leukocytospermia is a kind of common disease of male reproductive tract infection , which is usually caused by bacterial infection . an increase of white blood cells in seminal plasma can lead to the decrease of sperm quality and the increasing number of inflammatory cytokines such as interleukin il-6 is the main factor involved in the process . according to current studies , paf is a kind of cytokine which has many kinds of biological activities , such as inflammation factors and sperm cell activation factors . how does the paf change and what role does it play the role during the reproductive tract infection ? the purpose of our study was to observe the expression of paf and tnf- in seminal plasma of patients with leukocytospermia . male patients age from 23 to 40 years old , who came to the urology surgical department of our hospital from april to september 2011 , were enrolled . according to who directives , 22 cases with leukocytospermia and 15 normal males were chosen . all the patients did not have any urinary , reproductive , blood , or endocrine diseases . the patients who have ever suffered from mumps , cryptorchidism and sexual dysfunction and ever accepted radiotherapy or chemotherapy were excluded . the study was admitted by the local ethical committee , and written informed consent was obtained from all participants . the semen should be obtained in one time by using masturbation method and be placed into disposable sterile dry plastic container with cover . after the full liquefaction of semen plasma , the computer - assisted semen analysis ( casa ) carried out a routine analysis . the rest of the seminal plasma was collected and accepted centrifugal test for 10 minutes at 4000 r / min , the upper layer of seminal plasma was placed into eppendorf tube and stored at 20c for reservation . density count of seminal plasma white blood cell in seminal plasma refer to peroxidase dyeing method , recommended by the who . human platelet activation factor ( paf ) enzyme league immune kit and human tumor necrosis factor ( tnf- ) enzyme league immune kit were bought from jiahui biotechnology company ( rd import repacking ) , beijing weili wjy9000 sperm analyzer , low temperature centrifuge ( sigma , usa ) , 37c constant temperature water - bath box , full - wavelength enzyme standard instrument ( finland leibo company ) . the operator should operate strictly in accordance with the manual of elisa kit for inspecting tnf- and paf . the od value should be read on enzyme standard instrument within 15 minutes at 450  nm wavelength . normal characteristic test and homogeneity test of variance would be carried out before intragroup comparison of paf and tnf- expression , and t - student test was adopted . there are two kinds of correlation analyses here , straight line related analysis and spearman rank correlation analysis , which one should be adopted , it depends on whether the expression of paf or tnf- on normal distribution or not in the seminal plasma . significant difference was found in the aspects of sperm survival rate and vigor between leukocytospermia group and normal group , p < 0.01 , while the difference in sperm density and liquefaction time was not obvious , p > 0.01 ( table 1 ) . paf concentration in leukocytospermia group was ( 2.14  0.43  ng / ml ) , which was significantly lower than the normal group ( 6.21  1.38  ng / ml ) ; the difference was statistically significant ( p < 0.01 ) . wbc count in leukocytospermia group was ( 1.33  0.18 )  10/ml , and tnf- concentration was ( 5.51  1.46  ng / ml ) , which was significantly higher than that of normal group wbc ( 0.43  0.19 )  10/ml and tnf- ( 3.48  1.08  ng / ml ) , and the difference was statistically significant ( p < 0.01 ) ( table 2 ) .   in this group , paf has no significant correlation with sperm density and liquefaction time . and what 's more , it has positive correlation with sperm survival rate ( r = 0.452 , p < 0.01 ) and sperm vigor ( r = 0.642 , p < 0.01 ) . ( p > 0.01 ) . while it has negative correlation with sperm survival rate ( r = 0.415 , p < 0.01 ) and sperm vigor ( r = 0.725 , p < 0.01 ) ( table 3 ) . linear correlation analysis shows that wbc count has negative correlation to paf concentration in leukocytospermia group ( r = 0.62 ,   p < 0.01 ) ( figure 1 ) , however , it has positive correlation with tnf- concentration ( r = 0.77 , p < 0.01 ) ; paf concentration had significantly negative correlation to tnf- ( r = 0.68 , p < 0.01 ) ( figure 2 ) . leukocytospermia refers to the increase of white blood cell ( wbc ) density in seminal plasma which is more than 1  10/l , and it is mainly caused by the reproductive tract infection . the white blood cells in seminal plasma can produce many inflammatory cell factors . with the affection of these cell factors , the sperm quality , density and its vigor get lower ; sperm capacitation and acrosomal reaction would be affected as well , which lead to male infertility . paf is a kind of cell factors found in recent years , and it is involved in various physiological and pathological processes . sperm movement ability is the precondition of fertilization , wherein paf with certain concentration is considered to be one of the conditions to obtain certain movement ability . when the exogenous paf concentration is between 1  10 and 1  10 mol / l , the sperm 's motility is prominently increased after 120  min culture time . in animal experiments , the sperm motility can be immediately improved after exogenous paf treatment on freeze - thaw boar sperm ; paf concentration in seminal plasma of squirrel monkeys in the breeding season is significantly higher than that during the nonbreeding season , thereby , it is believed that paf plays an important role in the reproductive process . paf also participates in sperm capacitation and acrosomal reaction ( ar ) ; sperm capacitation can be affected through culturing with sperm together , thereby increasing the acrosomal reaction rate . ar% is different when paf concentration changes , relatively , high density ( 1  10  mol / l ) can induce ar better . in addition , paf can obviously increase the pregnancy rate of accepting artificial insemination treatment due to unexplained infertility . the seminal plasma of dog stored in low temperature has prominently increased