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

Oxidative stress in patients with coronavirus disease and end-stage renal disease: a pilot study

BACKGROUND

Oxidative stress, an imbalance between reactive oxygen species production and antioxidant capacity, increases in patients with coronavirus disease (COVID-19) or renal impairment. We investigated whether combined COVID-19 and end-stage renal disease (ESRD) would increase oxidative stress levels compared to each disease alone.

METHODS

Oxidative stress was compared among three groups. Two groups comprised patients with COVID-19 referred to the hospital with or without renal impairment (COVID-ESRD group [n = 18]; COVID group [n = 17]). The third group (ESRD group [n = 18]) comprised patients without COVID-19 on maintenance hemodialysis at a hospital.

RESULTS

The total oxidative stress in the COVID-ESRD group was lower than in the COVID group (p = 0.047). The total antioxidant status was higher in the COVID-ESRD group than in the ESRD (p < 0.001) and COVID (p < 0.001) groups after controlling for covariates. The oxidative stress index was lower in the COVID-ESRD group than in the ESRD (p = 0.001) and COVID (p < 0.001) groups. However, the three oxidative parameters did not differ significantly between the COVID and COVID-ESRD groups.

CONCLUSIONS

The role of reactive oxygen species in the pathophysiology of COVID-19 among patients withESRD appears to be non-critical. Therefore, the provision of supplemental antioxidants may not confer a therapeutic advantage, particularly in cases of mild COVID-19 in ESRD patients receiving hemodialysis. Nonetheless, this area merits further research.

Sustained post-rituximab B-cell depletion is common in ANCA-associated vasculitis and is affected by sex and renal function

OBJECTIVE

Despite the increasing use of rituximab in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), it remains unclear what the optimal dosing is, especially for maintenance of remission. A deeper understanding of post-rituximab B-cell repopulation patterns may aid better-tailored treatment.

METHODS

This is a monocentric, retrospective study including ANCA-positive AAV patients receiving a single course of rituximab induction. CD19+ B cells were longitudinally monitored with flow cytometry. B-cell repopulation was defined as CD19+ >10 cells/μL.

RESULTS

Seventy-one patients were included, the majority with microscopic polyangiitis (75%), myeloperoxidase-ANCA positivity (75%) and with renal involvement (79%). During a median follow-up of 54 months since the first rituximab infusion, 44 patients (62%) repopulated B cells, with a median time to repopulation of 39 months (range 7-102). Patients experiencing B-cell depletion lasting longer than the overall median time to repopulation (39 months) exhibited a lower risk of flare and higher risk of serious infection. In multivariate Cox regression, higher estimated glomerular filtration rate (eGFR) [hazard ratio (HR) 1.84, 95% confidence interval (CI) 1.13-2.98 per 30 mL/min/1.73 m2 eGFR] and female sex (HR 2.70, 95% CI 1.37-5.31) were independent predictors of increased rate of B-cell repopulation.

CONCLUSION

A subset of AAV patients develop sustained post-rituximab B-cell depletion, which associates with reduced risk of flare and increased risk of serious infection in the long term. Preserved renal function and female sex are associated with faster B-cell repopulation. These observations further highlight the need to personalize immunosuppression to improve clinical outcomes.

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.

Comparison of Humoral Response between Third and Fourth Doses of COVID-19 Vaccine in Hemodialysis Patients

Dialysis patients are more likely to die or become hospitalized from coronavirus disease 2019 (COVID-19). Currently, only a few studies have evaluated the efficacy of a fourth booster vaccination in hemodialysis (HD) patients and there is not enough evidence to recommend for or against a fourth booster vaccination. This study compared the humoral response and disease severity of patients on HD who received either three or four doses of COVID-19 vaccine. A total of 88 patients were enrolled. Humoral response to vaccination was measured by quantifying immunoglobulin G levels against the receptor binding domain of SARS-CoV-2 (anti-RBD IgG) at five different times and plaque reduction neutralization tests (PRNT) at two different times after vaccination over a period of 18 months. Antibody levels were measured at approximately two-month intervals after the first and second dose, then four months after the third dose, and then one to six months after the fourth dose of vaccine. PRNT was performed two months after the second and four months after the third dose of vaccine. We classified patients into four groups according to the number of vaccine doses and presence of COVID-19 infection. Severe infection was defined as hospital admission for greater than or equal to two weeks or death. There was no difference in antibody levels between naïve and infected patients except after a fourth vaccination, which was effective for increasing antibodies in infection-naïve patients. Age, sex, body mass index (BMI), dialysis vintage, and presence of diabetes mellitus (DM) did not show a significant correlation with antibody levels. Four patients who experienced severe COVID-19 disease tended to have lower antibody levels prior to infection. A fourth dose of SARS-CoV-2 vaccine significantly elevated antibodies in infection-naïve HD patients and may be beneficial for HD patients who have not been previously infected with SARS-CoV-2 for protection against severe infection.

Riding the Omicron BA.5 Wave: Improved Humoral Response after Vaccination with Bivalent Omicron BA.4-5-Adapted mRNA SARS-CoV-2 Vaccine in Chronic Hemodialysis Patients

Hemodialysis patients faced an excess morbidity and mortality during the COVID-19 pandemic. We evaluated the effect of second-generation mRNA vaccines against Omicron BA.4 and BA.5 variants of SARS-CoV-2 on humoral immunity. The study population comprised 66 adult hemodialysis patients who have encountered four SARS-CoV-2 antigen contacts through vaccination or infection. We assessed their humoral response using an anti-SARS-CoV-2 spike receptor binding domain IgG antibody assay (S-RBD-ab), measuring neutralizing antibodies against ancestral strain of SARS-CoV-2, Delta, and Omicron in a surrogate virus neutralization test (SVNT), and specifically against BA.5 in a plaque reduction neutralization test (PRNT) before and four weeks after vaccination with Comirnaty Original/Omicron BA.4-5. During the following six months, SARS-CoV-2 infections and symptom severity were documented. The bivalent mRNA vaccine led to a 7.6-fold increase in S-RBD-ab levels and an augmented inhibition of the Omicron variant in SVNT by 35% (median). Seroconversion in the Omicron BA.5-specific PRNT was attained by in 78.4% of previously negative patients (29/37). Levels of S-RBD-ab correlated with inhibition in the Omicron-specific SVNT and neutralization titers in the BA.5-PRNT. Eleven SARS-CoV-2 infections occurred in the six-month follow-up, none of which took a life-threatening course. The bivalent mRNA vaccine improved the SARS-CoV-2 virus variant-specific humoral immunity in chronic hemodialysis patients. Measurement of S-RBD-ab can be used in hemodialysis patients to estimate their humoral immunity status against Omicron BA.5.

Expression of Interferon Regulatory Factor 8 (IRF8) and Its Association with Infections in Dialysis Patients

Patients on dialysis have dysfunctions of innate and adaptive immune system responses. The transcriptional factor IRF8 (interferon regulatory factor 8) is primarily expressed in plasmacytoid cells (pDCs) and myeloid dendritic cells (mDCs), playing a crucial role in the maturation of dendritic cells, monocytes, and macrophages, and contributing to protection against bacterial infections. The current study analyzed the expression patterns of IRF8 and assessed its association with the risk of infections in 79 dialysis patients compared to 44 healthy controls. Different subsets of leukocytes and the intracellular expression of IRF8 were measured using flow cytometry. Compared to the healthy controls, the dialysis patients showed significantly reduced numbers of pDCs and significantly increased numbers of natural killer cells and classical and intermediate monocytes. The dialysis patients exhibited decreased numbers of IRF8-positive dendritic cells (pDC p < 0.001, mDC1 p < 0.001, mDC2 p = 0.005) and increased numbers of IRF8-positive monocytes (p < 0.001). IRF8 expression in pDC, mDC, and classical monocytes was lower in the dialysis patients than in the controls. Dialysis patients who required hospitalization due to infections within one year of follow-up displayed significantly reduced IRF8 expression levels in pDCs compared to patients without such infections (p = 0.04). Our results suggest that reduced IRF8 expression in pDCs is a potential risk factor predisposing dialysis patients to serious infections.

