CD4 cell count and CD4 cell percentage in people co-infected with HIV and
hepatitis C is associated with markers of liver fibrosis and other indicators
of liver dysfunction, Canadian investigators report in the online edition of Clinical Infectious Diseases. The
research also showed that discordance between CD4 cell count and percentage was
present in almost two-thirds of co-infected patients.
believe their findings could have clinical applications and help to identify patients with significant liver
damage, “and thus may have clinical utility for identifying patients for whom
further liver disease staging using non-invasive methods or liver biopsy is
CD4 cell count is a key test in the care of
HIV-positive people. Overall, the percentage of total lymphocyte cells which
are CD4 cells can be correlated to the absolute CD4 cell count. For instance, a
CD4 cell percentage for a CD4 cell of 500 cells/mm3 would be 35%,
and the CD4 cell percentage for a CD4 cell count of 200 cells/mm3
would be 14%.
Studies conducted in
HIV-negative people who are infected with hepatitis C have shown that a
significant proportion have a discordance between their CD4 cell
count and CD4 cell percentage.
wished to see if this was also the case for co-infected people. They
therefore designed a prospective study involving 908 co-infected patients who
received care after 2003.
If someone had a CD4
cell percentage lower than expected for their CD4 cell count they were
classified as “low discordant”. A higher than expected CD4 cell percentage for
a CD4 cell count was categorised as “high discordant”.
The investigators were
especially eager to see if discordance was associated with liver fibrosis, an
AST-to-platelet ratio (APRI) score above 1.5, and the presence of a detectable
hepatitis C viral load.
Most of the patients
were men (74%) and their median age was 45% years. A third were current
injecting drug users. The majority of participants (80%) were taking antiretroviral
therapy and median CD4 cell count was 373 cells/mm3.
Hepatitis C infection
was spontaneously cleared by 11% of patients, and a similar proportion had a
history of end-stage liver disease. Just under a fifth had a APRI score above
Only 35% of participants
had a concordant CD4 cell count and percentage. A third of those taking part in the study were low
discordant and 31% were high discordant.
values of absolute CD4 cell count and CD4 percentage was common in our cohort
of co-infected patients,” comment the authors.
A history of end-stage
liver disease was associated with the presence of high discordance (adjusted
odds ratio [aOR] = 2.76; 95% CI, 1.14-6.67) as was an APRI score above 1.5
(aOR = 2.48; 95% CI, 1.19-5.15).
between progressive liver disease and discordance observed here supports the
findings of other studies in HCV mono-infection, and the hypothesis that the
development of portal hypertension and splenomegaly may lead to a degree of
sequestration of lymphocytes and other
cell lines,” note the investigators.
They also found that
patients who spontaneously cleared their hepatitis C infection were
significantly less likely to have high discordance than those with ongoing
hepatitis C replication (aOR = 0.08; 95% CI, 0.008-0.87).
“Further study is
required to determine whether regression of inflammation and fibrosis following
successful HCV eradication may lead to more concordant absolute CD4 cell counts
and CD4 cell percentage,” conclude the authors. They also believe further
research is needed to see if discordance is “associated with adverse clinical