Role of cysteine & glutathione in HIV infection & other diseases associated with muscle wasting & immunological dysfunction

The combination of abnormally low plasma cystine and glutamine
levels, low natural killer (NK) cell activity, skeletal muscle
wasting or muscle fatigue, and increased rates of urea
production defines a complex of abnormalities that is
tentatively called "low CG syndrome." These symptoms are found
in patients with HIV infection, cancer, major injuries,
sepsis, Crohn's disease, ulcerative colitis, chronic fatigue
syndrome, and to some extent in overtrained athletes.

The coincidence of these symptoms in diseases of different
etiological origin suggests a causal relationship. The low NK
cell activity in most cases is not life-threatening, but may
be disastrous in HIV infection because it may compromise the
initially stable balance between the immune system and virus,
and trigger disease progression. This hypothesis is supported
by the coincidence observed between the decrease of CD4+ T
cells and a decrease in the plasma cystine level.

In addition, recent studies revealed important clues about the role
of cysteine and glutathione in the development of skeletal muscle
wasting. Evidence suggests that 1) the cystine level is
regulated primarily by the normal postabsorptive skeletal
muscle protein catabolism, 2) the cystine level itself is a
physiological regulator of nitrogen balance and body cell
mass, 3) the cyst(e)ine-mediated regulatory circuit is
compromised in various catabolic conditions, including old
age, and 4) cysteine supplementation may be a useful therapy
if combined with disease-specific treatments such as antiviral
therapy in HIV infection.

1 Star2 Stars3 Stars4 Stars5 Stars (31 votes, average: 3.30 out of 5)

Leave a Reply