Demonstration of apoptosis-associated cleavage products of DNA, complement activation products SC5b-9 and C3d/dg, and immune complexes CIC-C3d, CIC-IgA, and CIC-IgG in the urine of patients with membranous glomerulonephritis

AIM

To investigate the involvement of complement activation and apoptosis in the pathogenesis of membranous glomerulonephritis by determining the concentrations of apoptosis-associated 180 bp nucleosomes and complement activation products SC5b-9 and C3d/dg in the urine of patients with membranous glomerulonephritis.

METHODS

Morning urine was taken from 15 patients with immunohistologically established membranous glomerulonephritis. Apoptosis-associated 180 bp nucleosomes, complement activation products SC5b-9, C3d/dg, and immune complexes CIC-C3d, CIC-IgA, and CIC-IgG were detected in the urine samples by using antigen-specific enzyme-linked immunosorbent assay.

RESULTS

Concentrations of measured parameters were expressed in units of standard deviation, ie, relatively to the average concentrations measured in healthy subjects. We found drastically increased concentrations of apoptosis-associated 180 bp nucleosomes (13.71+/-14.97; p=0.047), complement activation products SC5b-9 (197.07+/-134.88; p=0.003) and C3d/dg (38.70+/-43.35; p=0.048), and immune complexes CIC-C3d (11.01+/-13.39; p=0.74), CIC-IgA (7.93+/-4.38; p=0.001), and CIC-IgG (20.56+/-10.87; p=0.001) in the urine of patients with an active form of membranous glomerulonephritis. All studied molecules were absent, or present in very low concentrations, in healthy subjects and patients with membranous glomerulonephritis in remission. The mean differences between healthy controls and patients with the active disease were statistically significant in all parameters, except CIC-C3d.

CONCLUSIONS

There is an association of complement activation and apoptosis with membranous glomerulonephritis. Correlation analysis suggests that the excretion of apoptosis-associated 180 bp nucleosomes, SC5b-9, C3d/dg, and immune complexes containing IgA and IgG in the urine of patients with active membranous glomerulonephritis does not depend solely on the passive transport together with other proteins, but is probably an independent active process.

Microbial aetiology of community-acquired pneumonia in hospitalised patients

Adult patients hospitalised with community-acquired pneumonia were studied prospectively to determine the microbial aetiology of pneumonia. Between April 1996 and March 1997, blood and sputum samples were collected for culture. Throat swabs were obtained for isolation of viruses and for detection of antigens of Chlamydia pneumoniae, influenza viruses A and B, respiratory syncytial virus and parainfluenza virus. Antibodies against Legionella spp., Mycoplasma pneumoniae, Chlamydia pneumoniae, Chlamydia psittaci, Coxiella burnetii, influenza viruses A and B, respiratory syncytial virus, adenovirus and parainfluenza virus were tested in serum samples. Two hundred eleven patients were included in the study; paired sera were available from 152 patients. Blood culture was positive in 23 (10.9%) patients, Streptococcus pneumoniae being the bacterium isolated most frequently. A fourfold or greater rise or fall in the Chlamydia pneumoniae IgG and/or IgM antibody titre was found in 20 (9.5%) patients and a high antibody titre (> or = 1:512) in the first and/or the second serum sample in 18 (18.5%) patients. Antibodies confirming acute Mycoplasma pneumoniae infection were found in 12 (5.7%) patients, Legionella spp. in six (2.8%), Chlamydia psittaci in two and Coxiella burnetii in one. Three patients had pulmonary tuberculosis. Only two patients had a virus present in the throat swab (adenovirus in one patient and echovirus in the other), and in nine patients, viral antigen was detected. Acute viral infection was confirmed in 51 (24.1%) patients. Bacterial pneumonia was diagnosed in 84 (39.8%) patients, 23 of whom had concurrent viral infection. Acute viral pneumonia without any other identified pathogen was diagnosed in 28 patients. Streptococcus pneumoniae and Chlamydia pneumoniae were the most frequently identified microorganisms.

Electrochemotherapy with bleomycin in SA-1 tumor-bearing mice--natural resistance and immune responsiveness

Electrochemotherapy is an antitumor treatment that utilizes locally delivered electric pulses to increase the effectiveness of chemotherapeutic drugs in cells and tissues. Electric pulses permeabilize tumor cells to allow nonpermeant drugs such as bleomycin to enter the cells. Although preclinical data indicate that immune responsiveness of the organism is important for obtaining cures of the tumors after electrochemotherapy with bleomycin, it is not known how electrochemotherapy affects the immune system of the organism. The aim of the study was to determine the effects of electrochemotherapy with bleomycin on natural resistance and immune responsiveness. Natural resistance was evaluated by phagocytic and intracellular killing activity (oxidative burst) in monocytes and polymorphonuclear granulocytes from venous blood, and immune responsiveness by blast transformation of spleen mononuclear cells to mitogens. The percentage of monocytes in venous blood able to elicit oxidative burst was significantly increased 7 days after the electrochemotherapy and returned to normal values after 14 days. In addition, increased blast transformation of spleen mononuclear cells by stimulation with concanavalin A (T lymphocytes activity) was found 14 days after electrochemotherapy treatment. The results of our study demonstrate that electrochemotherapy with bleomycin affects the immune system of the organism