Lowering maintenance immune suppression in elderly kidney transplant recipients; connecting the immunological and clinical dots

The management of long-term immune suppressive medication in kidney transplant recipients is a poorly explored field in the area of transplant medicine. In particular, older recipients are at an increased risk for side effects and have an exponentially increased risk of infection-related death. In contrast, an aged immune system decreases the risk of acute T-cell-mediated rejection in older recipients. Recent advances in alloimmunity research have shown a rapid and substantial decline in polyfunctional, high-risk CD4⁺ T cells post-transplantation. This lowers the direct alloreactivity responsible for T-cell-mediated rejection, also known as donor-specific hyporesponsiveness. Chronic antibody-mediated rejection (c-aABMR) is the most frequent cause of kidney graft loss in the long term. However, in older adults, c-aABMR as a cause of graft loss is outnumbered by death with a functioning graft. In addition, DSA development and a diagnosis of c-aABMR plateau ~10 years after transplantation, resulting in a very low risk for rejection thereafter. The intensity of immune suppression regimes could likely be reduced accordingly, but trials in this area are scarce. Tacrolimus monotherapy for 1 year after transplantation seems feasible in older kidney transplant recipients with standard immunological risk, showing the expected benefits of fewer infections and better vaccination responses.

Comparison of Humoral Antibody Responses and Seroconversion Rates between Two Homologous ChAdOx1 nCoV-19 and mRNA-1273 Vaccination in Patients Undergoing Maintenance Hemodialysis

BACKGROUND

Hemodialysis patients are at an increased risk of SARS-CoV-2 infection and are excluded from preauthorization COVID-19 vaccine trials; therefore, their immunogenicity is uncertain.

METHODS

To compare the antibody responses to homologous ChAdOx1 and mRNA-1273 SARS-CoV-2 vaccination in hemodialysis patients, 103 age- and sex-matched hemodialysis patients with two homologous prime-boost vaccinations were recruited to detect anti-receptor-binding domain (RBD) IgG levels and seroconversion rates (SCRs) 14 days after a prime dose (PD14), before and 28 days after a boost dose (pre-BD0 and BD28).

RESULTS

Both mRNA-1273 and ChAdOx1 vaccinations elicited immunogenicity in study subjects, and the former induced higher anti-RBD IgG levels than the latter. The SCRs of both groups increased over time and varied widely from 1.82% to 97.92%, and were significantly different at PD14 and pre-BD0 regardless of different thresholds. At BD28, the SCRs of the ChAdOx1 group and the mRNA-1273 group were comparable using a threshold ≥ 7.1 BAU/mL (93.96% vs. 97.92%) and a threshold ≥ 17 BAU/mL (92.73% vs. 97.92%), respectively, but they were significantly different using a threshold ≥ 20.2% of convalescent serum anti-RBD levels (52.73% vs. 95.83%). The seroconversion (≥20.2% of convalescent level) at BD28 was associated with mRNA-1273 vaccination after being adjusted for age, sex, body mass index, and the presence of solicited reactogenicity after a prime vaccination.

CONCLUSION

Our prospective, observational cohort indicates that a full prime-boost mRNA-1273 vaccination is likely to provide higher immune protection in hemodialysis patients compared to ChAdOx1, and this population with a prime-boost ChAdOx1 vaccination should be prioritized for a third dose.

Anti-staphylococcus aureus adaptive immunity is impaired in end-stage renal disease patients on hemodialysis: one-year longitudinal study

Introduction

Patients with end-stage renal disease (ESRD) display defects in adaptive and innate immunity, increasing susceptibility to infection. Staphylococcus aureus (S. aureus) is a major cause of bacteraemia in this population and is associated with increased mortality. More information on the immune response to S. aureus in these patients is needed to inform effective vaccine development.

Methods

A longitudinal prospective study was carried out at two medical centers and included 48 ESRD patients who started chronic hemodialysis (HD) treatment ≤3 months before inclusion. Control samples were taken from 62 consenting healthy blood donors. Blood samples were obtained from ESRD patients at each visit, on month (M) 0 (beginning of HD), M6 and M12. Around 50 immunological markers of adaptive and innate immunity were assessed to compare immune responses to S. aureus in ESRD patients versus controls to document the changes on their immune profile during HD.

Results

S. aureus survival in whole blood was significantly higher in ESRD patients than in controls at M0 (P=0.049), while impaired oxidative burst activity was observed in ESRD patients at all timepoints (P<0.001). S. aureus-specific immunoglobulin G (IgG) responses to iron surface determinant B (IsdB) and S. aureus α hemolysin (Hla) antigens were lower in ESRD patients than in healthy donors at M0 (P=0.003 and P=0.007, respectively) and M6 (P=0.05 and P=0.03, respectively), but were restored to control levels at M12. Moreover, S. aureus-specific T-helper cell responses were comparable to controls for IsdB but were impaired for Hla antigen at all timepoints: 10% of ESRD patients responded to Hla at M0, increasing to 30% at M12, compared with 45% of healthy donors. B-cell and T-cell concentrations in blood were significantly reduced (by 60% and 40%, respectively) compared with healthy controls. Finally, upregulation of Human Leucocyte Antigen-DR (HLA-DR) and C-C chemokine Receptor type 2 (CCR2) was impaired at M0 but was restored during the first year of HD.

Conclusion

All together, these results show that adaptive immunity was largely impaired in ESRD patients, whereas innate immunity was less impacted and tended to be restored by HD.

Differences in the Profile of Circulating Immune Cell Subsets in Males with Type 2 Cardiorenal Syndrome versus CKD Patients without Established Cardiovascular Disease

Maladaptive activation of the immune system plays a key role in the pathogenesis of chronic kidney disease (CKD). Our aim was to investigate differences in circulating immune cells between type 2 cardiorenal syndrome (CRS-2) patients and CKD patients without cardiovascular disease (CVD). CRS-2 patients were prospectively followed up, with the primary endpoint being all-cause and cardiovascular mortality. Method: A total of 39 stable males with CRS-2 and 24 male CKD patients matched for eGFR (CKD-EPI) were enrolled. A selected panel of immune cell subsets was measured by flow cytometry. Results: Compared to CKD patients, CRS-2 patients displayed higher levels of proinflammatory CD14++CD16+ monocytes (p = 0.04) and T regulatory cells (Tregs) (p = 0.03), lower lymphocytes (p = 0.04), and lower natural killer cells (p = 0.001). Decreased lymphocytes, T-lymphocytes, CD4+ T-cells, CD8+ T-cells, Tregs, and increased CD14++CD16+ monocytes were associated with mortality at a median follow-up of 30 months (p < 0.05 for all). In a multivariate model including all six immune cell subsets, only CD4+ T-lymphocytes remained independent predictors of mortality (OR 0.66; 95% CI 0.50–0.87; p = 0.004). Conclusion: Patients with CRS-2 exhibit alterations in immune cell profile compared to CKD patients of similar kidney function but without CVD. In the CRS-2 cohort, CD4+ T-lymphocytes independently predicted fatal cardiovascular events.

Case report: A HIV-negative hemodialysis patient positive for pANCA with severe pneumocystis pneumonia: A case report and review of literature

RATIONALE

Pneumocystis pneumonia (PCP) is an opportunistic fungal infection that occurs in people with impaired or suppressed immunity such as patients with human immunodeficiency virus or organ transplant. However, the incidence and characteristics of PCP in the population with long-term hemodialysis is poorly described in the literature.

