Children with chronic renal failure have reduced numbers of memory B cells

Immune dysfunction in patients with end stage kidney disease; Immunosenescence - Review

The body's defense against environmental factors is realized by physical barriers and cells of both the innate and adaptive immune systems. Patients with end stage kidney disease (ESKD), especially those treated by hemodialysis, have changes in both the function and the number or percent of different leukocyte subsets. Changes were described at the level of monocytes and lymphocyte subsets, which are associated with immunodeficiencies and pro-inflammatory status correlated with degenerative changes and increased cardiovascular risk. These abnormalities have been compared over the past years with alterations appearing as a result ageing. Also, similitudes regarding immunosenescence observed in ESKD patients, in combination with chronic inflammation, are described as the so-called "inflammaging syndrome".

Distribution characteristics of circulating B cell subpopulations in patients with chronic kidney disease

This study compared the levels of circulating B cell subpopulations in patients with different stages of chronic kidney disease (CKD), investigated the effects of haemodialysis (HD) on the B cell-related immune spectrum in patients with end-stage renal disease, and evaluated the link between renal function and immune homeostasis. Overall, 197 patients with CKD (158 non-dialysis patients with CKD stages I-V and 39 end-stage patients undergoing maintenance HD) and 77 healthy controls were included. Compared to healthy controls, patients with CKD stages I-II showed no significant differences except for the proportion of transitional B cells; patients with CKD stage V showed a significant decrease in the proportions of transitional B cells and CD5+ B cells and a significant increase in double-negative (DN) B cells. Compared with early-stage patients with CKD, the absolute count of various B cell subpopulations in advanced-stage patients with CKD showed a significant decrease. The distribution of circulating B cell subpopulations in patients with CKD was significantly altered and was associated with CKD progression. Furthermore, the proportion of DN B cells and CD5+ B cells was inconsistent pre- and post-HD. This in-depth study of the immune status of patients with CKD may have important clinical value.

The role of neuroimmune and inflammation in pediatric uremia-induced neuropathy

Uremic neuropathy in children encompasses a wide range of central nervous system (CNS), peripheral nervous system (PNS), autonomic nervous system (ANS), and psychological abnormalities, which is associated with progressive renal dysfunction. Clinically, the diagnosis of uremic neuropathy in children is often made retrospectively when symptoms improve after dialysis or transplantation, due to there is no defining signs or laboratory and imaging findings. These neurological disorders consequently result in increased morbidity and mortality among children population, making uremia an urgent public health problem worldwide. In this review, we discuss the epidemiology, potential mechanisms, possible treatments, and the shortcomings of current research of uremic neuropathy in children. Mechanistically, the uremic neuropathy may be caused by retention of uremic solutes, increased oxidative stress, neurotransmitter imbalance, and disturbance of the blood-brain barrier (BBB). Neuroimmune, including the change of inflammatory factors and immune cells, may also play a crucial role in the progression of uremic neuropathy. Different from the invasive treatment of dialysis and kidney transplantation, intervention in neuroimmune and targeted anti-inflammatory therapy may provide a new insight for the treatment of uremia.

T-Lymphocyte Subsets Alteration, Infection and Renal Outcome in Advanced Chronic Kidney Disease

Background: T-lymphocyte subsets reflect patients' immune status and are associated with adverse outcomes in various diseases. However, the association between T-lymphocyte subsets and major infection and renal outcome in chronic kidney disease (CKD) patients has not been well-addressed.

Methods: Patients diagnosed with stage 3–5 of non-dialysis CKD were recruited, and healthy subjects were selected as the controls. T-lymphocyte subsets (CD3⁺, CD4⁺, CD8⁺) were detected by flow cytometry, and the CD4⁺/CD8⁺ T cell ratio was then calculated. Patients were divided into the normal-level group and the low-level group according to the clinical reference value. The primary outcomes were the major infection and renal outcome.

Results: A total of 410 CKD patients were enrolled; the average age was 47.25 years. Compared to the healthy controls, the level of CD3⁺, CD4⁺, CD8⁺ T cells, and the CD4⁺/CD8⁺ T cell ratio were significantly decreased in CKD patients (p < 0.05). During the median follow-up of 2.56 (quartile interval 1.24–3.46) years, major infections occurred in 15.10% of the CKD patients. The incidence of infection was significantly higher in the low-level group of CD3⁺, CD4⁺ T cells, and CD4⁺/CD8⁺ T cell ratio compared with the normal level groups. Kaplan-Meier analysis showed that the lower level of CD3⁺, CD4⁺ T cells, and CD4⁺/CD8⁺T cell ratio is associated with a greater risk of infection. Cox regression analysis further confirmed that low CD3⁺, CD4⁺ T cells, and CD4⁺/CD8⁺ T cell ratio were independent risk factors of infection in CKD patients. Moreover, during the follow-up, renal events occurred in 37.50% of patients. Kaplan-Meier analysis indicated that low levels of CD3⁺, CD4⁺, and CD8⁺ T cells are significantly associated with renal outcome in CKD patients. Cox regression analysis showed that low level of CD3⁺ T cells (HR = 2.407, 95% CI: 1.664–3.482, p < 0.001), CD4⁺ T cells (HR = 2.397, 95% CI: 1.633–3.518, p < 0.001) and CD8⁺ T cells (HR = 2.416, 95% CI: 1.476–3.955, p < 0.001) were independent risk factors for renal outcome after multivariable-adjusted.

