human
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND The Centers for Disease Control and Prevention ( CDC ) recommends hepatitis B virus ( HBV ) immunization for all hemodialysis ( HD ) patients because they are at high risk of infection . Several studies have shown that the development of protective antibody titers after HBV vaccination is much lower in HD patients . We hypothesized that human immunodeficiency virus ( HIV ) infection in patients with end-stage renal disease ( ESRD ) would further impair the immune response to hepatitis B vaccination . METHODS We performed a retrospective cohort study of patients undergoing long-term hemodialysis from 1990 to 2002 at the United States-based dialysis facilities of Gambro Corporation , North America . The response rate defined as an increase in anti-HBs levels > /=10 mIU/L after a month of the third dose of HBV vaccination was determined in HIV-infected and a r and omly selected group of ESRD patients . The demographic information , laboratory data , and hepatitis B surface antibody ( anti-HBs ) titers were recorded from the Gambro Corporation data base on these patients . RESULTS Of the 347 adult HIV ESRD patients , 116 received three doses of recombinant hepatitis B vaccination .  Seventy percent were male , and the majority ( 86 % ) were black . Of the 116 patients who received three doses of HBV vaccination , 62 ( 53.4 % ) developed protective antibody titers . This was comparable to the response rate of 50.4 % in the r and omly selected 220 non-HIV hemodialysis patients . Among HIV ESRD patients , the mean hemoglobin ( Hgb ) was higher in patients who developed protective antibody titers ( Hgb 11.61 + /- 2 vs. 10.55 + /- 1.86 , P value < 0.01 ) . On multivariate logistic regression analysis , higher Hgb was associated with protective antibody titers ( odds ratio : 1.34 , 95 % CI 0.99 - 1.72 ) . Seventy percent of the HIV-infected responders maintained protective antibody titers 6 months after vaccination . CONCLUSION Hepatitis B vaccination should be offered to all HIV-infected ESRD patients because over half of the patients with HIV and ESRD can develop protective antibodies Seroconversion after hepatitis B vaccine has been estimated to occur when the level of anti-HBs is higher than 10 IU/1 , but recently is has been considered that an antibody titer above 100 IU/1 is necessary to guarantee an efficacious protection . We prospect ively studied the evolution of anti-HBs after primary vaccination ( 3 doses ; Engerix B , 40 mu g each ) in 56 seronegative and not previously vaccinated hemodialysis patients . Three months after vaccine administration , seroconversion ( anti-HBs > 10 IU/1 ) was found in 43 patients ( 76.7 % ) , but an adequate response ( titer > 100 IU/1 ) was observed only in 30 ( 53.5 % ) . At 1 year after vaccination only 1 ( 3.3 % ) of the 30 cases with an effective response had lost his anti-HBs , while 12 of the 13 patients ( 92.3 % ) with an inadequate response ( anti-HBs between 10 and 100 IU/1 ) had no detectable antibodies ( p < 0.01 , chi2 ) . Considering that an antibody titer above 100 IU/1 following vaccination is necessary in order to maintain that level of antibody 1 year later , we analyzed the factors which influenced obtaining this level of antibody . Age , time on hemodialysis , serum albumin , Kt/V and protein catabolic rate did not affect the response to the vaccine . Females had a better response than males , and interestingly we found that hepatitis C virus ( HCV ) infection influenced the level of immunity . 27 out of the 43 HCV-negative cases ( 62.7 % ) obtained anti-HBs levels greater than 100 IU/1 , but only 3 out of the 13 HCV-infected patients ( 23 % ) had an anti-HBs above 100 IU/1 ( p < 0.01 , chi2 ) . Our results suggest that after hepatitis B vaccine , an antibody titer higher than 100 IU/1 is necessary to maintain the antibody level 1 year later , and that HCV infection may reduce the effectiveness of hepatitis B vaccine in hemodialysis patients The protective efficacy of three schedules of a recombinant hepatitis B vaccine was evaluated in 42 patients undergoing dialysis at a teaching hospital . The rate of seroconversion after vaccination was highest ( 82.3 % ) among the recipients of three 20-micrograms doses ( i.e. double the conventional dose for healthy adult ) at 0 , 1 and 2 months ( group II ) . The response was satisfactory ( 80 % ) among the recipients of three 20-micrograms doses at 0 , 1 and 6 months ( group III ) but was lowest with the single dose schedule of three 10-micrograms doses