PATIENT CONCERNS

We present a case of a 50-year-old female patient being transferred to our hospital in February 2022 with a 20-day history of cough and tight breath. She received amoxicillin and cephalosporin anti-infection treatment successively in local hospital but no significant improvement in symptoms. She had a 2-year history of hemodialysis and no relevant transplantation and human immunodeficiency virus infection. She was diagnosed as ANCA associated vasculitis (AAV) and given oral prednisone acetate (20 mg/day) and methotrexate (2.5 mg/week) half a year ago.

DIAGNOSES

Based on the patient's medical history, Lung computerized tomography image, the Next generation sequencing report, the patient was diagnosed with renal failure, anti-neutrophil cytoplasmic antibody associated vasculitis, and Pneumocystis pneumonia.

INTERVENTIONS

The dosage of immunosuppressant was reduced due to leucocyte dripping and fever, and antibiotic and antifungal treatment were also given. The patient's lung condition was getting worse and noninvasive ventilator was required to maintain blood oxygen. Blood filtration is used to remove toxins. Ganciclovir and trimethoprim-sulfamethoxazole was used based on the next generation sequencing report.

OUTCOMES

The patient died of respiratory failure.

LESSONS

The risk of PCP in hemodialysis patients may be higher than that in ordinary population, and the prognosis of patients with immunosuppression may be worse. Dynamic assessment of vasculitis activity is necessary for hemodialysis patients with AAV because infections may obscure lung symptoms of AAV. It is not recommended that hemodialysis patients with long-term immunosuppression should reduce or stop the dosage of immunosuppressive drugs during the treatment because it may aggravate the condition of PCP. There is still no clear conclusion on whether hemodialysis patients need preventive medicine, but the identification of risk factors and early diagnosis and treatment are important for the prognosis of PCP on hemodialysis population.

Prospective Analysis of B Lymphocyte Subtypes, before and after Initiation of Dialysis, in Patients with End-Stage Renal Disease

End-stage renal disease (ESRD) is followed by alterations in adaptive immunity. The aim of this study was to evaluate B lymphocyte subtypes in ESRD patients before and after hemodialysis (HD) or continuous ambulatory peritoneal dialysis (CAPD).

PATIENTS AND METHODS

CD5, CD27, BAFF, IgM and annexin were evaluated by flow cytometry on CD19+ cells in ESRD patients (n = 40), at time of initiating HD or CAPD (T0) and 6 months later (T6).

RESULTS

A significant reduction in ESRD-T0 compared to controls was noticed for CD19+, 70.8 (46.5) vs. 171 (249), p < 0.0001, CD19+CD5-, 68.6 (43) vs. 168.9 (106), p < 0.0001, CD19+CD27-, 31.2 (22.1) vs. 59.7 (88.4), p < 0.0001, CD19+CD27+, 42.1 (63.6) vs. 84.3 (78.1), p = 0.002, CD19+BAFF+, 59.7 (37.8) vs. 127.9 (123.7), p < 0.0001 and CD19+IgM+ cells, 48.9 (42.8) vs. 112.5 (81.7) (K/μL), p < 0.0001. The ratio of early/late apoptotic B lymphocytes was reduced (16.8 (10.9) vs. 110 (25.4), p = 0.03). CD19+CD5+ cells were the only cell type with an increased proportion in ESRD-T0 patients (2.7 (3.7) vs. 0.6 (1.1), p < 0.0001). After 6 months on CAPD or HD, CD19+CD27-(%) and early apoptotic lymphocytes were reduced further. The HD patients also showed a significant increase in late apoptotic lymphocytes, from 1.2 (5.7) to 4.2 (7.2) K/mL, p = 0.02.

CONCLUSIONS

B cells and most of their subtypes were significantly reduced in ESRD-T0 patients compared to controls, the only exception being CD19+CD5+ cells. Apoptotic changes were prominent in ESRD-T0 patients and were exacerbated by HD.

A Low Prognostic Nutritional Index Is a Risk Factor for High Peritoneal Transport Status in Patients Undergoing Peritoneal Dialysis

OBJECTIVES

A high peritoneal transport status is a risk factor for mortality and causes technical failure in patients on peritoneal dialysis (PD). High peritoneal transport status is associated with malnutrition and inflammation in patients with PD. The prognostic nutritional index (PNI) is a marker determined by the serum albumin level and lymphocyte count in the peripheral blood. The aim of this study is to investigate the association between PNI and high peritoneal transport status in patients with PD.

METHODS

We retrospectively investigated patients with PD from January 1, 2013 to May 31, 2020, in 4 PD centers. Patients with PD were divided into 2 groups according to PNI quartiles: the low PNI group (PNI ≤ 36.6) and the high PNI group (PNI > 36.6). The demographics and clinical and laboratory baseline data of the 2 groups were collected and compared. The association between PNI and high peritoneal transport status was analyzed by multivariate logistic regression analysis.

RESULTS

A total of 404 patients with PD were enrolled in our study. A total of 77 (19.06%) patients had high peritoneal transport status. After adjusting for age, sex, body mass index, hypertension, diabetes mellitus, residual urine volume, current smoking status, pre-existing cardiovascular disease, hemoglobin, white blood cell count, triglycerides, and intact parathyroid hormone, low PNI levels were significantly associated with high peritoneal transport status (odds ratio 3.42, 95% confidence interval 1.82-5.18, P = .0056). Subgroup analysis showed that there was no interaction among PNI and age, sex, diabetes, body mass index, pre-existing cardiovascular disease, or current smoking.

CONCLUSION

As a marker for malnutrition and inflammation, a low level of PNI is an independent risk factor for high peritoneal transport status in patients with PD.

Different Types of Chronic Inflammation Engender Distinctive Immunosenescent Profiles in Affected Patients

Immunosenescence encompasses a spectrum of lymphocyte phenotypic alterations. The aim of the study was to evaluate immunosenescent effect of two different forms of chronic inflammation, Systemic Lupus Erythematosous (SLE), a systemic autoimmune disease, and End-Stage Kidney Disease (ESKD), a chronic inflammatory disorder. Certain lymphocyte surface molecules, including CD31, CD45RA, CCR7, CD28, CD57, for T, and IgD, CD27 for B lymphocytes, were analyzed by flow cytometry in 30 SLE and 53 ESKD patients on hemodialysis (HD), and results were compared to 31 healthy controls (HC) of similar age, gender, and nationality. Significant Lymphopenia was evident in both SLE and ESKD-HD patients, compared to HC, affecting B cells 75.4 (14.4−520.8), 97 (32−341), and 214 (84−576) cells/μL, respectively, p < 0.0001, and CD4 cells 651.2 (71.1−1478.2), 713 (234−1509), and 986 (344−1591) cells/μL, respectively, p < 0.0001. The allocation of B cell subpopulations was remarkably different between SLE and ESKD-HD patients. SLE showed a clear shift to senescence (CD19IgD-CD27−) cells, compared to ESKD-HD and HC, 11.75 (10)% vs. 8 (6) vs. 8.1 (10), respectively. Regarding T lymphocytes, Central Memory CD8 cells predominated in both SLE and ESKD-HD patients compared to HC, 53 (50)%, 52 (63), and 24 (64)%, respectively, while ESKD-HD but not SLE patients also had increased expression of CD4CD28− and CD8CD28− cells. In conclusion, both diseases are followed by significant lymphopenia; however, the senescent phenomenon affects the B lymphocyte compartment in SLE patients and T lymphocytes in ESKD-HD patients.