Conclusion: CKD patients had a defect in T-lymphocyte subpopulation. T-lymphocyte subsets were closely associated with infection and renal outcome in CKD patients. Suggesting T-lymphocyte subsets are independent predictors of infection and renal outcome in CKD patients.

Assessment of variation in B-cell receptor heavy chain repertoire in patients with end-stage renal disease by high-throughput sequencing

Background/Aims: End-stage renal disease (ESRD), characterized by progressive loss of rental function during the disease course, has been reported to be correlated with immune dysregulation. To date, a majority of previous studies on immune response to ESRD have been focused on the T-cell response. This prospective study was to assess the B-cell receptor (BCR) heavy chain repertoire in ESRD patients.Materials and methods: A total of 10 ESRD patients and six healthy controls were prospectively enrolled in this study. BCR immunoglobulin heavy chain (IGH) repertoire in the peripheral blood from ESRD patients and healthy individuals were analyzed by means of next generation sequencing (NGS) in combination with multiplex PCR, Illumina sequencing, and the international ImMunoGeneTics database (IMGT).Results: Abnormal BCR complementary-determining region 3 (CDR3) sequences were identified in relation to ESRD. We also found that the degree of the B-cell clonal expansion in the ESRD group was significantly greater than that in the control group (p < .05), whereas the distributions of BCR CDR3, V, D, J, and V-J gene segments were comparable between the ESRD and control groups. T-test for analysis of the distribution ratio of the V, D, J, and V-J genes revealed five up-regulated genes and nine down-regulated genes associated with ESRD, and there were significant differences between the ESRD and control groups (p < .05).Conclusions: We have provided a successful approach to analyzing peripheral B-cell repertoire in ESRD patients, and the results suggest a direct correlation between the BCR repertoire and ESRD. The ESRD-specific BCR CDR3 sequences may hold promise for potentially therapeutic benefit.

Infectious Disease Risk in Dialysis Patients: A Transdisciplinary Approach

PURPOSE OF REVIEW

Infections are a major contributor to morbidity and mortality in end-stage renal disease (ESRD) patients. A better understanding of the interplay between infectious processes and ESRD may eventually lead to the development of targeted treatment strategies aimed at lowering overall disease morbidity and mortality. Monogenic causes are a major contributor to the development of adult chronic kidney disease (CKD). Recent studies identified a genetic cause in 10% to 20% of adults with CKD. With the introduction of whole-exome sequencing (WES) into clinical mainstay, this proportion is expected to increase in the future. Once patients develop CKD/ESRD due to a genetic cause, secondary changes, such as a compromised immune status, affect overall disease progression and clinical outcomes. Stratification according to genotype may enable us to study its effects on secondary disease outcomes, such as infectious risk. Moreover, this knowledge will enable us to better understand the molecular interplay between primary disease and secondary disease outcomes.

SOURCES OF INFORMATION

We conducted a literature review using search engines such as PubMed, PubMed central, and Medline, as well as cumulative knowledge from our respective areas of expertise.

METHODS

This is a transdisciplinary perspective on infectious complications in ESRD due to monogenic causes, such as autosomal dominant polycystic kidney disease (ADPKD), combining expertise in genomics and immunology.

KEY FINDINGS

In ADPKD, infection is a frequent complication manifesting primarily as lower urinary tract infection and less frequently as renal infection. Infectious episodes may be a direct consequence of a specific underlying structural abnormality, for example the characteristic cysts, among others. However, evidence suggests that infectious disease risk is also increased in ESRD due to secondary not-well-understood disease mechanisms. These disease mechanisms may vary depending on the underlying nature of the primary disease. While the infectious disease risk is well documented in ADPKD, there are currently insufficient data on the risk in other monogenic causes of ESRD. WES in combination with novel technologies, such as RNA sequencing and single-cell RNA sequencing, can provide insight into the molecular mechanisms of disease progression in different monogenic causes of CKD/ESRD and may lead to the development of novel risk-stratification profiles in the future.

LIMITATIONS

This is not a systematic review of the literature and the proposed perspective is tainted by the authors' point of view on the topic.

IMPLICATIONS

WES in combination with novel technologies such as RNA sequencing may enable us to fully unravel underlying disease mechanisms and secondary disease outcomes in monogenic causes of CKD and better characterize individual risk profiles. This understanding will hopefully facilitate the development of novel targeted therapies.