at 0 , 1 and 2 months ( group I ) . Seroconverters from all the three groups received a booster dose ( each equal to his scheduled dose ) at 12 months . Those who did not seroconvert from groups I and II were shifted to group III . The rate of seroconversion was higher in female ( 88.9 % ) than in male patients ( 66.7 % ) and in younger patients less than 30 years ( 83.3 % ) than in elderly patients more than 50 years . Patients undergoing peritoneal dialysis also responded much better ( 93.3 % ) than the hemodialysis patients ( 66.7 % ) . In conclusion , a schedule of double the conventional dose of the vaccination for healthy adults at 0 , 1 , 2 , and 12 months seems to give a better seroconversion and higher response to the HB vaccine , but a further large-scale study is needed to confirm this finding and also to look into the difference in response between male and female , younger and older patients and the difference in response between HD and PD patients We have recently shown that the human antibody response to the  hepatitis B virus surface antigen ( HBsAg ) vaccine  is major histocompatibility complex ( MHC ) associated . In studies of nonresponders to the vaccine , we found an increased incidence of individuals homozygous for human histocompatibility leukocyte antigen ( HLA ) proteins associated with the extended ( conserved ) haplotype [ HLA- B8,SC01,DR3 ] . In later prospect i ve vaccination trials , we showed that none of five individuals homozygous for this haplotype developed more than 1,300 radioimmunoassay ( RIA ) units of antibody ( mean , 467 RIA units ) , while all heterozygotes made at least 2,500 RIA units ( mean antibody level , 15,608 units ) . Our results suggested that [ HLA- B8,SC01,DR3 ] lacks an immune response gene for HBsAg , and that response is inherited in a dominant fashion . To provide further evidence for this hypothesis , we have now analyzed the results of HBsAg immunization in families . 43 members of 10 families were immunized with the hepatitis B vaccine  , including seven families where at least one member bore the haplotype [ HLA-B8,SC01,DR3 ] , and three families where one member had already received , but failed to respond to , the vaccine . In two of these three families , the presence of [ HLA-B8,SC01,DR3 ] was subsequently found . Of nine MHC-identical sibling pairs in the study , both members of eight pairs had similar antibody responses ( five nonresponder and three responder pairs ) . In all families with such sibling pairs , including the discordant pair , rank-ordering members by antibody level demonstrated that no relative 's value came between the sibling pair values . Furthermore , of nine [HLA-B8,SC01,DR3]-haplotype- homozygous individuals , six were nonresponders , and two others had only low-normal responses . [HLA-B8,SC01,DR3]-heterozygous family members always had higher levels of antibody than their homozygous relatives . Linkage analysis of nonresponse to HLA haplotypes revealed a maximum likelihood LOD ( logarithm of the odds ) score of 6.3 at a recombination fraction of 0.1 . The MHC association with lack of antibody response to HBsAg was not seen with tetanus immunization , where 1 of 20 HBsAg responders and 1 of 21 poor or nonresponders had tetanus titers of less than 1:512 ; both tetanus nonresponders were [ HLA-B8,SC01,DR3 ] heterozygotes . Our results indicate that : ( a ) response to the HBsAg vaccine is MHC linked , and inherited in a dominant fashion ; ( b ) an abnormal or missing immune response ( Ir ) gene for HBsAg is a characteristic of most examples of the extended haplotype [ HLA- B8,SC01,DR3 ] ; and ( c ) other haplotypes also have abnormal or missing Ir genes for HBsAg Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more Epidemiological studies suggest various kinds of immune dysregulation in hemodialysis ( HD ) patients . The aim of this study was to investigate the relationship between immune functions and nutritional status of HD patients . We studied 54 patients with ESRD on chronic HD , included 34 females and 20 males with mean age 46.6 ± 16.3 ( 18–77 ) years .  