Two Cases of Autoimmune Thyroid Disorders after COVID Vaccination in Dialysis Patients

SARS-CoV-2 infection and vaccination have been associated with autoimmune thyroid dysfunctions. Autoimmune/inflammatory syndrome induced by adjuvants (ASIA) and molecular mimicry have been referred to as potential causes. Such a case has not been reported in immunocompromised end-stage renal disease (ESRD) patients. Herein we present two dialysis patients with no previous history of thyroid disease who developed immune mediated thyroid disorders after BNT162b mRNA vaccine against SARS-CoV-2. The first patient is a 29-year-old man on hemodialysis diagnosed with Grave’s disease four months post-vaccination and the second one is a 67-year-old female on peritoneal dialysis who developed Hashimoto’s thyroiditis two months post-vaccination. Grave’s disease is uncommon in dialysis patients, whereas Hashimoto’s thyroiditis has a higher incidence in this population. Time proximity in both cases suggests potential causality. To our knowledge, this is the first report of de novo immune-mediated thyroid disorders in dialysis patients following vaccination against SARS-CoV-2.

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.

Effectiveness and safety of Belimumab combined with standard therapy in severe active lupus nephritis requiring kidney replacement therapy: A case report and literature review

Lupus Nephritis (LN) is the most common manifestation of severe organ damage for systemic lupus erythematosus (SLE) patients. Severe active LN could result in acute kidney injury (AKI), which could even require Kidney Replacement Therapy (KRT). Therefore, there needs to be a more proactive and safe induction therapy to quickly and effectively control renal immune inflammation, maintain kidney function or reverse kidney damage. While multiple clinical studies have proven the efficacy and safety of Belimumab in treating SLE and LN, these studies have not included cases of severe LN requiring KRT. We observed the effectiveness and safety of Belimumab in treating four severe active LN patients undergoing KRT. With Belimumab administered at a dosage of 10mg/kg, all four patients were able to discontinue KRT with no adverse events (AEs) to date ultimately. These cases provided an excellent basis for the application of Belimumab combined with standard therapy to LN patients with a medium to severe kidney injury.

Efficacy and safety of belimumab in systemic lupus erythematosus patients with severe lupus nephritis requiring renal replacement therapy

BACKGROUND

Systemic lupus erythematosus is a chronic inflammatory autoimmune disease that has various manifestations. Lupus nephritis is a common and severe presentation, which results in increased morbidity and mortality. Belimumab added on standard therapy has been proved to induce disease remission and improve renal parameters. However, the use of belimumab has not been explored in patients requiring dialysis treatment.

METHODS

Seven patients diagnosed as SLE with renal involvement requiring dialysis, who received belimumab in addition to steroids or immunosuppressants were identified. Clinical and biological data were extracted from medical records and laboratory databases. Ten mg/kg belimumab was applied on day 1, 15, 29, and every 28 days thereafter for a total of 8 dose. Renal parameters including urine output and serum creatinine level, immunologic index including anti-ds-DNA antibody titer and complement level, and disease activity were documented to reveal the response to belimumab.

RESULTS

After belimumab therapy, all the 7 patients receiving dialysis therapy showed immunologic improvement. Disease activity significantly declined from 16.5 to 5.33 using SLEDAI-2K score. Apart from patient 7 on maintenance dialysis, 5 of 6 patients had increased urine output and were out of dialysis treatment. Patient 5 and 6 showed significant decrease in serum creatinine level. Only one pulmonary infection was documented.

CONCLUSIONS

Belimumab added to steroids or immunosuppressive agents was able to improve renal and immunologic parameters and decrease disease activity of SLE patients receiving dialysis treatment. The safety issue is promising with no severe adverse effect recorded. Further large, controlled, randomized clinical trials are required to confirm the results.

BNT162b2 vaccine effectiveness in chronic kidney disease patients – an observational study

Background

chronic kidney disease (CKD) is a risk factor for severe COVID-19. We aimed to evaluate real-life effectiveness of the BNT162b2 mRNA vaccine for a range of outcomes in patients with CKD compared to matched controls.

Methods

Data from Israel's largest healthcare organization were retrospectively used. Vaccinated CKD (eGFR&lt;60ml/min/1.73m2) and maintenance dialysis patients were matched to vaccinated controls without CKD (eGFR&gt; = 60ml/min/1.73m2) according to demographic and clinical characteristics. Study outcomes included documented infection with SARS-CoV-2, symptomatic infection, COVID-19 related hospitalization, severe disease, and death. Vaccine effectiveness was estimated as the risk ratio [RR] at days 7-28 following the second vaccine dose, using the Kaplan–Meier estimator. Effectiveness measures were also evaluated separately for various stages of CKD.

Results

There were 67,861 CKD patients not treated with dialysis, 2,606 hemodialysis patients, and 70,467 matched controls. The risk of sever disease (RR1.84, 95% CI 0.95-2.67) and death (RR 2.00, 95% CI 0.99-5.20) was increased in non-dialysis CKD patients compared with controls without CKD following vaccination.

For the subgroup of patients with eGFR below 30 ml/min/1.73m2, the risk of severe disease and death was increased compared to controls (RR 6.42, 95% CI 1.85-17.51 and RR 8.81, 95% CI 1.63-13.81, respectively). The risks for all study outcomes was increased in hemodialysis patients, compared with controls.

Conclusion

Two doses of the BNT162b2 vaccine were found less efficient for patients with eGFR&lt;30ml/min/1.73m2. Risk in hemodialysis patients is increased for all outcomes. These results suggest prioritizing patients with eGFR&lt;30ml/min/1.73m2 for booster shots, pre and post exposure prophylaxis, and early COVID-19 therapy.

Soluble uric acid inhibits β2 integrin-mediated neutrophil recruitment in innate immunity

Neutrophils are key players during host defense and sterile inflammation. Neutrophil dysfunction is a characteristic feature of the acquired immunodeficiency during kidney disease. We speculated that the impaired renal clearance of the intrinsic purine metabolite soluble uric acid (sUA) may account for neutrophil dysfunction. Indeed, hyperuricemia (HU, serum UA of 9-12 mg/dL) related or unrelated to kidney dysfunction significantly diminished neutrophil adhesion and extravasation in mice with crystal- and coronavirus-related sterile inflammation using intravital microscopy and an air pouch model. This impaired neutrophil recruitment was partially reversible by depleting UA with rasburicase. We validated these findings in vitro using either neutrophils or serum from patients with kidney dysfunction-related HU with or without UA depletion, which partially normalized the defective migration of neutrophils. Mechanistically, sUA impaired β2 integrin activity and internalization/recycling by regulating intracellular pH and cytoskeletal dynamics, physiological processes that are known to alter the migratory and phagocytic capability of neutrophils. This effect was fully reversible by blocking intracellular uptake of sUA via urate transporters. In contrast, sUA had no effect on neutrophil extracellular trap formation in neutrophils from healthy subjects or patients with kidney dysfunction. Our results identify an unexpected immunoregulatory role of the intrinsic purine metabolite sUA, which contrasts the well-known immunostimulatory effects of crystalline UA. Specifically targeting UA may help to overcome certain forms of immunodeficiency, for example in kidney dysfunction, but may enhance sterile forms of inflammation.

Mortality due to COVID-19 in renal transplant recipients, related to variants of SARS-CoV-2 and vaccination in Mexico

Background

SARS-CoV-2 infection in transplant patients has shown greater lethality and vaccination in this group of patients has shown less information. The objective of this study is to show the statistics in Mexico of lethality in kidney recipients infected with COVID-19 in relation to vaccination and variants of the coronavirus.

Methods

This is a bibliographic search of kidney transplant recipient patients since the start of the pandemic in Mexico to determine lethality after SARS-CoV-2 compared to the general population and in relation to patients, the 4 most important infectious peaks in the country due to identified variants, and also before and after vaccination.

