory response and stimulated the gastric mucus secretion and it prompts further experiments for delineation of the mechanism of these actions as well as clinical trials.

Evaluation of the immunomodulatory effects of the macrolide antibiotic, clarithromycin, in female B6C3F1 mice: a 28-day oral gavage study

The macrolide antibiotic, clarithromycin, is used extensively to treat bacterial infections associated with pneumonia, duodenal ulcers, and the advanced stages of human immunodeficiency viral (HIV) infection. In addition to its antimicrobial properties, several studies have indicated that clarithromycin also has anti-inflammatory and immunomodulatory properties. In this study, clarithromycin's immunomodulatory properties were evaluated using female B6C3F1 mice and a panel of immune assays that were designed to evaluate potential changes in innate, and acquired cellular and humoral immune responses. Female B6C3F1 mice were treated daily by gavage with clarithromycin (0, 125, 250, and 500 mg/kg) for 28 days then evaluated for immunomodulation. Minimal immunological changes were observed after 28 days of treatment. A slight increase in the number of spleen antibody-forming cells was observed at the 250 mg/kg treatment level, but not at other doses. Serum IgM levels were unaffected by the clarithromycin treatment. A significant increase in the number of splenic macrophages was also observed in mice treated with 125 mg/kg of clarithromycin, but this increase was not observed at the other treatment levels. Innate and cell-mediated immunity, as measured by natural killer cell activity, and mixed leukocyte and cytotoxic T cell response, respectively, were unchanged following treatment with clarithromycin. These results suggest that the immune system is not a target for clarithromycin at doses of 500 mg/kg or below.

Clarithromycin attenuates mastectomy-induced acute inflammatory response

Based on the observation that administration of clarithromycin led to an attenuation of the inflammatory response induced by surgical trauma in a guinea pig model, we investigated the potential beneficial effects of clarithromycin on the local and systemic inflammatory response in patients undergoing mastectomy in an open-label prospective study. During a 16-month period, 54 patients who underwent mastectomy were randomly divided into two groups. In one group, the patients received oral clarithromycin at a dose of 500 mg twice a day, from the day before to 3 days after mastectomy. There was no significant difference in the incidence of antibiotic prophylaxis-related toxicities or postoperative infections between the patients who received clarithromycin and those who did not. Clarithromycin treatment was significantly associated with an attenuation of febrile response, tachycardia, tachypnea, and an increase in monocyte counts (P, <0.0001, <0.01, <0.05, and <0.01, respectively). Clarithromycin also reduced the intensity and duration of postoperative pain (P, <0.05 and <0.005, respectively) and increased the range of motion of the involved shoulder (P < 0.05 for abduction and flexion). We conclude that clarithromycin effectively modulates the acute inflammatory response associated with mastectomy and produces a better clinical outcome.

Enhancement by ampicillin of antibody responses induced by a protein antigen and a DNA vaccine carried by live-attenuated Salmonella enterica serovar Typhi

Live-attenuated Salmonella species are effective carriers of microbial antigens and DNA vaccines. In a mouse model, the immunoglobulin M (IgM) and total antibody levels directed toward the lipopolysaccharide of Salmonella enterica serovar Typhi were significantly enhanced at day 21 after oral immunization with live-attenuated serovar Typhi (strain Ty21a) when ampicillin was concomitantly administered (P < 0.05 and P < 0.005, respectively). The heat-killed Ty21a-stimulated lymphocyte proliferation indices for the ampicillin group at day 21 were significantly higher than those for the normal saline (NS) group (P < 0.005, P < 0.001, and P < 0.01) for all three doses of antigen (10(4), 10(5), and 10(6) heat-killed Ty21a per well, respectively). The 50% lethal doses for mice from the ampicillin and NS groups immunized with Ty21a with pBR322 after wild-type serovar Typhi challenge on day 24 were 3.4 x 10(7) and 5.0 x 10(6) CFU, respectively. The fecal bacterial counts for the ampicillin group at days 1, 3, and 5 were significantly lower than those for the NS group (P < 0.01, P < 0.01, and P < 0.05, respectively), and there was a trend toward recovery of Ty21a in a larger number of mice from the ampicillin group than from the NS group. Furthermore, the IgG2a levels directed toward tetanus toxoid were significantly enhanced at days 7 and 21 after oral immunization with Ty21a that carried the fragment c of tetanus toxoid when ampicillin was concomitantly administered (P < 0.05 and P < 0.005, respectively), and the IgM and total hepatitis B surface antibody levels were significantly enhanced at days 7 (P < 0.005 and P < 0.05, respectively) and 21 (P < 0.01 and P < 0.05, respectively) after oral immunization with Ty21a that carried the DNA vaccine that encodes hepatitis B surface antigen when ampicillin was concomitantly administered. The present observation may improve the efficacy of the protein antigens and DNA vaccines carried in live-attenuated bacteria, and further experiments should be carried out to determine the best antibiotics and dosage regimen to be used, as well as the best carrier system for individual protein antigens and DNA vaccines.

