World Journal of AIDS, 2012, 2, 232-236
http://dx.doi.org/10.4236/wja.2012.23030 Published Online September 2012 (http://www.SciRP.org/journal/wja)
229
Levels of Immunoglobulin Classes Are Not Associated with
Severity of HIV Infection in Nigerian Patients
Oluwaseun O. Akinpelu1, Yetunde A. Aken’Ova2, O. Ganiyu Arinola3
1Department of Haematology, College of Health Sciences, Ladoke Akintola University of Technology, Ogbomoso, Nigeria;
2Department of Haematology, College of Medicine, University of Ibadan, Ibadan, Nigeria; 3Department of Immunology, College of
Medicine, University of Ibadan, Ibadan, Nigeria.
Email: ibukunpelu@yahoo.com
Received May 3rd, 2012; revised June 6th, 2012; accepted June 21st, 2012
ABSTRACT
The serum concentrations of immunoglobulin G (IgG), immunoglobulin A (IgA), immunoglobulin M (IgM), total pro-
tein and albumin were measured in 35 Human Immunodeficiency Virus—positive, HAART (highly active antiretroviral
therapy) naïve subjects attending the PEPFAR (President’s Emergency Plan for AIDS relief) clinic, University College
Hospital, Ibadan and in 30 apparently healthy control subjects to assess the relationship between serum protein, immu-
noglobulin concentrations and laboratory indices of HIV disease (CD4 cell counts and viral load). Serum IgG (1008.6 ±
530.7 mg/dL), IgA (170.4 ± 69 mg/dL) and total protein (9.9 ± 1.7 g/dL) levels were higher among HIV positive sub-
jects compared with mean values in healthy subjects (549.8 ± 193.8 mg/dL, 106.8 ± 26.4 mg/dL and 7.8 ± 0.5 g/dL re-
spectively). The median serum IgM concentration (131 mg/dl) was significantly higher in HIV positive subjects com-
pared with 35 mg/dL in healthy controls (p < 0.001). Mean serum albumin concentration was significantly lower among
HIV positive subjects (3.7 ± 0.7 g/dL), compared with 4.3 ± 0.3 g/dL in healthy subjects (p < 0.001). There were no
significant differences observed in the levels of the immunoglobulin classes when HIV subjects with CD4 counts of
<200 cell/µL were compared with subjects with CD4 counts > 200 cells/µL. There was also no statistically significant
correlation observed between viral load and serum immunoglobulin levels.
Keywords: HIV; Immunoglobulins
1. Introduction
The Human Immunodeficiency Virus—Acquired Immu-
nodeficiency Syndrome (HIV-AIDS) pandemic contin-
ues to be one of the leading causes of infectious disease
morbidity and mortality worldwide especially in sub-
Saharan Africa. Although the sub-continent accounts for
ten percent (10%) of the world’s population, seventy
percent (70%) of the 40 million persons who were living
with AIDS at the end of 2001 were in Sub-Saharan Af-
rica [1].
HIV infection results in a gradually progressive dis-
ease with multisystem involvement, multiple opportunis-
tic infections and many types of cancers. HIV infection
also has serious consequences on the immune system of
the body with a resultant progressive immunodeficiency
that leaves the body vulnerable to pathogens and the de-
velopment of malignancies [1]. This underscores the
need for an array of laboratory technical innovations for
the diagnosis and monitoring of the infection.
Plasma viral load and CD4+ T cell counts in conjunc-
tion with the patient’s clinical status are presently the
gold standards of assessing and monitoring the clinical
progression in HIV infection [2]. The routine use of these
parameters in developing countries is limited by high
cost, availability of required technology and trained per-
sonnel.
Other surrogate markers have been used for monitor-
ing the progression of HIV infection and assessing re-
sponse to therapy. These include lymphocyte phenotypic
markers like CD38, HLA-DR, IL-2R, CD45RO and
markers of apoptosis such as Fas [3]. A large number of
soluble markers of immune activation have also been
evaluated as prognostic indicators in HIV infection.
These include serum/plasma levels of neopterin, β2-mi-
croglobulin, tumour necrosis factor alpha (TNFα), solu-
ble CD8+ and other soluble cytokine receptors [3]. How-
ever a common factor in the use of these markers is the
cost involved in performing these assays which unfortu-
nately, would set them beyond the reach of poorer na-
tions.
