Activated and regulatory T lymphocyte populations in chronic hemodialysis patients

The influence of haemodialysis on CD4+ T-cell counts in people living with human immunodeficiency virus with end-stage kidney disease

Background

In South Africa it is estimated that 7.9 million people are living with human immunodeficiency virus (HIV). HIV is associated with an increased risk of kidney disease. For people living with HIV (PLWH) who develop end-stage kidney disease (ESKD), access to renal replacement therapy can be difficult. Kidney transplantation is a cost-effective option, with improved overall survival and better quality of life. In Johannesburg, the eligibility criteria for kidney transplantation include a sustained CD4+ T-cell count of > 200 cells/μL and suppressed HIV replication.

Objective

To investigate the influence of haemodialysis on the lymphocyte subsets in PLWH with ESKD. In addition, all available %CD4+ T-cell counts, absolute CD4+ T-cell counts and viral load measurements were collected to assess the longitudinal trends of these measurements in PLWH with ESKD.

Methods

This was a cross-sectional study comparing two groups. The HIV-infected study participants (n = 17) and HIV-uninfected controls (n = 17) were recruited from renal dialysis centres in Johannesburg from 2017 to 2018. Demographic data and social data were collected from all the study participants (n = 17). Blood samples were collected from all the study participants (before and after a haemodialysis session), and the lymphocyte subsets were then measured. The available longitudinal data for the serial CD4+ T-cell counts and HIV viral loads were collected (n = 14).

Results

Our cohort showed a statistically significant increase in the post-dialysis percentage of CD4+ T cells (5%, p < 0.001) and the absolute CD4+ T-cell counts (21 cells/µL, p < 0.03). The longitudinal trend analysis for the percentage of CD4+ T cells revealed a significant increase in five participants (36%), and a single patient (7%) had a significant decrease in the longitudinal trend analysis for the absolute CD4+ T-cell counts. The longitudinal trend analysis for HIV viral load revealed the majority of our participants were not virologically suppressed.

Conclusion

This study showed that haemodialysis does not have an immediate negative impact on CD4+ T-cell count, suggesting that immunologic recovery is not impeded by treatment of the underlying ESKD.

AP-VAS 2012 case report: two patients with rheumatoid arthritis suspected of relapsed microscopic polyangiitis after initiation of dialysis

We report two patients with rheumatoid arthritis (RA) who were suspected of microscopic polyangiitis during maintenance dialysis. Case 1 was a 52-year-old woman with RA diagnosed at the age of 38 years and treated successfully with gold compounds. At the age of 43 years, she presented with progressive renal dysfunction and abnormal urine sediments, and a renal biopsy revealed crescentic nephritis with advanced glomerular sclerosis. Myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA) was not measured on that occasion. She reached end-stage renal failure within 4 months and started peritoneal dialysis. Eight years later, soon after she was switched to hemodialysis, she developed fever of unknown origin. MPO-ANCA was elevated to 37 EU, although there were no other signs or symptoms suggestive of vasculitis. After taking prednisolone orally (10 mg/day), her fever withdrew, and MPO-ANCA became undetectable. Case 2 was a 71-year-old woman with RA diagnosed at the age of 60 years and treated with gold compounds. She developed renal failure of unknown cause (no biopsy was performed), and started hemodialysis at the age of 69 years. One year later, she presented with fever and subsequently developed cough with hemoptysis. MPO-ANCA was elevated to 62 EU. Treatment with azathioprine 50 mg and prednisolone 35 mg daily brought remarkable clinical improvement, and MPO-ANCA became undetectable. These cases highlight the importance of measuring ANCA even in RA patients on dialysis who present with fever of unknown origin or with underlying kidney disease of uncertain etiology.

Management of HIV-infected patients with ESRD

Patients infected with human immunodeficiency virus (HIV) often progress to ESRD. In the era of highly active antiretroviral therapy, the care of these patients has become increasingly complex as survival has improved. Patients infected with HIV who also have ESRD are at risk for critical interactions between medication regimens to treat both of these conditions. Within this population, hemo- and peritoneal dialysis as well as kidney transplantation are life sustaining but present a host of obstacles related to HIV monitoring and risk of transmission, access thrombosis, infection, and rejection. Knowledge of antiretroviral regimens, drug interactions, and HIV resistance as well as the management of ESRD in the presence of HIV infection will improve the care of these unique patients.

Continuous venovenous hemofiltration: effects on monocyte and lymphocyte immunophenotype in critically ill patients

The aim of this study was to test the hypothesis that continuous venovenous hemofiltration (CVVH) increases HLA-DR expression on monocytes and T lymphocytes in critically ill patients. 24 septic (SP) and 10 non-septic (NSP) medical ICU patients with acute renal failure were studied prospectively. The ultrafiltration rate was 20-30 ml.kg(-1).h(-1). The total and differential white cell counts were measured and CD3+ lymphocyte count, HLA-DR expression on CD14+ monocytes and CD3+ lymphocytes were analysed by two-colour flow cytometry before, 4 and 24 h after CVVH initiation, respectively. CVVH did not influence leukocyte, granulocyte, total lymphocyte and CD3+ lymphocyte counts in both groups of patients. The percentage of HLA-DR+/CD14+ monocytes in SP revealed no changes, whereas it decreased after 4 h of CWH in NSP (p < 0.05). The percentage of HLA-DR+/CD3+ lymphocytes in SP decreased after 24 h (p < 0.05), whereas it remained unchanged in NSP. We conclude that CWH initiation is not associated with the increase of HLA-DR expression on CD14+ monocytes and T lymphocytes in critically ill patients with acute renal failure.