Association of serum immunoglobulin G level with peritonitis in patients undergoing peritoneal dialysis: An analytical study

Introduction: Peritonitis is one of the most common complications of peritoneal dialysis. On the other hand, reduced levels of immunoglobulins (Igs), mainly IgG, can increase the risk of infection in various pathologic conditions. Here, we aimed to determine the association of severity and frequency of peritonitis with serum IgG levels in peritoneal dialysis patients. Methods: 100 patients with chronic renal failure referred to Imam Reza Hospital, Tabriz, Iran, for peritoneal dialysis were included in the study. Serum IgG levels were measured in all of these patients at the beginning of the study and after six months of follow-up. In case of peritonitis, serum IgG levels were also measured, and samples were sent to Imam Reza Hospital laboratory for analysis. Results: 40 cases (40%) were women, and 60 cases (60%) were men with a mean age of 47 years. 24 cases (24.0%) had at least one episode of peritonitis during the study. Among those with peritonitis, 14 cases (60.9%) had at least one more peritonitis episode in the 6-month follow up. The mean serum IgG levels were 1079 mg/dl and 429 mg/dl at the beginning and after six months of follow up, respectively. The difference was shown to be statistically significant (P = 0.006). There was no correlation between serum IgG level reduction and peritonitis in these patients (P > 0.999). Conclusion: This study found reduced levels of serum IgG in patients undergoing peritoneal dialysis. However, it was not associated with increased risk of peritonitis in these patients.

CD19+ B-Cells, a New Biomarker of Mortality in Hemodialysis Patients

Background and objectives

Mortality of patients on hemodialysis (HD) remains very high despite recent improvements in HD techniques. Cardiovascular (CV) complications and infections are the main causes of death. Some studies suggest that disturbances in the immune system could play a role in this disproportionate mortality, through the links of immunity with inflammation and propensity to infections. However, few studies have addressed the role of lymphocyte populations and the global and CV mortality of HD patients.

Aim

To analyze the relationship of peripheral blood lymphocyte populations (PBLP) and all-cause and CV mortality of HD patients.

Design, setting, participants, and measurements

We design a prospective observational single center study in a cohort of HD prevalent patients. PBLP were analyzed at baseline and after 1 year and patients were followed for a 5-year period. Main outcomes were all-cause and CV mortality.

Results

One hundred and four patients (51% male, mean age 64.8 ± 15 years) were included. Follow-up was 18 (7–47) months. Fifty-five patients (52.8%) died, main causes of death being CVD (40%) and infections (29.1%). Low total lymphocyte counts were found in 47 patients (45.2%), and the most frequency lymphopenias were CD19⁺ B-cell (57.7%), CD3⁺ (40.4%), and CD4⁺ (36.5%). After 1 year, all determinations were lower except CD56⁺CD16⁺CD3⁻ natural killer. Patient survival was significantly lower in patients with a CD19⁺ B-cell count < 100 cells/μL at baseline as compared to patients with CD19⁺ B-cell ≥ 100 cells/μL counts at the end of follow-up (16.5 vs 54%, p = 0.003). By multivariable analysis, age, history of CV disease, Charlson index, a KT/V < 1.2, and a CD19⁺ B-cell count < 100 cells/μL at baseline and after 1-year were factors associated with of all-cause mortality. A CD19⁺ B-cell count < 100 cells/μL at baseline was associated with CV mortality.

Conclusion

CD19⁺ B-cell lymphopenia is very common among HD patients, and it could be an independent predictor of all-cause and CV mortality. More studies are needed to confirm these findings.

Humoral immunity to memory antigens and pathogens is maintained in patients with chronic kidney disease

Patients with chronic kidney disease (CKD) have an increased risk of infection and poorer responses to vaccination. This suggests that CKD patients have an impaired responsiveness to all antigens, even those first encountered before CKD onset. To examine this we evaluated antibody responses against two childhood vaccine antigens, tetanus (TT) and diphtheria toxoids (DT) and two common pathogens, cytomegalovirus (CMV) and Salmonella enterica serovar Enteritidis (SEn) in two independent cohorts consisting of age-matched individuals with and without CKD. Sera were evaluated for antigen-specific IgG titres and the functionality of antibody to SEn was assessed in a serum bactericidal assay. Surprisingly, patients with CKD and control subjects had comparable levels of IgG against TT and DT, suggesting preserved humoral memory responses to antigens encountered early in life. Lipopolysaccharide-specific IgG titres and serum bactericidal activity in patients with CKD were also not inferior to controls. CMV-specific IgG titres in seropositive CKD patients were similar or even increased compared to controls. Therefore, whilst responses to new vaccines in CKD are typically lower than expected, antibody responses to antigens commonly encountered prior to CKD onset are not. The immunodeficiency of CKD is likely characterised by failure to respond to new antigenic challenges and efforts to improve patient outcomes should be focussed here.