We measured the height and dry weight of all patients . The BMI was calculated by dividing weight ( kg ) by height squared ( m2 ) . In all patients serum urea , creatinine , albumin , iron , cholesterol , triglyceride , CRP , IgG , IgM , IgA , CD4 , CD8 , CD19 , CD16 - 56 lymphocytes were measured . Kt/V values were calculated according to DOQI guideline . In this study , a positive correlation between albumin , cholesterol , and triglyceride levels as nutritional parameters and immune functions in terms of total and subtype lymphocyte counts was observed . Further prospect i ve studies are needed to determine the clinical importance of this finding and the appropriate means of measurement and effects of nutrition on immune function in hemodialysis patients BACKGROUND Hyperphosphatemia is one of the main factors in the pathogenesis of secondary hyperparathyroidism . In addition , in dialysis patients elevated levels of phosphate and calcium times phosphate ( Ca x P ) ion product are associated with extraskeletal calcifications , as well as an increased risk of death . Cardiovascular calcifications may possibly be related to the high cardiovascular mortality seen in dialysis patients . In the USA the prevalence of hyperphosphatemia among dialysis patients is very high , over 60 % of patients having serum P levels > 5.5 mg/dl , but no data are available for the Italian population , which follows different diet and dialysis schedules . METHODS We looked at a r and om sample of 638 patients enrolled in 29 outpatient dialysis units in Southern Italy ( Campania and Sicily ) . Data were central ly analyzed after extraction from a computerized data base . In each patient the average of two or more values obtained in the six-month observation period ( from Jan. 99 to June 99 ) was calculated . Mean age was 61.2 years ( 95 % CI 59.9 - 62.5 ) years , dialytic age 72.2 months ( 95 % CI 67.4 - 77.0 ) . RESULTS Mean + /- SD ( 95 % CI ) levels of phosphate were 5.74 + /- 1.57 ( 5.62 - 5.86 ) mg/dl ; total calcium 9.06 + /- 0.98 ( 8.98 - 9.14 ) mg/dl ; Ca x P 51.4 + /- 14.4 ( 50.3 - 52.5 ) mg2/dl2 ; alkaline phosphatase was 167 + /- 119 ( 157 - 177 ) IU/L ; intact parathyroid hormone ( PTH ) levels , available in a subset of 239 patients , were 318 + /- 413 ( 265 - 370 ) pg/ml . Among these patients 51.6 % had serum P > 5.5 mg/dl , 36 % > 6 mg/dl ; Ca x P levels were > 55 mg2/dl2 in 35.5 % of the population , 24 % > 60 mg2/dl2 ; iPTH levels were < 100 pg/ml in 43 % ; 25.4 % had hyperparathyroidism ( defined as iPTH > 400 pg/ml ) , and only 19.5 % of patients had PTH in the desired interval of 100 to 250 pg/ml . CONCLUSIONS Compared to data reported from the USA , mean levels of phosphate , Ca x P , and P 
    Output:
    
agent
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND The Centers for Disease Control and Prevention ( CDC ) recommends hepatitis B virus ( HBV ) immunization for all hemodialysis ( HD ) patients because they are at high risk of infection . Several studies have shown that the development of protective antibody titers after HBV vaccination is much lower in HD patients . We hypothesized that human immunodeficiency virus ( HIV ) infection in patients with end-stage renal disease ( ESRD ) would further impair the immune response to hepatitis B vaccination . METHODS We performed a retrospective cohort study of patients undergoing long-term hemodialysis from 1990 to 2002 at the United States-based dialysis facilities of Gambro Corporation , North America . The response rate defined as an increase in anti-HBs levels > /=10 mIU/L after a month of the third dose of HBV vaccination was determined in HIV-infected and a r and omly selected group of ESRD patients . The demographic information , laboratory data , and hepatitis B surface antibody ( anti-HBs ) titers were recorded from the Gambro Corporation data base on these patients . RESULTS Of the 347 adult HIV ESRD patients , 116 received three doses of recombinant hepatitis B vaccination .  Seventy percent were male , and the majority ( 86 % ) were black . Of the 116 patients who received three doses of HBV vaccination , 62 ( 53.4 % ) developed protective antibody titers . This was comparable to the response rate of 50.4 % in the r and omly selected 220 non-HIV hemodialysis patients . Among HIV ESRD patients , the mean hemoglobin ( Hgb ) was higher in patients who developed protective antibody titers ( Hgb 11.61 + /- 2 vs. 10.55 + /- 1.86 , P value < 0.01 ) . On multivariate logistic regression analysis , higher Hgb was associated with protective antibody titers ( odds ratio : 1.34 , 95 % CI 0.99 - 1.72 ) . Seventy percent of the HIV-infected responders maintained protective antibody titers 6 months after vaccination . CONCLUSION Hepatitis B vaccination should be offered to all HIV-infected ESRD patients because over half of the patients with HIV and ESRD can develop protective antibodies Seroconversion after hepatitis B vaccine has been estimated to occur when the level of anti-HBs is higher than 10 IU/1 , but recently is has been considered that an antibody titer above 100 IU/1 is necessary to guarantee an efficacious protection . We prospect ively studied the evolution of anti-HBs after primary vaccination ( 3 doses ; Engerix B , 40 mu g each ) in 56 seronegative and not previously vaccinated hemodialysis patients . Three months after vaccine administration , seroconversion ( anti-HBs > 10 IU/1 ) was found in 43 patients ( 76.7 % ) , but an adequate response ( titer > 100 IU/1 ) was observed only in 30 ( 53.5 % ) . At 1 year after vaccination only 1 ( 3.3 % ) of the 30 cases with an effective response had lost his anti-HBs , while 12 of the 13 patients ( 92.3 % ) with an inadequate response ( anti-HBs between 10 and 100 IU/1 ) had no detectable antibodies ( p < 0.01 , chi2 ) . Considering that an antibody titer above 100 IU/1 following vaccination is necessary in order to maintain that level of antibody 1 year later , we analyzed the factors which influenced obtaining this level of antibody . Age , time on hemodialysis , serum albumin , Kt/V and protein catabolic rate did not affect the response to the vaccine . Females had a better response than males , and interestingly we found that hepatitis C virus ( HCV ) infection influenced the level of immunity . 27 out of the 43 HCV-negative cases ( 62.7 % ) obtained anti-HBs levels greater than 100 IU/1 , but only 3 out of the 13 HCV-infected patients ( 23 % ) had an anti-HBs above 100 IU/1 ( p < 0.01 , chi2 ) . Our results suggest that after hepatitis B vaccine , an antibody titer higher than 100 IU/1 is necessary to maintain the antibody level 1 year later , and that HCV infection may reduce the effectiveness of hepatitis B vaccine in hemodialysis patients The protective efficacy of three schedules of a recombinant hepatitis B vaccine was evaluated in 42 patients undergoing dialysis at a teaching hospital . The rate of seroconversion after vaccination was highest ( 82.3 % ) among the recipients of three 20-micrograms doses ( i.e. double the conventional dose for healthy adult ) at 0 , 1 and 2 months ( group II ) . The response was satisfactory ( 80 % ) among the recipients of three 20-micrograms doses at 0 , 1 and 6 months ( group III ) but was lowest with the single dose schedule of three 10-micrograms doses at 0 , 1 and 2 months ( group I ) . Seroconverters from all the three groups received a booster dose ( each equal to his scheduled dose ) at 12 months . Those who did not seroconvert from groups I and II were shifted to group III . The rate of seroconversion was higher in female ( 88.9 % ) than in male patients ( 66.7 % ) and in younger patients less than 30 years ( 83.3 % ) than in elderly patients more than 50 years . Patients undergoing peritoneal dialysis also responded much better ( 93.3 % ) than the hemodialysis patients ( 66.7 % ) . In conclusion , a schedule of double the conventional dose of the vaccination for healthy adults at 0 , 1 , 2 , and 12 months seems to give a better seroconversion and higher response to the HB vaccine , but a further large-scale study is needed to confirm this finding and also to look into the difference in response between male and female , younger and older patients and the difference in response between HD and PD patients We have recently shown that the human antibody response to the  hepatitis B virus surface antigen ( HBsAg ) vaccine  is major histocompatibility complex ( MHC ) associated . In studies of nonresponders to the vaccine , we found an increased incidence of individuals homozygous for human histocompatibility leukocyte antigen ( HLA ) proteins associated with the extended ( conserved ) haplotype [ HLA- B8,SC01,DR3 ] . In later prospect i ve vaccination trials , we showed that none of five individuals homozygous for this haplotype developed more than 1,300 radioimmunoassay ( RIA ) units of antibody ( mean , 467 RIA units ) , while all heterozygotes made at least 2,500 RIA units ( mean antibody level , 15,608 units ) . Our results suggested that [ HLA- B8,SC01,DR3 ] lacks an immune response gene for HBsAg , and that response is inherited in a dominant fashion . To provide further evidence for this hypothesis , we have now analyzed the results of HBsAg immunization in families . 