Results

The global lethality is 26.91% from the beginning of the pandemic to April 9, 2022 in kidney recipients in Mexico (130 deaths of 483 infected kidney transplant recipients) compared to the national lethality of 5.60%. Variant B. 1.1.220 represented the highest lethality with 30.43% and the lowest lethality was Omicron with 16.41%. The lethality prior to vaccination was 30.94% and 23.46% after it.

Conclusion

Both some variants and vaccination have influenced a lower lethality due to COVID-19 in Mexico in kidney transplant patients; It is important to consider global recommendations, such as a third or fourth dose, a combination of mRNA vaccines and vectors in order to reduce lethality in this group of patients.

Adequacy of Hemodialysis Serves as an Independent Predictor of Humoral Response to ChAdOx1 Prime-Boost Vaccination in Hemodialysis Patients

Background: Immune response assessed by the quantification of neutralizing antibodies (nAbs) and predictors associated with immunogenicity after the prime-boost ChAdOx1 (Oxford−AstraZeneca) COVID-19 vaccine in hemodialysis (HD) patients remains unclear. Methods: This prospective study enrolled 174 HD patients and 67 healthy subjects to evaluate antibodies against the spike protein 1 and receptor-binding domain of severe acute respiratory syndrome coronavirus type 2 after prime-booster vaccination, by using enzyme-linked immunosorbent assay and applied spline-based generalized additive model regression analysis to predict 50% neutralization titer (NT50). The correlation between HD parameters and NT50 was analyzed. Results: NT50 was lower in HD patients compared with healthy controls after the prime-boost dose (p < 0.001). The geometric mean titer ratios were higher in first-dose seronegative than in the seropositive subgroup in HD patients and healthy controls (6.96 vs. 2.36, p = 0.002, and 9.28 vs. 1.26, p = 0.011, respectively). After two doses of ChAdOx1, one-way ANOVA showed that Ca × P was positively associated with NT50 (p trend = 0.043) and multiple linear regression showed the similar results (p = 0.021). Kt/V (a quantification of dialysis adequacy) (OR = 20.295, p = 0.005) could independently predict seroconversion (NT50 ≥ 35.13 IU/mL). Conclusion: Adequacy of hemodialysis could independently predict seroconversion in HD subjects vaccinated with prime-boost doses of ChAdOx1.

B Cell Composition Is Altered After Kidney Transplantation and Transitional B Cells Correlate With SARS-CoV-2 Vaccination Response

Background

The COVID-19 pandemic has major implications on kidney transplant recipients (KTRs) since they show increased mortality due to impaired immune responses to SARS-CoV-2 infection and a reduced efficacy of SARS-CoV-2 vaccination. Surprisingly, dialysis patients have shown superior seroconversion rates after vaccination compared to KTRs. Therefore, we investigated peripheral blood B cell (BC) composition before and after kidney transplantation (KT) and aimed to screen the BC compartment to explain impaired antibody generation.

Methods

A total of 105 patients were recruited, and multicolor flow cytometric phenotyping of peripheral venous blood BC subpopulations was performed before and 1 year after KT. Complete follow-up was available for 71 individuals. Anti-SARS-CoV-2 antibodies were collected retrospectively and were available for 40 subjects, who had received two doses of an mRNA-based vaccine (BNT162b2 or mRNA-1273).

Results

Overall, relative BC frequencies within lymphocytes decreased, and their absolute counts trended in the same direction 1 year after KT as compared to CKD G5 patients. Frequencies and absolute numbers of naïve BCs remained stable. Frequencies of double negative BCs, a heterogeneous subpopulation of antigen experienced BCs lacking CD27 expression, were increased after KT, yet their absolute counts were similar at both time points. Transitional BCs (TrBCs) and plasmablasts were significantly reduced after KT in absolute and relative terms. Memory BCs were affected differently since class-switched and IgM-only subsets decreased after KT, but unswitched and IgD-only memory BCs remained unchanged. CD86⁺ and CD5⁺ expression on BCs was downregulated after KT. Correlational analysis revealed that TrBCs were the only subset to correlate with titer levels after SARS-CoV-2 vaccination. Responders showed higher TrBCs, both absolute and relative, than non-responders.

Conclusion

Together, after 1 year, KTRs showed persistent and profound compositional changes within the BC compartment. Low TrBCs, 1 year after KT, may account for the low serological response to SARS-CoV-2 vaccination in KTRs compared to dialysis patients. Our findings need confirmation in further studies as they may guide vaccination strategies.

Risks of central nervous system infections and related mortality in patients undergoing dialysis

INTRODUCTION

This study aimed to investigate the risks of central nervous system (CNS) infections and related mortality in patients with end-stage renal disease (ESRD) undergoing dialysis.

METHODS

Incident dialysis patients were identified from 2000 to 2013. The risks of CNS infection and related mortality were analyzed.

RESULTS

The adjusted hazard ratio (HR) of CNS infection in the ESRD group compared with the control group was 3.46 (95% confidence interval [CI] 2.75-4.35). The adjusted odds ratio (OR) of 90-day mortality following CNS infections in the ESRD group in comparison with the control group was 5.99 (95% CI 2.78-12.9). The adjusted HR of overall CNS infection for the peritoneal dialysis (PD) group in comparison with the hemodialysis (HD) group was 1.07 (95% CI 0.63-1.82). Influenza vaccination was associated with a lower risks of CNS infection in dialysis patients (adjusted HR: 0.38, 95% CI 0.30-0.48). The adjusted OR of 90-day mortality following CNS infection for the PD group in comparison with the HD group was 1.01 (95% CI 0.55-1.87).

CONCLUSIONS

The risks of CNS infections and related mortality were remarkably high in dialysis patients with no significant difference between patients with ESRD under HD and PD treatment.

Secondary Immunodeficiency Related to Kidney Disease (SIDKD)-Definition, Unmet Need, and Mechanisms

Kidney disease is a known risk factor for poor outcomes of COVID-19 and many other serious infections. Conversely, infection is the second most common cause of death in patients with kidney disease. However, little is known about the underlying secondary immunodeficiency related to kidney disease (SIDKD). In contrast to cardiovascular disease related to kidney disease, which has triggered countless epidemiologic, clinical, and experimental research activities or interventional trials, investments in tracing, understanding, and therapeutically targeting SIDKD have been sparse. As a call for more awareness of SIDKD as an imminent unmet medical need that requires rigorous research activities at all levels, we review the epidemiology of SIDKD and the numerous aspects of the abnormal immunophenotype of patients with kidney disease. We propose a definition of SIDKD and discuss the pathogenic mechanisms of SIDKD known thus far, including more recent insights into the unexpected immunoregulatory roles of elevated levels of FGF23 and hyperuricemia and shifts in the secretome of the intestinal microbiota in kidney disease. As an ultimate goal, we should aim to develop therapeutics that can reduce mortality due to infections in patients with kidney disease by normalizing host defense to pathogens and immune responses to vaccines.

SARS-CoV-2 infection in dialysis and kidney transplant patients: immunological and serological response

Background

Dialysis and kidney transplant patients with moderate-severe COVID-19 have a high mortality rate, around 30%, that is similar in the two populations, despite differences in their baseline characteristics. In these groups, the immunology of the disease has been poorly explored.

Methods

Thirty-two patients on dialysis or with kidney transplant and SARS-CoV-2 infection requiring hospitalization (COV group) were included in our study. Lymphocyte subsets, dendritic cell (DC) counts and monocyte activation were studied. SARS-CoV-2 anti-spike/anti-nucleocapsid were monitored, and baseline cytokines and chemokines were measured in 10 patients.