Th17/Treg Imbalance Induced by Dietary Salt Variation Indicates Inflammation of Target Organs in Humans

The functions of T helper 17 (Th17) and regulatory T (Treg) cells are tightly orchestrated through independent differentiation pathways that are involved in the secretion of pro- and anti-inflammatory cytokines induced by high-salt dietary. However, the role of imbalanced Th17/Treg ratio implicated in inflammation and target organ damage remains elusive. Here, by flow cytometry analysis, we demonstrated that switching to a high-salt diet resulted in decreased Th17 cells and reciprocally increased Treg cells, leading to a decreased Th17/Treg ratio. Meanwhile, Th17-related pathway was down-regulated after one day of high salt loading, with the increase in high salt loading as shown by microarray and RT-PCR. Subsequently, blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) observed hypoxia in the renal medulla (increased R2^* signal) during high-salt loading, which was regressed to its baseline level in a step-down fashion during low-salt feeding. The flow-mediated vasodilatation (FMD) of the branchial artery was significantly higher on the first day of high salt loading. Collectively, these observations indicate that a short-term increase in dietary salt intake could induce reciprocal switches in Th17/Treg ratio and related cytokines, which might be the underlying cellular mechanism of high-salt dietary induced end organ inflammation and potential atherosclerotic risk.

Lymphocyte depletion and subset alteration correlate to renal function in chronic kidney disease patients

BACKGROUND

It is widely accepted that chronic renal failure is associated with severe alterations of immune system. However, few studies looked into the immune alteration in earlier stage of chronic kidney disease (CKD) patients. To characterize immune defect in CKD patients, we performed lymphocyte subset analysis and explored its relationship to renal function in this population.

METHODS

472 CKD patients were enrolled in this study. Lymphocyte subsets (CD19(+), CD3(+), CD3(+)CD4(+), CD3(+)CD8(+), CD56(+)CD16(+)) were determined by flow cytometry. Clinical and laboratory data were collected. Patterns of immune cells in different stages of CKD were compared. Multivariate linear regression was used to evaluate the relationship between lymphocyte subset group and renal function. Correlation analysis was used to assess the relationship between lymphocyte subset and other clinical and laboratory data.

RESULTS

Decreased lymphocyte counts occurred long before the end stage of renal disease. Increased NK cell percentage was negatively related to estimated glomerular filtration rate (eGFR) (r = -0.259, p < 0.001) while B cell percentage was positively related to eGFR (r = 0.249, p < 0.001). Further multivariate linear regression showed increased B cell percentage (β = 16.470, 95%CI [1.018-31.922], p = 0.037) and decreased NK cell percentage (β = -10.659, 95%CI [-20.063 to -1.254], p = 0.026) were independently correlated with higher eGFR, respectively. Patients with lower NK cell percentage and higher B cell percentage tended to have the best renal function.

CONCLUSIONS

Lymphocyte depletion and subset alteration occurred during the progress of CKD. Further studies are needed to clarify the role of immune system in CKD and to expand our knowledge about the effect of uremia on the structure and function of immune system.

Expression of chemokine receptors on peripheral blood T cells in children with chronic kidney disease

Chemokine receptors play a role in leukocyte recruitment, activation, and maintaining effector functions and regulate adaptive immune response and angiogenesis. The study aimed at flow cytometric analysis of T cell subsets with selected surface chemokine receptors (CCR4, CCR5, CCR7, CXCR3, and CXCR4) or receptor combination in peripheral blood of children with chronic kidney disease (CKD) on hemodialysis (HD). The percentage of T lymphocytes with CD8 and combined CD28,CCR7 expression was higher in HD children. The percentage of T lymphocytes expressing CCR7, CD28,CCR7, and CXCR4,CD8 was increased in children on conservative treatment. Total number (tn) of CXCR4+ cells was reduced in children on hemodialysis. The tn of T CXCR3+ cells was lower in children on conservative treatment. During HD the percentage of T CD4+ cells was higher and of T CXCR3+ lymphocytes was lower after HD session as compared to 15 min of session duration. During HD tn of T cells with expression of CCR4, CCR5, CCR7, CXCR3, and CXCR4 was constant. The alteration of chemokine receptors expression in children with CKD occurs early in the development. Diminished expression of CXCR3, CXCR4 on T cells in patients with CKD on HD might result in impaired inflammatory response. Increased CCR7+ T cell percentage could be responsible for the alteration of migration of cells into secondary lymphatic organs.

Increased incidence of adenoidectomy and tonsillectomy in children with renal transplantation

BACKGROUND

Previous studies have found that pediatric solid organ transplant recipients suffer from adenotonsillar hyperplasia. However, as this condition is also common in normal children, it remains unclear whether the incidence is truly increased. The aim of this study was to compare the incidences of surgery on the adenoids and tonsils of normal children with those receiving renal transplants and to define risk factors in the transplant population.

METHODS

Data on 49 consecutive children from a single renal transplant unit were compared to data from a large governmental survey of healthy German children (KiGGS). For analysis of 'survival without operation', controls were matched for gender, region and immigration status (n = 8,650), as well as for age to compare incidence rates (n = 637).

RESULTS

The age-matched solid organ transplant recipients had a higher incidence of adenoidectomies [2.3-fold, [95 % confidence interval (CI) for relative risk 1.6-3.3) and a higher incidence of tonsillectomies/tonsillotomies (3.5-fold, 95 % CI 2.1-5.7). The normal peak of adenoidectomies was delayed by 2 years in the pre-school group, and transplanted teenagers showed an extra peak for both operations. Boys and those transplanted at a younger age were significantly more likely to need adenoidectomies. Ciclosporin levels, Epstein-Barr virus and cytomegalovirus infections did not influence the incidence of operations.