43 members of 10 families were immunized with the hepatitis B vaccine  , including seven families where at least one member bore the haplotype [ HLA-B8,SC01,DR3 ] , and three families where one member had already received , but failed to respond to , the vaccine . In two of these three families , the presence of [ HLA-B8,SC01,DR3 ] was subsequently found . Of nine MHC-identical sibling pairs in the study , both members of eight pairs had similar antibody responses ( five nonresponder and three responder pairs ) . In all families with such sibling pairs , including the discordant pair , rank-ordering members by antibody level demonstrated that no relative 's value came between the sibling pair values . Furthermore , of nine [HLA-B8,SC01,DR3]-haplotype- homozygous individuals , six were nonresponders , and two others had only low-normal responses . [HLA-B8,SC01,DR3]-heterozygous family members always had higher levels of antibody than their homozygous relatives . Linkage analysis of nonresponse to HLA haplotypes revealed a maximum likelihood LOD ( logarithm of the odds ) score of 6.3 at a recombination fraction of 0.1 . The MHC association with lack of antibody response to HBsAg was not seen with tetanus immunization , where 1 of 20 HBsAg responders and 1 of 21 poor or nonresponders had tetanus titers of less than 1:512 ; both tetanus nonresponders were [ HLA-B8,SC01,DR3 ] heterozygotes . Our results indicate that : ( a ) response to the HBsAg vaccine is MHC linked , and inherited in a dominant fashion ; ( b ) an abnormal or missing immune response ( Ir ) gene for HBsAg is a characteristic of most examples of the extended haplotype [ HLA- B8,SC01,DR3 ] ; and ( c ) other haplotypes also have abnormal or missing Ir genes for HBsAg Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more Epidemiological studies suggest various kinds of immune dysregulation in hemodialysis ( HD ) patients . The aim of this study was to investigate the relationship between immune functions and nutritional status of HD patients . We studied 54 patients with ESRD on chronic HD , included 34 females and 20 males with mean age 46.6 ± 16.3 ( 18–77 ) years .  We measured the height and dry weight of all patients . The BMI was calculated by dividing weight ( kg ) by height squared ( m2 ) . In all patients serum urea , creatinine , albumin , iron , cholesterol , triglyceride , CRP , IgG , IgM , IgA , CD4 , CD8 , CD19 , CD16 - 56 lymphocytes were measured . Kt/V values were calculated according to DOQI guideline . In this study , a positive correlation between albumin , cholesterol , and triglyceride levels as nutritional parameters and immune functions in terms of total and subtype lymphocyte counts was observed . Further prospect i ve studies are needed to determine the clinical importance of this finding and the appropriate means of measurement and effects of nutrition on immune function in hemodialysis patients BACKGROUND Hyperphosphatemia is one of the main factors in the pathogenesis of secondary hyperparathyroidism . In addition , in dialysis patients elevated levels of phosphate and calcium times phosphate ( Ca x P ) ion product are associated with extraskeletal calcifications , as well as an increased risk of death . Cardiovascular calcifications may possibly be related to the high cardiovascular mortality seen in dialysis patients . In the USA the prevalence of hyperphosphatemia among dialysis patients is very high , over 60 % of patients having serum P levels > 5.5 mg/dl , but no data are available for the Italian population , which follows different diet and dialysis schedules . METHODS We looked at a r and om sample of 638 patients enrolled in 29 outpatient dialysis units in Southern Italy ( Campania and Sicily ) . Data were central ly analyzed after extraction from a computerized data base . In each patient the average of two or more values obtained in the six-month observation period ( from Jan. 99 to June 99 ) was calculated . Mean age was 61.2 years ( 95 % CI 59.9 - 62.5 ) years , dialytic age 72.2 months ( 95 % CI 67.4 - 77.0 ) . RESULTS Mean + /- SD ( 95 % CI ) levels of phosphate were 5.74 + /- 1.57 ( 5.62 - 5.86 ) mg/dl ; total calcium 9.06 + /- 0.98 ( 8.98 - 9.14 ) mg/dl ; Ca x P 51.4 + /- 14.4 ( 50.3 - 52.5 ) mg2/dl2 ; alkaline phosphatase was 167 + /- 119 ( 157 - 177 ) IU/L ; intact parathyroid hormone ( PTH ) levels , available in a subset of 239 patients , were 318 + /- 413 ( 265 - 370 ) pg/ml . Among these patients 51.6 % had serum P > 5.5 mg/dl , 36 % > 6 mg/dl ; Ca x P levels were > 55 mg2/dl2 in 35.5 % of the population , 24 % > 60 mg2/dl2 ; iPTH levels were < 100 pg/ml in 43 % ; 25.4 % had hyperparathyroidism ( defined as iPTH > 400 pg/ml ) , and only 19.5 % of patients had PTH in the desired interval of 100 to 250 pg/ml . CONCLUSIONS Compared to data reported from the USA , mean levels of phosphate , Ca x P , and P 
    Output:
    