Selective sequestration of cytokine-producing monocytes during hemodialysis treatment

The spleen size in patients undergoing hemodialysis

Introduction:

Inflammation promotes the progression of chronic renal failure, and the start of dialysis worsens inflammation. The enlargement of the spleen is associated with inflammation, and patients on hemodialysis may show a large spleen. The aim of the present study was to compare the spleen size of patients undergoing hemodialysis versus controls to update this thread.

Methods:

Controls and patients were eligible to participate in the study provided they were negative for serological markers of hepatitis B and C viruses and HIV, if they had no lymphoproliferative disorder, and if they were at least 18 years of age. Age, sex, and the duration of dialysis were recorded. Laboratory variables (hemoglobin, hematological cell count, serum creatinine) and the underlying cause of end-stage renal disease were analyzed. The spleen sizes of the patients were divided into tertiles.

Results:

The 75 controls and 168 patients selected were sex-matched. The patients were older, had larger spleens and lower platelet counts than controls. The relationship between spleen size and age in the controls and patients was quite similar. The patients in the first tertile of spleen size compared with those in the third were older and had a higher platelet counts. The underlying disease and dialysis vintage had no effect on spleen size.

Discussion:

The patients had larger spleens and a greater range of spleen sizes than the controls. In patients, the association between larger and smaller spleen with lower and higher platelet counts, respectively, sparked the speculation of occurrence of hypersplenism and hyposplenism.

Monocytes in Uremia

Monocytes play an important role in both innate immunity and antigen presentation for specific cellular immune defense. In patients with chronic renal failure, as well as those treated with maintenance hemodialysis, these cells are largely dysregulated. There is a large body of literature on monocyte alterations in such patients. However, most of the publications report on small series, there is a vast spectrum of different methods and the heterogeneity of the data prevents any meta-analytic approach. Thus, a narrative review was performed to describe the current knowledge. Monocytes from patients with chronic renal failure differ from those of healthy individuals in the pattern of surface molecule expression, cytokine and mediator production, and function. If these findings can be summarized at all, they might be subsumed as showing chronic inflammation in resting cells together with limited activation upon immunologic challenge. The picture is complicated by the fact that monocytes fall into morphologically and functionally different populations and population shifts interact heavily with dysregulation of the individual cells. Severe complications of chronic renal failure such as impaired immune defense, inflammation, and atherosclerosis can be related to several aspects of monocyte dysfunction. Therefore, this review aims to provide an overview about the impairment and activation of monocytes by uremia and the resulting clinical consequences for renal failure patients.

Hypervolemia-Induced Immune Disturbances Do Not Involve IL-1ß but IL-6 and IL-10 Activation in Haemodialysis Patients

Dysregulated fluid homeostasis is frequent in haemodialysis (HD) patients and is linked to inflammation which may be elicited by endotoxemia. The impact of hypervolemia on immune cells has not been studied in detail. Therefore, we analysed the hypervolemic activation of peripheral blood mononuclear cells (PBMCs) in HD with special focus on the NLRP3 inflammasome response. First, 45 HD were included in the observational study. Immune parameters including cell counts, caspase-1, oxidative stress, cytokine gene expression and serum analysis (IL-1ß, IL-6, IL-10) were all measured at two time points. Fluid status was evaluated by electrical bioimpedance vector analysis, defining hypervolemia (H) as >75 vector percentile. Then, 17 patients were classified as hypervolemic (H-HD), 19 as normovolemic (N-HD) and 9 failed to meet the inclusion criteria. Monocytes were elevated and lymphocytes were decreased by hypervolemia. NLRP3 inflammasome components, caspase-1 and IL-1ß expression were not statistically different between the two groups. Serum IL-6 levels were significantly elevated in H-HD. IL-10 mRNA transcripts were elevated by 2-fold in H-HD but were not efficiently translated. We conclude that the NLRP3 inflammasome is not activated by hypervolemia thus refuting the thesis that endotoxemia may be a main driver for inflammation in H-HD. Nevertheless, inflammation is generally higher in H-HD compared to N-HD patients and is not sufficiently balanced by anti-inflammatory mechanisms.