CONCLUSION

Children receiving renal transplants are at markedly increased risk of adenotonsillar hyperplasia requiring surgery, especially males and young recipients.

Peripheral B-cell phenotype and BAFF levels are associated with HLA immunization in patients awaiting kidney transplantation

BACKGROUND

The role of B-cell subsets in human leukocyte antigen (HLA)-specific humoral responses in patients with end-stage renal disease is poorly documented. The objective of this study was to analyze the potential association between B-cell subsets distribution and anti-HLA antibodies before kidney transplantation.

METHODS

The authors studied by flow cytometry peripheral B-cell subsets and serum levels of BAFF, the main homeostatic cytokine for peripheral B cells, in 101 consecutive end-stage renal disease patients admitted for transplantation.

RESULTS

In patients with HLA antibodies detected with Luminex single antigen, the proportion of activated naive B cells (Bm2) was significantly higher (64.4 ± 15.1% vs. 52.5 ± 19.1% in HLA antibody-negative patients, P=0.0008) at the expense of memory B cells, as were BAFF serum levels (1,651 ± 1,297 vs. 1,139 ± 693 pg/mL, P<0.0001). Proportion of Bm2 and BAFF levels were positively associated with the diversity of anti-HLA antibodies. In multivariate analysis, besides HLA-immunizing events (pregnancy and previous transplantation), proportion of Bm2 cells but not of other B-cell subsets or BAFF levels was independently associated with the presence and diversity of anti-HLA antibodies. High proportion of Bm2 cells before transplantation was associated with an increased risk of developing de novo donor-specific antibodies during the first year posttransplant. The authors did not find any association between the frequency of antibody-mediated rejection and pretransplant proportion of any B-cell subset or BAFF serum levels.

CONCLUSION

Increased proportions of activated naive B cells are linked with pretransplant HLA immunization and the development of posttransplant donor-specific antibodies.

Lymphocyte populations and apoptosis of peripheral blood B and T lymphocytes in children with end stage renal disease

BACKGROUND

End stage renal disease (ESRD) is a worldwide devastating health problem due to its increased prevalence in the population and high association with several pathologic conditions including immunodeficiency, which makes a significant contribution to morbidity and mortality.

AIM

The present study aimed at analysis of T and B lymphocyte subpopulation and the detection of flowcytometric apoptosis markers on peripheral B and T lymphocytes in a cohort of children with ESRD.

SUBJECTS AND METHODS

A case-control study was conducted on 28 children with ESRD. In addition, 30 age and sex matched healthy children were included as a control group. We used Annexin V-FITC binding assay as a sensitive probe for identifying cells undergoing apoptosis.

RESULTS

Circulating neutrophils, T and B lymphocytes were lower in patient group. In addition, apoptotic B and T lymphocytes occurred more frequently in children with ESRD than in the control group.

CONCLUSION

Our finding of low numbers of circulating neutrophils, T and B lymphocytes, and increased portion of apoptotic B and T lymphocytes in children with ESRD, may emphasize the fact that these derangements are the main mechanisms responsible for the impairment of the immune system in ESRD children, also it adds to the fact that both cellular and humoral immunity affected in ESRD children. Finally, uremia and increased peripheral lymphocyte apoptosis were the major causes of lymphocyte populations' depletion in our ESRD patients.

Evaluation of renal function and immune system cells in elderly individuals from São Paulo City

OBJECTIVES

Both renal function and immune system function decline with age. Although controversial, a significant number of studies have shown that the decline in kidney function is associated with the worsening of the immune system. These findings are reinforced by the increased susceptibility to infections and deficient immunization coverage after vaccination both in patients with chronic renal disease and in elderly individuals. Our objective was to evaluate a non-institutionalized elderly population from São Paulo City and correlate the estimated glomerular filtration rate with the percentage of lymphocytes in circulation.

METHODS

A random population of 237 individuals (107 men and 130 women), ranging in age from 60 to 101 years, who were enrolled in the Health, Well-Being and Aging Study was evaluated for renal function (Modification on Diet in Renal Disease formula) and lymphocyte percentage (flow cytometry).

RESULTS

Aging was associated with a decrease in the estimated glomerular filtration rate in both male and female individuals. We did not identify a significant correlation between the estimated glomerular filtration rate and either the percentage of CD4, CD8, and B cells or CD4/CD8 ratio. The median percentage of CD8+ T cells was significantly lower in individuals with an estimated glomerular filtration rate >60 mL/min/1.73 m².

CONCLUSIONS

In this study, no statistical correlation was found between the estimated glomerular filtration rate and either the lymphocyte phenotype (CD4+,CD8+, and CD19+ cells) or the CD4/CD8 ratio in blood.

