Mitochondrial depolarisation and oxidative stress in rheumatoid arthritis patients.
OBJECTIVE
To investigate mitochondrial membrane integrity, lipid peroxidation and cytotoxicity in peripheral lymphocytes (PL) from rheumatoid arthritis (RA) patients.


METHODS
South African black RA patients (HIV(-)) were recruited into the study. Mitochondrial membrane potential (Deltapsi(m)) was analysed in PL using the JC-1 dye distribution assay and flow cytometry. Correlations between Deltapsi(m) and clinical parameters were tested for statistical significance. Cytotoxicity (LDH) and lipid peroxidation (thiobarbituric acid reactive substances (TBARS)) was also determined.


RESULTS
Our findings show significantly elevated levels of cytotoxicity (p=0.0029) and lipid peroxidation (p=0.0030) in RA. A significantly higher percentage of circulating PL contained depolarised mitochondria (p=0.0003) which correlated with disease activity and C-reactive protein levels in patients. Collapse of Deltapsi(m) also negatively correlated to absolute lymphocyte counts (r=-0.4041; p=0.0197).


CONCLUSIONS
These findings suggest a possible role for mitochondrial membrane alterations in the pathology of RA.
Moodley
Devapragasan
D
Disciplines of Medical Biochemistry, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Private Bag 7, Congella 4013 Durban, South Africa.
Mody
Girish
G
Patel
Neeta
N
Chuturgoon
Anil A
AA
D001172:Arthritis, Rheumatoid / Q000097:blood / Q000503:physiopathology*; D001562:Benzimidazoles; D002232:Carbocyanines; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000097:blood; D018655:Lymphocyte Count; D053078:Membrane Potential, Mitochondrial / Q000502:physiology*; D018384:Oxidative Stress
D001562:Benzimidazoles; D002232:Carbocyanines; C068624:5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolocarbocyanine; D007770:L-Lactate Dehydrogenase