based on hcv antibody and rna viral profiles , patients were stratified into two groups : 
 patients who spontaneously cleared hcv and patients with chronic hcv infection who 
 continued to have detectable rna titres .
however , the patients with chronic hcv 
 infection and detectable viral rna presented significantly increased alt and ast levels 
 compared with the patients who had spontaneously cleared hcv .
genotype 1a was found in 
 all of the chronically infected patients with detectable rna .
fibrosis staging 
 determined by elastography was conducted in a small number of participants ( 6 ) from the 
 chronic hcv group .
patients with distinct stages of liver disease were included in the 
 study and cirrhosis ( f4 ) was found exclusively in one of these patients ( table ) . 

tableclinical and demographic characteristics of the patientscharacteristicshcv+ ( n = 16)hcv- ( n = 17)pgender [ female ( % ) ] 68.7576.4-mean age ( years  sd)53.13  10.349.12  12.830.332mean alt ( ui / l  sd)64.43  41.1429.8  15.070.005mean ast ( ui / l  sd)61.86  42.4529.8  16.740.012positive anti - hcv1617-viral genotype1aundetectable - mean viral titre ( ui / l  sd)1.064 x 10 ^ 7  1.56 x 10 ^ 7undetectable- 

 lipid profile ( mg / dl )  col170.2  52.67177.3  59.420.724 
tg157.3  76.96148.6  63.40.728  hdl38.27  9.7440.29  7.60.514  ldl100.5  50.78119.9  340.210  vldl31.4  15.2830.29  130.826body mass index ( kg / m)22.94  1.3822.9  1.260.925grade of fibrosis ( n )  f11 - -f1-f21 - -f21 - -f2-f32 - -f41 - -alt : alanine aminotransferase ; ast : aspartate aminotransferase ; col : 
 cholesterol ; hcv- : patients who exhibited positive anti - hepatitis c virus 
 test results and undetectable hcv rna titres for more than six months . 

averages of quantitative variables are expressed as mean  standard 
 deviation ( sd ) ; hcv+ : chronically hcv - infected patients who exhibited 
 positive anti - hcv test results and detectable hcv genotype 1a viral rna 
 titres for more than six months ; hdl : high density lipoprotein ; ldl : low 
 density lipoprotein ; tg : triglyceride ; vldl : very low density 
 lipoprotein . 
  alt : alanine aminotransferase ; ast : aspartate aminotransferase ; col : 
 cholesterol ; hcv- : patients who exhibited positive anti - hepatitis c virus 
 test results and undetectable hcv rna titres for more than six months . 