Early T cell activation correlates with expression of apoptosis markers in patients with end-stage renal disease

ABSTRACT. End-stage renal failure (ESRF) and chronic hemodialysis (HD) induce a state of immunodeficiency that involves T cell-mediated responses. A decreased T cell number combined with a reduced T cell lifespan and an increased T cell activation might play a role in the immune impairment associated with ESRF and chronic HD. Increased T cell activation associated with immunodeficiency suggests that activated T cells may be driven to apoptosis. To test this hypothesis, CD3+ T cell activation (CD69) and apoptosis (annexin V, CD95 (Fas), and DNA fragmentation) were analyzed in a case control study after blood draw sampling (ex vivo), in culture conditions, and after phytohemagglutinin or anti-CD3 stimulation. Ex vivo evaluation of T cells showed an increased number of activated CD69+ T cells in chronic HD patients (142 +/- 5 cells/mm3) compared with patients with ESRF (115 +/- 2 cells/mm3, P = 0.04) and controls (74 +/- 2 cells/mm3, P = 0.0006). These data were confirmed in culture conditions and after stimulation. Similarly, annexin V and CD95 (Fas)-positive T cells were more numerous in both patient groups than in controls, irrespective of the experimental conditions (P < or = 0.005 for both markers), and their percentage was always significantly higher in chronic HD patients than in patients with ESRF. The amount of DNA fragmentation was also significantly higher in the cultured resting T cells of chronic HD patients (37 +/- 3%) than in those of patients with ESRF (25 +/- 3%) and controls (20 +/- 2%) (P = 0.01). Percentage of cultured resting T cells expressing both CD69 and annexin V markers was higher in chronic HD patients (17 +/- 4%) than in patients with ESRF (10 +/- 4%) and controls (6 +/- 2%), (P = 0.005). After stimulation (phytohemagglutinin or anti-CD3), CD69+ T cell apoptosis increased by 2.4-fold in chronic HD patients compared with 1.8-fold in patients with ESRF and only 1.2-fold in controls (P = 0.001). T cells from chronic HD patients and patients with ESRF thus showed an aberrant state of early activation that contrasted with an increased proportion of annexin V and CD95 (Fas)-positive T cells engaged in apoptosis, as confirmed by DNA fragmentation. Increased susceptibility to early activated T cell apoptosis is not only associated with uremia, but is also enhanced by HD procedure. This may account for the T lymphopenia, progressive immunodeficiency, and increased infection risk seen in these patients.

The leukointegrin alpha d/beta 2 (alpha d/CD18): specific changes in surface expression in patients on hemodialysis

Alpha d/CD18 is a newly discovered leukocyte adhesion molecule with sequence homology to CD11a, b and c of the beta 2 integrin family. Little is known about alpha d expression in vivo, particularly how it compares with the other beta 2 integrins. Previous studies have demonstrated that beta 2 integrin expression, particularly CD11b, is upregulated in vivo during hemodialysis (HD) with complement activating membranes. These changes may contribute to the immunologic abnormalities seen in HD patients. Given the well described changes of beta 2 integrins in these patients, we hypothesized that alpha d expression could also be altered by HD. Using flow cytometry with two specific antibodies to alpha d, alpha d expression in healthy adults (n = 16) was compared on macrophages (MO) > polymorphonuclear cells (PMNs) > lymphocytes (LY). Phorbol ester treatment of leukocytes in vitro significantly increased expression on MO and PMN, but not LY. Chronic HD patients at baseline (n = 15) had elevated (P < 0.05) alpha d mean channel fluorescence (MCF) on MOs, PMNs and LYs compared to normals. PMN alpha d MCF increased at 15 min into HD, but then returned to baseline levels at 180 min. Alpha d MCF for LYs decreased at 180 min, while MOs levels were unchanged. Alpha d expression is increased in chronic renal failure and further regulated by hemodialysis, but with unique characteristics compared to the other beta 2 integrins. Alpha d may be important in abnormal cell-cell contacts in renal failure.

VLA-4 and its ligands: relevance to kidney diseases

Alterations in cellular immunity have been implicated in many kidney diseases. The role of the adhesion molecule VLA-4 and its known ligands VCAM-1 and CS-1 have just begun to be evaluated in association with kidney diseases. VCAM-1 in human kidney is normally expressed in the Bowman's capsule, in the proximal renal tubule, and in the vascular endothelium. Up-regulation of VCAM-1 expression is seen in many different forms of glomerulonephritis as well as in a mouse model of lupus nephritis. Up-regulation of VCAM-1 expression is observed in the renal allograft with acute cellular rejection, and correlates with areas of leukocyte infiltration and vascular inflammation. CS-1 may also be up-regulated in the rejecting kidney. Animal studies on cardiac transplantation demonstrate that blockade of VLA-4 or VCAM-1 can attenuate transplant rejection. Hemodialysis patients, known to have a cellular immunodeficiency, have increased levels of soluble VCAM-1 in their serum. There is increasing evidence that there are alterations in VLA-4, VCAM-1 and CS-1 in association with kidney diseases. Further studies will be required to delineate the role of these molecules in the immunopathogenesis of select kidney diseases and the possibility of intervening in these adhesion pathways to ameliorate clinical syndromes.