Dysregulation of the polymorphonuclear leukocyte--Candida spp. interaction in HIV-positive patients.

OBJECTIVE: In HIV-infected patients there is an increased frequency of fungal infections. Dysregulation of the response of phagocytic cells to fungal pathogens may be involved. DESIGN: Phagocytosis of Candida spp., consecutive intracellular production of reactive oxygen species, and candicidal activity were analysed in polymorphonuclear leukocytes (PML) from HIV-1-infected patients, who were at stage C3 of the 1993 revised Centers for Disease Control and Prevention classification system, by means of flow cytometry. METHODS: Phagocytic ability was assessed by measuring uptake of fluorescein isothiocyanate-labelled Candida albicans, C. krusei and C. glabrata. Reactive oxygen intermediate production was estimated by the quantity of dihydrorhodamine-123 converted to rhodamine-123 intracellularly. The candicidal effect was assessed by the propidium iodide uptake of killed yeast cells. RESULTS: As compared to PML of healthy, HIV-negative controls, PML of AIDS patients exhibited an increased phagocytic activity and a similar ability to generate reactive oxygen products. In contrast, PML of AIDS patients displayed a decreased candicidal activity (P < 0.05 compared to controls). CONCLUSION: These results suggest that in patients with advanced HIV-1 infection the impairment of non-oxidative killing mechanisms of phagocytic cells may contribute to the high incidence of fungal infections.

Increased serum laminin and angiogenin concentrations in patients with peripheral arterial occlusive disease.

AIM: To measure serum laminin and angiogenin concentrations in patients with peripheral arterial occlusive disease (PAOD) Fontaine stages IIb, III, and IV. METHODS: The study population comprised 38 patients (20 men and 18 women) with stage IV PAOD, 11 patients (six men and five women) with stage III PAOD, 18 patients (10 men and eight women) with stage IIb PAOD, and 23 patients (10 men and 13 women) with deep vein thrombosis. Fifteen normal subjects (matched for risk factors) and 10 patients (five men and five women) without PAOD served as controls. Serum samples were obtained at admission and serum laminin and angiogenin concentrations were measured using an enzyme linked immunosorbent assay. RESULTS: Patients with stage IV PAOD had higher serum laminin (mean +/- SEM; 826 +/- 97 ng/ml) and angiogenin concentrations (467 +/- 26 pg/ml) than normal subjects (laminin: 379 +/- 21 ng/ml; angiogenin: 358 +/- 16 pg/ml) and patients without PAOD (laminin: 277 +/- 34 ng/ml; angiogenin: 406 +/- 25 pg/ml). A significant correlation was found between angiogenin and laminin and between serum laminin and fibrinogen concentrations in patients with stage IV disease. CONCLUSIONS: Raised laminin and angiogenin concentrations may be indicators of endothelial damage caused by reduced vascular perfusion or compensatory revascularisation, or both.

The effect of artemisinin on granulocyte function assessed by flow cytometry.

The effect of dihydroartemisinin, artemisinin and artesunate (0.1, 0.5, 5 and 50 mg/L) on phagocytic function and release of reactive oxygen products by neutrophils was studied by flow cytometry. Incubation with dihydroartemisinin, artemisinin and artemether resulted in a decreased capacity to phagocytose Escherichia coli (0.1-50 mg/L: 62-40%, 66-32% and 59-47% of the control values, respectively; P < 0.001 for all). Conversely, the derivatives enhanced the intracellular generation of reactive oxygen intermediates (0.1-50 mg/L: 146-140%, 174-197% and 188-136% of the control values, respectively; P < 0.001 for all). Artemisia derivatives enhance the reactive oxygen response of neutrophils but depress their phagocytic ability at therapeutic blood levels.

Serum laminin and basic fibroblast growth factor concentrations in patients with complicated Plasmodium falciparum malaria.

Serum concentrations of laminin and basic fibroblast growth factor (FGF) were measured in 20 patients suffering from complicated Plasmodium falciparum malaria in Bangkok. Significant higher mean serum concentrations of laminin were determined prior to treatment (1973 ng/ml) and 7 days after starting medication (1025 ng/ml) in comparison to the control (412 ng/ml). The values remained numerically higher for at least 21 days. With regard to serum basic FGF concentrations, a peak was found 7 day after starting treatment (35.61 pg/ml). In addition, a significant correlation was found for parasite clearance time and basic FGF concentration on day 7 (P < 0.01). These increased values of laminin and basic FGF may be the consequence of endothelial and basement membrane damage induced by sequestration of the parasites. Furthermore, basic FGF might play a role in endothelial repair mechanisms after the clearance of the parasites.

