
Assessment of serum cytokine levels in Brucella seropositive cattle / Tuzcu et al. __________________________________________________
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In this study, the average of IFN–γ levels measured in blood serums 
taken from seropositive 21 days ago, seropositive 7 months 21 days 
pregnant vaccinated, 7 months pregnant vaccinated, seronegative 
who gave birth 21 days ago, and 7 months pregnant seronegative 
groups were determined as averaged 633.04, 494.03, 140.43, 141.54, 
48.14 and 48.32 ng·mL
-1
, respectively. IFN–γ averages, which were 
determined as 48.14 ng·mL
-1
 and 48.32 ng·mL
-1
 in the control group, 
were similiar with the levels determined by Ercan et al. [26] in healthy 
cattle. IFN–γ averages determined in the disease groups were found 
to be higher compared to the vaccinated groups and control groups, 
and this difference was statistically important (P<0.05). Similar results 
obtained in this study with the study of Ahmed et al. [7], in which they 
determined IFN–γ levels in 27 patients with acute brucellosis and 15 
healthy adult individuals, IFN–γ levels were found to be statistically 
signicantly higher in the brucellosis group compared to the control 
group (P<0.05). Diez–Ruiz et al. [16] reported that serum IFN–γ and 
Neopterin levels were found to be signicantly higher in patients 
with brucellosis than in the healthy control group. Akbulut et al. [19] 
compared serum cytokine levels in 35 patients with brucellosis and a 
control group of 20 people, and reported that the averages of serum 
IFN–γ and TNF–α levels were higher in patients with brucellosis than 
in the control group. El–Boshy et al. [20] compared B. abortus and 
B. melitensis infected camels with healthy camels and reported that 
they found lower TNF–α and IFN–γ levels in camels with brucellosis. 
In the study of Odbileg et al. [27] in camels, cytokine levels produced 
by peripheral blood mononuclear cells in response to B. abortus 
S19 vaccine were determined and it was revealed that IFN–γ level 
increased during the rst week after vaccination. They detected low 
level of TNF–α expression compared to the control group. In this study, 
TNF–α and IFN–γ levels measured in the serums of the VG were found 
to be higher than CG. In studies, low TNF–α in brucellosis patients was 
attributed to the short half–life of TNF–α Ahmed et al. [7], while high 
TNF–α could be explained by its being a proinammatory mediator 
and a high IFN–γ level.
It has been shown in different studies that the serum levels of 
PCT, which is measured below 0.1 ng·mL
-1
 in the blood serums of 
healthy individuals, increases at least ve times in bacterial infections, 
exceeds 10 ng·mL
-1
 and even exceeds 1,000 ng·mL
-1
 [12, 13, 28]. In this 
study, the averages of PCT levels in blood serums taken from DG1, DG2, 
VG1, VG2, CG1, CG2 were determined as 139.24, 31.86, 30.9, 31.51, 30.71 
and 28.88 ng·mL
-1
, respectively. Serum PCT levels determined in the 
CG, VG and DG2 were similar with the results determined in healthy 
cattle by Ercan et al. [26]. The fact that the PCT level determined in the 
abortion group was higher than the other groups is consistent with the 
studies showing that the PCT level increased in bacterial infections 
[12, 13, 28, 29]. Undetermining difference between the other groups 
and the control group may be related to the short half–life of PCT.
Neopterin is a cytokine synthesized from monocytes and macrophages 
as a result of stimulation of IFN–γ released from active T lymphocytes. 
Neopterin is a sensitive indicator of cellular immunity Ercan et al. [26]. 
Irmak et al. [30] investigated the diagnostic value of Neopterin levels 
in the follow–up of treatment in 20 patients with brucellos is and 
reported that Neopterin levels could be used in the follow–up of 
patients with Brucellosis and evaluating the success of treatment. 
Diez–Ruiz et al. [16] reported that serum IFN–γ and Neopterin levels 
in patients with brucellosis were signicantly higher than the healthy 
control group. Akbulut et al. [19] investigated serum neopterin levels 
in 30 brucellosis and 30 healthy control groups. They reported that 
serum Neopterin levels in patients with brucellosis were signicantly 
higher than the healthy CG group. In this study, the averages of 
neopterin levels in blood serums taken from DG1, DG2, VG1, VG2, CG1, 
CG2 were determined as 8.80, 7.31, 4.02, 3.89, 1.92 and 1.67 ng·mL
-1
, 
respectively. The averages of Neopterin, which were determined 
as 1.92 ng·mL
-1
 and 1.67 ng·mL
-1
 in CG were similar with the results 
determined in the healthy cattle by Ercan et al. [26]. The averages 
of Neopterin levels in DG were found to be higher than the VG, CG. 
This difference was statistically important (P<0.05). The determined 
results are compatible with the literature [16, 19, 30].
There are few studies investigating cytokine levels in farm animals 
to elucidate the pathogenesis of brucellosis [20, 27]. In this study, 
serum levels of biological markers such as TNF–α, IFN–γ, Neopterin 
and PCT, which are used in the diagnosis and prognosis of infectious 
diseases in human medicine, were tried to be revealed in Brucellosis 
and Brucella–vaccinated cows.
CONCLUSION
In conclusion, although the fact that serum TNF–α, IFN–γ, Neopterin 
levels were determined to be quite high in cattle with brucellosis is 
thought to be helpful in the diagnosis and monitoring of brucellosis, it 
was concluded that there is a need for controlled studies comparing 
TNF–α, IFN–γ, Neopterin levels in more herds with brucellosis in order 
to determine whether TNF–α, IFN–γ, Neopterin levels can be used in 
the diagnosis of brucellosis in the cattle.
Conict of interest
There is no conict of interest between the authors.
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