averages of quantitative variables are expressed as mean  standard 
 deviation ( sd ) ; hcv+ : chronically hcv - infected patients who exhibited 
 positive anti - hcv test results and detectable hcv genotype 1a viral rna 
 titres for more than six months ; hdl : high density lipoprotein ; ldl : low 
 density lipoprotein ; tg : triglyceride ; vldl : very low density 
 lipoprotein . in an attempt to rule out the influence of overweight and obesity on the clearance or 
 evolution of chronic hcv infection , this study only included samples from patients with 
 a normal body mass index .
no differences in the lipid profiles of the analysed groups 
 were found ( table ) .
representative dot blots 
 showing the relative expression of cytokines in the study groups are shown in a , b in 
 figure
. a low detection rate of certain 
 cytokines , including il-2 , il-6 , il-5 , ifn- , il-7 , tnf- , mcp-1 ( ccl-2 ) , mcp-3 ( ccl-7 ) , 
 mig ( ccl-9 ) , gro- , gro , il-3 , gmcsf and gcsf , was observed in our study groups ( a - c in 
 figure ) .
interestingly , compared with chronic 
 hcv - infected patients with detectable rna , the patients who spontaneously cleared hcv 
 displayed increased levels of il-1 , tnf- , tgf- , mcp-2 ( ccl-8 ) , il-13 and il-15 ( d - f , 
 i , k , l in figure , respectively ) .
in contrast , the 
 chronic hcv - infected patients with detectable rna showed increased levels of il-8 and 
 rantes ( ccl-5 ) compared with patients who spontaneously cleared hcv ( h , j in figure , respectively ) .
no significant differences 
 were found in il-10 levels . however , there was a trend towards increased il-10 levels in 
 the chronic hcv - infected patients with detectable rna ( g in figure ) .
viral and host factors are related to the progression of hcv infection . in 2009 , it was 
 demonstrated that hcv viral clearance is associated with genetic variation in the 
 il-28b gene ( ge et al .
numerous studies have been conducted on this 
 family of cytokines and have led to several inconsistencies and controversies , including 
 the possible correlation between serum protein levels and disease outcomes in chronic 
 viral hepatitis patients ( torres et al .
thus , it is accepted that variations in the profile of cytokines involved in the immune 
 response may contribute to the ability to clear hcv .
these studies have mainly been 
 conducted in regions where the virus is endemic ( shi et 
 al .
2012 ) , thus information on populations in regions of low endemicity is 
 scarce . herein , we characterised serum cytokine expression profiles in mexican 
 hcv - infected patients and found subtle differences in the cytokine profiles between 
 distinct clinical courses of hcv infection . in our study , persistent infection with 
 detectable genotype 1a viral content resulted in a proinflammatory profile characterised 
 by increased levels of il-8 and rantes ( ccl-5 ) and a trend towards increased il-10 
 levels .
these findings correlate with in vitro studies that have shown that natural 
 killer cells from hcv - infected patients are impaired in their capacity to activate 
 dendritic cells due to the overproduction of il-10 ( jinushi et al .
likewise , the increased levels of il-8 found in the 
 chronic hcv group in the present study may be related to the association between il-8 
 production and ifn- inhibition described in both in vivo and in vitro studies ( khabar et al .
moreover , the analysis of cytokines in 
 each patient revealed a trend towards higher serum concentrations of il-10 and il-8 in 
 patients with more severe liver damage ( f2-f3 and f4 ) ( data not shown ) .
altogether , our 
 findings suggest that il-10 and il-8 overproduction may contribute to a lower 
 probability of viral clearance , whereas homeostasis between pro - inflammatory [ il-1  , 
 tnf- , mcp-2 ( ccl-8 ) ] , anti - inflammatory ( tgf- ) , fibrogenic ( il-13 ) and 
 immunoregulatory ( il-15 ) profiles allows for viral clearance , as observed in patients 
 with undetectable viral rna levels .
however , large - scale studies with adequate 
 statistical power to support this hypothesis are needed .
furthermore , given that our 
 data do not rule out the possibility that cytokine levels may be a consequence and not 
 the cause of hcv clearance , future studies aimed at analysing the possibility of a 
 reverse causation are necessary .
the progression of hcv infection is associated with the characteristics of lipid 
 profiles in chronic hcv patients .
in fact , it is accepted that lipid components 
 associated with hcv infection are finely modulated in the mexican population ( fierro et al .
future studies that 
 include overweight and obese individuals will allow the determination of the exact role 
 of lipids in viral clearance .
we previously reported the influence of cytokines on the development of distinct 
 clinical courses in children infected with hepatitis a ( fierro et al .
2014 ) and on the development of occult hepatitis b virus infection in native 
 mexican groups ( fierro et al .
2011 ) . herein , our 
 findings suggest that cytokine expression can influence the extent of hcv development 
 and provide important insights into cytokine - mediated mechanisms underlying the 
 long - term persistence of hcv . in this context , efforts to determine whether biomarkers , 
 including serum cytokines , can accurately predict the outcome of hcv infection are 
 valuable for establishing better hcv control strategies in latin american regions .
 the mechanisms related to the spontaneous clearance of hepatitis c virus ( hcv ) have 
 been primarily studied in regions where the infection is endemic . 
 results of prior 
 studies have been extrapolated to populations with low endemicity , such as mexico . 
 herein , we determined the cytokine profiles in serum samples from mexican patients 
 who spontaneously cleared hcv and patients chronically infected with hcv genotype 1a . 
 
 chronic hcv - infected patients displayed increased interleukin ( il)-8 and regulated 
 upon activation , normal t - cell expressed and secreted ( ccl-5 ) secretion , whereas 
 patients who spontaneously cleared hcv showed augmented levels of il-1 alpha , tumour 
 necrosis factor - alpha , transforming growth factor - beta , monocyte chemoattractant 
 protein-2 ( ccl-8 ) , il-13 and il-15 . our study suggeststhat cytokine profiles may 
 predict disease outcome during hcv infection . 