Serum fetuin-A levels and association with hematological parameters in chronic kidney disease and hemodialysis patients

Aim

The objective of the current study is to examine the association between serum fetuin-A concentrations and some other inflammation markers neutrophil to lymphocyte ratio (NLR), mean platelet volume (MPV) and C reactive protein (CRP) in patients with chronic kidney disease (CKD) and hemodialysis.

Methods

The study subjects are composed of healthy volunteers (n = 47) and two patient groups; CKD patients (n = 26) and hemodialysis patients (n = 33). We measured serum glucose, urea, creatinine, total protein, albumin, sodium, potassium, calcium, phosphorus, iron, alkaline phosphatase, parathyroid hormone, ferritin and CRP levels by auto-analyzer and fetuin-A levels by ELISA method. Also, complete blood count parameters were analyzed and NLR was calculated.

Results

There were significant differences in serum fetuin-A concentrations, NLR and MPV values among three groups (p < 0.001, p < 0.001, p < 0.001). The correlation analyses revealed that fetuin-A negatively correlated with urea, creatinine, ferritin, and CRP concentrations (r: 0.349, 0.367, 0.399, 0.550, respectively, p < 0.05).

Conclusion

Fetuin-A is lower in CKD and hemodialysis patients than the control group; supporting as a negative acute phase reactant. Determination of serum fetuin-A, NLR and MPV might be useful to assess inflammation in CKD and hemodialysis patients.

Inflammatory status in chronic renal failure: The role of homocysteinemia and pro-inflammatory cytokines

AIM: To evaluate determinants of inflammatory markers in chronic renal failure patients according to the level of glomerular filtration rate.

METHODS: One hundred fifty four patients (Age: 44 ± 06 years; male/female: 66/88) with chronic renal failure (CRF) were divided into 6 groups according to the National Kidney Foundation (NKF) classification. They included 28 primary stage renal failure patients (CRF 1), 28 moderate stage renal failure patients (CRF 2), 28 severe stage renal failure patients (CRF 3), 18 end-stage renal failure patients (CRF 4), 40 hemodialysis (HD) patients, and 12 peritoneal dialysis (PD) patients. Tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) and C-reactive protein (CRP) were analyzed by immunosorbent assay kit (ELISA) (Cayman Chemical’s ACETM EIA kit). Immunoassay methods were used for total homocysteine (tHcy) (fluorescence polarization immunoanalysis HPLC, PerkinEmer 200 series), transferrin (MININEPHTM human transferin kit: ZK070.R), ferritin (ADVIA Centaur) and fibrinogen analysis (ACL 200). Differences between groups were performed using SPSS 20.0 and data are expressed as the mean ± SD.

RESULTS: Results showed that in comparison with CRF 1 group and other groups, TNF-α and IL-6 levels were respectively more elevated in HD (16.38 ± 5.52 pg/mL vs 0.39 ± 0.03 pg/mL, 11.05 ± 3.59 pg/mL vs 8.20 ± 0.22 pg/mL, P < 0.001) and PD (14.04 ± 3.40 pg/mL vs 0.39 ± 0.03 pg/mL, 10.15 ± 1.66 pg/mL vs 8.20 ± 0.22 pg/mL, P < 0.001). IL-1β levels were increased in HD (9.63 ± 3.50 pg/mL vs 3.24 ± 0.10 pg/mL, P < 0.001) and CRF 4 (7.76 ± 0.66 pg/mL vs 3.24 ± 0.10 pg/mL, P < 0.001) patients than in CRF 1 and in the other groups. Plasma tHcy levels were higher in HD (32.27 ± 12.08 μmol/L) and PD (28.37 ± 4.98 μmol/L) patients compared to the other groups of CRF (P < 0.001). The serum CRP level was significantly increased in HD (18.17 ± 6.38 mg/L) and PD (17.97 ± 4.85 mg/L) patients compared to the other groups of CRF patients (P < 0.001). The plasma fibrinogen level was more elevated in HD (6.86 ± 1.06 g/L) and CRF 4 (6.05 ± 0.57 g/L) than in the other groups (P < 0.001). Furthermore; the ferritin level was higher in HD (169.90 ± 62.16 ng/mL) and PD (90.08 ± 22.09 ng/mL) patients compared to the other groups of CRF (P < 0.001). The serum transferrin value was significantly decreased especially in PD (1.78 ± 0.21 g/L) compared to the other groups (P < 0.001). We found a negative correlation between glomerular filtration rate (GFR), TNF-α levels (r = -0.75, P < 0.001), and tHcy levels (r = -0.68, P < 0.001). We observed a positive correlation between GFR and transferrin levels (r = 0.60, P < 0.001).