In the light of the foregoing, it is desirable to identify
other surrogate markers of disease progression that are
relatively inexpensive and technically simple which
Copyright © 2012 SciRes. WJA
Levels of Immunoglobulin Classes Are Not Associated with Severity of HIV Infection in Nigerian Patients 233
could help the clinician to effectively monitor the course
of infection and decide when to initiate therapy [4]. This
would be especially welcome in developing countries
where health budgets are less robust. Arinola et al. (2005)
[5,6] from Nigeria and Lyamuya et al. (1999, 1994) [7,8]
from Tanzania have previously demonstrated elevated
serum immunoglobulin levels in HIV seropositive indi-
viduals. Furthermore, a steady rise in IgA with progres-
sion to AIDS has been demonstrated in different cohorts
of patients [4,9]. These studies did not relate immu-
noglobulin levels with viral loads. This study was aimed
at measuring serum levels of immunoglobulin subclasses
in relation to CD4+ severity grouping of HIV-positive,
HAART-naive individuals to assess the potential of im-
munoglobulin classes in the prognosis and monitoring of
HIV infection.
2. Materials and Methods
This study was approved by the Joint UI/UCH Ethical
Committee.
2.1. Subjects
A comparative study was carried out between September
2008 and November 2008 on thirty five (35) newly di-
agnosed HIV positive patients, who were not on antiret-
roviral therapy. The patients were recruited into the study
at the PEPFAR clinic based at the University College
Hospital, Ibadan, Nigeria. Only asymptomatic patients
with a confirmed diagnosis of HIV infection were in-
cluded. Pregnant female patients were excluded from the
study. Blood samples were taken for serum immu-
noglobulin quantitation, total protein and albumin after
informed consent was granted. Control samples were
obtained from thirty (30) healthy adult HIV-negative
blood donors at the blood bank of the University College
Hospital and volunteer staff. Demographic data was ob-
tained from each subject.
2.2. Laboratory Analysis
Sample collection: 5 ml of venous blood was drawn
from superficial veins of the antecubital fossa with mini-
mal trauma. The blood samples were dispensed into ster-
ile bottles without additives for the assay of total serum
protein, albumin and immunoglobulins (IgG, IgA, IgM).
Blood was centrifuged to obtain serum which was sepa-
rated and stored at –70˚C until the time of assay.
CD4+ cell counts: Peripheral blood mononuclear cells
obtained from heparinized fresh blood samples of sub-
jects were labeled with fluorescent anti-CD3, anti-CD4,
or anti-CD8 specific monoclonal antibodies and analyzed
on a Cyflow (Partec©, Germany) flow cytometer at the
Virology laboratory of the UCH Ibadan to obtain abso-
lute CD4 cell counts.
HIV viral load: HIV RNA levels in subject plasma
samples were quantified using the AMPLICOR HIV-1
MONITOR TEST version 1.5 (Roche©). This is based on
polymerase chain reaction technology to achieve maxi-
mum sensitivity for the quantitative detection of HIV
RNA in anticoagulated plasma.
Serum total protein and albumin: Serum total protein
and albumin were assayed using a Roche© Hitachi 902
auto-analyser which operates based on spectrophotomet-
ric principles.
Serum Immunog lobulins: Immunoglobulin classes were
quantified using immunoplates based on the anti-gen-
antibody precipitation reaction in agar gel.
2.3. Statistical Analysis
This was carried out using the SPSS statistical software
version 16. Descriptive statistics were generated for vari-
ables; mean and standard deviation for normally distrib-
uted quantitative variables while median and range were
generated for skewed quantitative variables.
Inferential Statistics: Student t-test was used to com-
pare the mean of normally distributed variables while
Mann-Whitney test was used to compare the median of
skewed quantitative variables. Correlation testing was
carried out using the Pearson’s correlation test. All statis-
tical tests were two-tailed at the 5% probability level.
3. Results
A total of 35 HIV positive individuals were recruited into
this study. These consisted of 12 male and 23 female
subjects with a mean age of 31 years. There were 30
control subjects including 13 males and 17 females. The
total study population consisted of 65 individuals and the
results are presented below (see Tables 1-3).
4. Discussion
It is noteworthy that several investigators have estimated
serum immunoglobulin profile of HIV-positive patients
in different countries [4,7-10]. In this study, the serum
immunoglobulin profile of HIV sero-positive individuals
attending the PEPFAR Clinic, UCH was measured.