Results

The COV group, compared to healthy subjects and uninfected dialysis/kidney transplant controls, showed lower numbers of CD4 + and CD8 + T cells, Natural-Killer (NK), B cells, plasmacytoid and myeloid DCs, while the proportion of terminally differentiated B-cells was increased. IL6, IL10, IFN-α and chemokines involved in monocyte and neutrophil recruitment were higher in the COV group, compared to uninfected dialysis/kidney transplant controls.

Patients with severe disease had lower CD4 + , CD8 + and B-cell counts and lower monocyte HLA-DR expression. Of note, when comparing dialysis and kidney transplant patients with COVID-19, the latter group presented lower NK and pDC counts and monocyte HLA-DR expression. Up to 60 days after symptom onset, kidney transplant recipients showed lower levels of anti-spike antibodies compared to dialysis patients.

Conclusions

During SARS-CoV-2 infection, dialysis and kidney transplant patients manifest immunophenotype abnormalities; these are similar in the two groups, however kidney transplant recipients show more profound alterations of the innate immune system and lower anti-spike antibody response.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s40620-021-01214-8.

Neutralization Assessments Reveal High Cardiothoracic Ratio and Old Age as Independent Predictors of Low Neutralizing Antibody Titers in Hemodialysis Patients Receiving a Single Dose of COVID-19 Vaccine

BACKGROUND

Data are lacking regarding predictors of quantification of neutralizing antibodies (nAbs) based on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 50% neutralization titer (NT50) after a single dose of COVID-19 vaccine in hemodialysis (HD) patients.

METHODS

This prospective single-center study enrolled 200 HD patients and 82 healthy subjects to estimate antibodies against the SARS-CoV-2 viral spike protein 1 and receptor-binding domain after a first dose of a COVID-19 vaccine (ChAdOx1 or mRNA-1273), measured by enzyme-linked immunosorbent assay and applied spline-based generalized additive model regression analysis to predict NT50 converted to international units.

RESULTS

After the first dose of ChAdOx1, multiple linear regression showed that age (p = 0.011) and cardiothoracic ratio (p = 0.002) were negatively associated with NT50. Older age (OR = 0.958, p = 0.052) and higher cardiothoracic ratio (OR < 0.001, p = 0.037) could predict negative humoral response (NT50 < 35.13 IU/mL). NT50 was lower in HD patients compared with healthy controls receiving ChAdOx1 (10.68 vs. 43.01 IU/m, p < 0.001) or mRNA-1273 (36.39 vs. 262.2 IU/mL, p < 0.001). ChAdOx1 elicited lower GMTs than mRNA-1273 in the HD cohort (10.68 vs. 36.39 IU/mL, p < 0.001) and in healthy controls (43.01 vs. 262.22 IU/mL, p < 0.001).

CONCLUSION

High cardiothoracic ratio and old age could independently predict a decline in nAb titers in an HD cohort vaccinated with a single dose of ChAdOx1.

The Humoral Immune Response to BNT162b2 Vaccine Is Associated With Circulating CD19+ B Lymphocytes and the Naïve CD45RA to Memory CD45RO CD4+ T Helper Cells Ratio in Hemodialysis Patients and Kidney Transplant Recipients

Background

The humoral and cellular immune responses to SARS-COV-2 vaccination remain to be elucidated in hemodialysis (HD) patients and kidney transplant recipients (KTRs), considering their baseline immunosuppressed status. The aim of our study was to assess the associations of vaccine-induced antibody responses with circulating lymphocytes sub-populations and their respective patterns of alterations in maintenance HD patients and KTRs.

Materials and Methods

We included 34 HD patients and 54 KTRs who received two doses of the mRNA-vaccine BNT162b2. Lymphocyte subpopulations were analyzed by flow cytometry before vaccination (T0), before the second vaccine dose (T1) and 2 weeks after the second dose (T2). The anti-SARS-CoV2 antibody response was assessed at T1 and at T2.

Results

31 HD patients (91.8%) and 16 KTRs (29.6%) became seropositive at T2. HD patients who became seropositive following the first dose displayed higher CD19+ B lymphocytes compared to their seronegative HD counterparts. A positive correlation was established between CD19+ B cells counts and antibody titers at all time-points in both groups (p < 0.001). KTRs showed higher naïve CD4+CD45RA+ T helper cells compared to HD patients at baseline and T2 whereas HD patients displayed higher memory CD45RO+ T cells compared to KTRs at T2. The naïve CD4+CD45RA to memory CD4+CD45RO+ T helper cells fraction was negatively associated with antibody production in both groups.

Conclusions

Our study provides a potential conceptual framework for monitoring vaccination efficacy in HD patients and KTRs considering the correlation established between CD19+ B cells, generation of memory CD4+ T helper cells and anti SARS-CoV2 antibody response to vaccination.

The Association of Circulating CD14++CD16+ Monocytes, Natural Killer Cells and Regulatory T Cells Subpopulations With Phenotypes of Cardiovascular Disease in a Cohort of Peritoneal Dialysis Patients

The altered expression of immune cells including monocyte subsets, natural killer (NK) cells and CD4+CD25+ regulatory T cells (Tregs) in end-stage kidney disease, affect the modulation of inflammation and immunity with significant clinical implications. The aim of this study was to investigate the profile of specific immune cells subpopulations and their correlations with phenotypes of established cardiovascular disease (CVD), including coronary artery disease (CAD) and heart failure (HF) in peritoneal dialysis (PD) patients.

Materials and Methods: 29 stable PD patients and 13 healthy volunteers were enrolled. Demographic, laboratory, bioimpedance measurements, lung ultrasound and echocardiography data were collected. The peripheral blood immune cell subsets analysis was performed using flow cytometry.

Results: PD patients compared to normal controls had lower total lymphocytes (22.3 ± 6.28 vs. 31.3 ± 5.54%, p = <0.001) and B-lymphocytes (6.39 ± 3.75 vs. 9.72 ± 3.63%, p = 0.01) as well as higher CD14++CD16+ monocytes numbers (9.28 ± 6.36 vs. 4.75 ± 2.75%, p = 0.0002). PD patients with prevalent CAD had NK cells levels elevated above median values (85.7 vs. 40.9%, p = 0.04) and lower B cells counts (3.85 ± 2.46 vs. 7.2 ± 3.77%, p = 0.03). Patients with increased NK cells (>15.4%) had 3.8 times higher risk of CAD comparing with patients with lower NK cell levels (95% CI, 1.86 – 77.87; p = 0.034). B cells were inversely associated with the presence of CAD (increase of B-lymphocyte by 1% was associated with 30% less risk for presence of CAD (95% CI, −0.71 – 0.01; p = 0.05). Overhydrated patients had lower lymphocytes counts (18.3 ± 4.29% vs. 24.7 ± 6.18%, p = 0.006) and increased NK cells [20.5% (14.3, 23.6) vs. 13.21% (6.23, 19.2), p = 0.04)]. In multiple logistic regression analysis the CRP (OR 1.43; 95% CI, 1.00 – 2.05; p = 0.04)] and lymphocytes counts (OR 0.79; 95% CI, 0.63–0.99; p = 0.04)] were associated with the presence of lung comets. Patients with higher NK cells (>15.4%, n = 15) were more likely to be rapid transporters (D/P creatinine 0.76 ± 0.1 vs. 0.69 ± 0.08, p = 0.04). Patients displaying higher Tregs (>1.79%) were older (70.8 ± 10.7 years vs. 57.7 ± 14.7years, p = 0.011) and had higher nPCR (0.83 ± 0.14 vs. 0.91 ± 0.17, p = 0.09).

Conclusion: Future research is required to evaluate the role of immune cells subsets as potential tools to identify patients at the highest risk for complications and guide interventions.