High-dose catecholamine treatment decreases polymorphonuclear leukocyte phagocytic capacity and reactive oxygen production.

Flow cytometry was used to study phagocytic function (uptake of fluorescein isothiocyanate-labeled bacteria) and release of reactive oxygen products (dihydrorhodamine 123 converted to rhodamine 123) following phagocytosis by neutrophil granulocytes of heparinized whole blood treated with adrenaline, noradrenaline, dopamine, dobutamine, or orciprenaline. Reduced neutrophil phagocytosis and reactive oxygen production were seen at 12 micrograms of adrenaline per liter (72% each compared with control values); at 120 micrograms of noradrenaline (72% each), dobutamine (83 and 80%, respectively), and orciprenaline (81 and 80%, respectively) per liter; and at 100 micrograms of dopamine per liter (66 and 70%) (P < 0.05 for all). At these dosages, neutrophil chemotaxis was reduced to < 50% of control values for all catecholamines. Treatment with catecholamines at lower dosages had no significant effect on phagocytosis or generation of reactive oxygen products or chemotaxis. The phagocytic capacity of granulocytes was related to the generation of reactive oxygen products (r = 0.789; P < 0.05). The results demonstrate that catecholamines have a suppressive effect on the response of phagocytic cells to bacterial pathogens at high therapeutic levels in blood.

Elevated levels of soluble CD14 in serum of patients with acute Plasmodium falciparum malaria.

Serum sCD14, tumour necrosis factor-alpha (TNF-alpha), IL-6, and endotoxin were analysed in 45 patients with complicated malaria, in 14 patients with Gram-negative septicaemia and in 24 healthy subjects by ELISA. Malaria patients with renal failure (n = 16) had higher levels than patients without renal failure (n = 29) (8116 + 1440 micrograms/l versus 9453 + 1017 micrograms/l; P < 0.05) and both had higher levels than patients with septicaemia (6155 + 1635 micrograms/l) and normal subjects (2776 + 747 micrograms/l). A significant correlation between sCD14 and IL-6 (r = 0.756) and TNF (r = 0.822) existed. However, no relation between sCD14 and serum endotoxin or indices of clinical disease severity (parasitaemia, fever, parasite or fever clearance time) was seen. Although the role of sCD14 in malaria remains to be determined, elevated levels may participate in the inflammatory response in complicated malaria.

Increased serum concentration of soluble CD14 is a prognostic marker in gram-positive sepsis.

Increased serum sCD14 concentrations are associated with poor outcome in Gram-negative sepsis and trauma patients. In the present study serum sCD14 concentrations were measured in patients with Gram-positive sepsis and compared with Gram-negative septic and nonseptic intensive care unit patients. Furthermore, serum sCD14 concentration was correlated with patient's outcome. Serum samples of 28 Gram-positive (8 nonsurvivors/20 survivors) and 10 Gram-negative bacteriemic patients (3 nonsurvivors/7 survivors) were obtained at the day they met the sepsis criteria defined by Bone et al. (Day 0) and at Days 4 and 7 and compared with 10 nonseptic ICU patients and 10 healthy volunteers. Serum concentrations of sCD14 were measured by ELISA. Significantly higher sCD14 serum concentrations were found on Days 4 and 7 in Gram-positive nonsurvivors than in Gram-positive survivors (Day 4: 5.85 +/- 0.48 vs 4.07 +/- 0.43 microgram/ml, P < 0.05; Day 7: 6.12 +/- 0.46 vs 3.53 +/- 0.33 microgram/ml, P < 0.01). In addition, sCD14 concentrations of Gram-positive nonsurvivors were significantly higher than those of nonseptic ICU patients and healthy volunteers at any time of observation. However, no significant difference was calculated between Gram-positive and Gram-negative patients. Summarizing our results, the serum level of sCD14 could be proven to be a good prognostic marker in the course of Gram-positive sepsis. Increased levels are associated with a high mortality.