Patients were aged between 22 years to 42 years with a
mean age of 31 years. Twelve of these were male while
23 were females. This may not reflects the true sex
prevalence given the greater inclination of women to
attend health facilities than men in this environment. The
present study was hospital-based. The UNAIDS 2008
report [11] indicates that the percentage of women
among people living with HIV has remained stable (at
50%) for several years.
The findings in this study showed that the mean serum
levels of IgG, IgA, IgM and total protein in HIV- posi-
tive person were significantly elevated (see Table 1).
Copyright © 2012 SciRes. WJA
Levels of Immunoglobulin Classes Are Not Associated with Severity of HIV Infection in Nigerian Patients
Copyright © 2012 SciRes. WJA
234
Table 1. Serum concentrations of immunoglobulins and proteins in study population.
Subjects n IgG* (mg/dL) IgA* (mg/dL) Tot. protein* (g/dL)Albumin* (g/dL) IgM** (mg/dL)
HIV negative 30 549.8 (193.8) 106.8 (26.4) 7.8 (0.5) 4.3 (0.3) 35 (52)
HIV positive 35 1008.6 (530.7) 170.4 (69.) 9.9 (1.7) 3.7 (0.7) 131 (2191)
t-test p < 0.001 p < 0.001 p < 0.001 p < 0.001 Mann-Whitney test p < 0.001
*Mean values of serum IgG, IgA (mg/dL), total protein and albumin concentrations (g/dL) with standard deviation (in parentheses) and significance testing in
HIV negative and HIV positive subjects. **Median serum levels of IgM (mg/dL) with significance testing (range in parentheses).
Table 2. Comparison of mean Ig levels between HIV positive patients categorized by groups.
Subjects* CD4 n IgG (mg/dL) IgA (mg/dL) Total protein (g/dL) Albumin (g/dL)
>200 17 1096 (695.7) 176 (81.6) 9.5 (1.5) 3.7 (0.7)
<200 18 926.2(304.7) 165 (56.6) 10.2(1.8) 3.7 (0.8)
t-test p = 0.352 p = 0.645 p =0.242 P = 0.932
*HIV positive.
Table 3. Median IgM concentration-comparison between
groups of HIV positive patients (range in parentheses).
Subjects* n IgM (mg/dL)
CD4 > 200 17 131 (483)
CD4 < 200 18 69 (2191)
Mann-Whitney test p = 0.177
*HIV positive.
Though the literature is scanty on the pattern of serum
immunoglobulin in HIV-positive, HAART-naïve patients
in this environment, the observed mean increase in these
immunoglobulins and total protein levels is similar to
findings from previous studies in other countries [4-8].
This increase in Ig levels may imply polyclonal B-cell
activation with advancing disease [5,8]. Evidence from
some laboratories indicate that the viral envelope pro-
teins especially gp41 induce this polyclonal B-cell acti-
vation which results in excess abnormal immunoglobulin
production [4,5]. The role of this enhanced B-cell re-
sponse in the presence of HIV infection has been a
source of debate for many years. In spite of this observed
polyclonal B-cell activation and abundance of immu-
noglobulins, disease progression to AIDS occurs thereby
implying a failure of this humoral response to control the
infection [10,12]. This polyclonal activation may reflect
direct immune stimulation by one or more components of
the virus [10] and the generated antibody pool may con-
sist of neutralizing antibodies and auto-antibodies to a
large number of normal cellular proteins [6,13]. Previous
studies have indicated that the concentration of most
immunoglobulins in HIV-positive subjects of African
origin tend to be higher than their counterparts from
other parts of the world [10,14]. This variation in immu-
noglobulin profiles may be genetically determined or
may arise from numerous antigenic challenges, espe-
cially in the tropics from chronic viral and parasitic anti-
gen exposure. This may result in chronic stimulation of
B-cells and increased production of immunoglobulins
even in HIV-negative individuals [10,14]. However, the
significant drop in serum Ig levels in black African HIV
patients on ART compared with the untreated cohort
strongly suggest there might be a genetic difference in
B-cell response to HIV infection in people of African
descent compared with other races [14]. The mean serum
IgG level was significantly higher inHIV patients com-
pared with controls. These findings agree with the work
of Arinola et al. (1998) [6] and are also corroborated by
other workers in the African sub-continent. Chronically
HIV-infected individuals have been documented to ex-
hibit elevated serum IgG up to two times the normal lev-
els, although the major portion of these antibodies are not
HIV specific [13].