Comparing Humoral and Cellular Adaptive Immunity during Convalescent Phase of COVID-19 in Hemodialysis Patients and Kidney Transplant Recipients

Background. It is still unclear whether COVID-19 convalescent kidney transplant recipients (KTR) and hemodialysis (HD) patients can develop anti-SARS-CoV-2 adaptive immunity. The aim was to characterize and compare the immune response to the virus in HD patients and KTR. Methods. The study included 26 HD patients and 54 KTR—both convalescent (14 HD, 25 KTR) and unexposed. The immune response was assessed by determining the anti-SARS-CoV-2 antibodies in serum and specific T cell response via the interferon-gamma release assay (IGRA). Moreover, blood-morphology-derived parameters, immune cell phenotypes, and acute phase reactants were evaluated. Results. KRT and HD convalescents presented similar serum levels of anti-SARS-CoV-2 IgG and IgA. A negative correlation occurred between IgG and time after the infection was observed. There was a strong relationship between the prevalence of anti-SARS-CoV-2 cellular and humoral responses in both groups. Convalescent IGRA response was significantly higher in HD patients compared to KTR. Conclusions. HD patients and KTR develop humoral and cellular responses after COVID-19. The antibodies levels are similar in both groups of patients. SARS-CoV-2-reactive T cell response is stronger in HD patients compared to KTR. The SARS-CoV-2-specific IgG level decreases with time while IgA and a cellular response are maintained. IGRA proved to be a valuable test for the assessment of specific cellular immunity in immunocompromised HD patients and KTR.

End-Stage Renal Disease-Related Accelerated Immune Senescence: Is Rejuvenation of the Immune System a Therapeutic Goal?

End-stage renal disease (ESRD) patients exhibit clinical features of premature ageing, including frailty, cardiovascular disease, and muscle wasting. Accelerated ageing also concerns the immune system. Patients with ESRD have both immune senescence and chronic inflammation that are resumed in the so-called inflammaging syndrome. Immune senescence is particularly characterised by premature loss of thymic function that is associated with hyporesponsiveness to vaccines, susceptibility to infections, and death. ESRD-related chronic inflammation has multiple causes and participates to accelerated cardiovascular disease. Although, both characterisation of immune senescence and its consequences are relatively well-known, mechanisms are more uncertain. However, prevention of immune senescence/inflammation or/and rejuvenation of the immune system are major goal to ameliorate clinical outcomes of ESRD patients.

The Efficacy of COVID-19 Vaccines in Chronic Kidney Disease and Kidney Transplantation Patients: A Narrative Review

The SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) pandemic has posed a huge threat to global health because of its rapid spread and various mutant variants. Critical illness occurs in the elderly and vulnerable individuals, such as those with chronic kidney disease. The severity of SARS-CoV-2 infection is associated with the severity of chronic kidney disease (CKD)and even kidney transplantation (KT) because of the chronic use of immunosuppressive agents. To develop adaptive immunity against SARS-CoV-2, vaccination against the spike protein is important. Current phase III trials of vaccines against SARS-CoV-2 have not focused on a specific group of individuals, such as patients with CKD or those undergoing dialysis or kidney transplantation. Chronic use of immunosuppressive agents might disturb the immune response to the SARS-CoV-2 spike protein. On the basis of limited evidence, the immune compromised status of CKD patients might decrease neutralizing antibody development after a single dose of a specific vaccine. Boosting dosage more than the protocol might increase the titer of the neutralizing antibody in CKD patients. Further evidence is needed to understand the factors disturbing the immunogenicity of the SARS-CoV-2 vaccine, and CKD patients should receive the recommended dose of the SARS-CoV-2 vaccine due to their relatively immune compromised status.

Neutralizing Antibody Responses After SARS-CoV-2 Infection in End-Stage Kidney Disease and Protection Against Reinfection

INTRODUCTION

Patients with end-stage kidney disease (ESKD) represent a vulnerable group with multiple risk factors that are associated with poor outcomes after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Despite established susceptibility to infectious complications and the importance of humoral immunity in protection against SARS-CoV-2, few studies have investigated the humoral immune response to SARS-CoV-2 within this population. Here, we evaluate the seroprevalence of SARS-CoV-2 in patients awaiting renal transplantation and determine whether seroconverted patients with ESKD have durable and functional neutralizing activity against SARS-CoV-2.

METHODS

Serum samples were obtained from 164 patients with ESKD by August 2020. Humoral immune responses were evaluated by SARS-CoV-2 spike S1 subunit and nucleoprotein semiquantitative enzyme-linked immunosorbent assay (ELISA) and SARS-CoV-2 spike pseudotype neutralization assay.

RESULTS

All patients with ESKD with reverse-transcriptase polymerase chain reaction (RT-PCR)-confirmed infection (n = 17) except for 1 individual seroconverted against SARS-CoV-2. Overall seroprevalence (anti-S1 and/or anti-N IgG) was 36% and was higher in patients on hemodialysis (44.2%). A total of 35.6% of individuals who seroconverted were asymptomatic. Seroconversion in the absence of a neutralizing antibody (nAb) titer was observed in 12 patients, all of whom were asymptomatic. Repeat measurements at a median of 93 days from baseline sampling revealed that most individuals retained detectable responses although a significant drop in S1, N and nAb titers was observed.

CONCLUSION

Patients with ESKD, including those who develop asymptomatic disease, routinely seroconvert and produce detectable nAb titers against SARS-CoV-2. Although IgG levels wane over time, the neutralizing antibodies remain detectable in most patients, suggesting some level of protection is likely maintained, particularly in those who originally develop stronger responses.

Relationship of transitional regulatory B and regulatory T cells and immunosuppressive drug doses in stable renal transplant recipients

OBJECTIVES

Regulatory B cells (Bregs) and T cells (Tregs) are thought to be involved in the regulation of graft acceptance in renal transplant recipients. However, mechanisms that affect Breg differentiation and interaction with Tregs are rather unclear.

METHODS

Using eight-color-fluorescence flow cytometry, Tregs and CD19+ CD24hiCD38hi Bregs were analyzed in whole blood samples of 80 stable kidney transplant recipients, 20 end-stage renal disease (ESRD) patients and 32 healthy controls (HC). In addition, differentiation of Bregs and Tregs was studied in different micromilieus using cocultures with strongly enriched B-lymphocytes and autologous peripheral blood mononuclear cells stimulated with CpG and phytohemagglutinin.

RESULTS

Bregs were higher in HC than in ESRD patients and lowest in transplant recipients. Bregs were higher early as compared to late posttransplant. Posttransplant, high Bregs were associated with higher glomerular filtration rate (GFR) and lower C-reactive protein (CRP). Higher doses and blood levels of ciclosporine, tacrolimus, and mycophenolate mofetil as well as higher doses of steroids were not associated with low Bregs. In contrast, most Treg subsets were lower when blood levels of ciclosporine, tacrolimus, and mycophenolate mofetil were higher. Tregs were not associated with Bregs, GFR, CRP plasma levels, and occurrence of rejection or infection. In vitro, differentiation of Bregs was strongly dependent on T cell support and was blocked by excessive or lacking T-cell help. Tregs were not associated with Breg numbers in vitro.

CONCLUSION

Bregs appear to be insensitive to high doses of posttransplant immunosuppressive drugs. The protracted Breg decrease posttransplant might be caused by impaired T cell support attributable to immunosuppressive drugs.