Effect of uremia on structure and function of immune system

End-stage renal disease (ESRD) is simultaneously associated with immune activation, marked by systemic inflammation, and immune deficiency. Systemic inflammation contributes to atherosclerosis, cardiovascular disease, cachexia, and anemia, whereas immune deficiency leads to impaired response to vaccination, and increased incidence and severity of microbial infections. ESRD-associated inflammation and immune deficiency are associated with the following: (a) general expansion of monocytes and elevations of their basal integrin, Toll-like receptor (TLR)-2, TLR-4 expression, cytokine production, and reactive oxygen species (ROS) generation and reduced phagocytic capacity, (b) depletion and impaired inhibitory activity of regulatory T cells, (c) spontaneous activation, degranulation, increased basal ROS production, decreased phagocytic capacity, and increased apoptosis of the circulating polymorphonuclear leukocytes, (d) upregulation of ROS production machinery and chemokine expression in the cellular constituents of various tissues, highlighting participation of nonimmune cells in the prevailing inflammatory state, (e) depletion of the antigen-presenting dendritic cells, (f) reduced CD4/CD8 T cell ratio and depletion of naïve and central memory T cells, (g) diffuse B cell lymphopenia leading to impaired humoral immunity, and (h) increased proinflammatory activity of low-density lipoprotein and reduced anti-inflammatory capacity of high-density lipoprotein. Thus, ESRD-associated inflammation is due to activation of innate immune system, orchestrated by monocytes, macrophages, granulocytes, and cellular constituents of other organs/tissues. This is coupled with immune deficiency that is caused by depletion of dendritic cells, naïve and central memory T cells and B cells, and impaired phagocytic function of polymorphonuclear leukocytes and monocytes.

Splenectomy associated changes in IgM memory B cells in an adult spleen registry cohort

Asplenic patients have a lifelong risk of overwhelming post-splenectomy infection and have been reported to have low numbers of peripheral blood IgM memory B cells. The clinical value of quantitation of memory B cells as an indicator of splenic abnormality or risk of infection has been unclear. To assess changes in B cell sub-populations after splenectomy we studied patients recruited to a spleen registry (n = 591). A subset of 209 adult asplenic or hyposplenic subjects, and normal controls (n = 140) were tested for IgM memory B cells. We also determined a) changes in IgM memory B cells with time after splenectomy using the cross-sectional data from patients on the registry and b) the kinetics of changes in haematological markers associated with splenectomy(n = 45). Total B cells in splenectomy patients did not differ from controls, but memory B cells, IgM memory B cells and switched B cells were significantly (p<0.001) reduced. The reduction was similar for different indications for splenectomy. Changes of asplenia in routine blood films including presence of Howell-Jolly bodies (HJB), occurred early (median 25 days) and splenectomy associated thrombocytosis and lymphocytosis peaked by 50 days. There was a more gradual decrease in IgM memory B cells reaching a stable level within 6 months after splenectomy. IgM memory B cells as proportion of B cells was the best discriminator between splenectomized patients and normal controls and at the optimal cut-off of 4.53, showed a true positive rate of 95% and false positive rate of 20%. In a survey of 152 registry patients stratified by IgM memory B cells around this cut-off there was no association with minor infections and no registry patients experienced OPSI during the study. Despite significant changes after splenectomy, conventional measures of IgM memory cells have limited clinical utility in this population.

Comparison of hepatitis B surface antibody decay rates after vaccination between hemodialysis and peritoneal dialysis patients

BACKGROUND AND OBJECTIVES

The available information about maintaining effective immunity after hepatitis B virus (HBV) vaccination in dialysis patients is limited. The aim of this study was to determine whether a difference exists in the persistence of immunity between hemodialysis (HD) and peritoneal dialysis (PD) patients. We compared the decay rate of hepatitis B surface antibody (anti-HBs) titers after HBV vaccination between HD and PD patients.

DESIGN, SETTING, PARTICIPANTS, AND MEASURES

A total of 103 HD and 53 PD patients who were completely vaccinated were enrolled. We examined their anti-HBs titers at the 1st month after vaccination then annually thereafter. Changes in the anti-HBs titers were assessed by comparing annual geometric mean titers (GMTs).

RESULTS

The slopes of the anti-HBs titer decay rates plotted on a logarithmic scale for the HD and PD groups were -23.41 and -31.48, respectively. The decay rate of the PD group was significantly faster than that of the HD group (P=0.0053).

CONCLUSION

The decay rate of anti-HBs titers in the PD group was faster than that in the HD group. Hepatitis B vaccination could not offer long-term protection in HD or PD patients. Post-vaccination testing every 6-12 months is necessary and revaccination may be protective in dialysis patients, especially in hyper-endemic areas of hepatitis B infection.

The evaluation of Tetanus-diphtheria (Td) vaccine impacts on immune response to hepatitis B (HB) vaccine in non-responder dialysis patients

BACKGROUND

The Hepatitis B (HB) vaccine response in hemodialysis patients is less than healthy individuals. Different strategies have been taken into account to improve the response rate. This study aimed to evaluate the effect of tetanus and diphtheria (Td) vaccine as an adjuvant therapy to HB vaccination.