Clarithromycin attenuates cyclophosphamide-induced mucositis in mice

No universally recognized agent is available for prophylaxis or therapy of mucositis induced by chemotherapy or chemo-radiotherapy. The effect of clarithromycin on the severity of mucositis induced by cyclophosphamide was investigated using a mouse model. Four cross-sections of small intestine (levels A, B, C, and D) were taken at equivalent intervals at day 5 after cyclophosphamide (400 mg kg(-1)) administration. The sections were stained with haematoxylin and eosin, and were graded for the degree of mucositis histologically. At section level B, the number of mice with no mucositis (grade 0) in the clarithromycin group was significantly greater than that in the ceftriaxone group (P<0.05). At levels B and C, the number of mice with no mucositis (grade 0) in the clarithromycin group was significantly greater than that in the normal saline (NS) group (P<0.05). At level C, the number of mice with grade 2 mucositis in the ceftriaxone group was significantly greater than that in the NS group (P<0.05). When the number of sections at all levels were analyzed together, the number of mice with no mucositis (grade 0) in the clarithromycin group was significantly greater than that in the ceftriaxone and NS groups (P<0.05). The present observation suggests that clarithromycin and ceftriaxone attenuates and aggravates cyclophosphamide-induced mucositis. It prompts clinical trials in bone marrow transplant (BMT) recipients receiving cyclophosphamide for conditioning, and reconsideration in the use of ceftriaxone in the treatment of neutropenic fever in BMT recipients.

Antibiotics modulate vaccine-induced humoral immune response

The effects of antibiotics on the antigen-specific humoral immune response are not known. Macrolides, tetracyclines, and beta-lactams are commonly prescribed antibiotics. The first two are known to have immunomodulatory activities. The effects of clarithromycin, doxycycline, and ampicillin on the primary and secondary antibody responses to tetanus toxoid, a pneumococcal polysaccharide vaccine, a hepatitis B virus surface antigen (HBsAg) vaccine, and live attenuated Salmonella typhi (Ty21a) were investigated using a mouse model. For the mice receiving the tetanus toxoid, the immunoglobulin M (IgM) level of the clarithromycin group at day 7 was significantly lower than the corresponding antibody level of the normal saline (NS) group. For the mice receiving the pneumococcal polysaccharide vaccine, the total antibody and IgM levels of the clarithromycin group and the IgM level of the doxycycline group at day 7 were significantly lower than the corresponding antibody levels of the ampicillin and NS groups. For the mice receiving the HBsAg vaccine, the IgM level of the doxycycline group at day 7 was significantly lower than the corresponding antibody levels of the clarithromycin and NS groups, while the IgM level of the clarithromycin group at day 28 was significantly lower than the corresponding antibody levels of the doxycycline, ampicillin, and NS groups. For the mice receiving all three vaccines, there were no statistically significant differences between any of the antibody levels of the ampicillin group and the corresponding antibody levels of the NS group. For the mice receiving Ty21a, the total antibody levels of the ampicillin group at days 7 and 21 were significantly higher than the corresponding antibody levels of the NS group. Moreover, the IgM levels of the clarithromycin, doxycycline, and ampicillin groups at days 7 and 21 were significantly higher than the corresponding antibody levels of the NS group. Furthermore, the total antibody level of the ampicillin group at day 21 was significantly higher than the corresponding antibody level of the doxycycline group. For all four vaccines, there were no statistically significant differences among the serum levels of interleukin-10 and gamma interferon for the mice treated with the various antibiotics. We conclude that clarithromycin and doxycycline, but not ampicillin, suppress the antibody responses of mice to T-cell-dependent and T-cell-independent antigens, whereas all three antibiotics enhance the antibody response to live attenuated mucosal bacterial vaccines.