Immunoglobulin G is the dominant anti HIV-immu-
noglobulin isotype and its anti-retroviral subclass reac-
tivity consists mainly of IgG1 and IgG3 [13]. One study [8]
reported that with the progression to AIDS, the mean
serum levels of total IgG, IgG1 and IgG2 did not change
but the IgG3 level increased significantly while IgG4 lev-
els fell significantly. This suggests that monitoring serum
total IgG and IgG subclasses may provide crucial infor-
mation in monitoring disease progression.
The mean serum levels of IgA in this study were found
to be 170.4 mg/dL for HIV positive subjects and 106.8
mg/dL for HIV negative subjects. This difference was
statistically significant and confirms the findings of pre-
Levels of Immunoglobulin Classes Are Not Associated with Severity of HIV Infection in Nigerian Patients 235
vious studies [4,6,8]. IgA is the most important immu-
noglobulin involved in mucosal defenses [4,13]. The
same trend on the IgG levels was observed with systemic
total IgA levels increasing during progression to AIDS
[4]. Polyclonal immune activation and production of
specific cytokines (IL 5 and IL 6) appear to be some of
the mechanism responsible. However slight elevations of
IgA may simply be a reflection of genetic and environ-
mental factors within an African population. Common
viral infections are initiated by local invasion of epithet-
lial surfaces, which initially induces local production of
interferon and secretory IgA from these surfaces [10].
Serum IgA antibodies have also been shown to have neu-
tralizing activity on HIV [10] but this effect diminishes
with disease progression allowing passage of IgA into
the blood and resulting in increased serum levels of IgA.
The median serum levels of IgM were also signifi-
cantly higher in HIV-positive than HIV negative subjects
(p < 0.001). This also confirms findings of previous
studies [6,8]..
In this study, the HIV positive subjects were further
stratified into two groups based on their CD4+ T cell
count into those with CD4+ cell count < 200 cells/µL and
those with >200 cells/µL. This was done to compare
CD4 cell count with serum immunoglobulin levels among
the HIV sero-positive subjects and to determine any as-
sociation between CD4 cell counts and observed serum
Ig levels. There were no statistically significant differ-
ences in these values (p > 0.05). These findings are simi-
lar to those in a study in Tanzania [7] which reported an
insignificant correlation between high serum immu-
noglobulin levels and CD4 count.
Low albumin levels have also been associated with
HIV disease progression and one study [15] reported that
among 453 HIV infected individuals, albumin < 35 g/l
(3.5 g/dl) was associated with faster progression to AIDS.
Other studies have associated low albumin levels with
all-cause mortality in AIDS; however it could not be de-
termined whether low albumin levels among these indi-
viduals were caused by HIV infection or were reflective
of the inherent state of health of the individual. Different
hypotheses have been proposed to explain the low levels
of albumin seen in HIV infection [15]. Some studies
have demonstrated that HIV co-infection with HCV ac-
celerates the progression of liver disease while other
studies have found albumin to be a significant predictor
of HIV disease progression even among those not in-
fected with HCV [16]. It is also possible that low that
low albumin levels may reflect the effects of anorexia,
poor nutritional status or chronic inflammation (albumin
is a negative acute phase reactive protein whose levels
can possibly be depressed by elevated levels of TNF and
IL-1 during chronic inflammation) [15]. In this study,
mean serum albumin was 4.3 g/dL among HIV negative
subjects and 3.7 g/dL among HIV positive subjects. This
difference was statistically significant. However no sig-
nificant difference was observed among HIV positive
subjects with CD4 cell count 200 cells/µL versus those
with CD4 counts < 200 cells/µL.
In this study serum IgA, IgG and IgM concentration
were non-significantly correlated to viral loads in all HIV
positive subjects (r = –0.206, –0.032 and –0.316 respec-
tively).
5. Conclusions
This study confirms that serum levels of total protein,
IgG, IgA and IgM are elevated in the course of HIV in-
fection while serum albumin levels are lower.
Although the value of immunoglobulin concentration
in predicting CD4+ cell count may appear limited on its
own, measuring levels in conjunction with other bio-
chemical parameters (such as the serum albumin levels)
may potentially be used to monitor both disease pro-
gression and response to HAART. This might be used to
advantage in low resource settings as the cost for anti-
body measurements is much lower than that for HIV
RNA determination.
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