METHODS

Sixty three end-stage renal disease patients were recruited on dialysis that were older than 18 years and had passed at least 3 doses of HB vaccination schedule, and had HBS antibody (Ab) with titer less than 10 IU/L. The patients were divided into two groups; A (30 patients) and B (33 patients). Both of the groups received a 3-dose HB vaccination schedule of 40 μ g intramuscularly in the left deltoid muscle at 0, 1 and 6 months. Group A also received Td vaccine intramuscularly simultaneous with the first dose of HB vaccine. HBS Ab was measured in periods of 1 and 6 months after completion of the vaccination.

RESULTS

One month after completion of the vaccination, group A had better but not significant response rate (96%) than group B (83.9%) (p > 0.05); in addition, after 6 month there was no difference between the two groups (87.5% vs. 83.3%) (p > 0.05). Patients with HCV infection had lower response rate than patients who did not have HCV infection (33.3% vs. 92.5%) (p < 0.05). Age had negative effect on immune response to HB vaccination (r = -0.339; p = 0.005).

CONCLUSIONS

The use of Td vaccine concurrent with HB vaccination may increase the response rate in non-responder individuals; however, it seems it does not have any role in the persistence of immune response. Age and HCV infection negatively affected the response to HB vaccination in dialysis patients.

Effect of end-stage renal disease on B-lymphocyte subpopulations, IL-7, BAFF and BAFF receptor expression

BACKGROUND

End-stage renal disease (ESRD) results in increased susceptibility to infections, impaired response to vaccination and diffuse B-cell lymphopenia. However, the precise nature and mechanism of ESRD-induced B-cell lymphopenia remains unclear. Therefore, we studied the distribution of major B-cell subsets, B-cell growth, differentiation and survival factors, IL-7 and BAFF, and their receptors in 21 haemodialysis patients and 21 controls.

METHODS

Innate B1 cells (CD19+, CD5+), conventional B2 cells (CD19+, CD5-), newly formed transitional B cells (CD19+, CD10+, CD27-), naïve B cells (CD19+, CD27-) and memory B cells (CD19+, CD27+) and BAFF receptor were quantified by flow cytometry. Plasma IL-7, BAFF, IL-6, TNF-alpha and IL-10 were measured by ELISA.

RESULTS

The ESRD group exhibited significant reductions of all B-cell subpopulations except for transitional B cells that were less severely affected. No significant difference was found in B-cell apoptosis between the ESRD and control groups. Moreover, plasma IL-7 and BAFF levels were elevated in ESRD patients, therefore excluding their deficiencies as a possible culprit. However, BAFF receptor expression was significantly reduced in transitional but not mature B cells in the ESRD group. Interestingly, B-cell activation with the TLR9 agonist resulted in significantly greater production of IL-6 and TNF alpha but not IL-10 in the ESRD group.

CONCLUSIONS

Thus, despite elevation of B-cell growth, differentiation and survival factors, ESRD patients exhibited diffuse reduction of B-cell subpopulations. This was associated with the down-regulation of BAFF receptor in transitional B cells. The latter can, in part, contribute to B-cell lymphopenia by promoting resistance to the biological actions of BAFF that is a potent B-cell differentiation and survival factor.

Role of the spleen in peripheral memory B-cell homeostasis in patients with autoimmune thrombocytopenia purpura

The effect of splenectomy on circulating memory B cells in autoimmune thrombocytopenia purpura (AITP) patients has not yet been addressed. We therefore analyzed the distribution and phenotypic characteristics of B-cell subsets in non-splenectomized and splenectomized AITP patients and controls, as well as CD95 expression after B cell activation. Decreased frequencies of memory B cells in splenectomized individuals were observed, with a rapid decline of CD27+IgD+ and a slower decrease of CD27+IgD- and CD27-/IgD- cells. Similar results were noted following splenectomy in healthy donors (HD). CD95+ B cells were substantially increased in all subsets in patients with active AITP, indicating their enhanced activation status. After splenectomy, the percentage of CD95+ B cells were further increased in the CD27+IgD- post-switch memory population in AITP, but not in HD. CD95+CD27+ memory B cells largely reside in the region in the human spleen analogous to the murine marginal zone. Thus, the spleen plays a fundamental role in controlling peripheral memory B cell homeostasis in both AITP and HD and regulates activated CD95+ B cells in patients with AITP.

In vivo effect of an immunostimulating bacterial lysate on human B lymphocytes

The aim of the present study is to investigate in humans the mechanism by which the oral vaccine Polyvalent Mechanical Bacterial Lysate (PMBL) can rapidly mobilize specific immune response and evaluate the efficacy of its immunostimulating activity in preventing recurrent infections of the upper respiratory tract (URTIs) in a group of patients with a medical history of URTI recurrence. Patients received, by sublingual route, PBML, an immunostimulating lysate obtained by mechanical lysis of the most common bacteria responsible for upper respiratory tract infections. The treatment was administered for 10 consecutive days/month for 3 consecutive months. After the end of the treatment period the patients were followed up for an additional 3 months. The frequency of IgM memory B cells and the expression of the activation marker CD25 in peripheral blood lymphocytes were measured using the flow cytometric method before the start and at days 30 and 90 of the treatment cycle. To correlate clinical results to immunological parameters, the patients were monitored at different time-points during the treatment and at the end of follow-up period. The results showed that PMBL exerts a therapeutic and preventing effect in acute and recurrent infections of the upper respiratory tract and that this effect correlated with the activation and enhancement of both IgM memory B lymphocytes (CD24+/CD27+ cells) and IL2 receptor-expressing lymphocytes (CD25+ cells) involved either in humoral or cellular immunity.