CONCLUSION: CRF was associated with elevated inflammatory markers. The inflammation was observed at the severe stage of CRF and increases with progression of renal failure.

HCV infection in haemodialysed patients: a role for serum IL-10 and TGF-beta1 in liver damage?

BACKGROUND

Hepatitis C virus (HCV) infection is often clinically silent in haemodialysed (HD) patients and their immune response may modulate liver damage in HCV infection. IL-10 and TGF-beta1 could play a role in this setting as, IL-10 down-regulates hepatic fibrosis, while TGF-beta1 is a pro-fibrotic cytokine.

AIM

To evaluate the role of IL-10 and TGF-beta1 in HD/HCV+ patients.

PATIENTS

71 HD/HCV+ patients (58 with normal [HD/HCV-N] and 13 with high serum transaminases [HD/HCV-H]), 40 non-uremic patients with chronic hepatitis C (HCV+), 56 HD anti-HCV- patients and 20 healthy volunteers (H).

METHODS

IL-10 and TGF-beta1 serum levels were assessed using ELISA tests. Liver histology was assessed by Ishak's score.

RESULTS

IL-10 serum levels were significantly higher in HD patients, both HCV+ (3.7+/-0.4 pg/ml; p<0.01) and HCV- (3.8+/-0.8 pg/ml; p<0.05) than in non-uremic HCV patients (2.3+/-0.4 pg/ml). Among the HD/HCV+ patients, IL-10 serum levels were similar in HD/HCV-N and in HD/HCV-H patients. Among the HD/HCV+ patients, IL-10 serum levels were similar in those with moderate histological damage compared to those with mild damage. TGF-beta1 serum levels were significantly lower in HD patients, both HCV+ (4.6+/-0.9 ng/ml) and HCV- (6.0+/-0.9 ng/ml) than in non-uremic HCV+ patients (8.1+/-1.1 ng/ml; p<0.001 and p<0.01, respectively), but similar to the values found in H (5.3+/-0.9 ng/ml; p=n.s.). No correlation was seen between IL-10 and TGF-beta1 serum levels in any of the groups considered.

CONCLUSIONS

Patients on haemodialysis treatment to have high levels of IL-10, which remain high even when patients are anti-HCV+, whereas the opposite is true of TGF-beta1. The cytokine pattern observed in HD patients is compatible with the hypothesis explaining the relatively benign evolution of HCV-related liver disease in HD patients, and has a pathophysiological role.

Decreased antigen-specific T-cell proliferation by moDC among hepatitis B vaccine non-responders on haemodialysis

Patients with end-stage kidney disease, whether or not on renal replacement therapy, have an impaired immune system. This is clinically manifested by a large percentage of patients unresponsive to the standard vaccination procedure for hepatitis B virus (HBV). In this study, the immune response to HBV vaccination is related to the in vitro function of monocyte-derived dendritic cells (moDC). We demonstrate that mature moDC from nonresponders to HBV vaccination have a less mature phenotype, compared to responders and healthy volunteers, although this did not affect their allostimulatory capacity. However, proliferation of autologous T cells in the presence of tetanus toxoid and candida antigen was decreased in non-responders. Also, HLA-matched CD4+ hsp65-specific human T-cell clones showed markedly decreased proliferation in the group of non-responders. Our results indicate that impairment of moDC to stimulate antigen-specific T cells provides an explanation for the clinical immunodeficiency of patients with end-stage kidney disease.