sperm movement performance through treatment with different concentrations of exogenous paf . research shows that the sperm movement performs best when the concentration is 1  10  m with 120  min of cultivating time , at the same time , atp concentration improves obviously as well . we also found that the mitochondrial function of the sperm through paf processing remains unchanged , and the integrity of sperm has not been damaged either . at the same time , it promotes the platelets and neutrophils to gather together under the pathologic state participate in super oxide formation , and it also promotes the protein phosphorylation process . it can also induce submucosal vasoconstriction , and induce neutrophils and other inflammatory cells to produce a large number of active oxygen and free radicals . it is confirmed that paf involves in gastric ulcer , alcoholic stomach injury , necrotizing enterocolitis , ischemic stomach , and small intestinal mucosal injury . in addition , it also plays an important role in acute pancreatitis and acute lung injury development [ 9 , 10 ] . as a result , the role paf which plays in reproductive tract infection is worth discussing . alpha subtype of tumor necrosis factor ( tnf- ) is a kind of important cell factor involved in the inflammation reaction progress . it is mainly produced by macrophages , and widely involved in inflammation response , immune response , endotoxin sex shock , and other pathologic process . at the same time , tnf- is a kind of cell factor , which has close relations with sterility occurrence and development . a certain amount of tnf- can significantly inhibit the activity of sperm acrosomal enzyme and acrosomal reaction . tnf- has certain influence on sperm mitochondrial function , it can interfere sperm energy metabolism and lower sperm movement ability . it may also promote the sperm apoptosis through the mitochondria apoptosis way , which causes infertility . tnf- also can reduce the amount of nitrate in normal sperm and affects no synthesis , which is necessary for sperm movement . studies have reported that paf and tnf- can mutually cooperate with each other to promote the progress of inflammatory response , such as acute lung injury , monilia infection , and necrotizing enterocolitis . how is the paf expression in the condition of reproductive tract infection ? and how does the interaction happens between paf and tnf- ? elisa method was adopted to observe the expression of paf and tnf- in seminal plasma of patients with leukocytospermia . the results show that paf level is lower , while tnf- is higher compared with that in the normal seminal plasma . after analyzing the expressions of paf and tnf- , the relation between them , and the white blood count , we found that the expression of paf and tnf- have negative correlation with each other ( r = 0.68 , p < 0.01figure 1 ) ; paf is negatively correlated with white blood cell count ( r = 0.62 ,  p < 0.01figure 2 ) ; tnf- has positive correlation to white blood cell count ( r = 0.77 , p < 0.01 ) . the existing research results showed that paf is favorable for sperm function activities , while tnf- could inhibit sperm function activities . so we believe that , under condition of reproductive tract infection , the organism increase the composition of cell factors which can inhibit sperm activity on one hand , such as tnf- , and decrease the composition of cell factors which can promote sperm on the other hand , such as paf , thereby affect sperm vigor . however paf level is lowered under the state of reproductive tract infection , this phenomenon is of great significance and worth being studied . the adjustment of paf is affected by several factors , wherein it is related to platelet activating factor acetylhydrolase ( paf - ah ) . paf - ah is specific to paf , its concentration is negatively correlated with paf . paf - ah level has significant negative correlation with sperm motility in panda seminal plasma and has negative correlation with the state of sperm movement too . the concentration of paf - ah in seminal plasma of male patient , whose spinal column was injured , is prominently higher than normal people ; meanwhile , it has negative correlation to sperm motility . in a study investigating the relation between paf - ah level and sperm vigor , the researchers found that when sperm motility was equal to or above 50% , paf - ah density was 442.03  14.37 iu / l , while when the vigor is below 50% , the paf - ah density is 882.16  18.45 this research also shows that paf - ah is an important factor to adjust paf . whether paf - ah plays an important role in lowering paf level in leukocytospermia or not , it is still worthy of further study . in conclusion , low expression of paf or high expression of tnf- in leukocytospermia affects the sperm quality , both of which contributed to sterility . the reason why paf shows a low expression during reproductive tract infection is still not clear now , and it is of important significance , which deserves further study .
objective . discuss the changes and roles of paf in the reproductive tract infection by observing the expression of platelet activating factor ( paf ) and tumor necrosis factor  ( tnf- ) in seminal plasma of patients with leukocytospermia 
 . methods . 
 the seminal plasma was obtained from 22 cases of leukocytospermia and 15 cases of normal males ; the peroxidase dyeing method was adopted for seminal plasma white blood count ; the elisa was adopted to test paf and tnf- concentration in seminal plasma . 
 result . 
 paf concentration ( 2.14  0.43  ng / ml ) of leukocytospermia group was significantly lower than the normal group ( 6.21  1.38  ng / ml , p < 0.01 ) while tnf- ( 5.51  1.46  ng / ml ) was significantly higher than that of normal group ( 3.48  1.08  ng / ml ) . 
 there was negative correlation between paf and tnf- , ( r = 0.68 , p < 0.01 ) ; the same situation existed in paf and wbc ( r = 0.62 , p < 0.01 ) ; but tnf- was positively correlated to wbc ( r = 0.77 , p < 0.01 ) . conclusion . 
 ( 1 ) low expression of paf and high expression of tnf- in leukocytospermia affect the sperm motility , which is one of the reasons that leads to infertility . 
 ( 2 ) lower expression of paf has its particularity during the reproductive tract infection .