Tacrolimus/Mycophenolate Mofetil Improved Natural Killer Lymphocyte Reconstitution One Year After Kidney Transplant by Reference to Cyclosporine/Azathioprine

BACKGROUND

Recently introduced immunosuppressive drugs are more potent to control graft rejection, but current concerns are raised regarding their potential to increase long-term neoplastic and infectious complications. Considering the role of B, T, or natural killer (NK) lymphocyte in controlling alloreactive, anti-infectious, and antitumoral immune responses, we compared the impact of two immunosuppressive regimens on lymphocyte subsets one year following kidney transplant.

METHODS

Multivariate regression analysis of variables affecting lymphocyte subset counts was retrospectively performed on 91 kidney-transplanted patients, analyzed before graft, at day 15 and 1-year postgraft. These patients were included in a randomized prospective open trial comparing tacrolimus/mycophenolate mofetil (FK/MMF) versus cyclosporine/azathioprine (CSA/Aza), both used in association with rabbit antithymocyte globulines (rATG) induction and prednisone.

RESULTS

Fifteen days postgraft, severe T and NK lymphocyte depletion were observed in all patients, while B cell counts were selectively higher in the FK/MMF group as compared to before graft. One-year posttransplant, NK cell counts and NK cell cytotoxicity was significantly higher in patients receiving FK/MMF therapy, as compared to CSA/Aza. Cytomegalovirus (CMV) infection during the first year posttransplant was also associated to higher NK, CD8, and CD4CD8 T cell counts at month 12.

CONCLUSIONS

In addition to its higher potential in preventing graft rejection, we show that after one year of transplant, FK/MMF better preserves NK innate immune effector cells and their cytotoxic potential. These data prompt to further evaluate the role of NK cells in relation to antiviral and tumoral surveillance of transplanted patients, which are common complications of long-term immunosuppression.

Differences in humoral immunity between a non-rejection group and a rejection group after ABO-incompatible renal transplantation

BACKGROUND

Renal transplantation across the blood barrier is a unique model for investigating the humoral response to different carbohydrate antigens. However, in such a renal transplantation, the characteristics of B cells as well as of the antibodies produced by B cells are less well defined.

METHODS

In the present study we investigated B cell subsets (i.e., the CD5(+) B-1 and CD5- B-2 subsets) by flow cytometric analysis, and their subclasses of antibody, by ELISA, in patients who had undergone renal transplantation across the blood barrier. The subjects consisted of five recipients with good function (group 1) and five recipients with graft loss (group 2) accompanied by antibody-titer elevation after ABO-incompatible renal transplantation.

RESULTS

The B-cell population analysis revealed that CD5(+) B-1 cells temporarily increased in all patients in both groups soon after transplantation, and that CD5- B-2 cells significantly increased 1 month after transplantation only in group 2. The antibody subclasses analysis showed mild elevation of immunoglobulin (Ig) G2 and IgM in group 1 as opposed to remarked elevation of IgG2, IgM and IgG1 in group 2.

CONCLUSIONS

The results of this study suggested that CD5(+) B-1 cell T-independent activation usually occurs soon after ABO-incompatible renal transplantation, but that CD5- B-2 cell T-dependent activation occurs only in patients who experience graft rejection.

Intracellular cytokines in peripheral blood leucocytes in children with chronic renal failure

We have previously shown that children with mild renal impairment show significant changes in leucocyte subsets and circulating cytokines, indicating that these patients show an increased inflammatory state. We hypothesised that measurement of intracellular cytokine production by lymphocytes and monocytes would more precisely define the immunological mechanism associated with the inflammatory state in children with pre-dialytic chronic renal failure. Blood was collected from children with chronic renal failure (CRF) who were not yet on dialysis and an age-matched control group. Leucocyte subsets and intracellular cytokine production were determined using flow cytometry. Children with CRF showed increased production of interleukin (IL)-12 by monocytes accompanied by decreased production of interferon (IFN)-gamma and increased production of IL-4 by T cells. There were no significant changes in the production of IL-8, IL-10, IL-6, IL-1alpha or tumour necrosis factor (TNF)-alpha by monocytes or in IL-2 or TNF-alpha production by T cells. There were no significant differences in total white cell count or lymphocyte count. There was a significant decrease in both B and NK cells. This study examines intracellular cytokine production in children with CRF in detail. It is the first to show that children with relatively mild renal failure display significant immunological changes of lymphocyte subsets and leucocyte cytokine production. These data provide a more accurate understanding of the immunological changes that may contribute to the clinical manifestations and progression of the disease.