Human monocyte CD163 expression inversely correlates with soluble CD163 plasma levels

BACKGROUND

CD163 is a monocyte/macrophage-restricted receptor involved in the clearance of hemoglobin-haptoglobin complexes and regulation of inflammatory processes. CD163 is shed from the cell surface and exists as a soluble form in plasma (sCD163). Monocyte CD163 and sCD163 are potential diagnostic tools in variety of disease states.

METHODS

We determined the relation between plasma sCD163 levels by enzyme-linked immunosorbent assay, membrane expressions of CD163, CD64, and CD14 on blood monocytes by flow cytometry, and monocyte counts in 129 random blood samples.

RESULTS

A strong inverse correlation was found between membrane CD163 expression and sCD163 levels (r = -0.65, P < 0.001). Monocyte CD163 expression and SCD163 levels did not correlate with the monocyte absolute count.

CONCLUSIONS

The inverse relation between monocyte surface CD163 expression and sCD163 levels in human blood suggests that plasma sCD163 is derived from circulating monocytes, in addition to an unknown component from tissue macrophages. The lack of correlation with the absolute monocyte number suggests that such a balance is driven by the functional state of monocytes, rather than simply by numerical changes in circulating cells. We propose that further clinical evaluations of CD163 as a diagnostic parameter should include simultaneous measurements of soluble and cell-bound forms of this antigen.

Balance between cytokine production by peripheral blood mononuclear cells and reactive oxygen species production by monocytes in patients with chronic kidney disease

Hemodialysis (HD) and peritoneal dialysis are associated with inflammatory events and immunological incompetence. The purpose of this study was to evaluate the effect of both uremia and dialysis modality on the production of cytokines and reactive oxygen species (ROS) by monocytes. four groups of subjects were studied: 28 chronic kidney disease (CKD) patients, 14 chronic HD patients, 14 patients on continuous ambulatory peritoneal dialysis (CAPD) patients, and 14 healthy volunteers, peripheral blood mononuclear cells (PBMC) were isolated from blood samples and incubated for 24 hr with or without lipopolysaccharide (LPS). TNF-alpha and IL-10 production by PBMC and serum levels of these cytokines were quantified by ELISA. Aliquots of whole blood were incubated in vitro and ROS production and phagocytosis were quantified by flow cytometry. Compared to the control group, Staphylococcus aureus-stimulated ROS production by monocytes was significantly lower in the HD group. The highest levels of unstimulated TNF-alpha production in vitro were observed in the HD group. In the CKD group, as well as in the whole population, there were a negative correlation between TNF-alpha production by unstimulated PBMC and ROS production by S. aureus-stimulated monocytes and a positive correlation between PMA-stimulated ROS production by monocytes and unstimulated and LPS-stimulated IL-10 production by PBMC suggesting that the pro-inflammatory state in CKD patients is associated with decreased response to infectious challenges.

Pulmonary activity on labeled leukocyte images: physiologic, pathologic, and imaging correlation

Accurate interpretation of labeled leukocyte images requires knowledge of pulmonary labeled leukocyte uptake: its prevalence and patterns and its correlation with technical, physiologic, and pathologic conditions as well as with other imaging findings. Images obtained shortly after injection of labeled cells are characterized by diffuse pulmonary activity, which decreases over time, until about 4 hours after injection when it becomes indistinguishable from background activity, remaining constant thereafter. Focal pulmonary uptake that is segmental or lobar in appearance is most often associated with bacterial pneumonia. Focal pulmonary uptake that is not segmental or lobar results from technical problems during labeling or reinfusion and is not usually associated with infection. Diffuse pulmonary uptake on images obtained more than 4 hours after reinjection of labeled cells is associated with a variety of pathologic conditions, some of the more common being opportunistic infection, radiation pneumonitis, pulmonary drug toxicity, adult respiratory distress syndrome, and sepsis. However, this pattern is almost never seen in bacterial pneumonia. When pulmonary uptake patterns are analyzed and correlated with the clinical situation, labeled leukocyte scintigraphy can provide useful information about pulmonary disease.