Higher CD19+CD25+ Bregs are independently associated with better graft function in renal transplant recipients

Background

The Identification of B cell subsets with regulatory functions might open the way to new therapeutic strategies in the field of transplantation, which aim to reduce the dose of immunosuppressive drugs and prolong the graft survival. CD25 was proposed as a marker of a B-cell subset with an immunosuppressive action termed Bregs. The effect of CD19 + CD25 + Bregs on graft function in renal transplant recipients has not yet been elucidated. We investigated a potential impact of CD19 + CD25 + Bregs on renal graft function as well as a possible interaction of CD19 + CD25 + Bregs with peripheral Tregs in healthy controls, end-stage kidney disease patients (ESKD), and renal transplant recipients. Moreover, we aimed to investigate the association of CD19 + CD25 + Bregs with serum IL-10, TGF-ß1, and IFN-γ in the same study groups.

Method

Thirty-one healthy controls, ninety renal transplant recipients, and eighteen ESKD patients were enrolled. We evaluated the CD19 + CD25 + Bregs and Treg absolute counts. Next, we investigated CD19 + CD25 + Bregs as predictors of good graft function in multiple regression and ROC analyses. Finally, we evaluated the association between CD19 + CD25+ Bregs and serum IL-10, TGF-ß, and IFN-γ.

Results

ESKD patients and renal transplant recipients showed lower counts of CD19 + CD25+ Bregs compared to healthy controls (p < 0.001). Higher CD19 + CD25+ Breg counts were independently associated with a better GFR in renal transplant recipients (unstandardized B coefficient = 9, p = 0.02). In these patients, higher CD19 + CD25+ Bregs were independently associated with higher Treg counts (unstandardized B = 2.8, p = 0.004). In ROC analysis, cut-offs for CD19 + CD25 + Breg counts and serum TGF-ß1 of 0.12 cell/μl and 19,635.4 pg/ml, respectively, were shown to provide a good sensitivity and specificity in identifying GFR ≥ 30 ml/min (AUC = 0.67, sensitivity 77%, specificity 43%; AUC = 0.65, sensitivity 81%, specificity 50%, respectively). Finally, a significant positive association between CD19 + CD25+ Bregs and TGF-ß1 was shown in renal transplant recipients (r = 0.255, p = 0.015).

Conclusions

Our findings indicate that higher counts of CD19 + CD25+ Bregs are independently associated with better renal function and higher absolute Treg counts in renal transplant recipients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02374-2.

Successful Treatment with Belimumab in a Patient with Refractory Systemic Lupus Erythematosus after Initiation of Hemodialysis: Considering the Synergistic Effect of Belimumab and Immunological Burn-Out Phenomenon in End-Stage Renal Disease Patients on Hemodialysis

BACKGROUND

In patients with systemic lupus erythematosus (SLE), disease activity can persist even after initiating dialysis. However, guidelines for the treatment of patients with SLE after dialysis is initiated have not yet been established.

CASE PRESENTATION

We describe the case of a 54-year-old Japanese woman who was diagnosed with SLE at age 12, progressed to end-stage renal disease (ESRD), and initiated hemodialysis for lupus nephritis. However, SLE activity persisted after hemodialysis. Cyclophosphamide and mycophenolate mofetil were administered in addition to prednisolone and immunoadsorption, but this treatment strategy was limited by side effects. The patient was subsequently treated with belimumab, and the activity of SLE decreased rapidly.

CONCLUSIONS

ESRD patients with SLE show no significant decrease in transitional B cells and have elevated levels of B-cell activating factor (BAFF). Both transitional B cells and BAFF are important therapeutic targets for belimumab, indicating that patients with ESRD may benefit from belimumab therapy. However, the effects of belimumab may be potentiated in patients with uremia, who may be more susceptible to adverse events such as infections. Patients with SLE who receive belimumab after initiation of hemodialysis therefore require careful follow-up. Here, we report the first case of belimumab administration in a patient with SLE after initiation of hemodialysis.

TGF-β1 Signaling: Immune Dynamics of Chronic Kidney Diseases

Chronic kidney disease (CKD) is a major cause of morbidity and mortality worldwide, imposing a great burden on the healthcare system. Regrettably, effective CKD therapeutic strategies are yet available due to their elusive pathogenic mechanisms. CKD is featured by progressive inflammation and fibrosis associated with immune cell dysfunction, leading to the formation of an inflammatory microenvironment, which ultimately exacerbating renal fibrosis. Transforming growth factor β1 (TGF-β1) is an indispensable immunoregulator promoting CKD progression by controlling the activation, proliferation, and apoptosis of immunocytes via both canonical and non-canonical pathways. More importantly, recent studies have uncovered a new mechanism of TGF-β1 for de novo generation of myofibroblast via macrophage-myofibroblast transition (MMT). This review will update the versatile roles of TGF-β signaling in the dynamics of renal immunity, a better understanding may facilitate the discovery of novel therapeutic strategies against CKD.

Uremia Coupled with Mucosal Damage Predisposes Mice with Kidney Disease to Systemic Infection by Commensal Candida albicans

Infections are the second major cause of mortality in patients with kidney disease and accompanying uremia. Both vascular access and non-access-related infections contribute equally to the infection-related deaths in patients with kidney disease. Dialysis is the most common cause of systemic infection by Candida albicans in these patients. C albicans also reside in the gastrointestinal tract as a commensal fungus. However, the contribution of gut-derived C albicans in non-access-related infections in kidney disease is unknown. Using a mouse model of kidney disease, we demonstrate that uremic animals showed increased gut barrier permeability, impaired mucosal defense, and dysbiosis. The disturbance in gut homeostasis is sufficient to drive the translocation of microbiota and intestinal pathogen Citrobacter rodentium to extraintestinal sites but not C albicans Interestingly, a majority of uremic animals showed fungal translocation only when the gut barrier integrity is disrupted. Our data demonstrate that uremia coupled with gut mucosal damage may aid in the translocation of C. albicans and cause systemic infection in kidney disease. Because most of the individuals with kidney disease suffer from some form of gut mucosal damage, these results have important implications in the risk stratification and control of non-access-related opportunistic fungal infections in these patients.

In vitro anti-inflammatory effects of vitamin D supplementation may be blurred in hemodialysis patients

OBJECTIVES

This study aimed to evaluate the potential anti-inflammatory effects of vitamin D supplementation under uremic conditions, both in vivo and in vitro, and its effects on the parameters of mineral metabolism.

METHODS

Thirty-two hemodialysis patients were randomly assigned to receive placebo (N=14) or cholecalciferol (N=18) for six months. Serum levels of calcium, phosphate, total alkaline phosphatase, intact parathyroid hormone (iPTH), and vitamin D were measured at baseline and after three and six months. The levels of fibroblast growth factor-23 (FGF-23), interleukin-1β (IL-1β), and high-sensitivity C-reactive protein (hs-CRP) were also measured at baseline and at six months. Human monocytes were used for in vitro experiments and treated with cholecalciferol (150 nM) and uremic serum. Cell viability, reactive oxygen species (ROS) production, and cathelicidin (CAMP) expression were evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, dichloro-dihydro-fluorescein diacetate assay, and real time-quantitative polymerase chain reaction, respectively.

RESULTS

Both patient groups were clinically and biochemically similar at baseline. After six months, the levels of vitamin D and iPTH were higher and lower, respectively, in the cholecalciferol group than in the placebo group (p<0.05). There was no significant difference between the parameters of mineral metabolism, such as IL-1β and hs-CRP levels, in both groups. Treatment with uremic serum lowered the monocyte viability (p<0.0001) and increased ROS production (p<0.01) and CAMP expression (p<0.05); these effects were counterbalanced by cholecalciferol treatment (p<0.05).

CONCLUSIONS

Thus, cholecalciferol supplementation is an efficient strategy to ameliorate hypovitaminosis D in hemodialysis patients, but its beneficial effects on the control of secondary hyperparathyroidism are relatively unclear. Even though cholecalciferol exhibited anti-inflammatory effects in vitro, its short-term supplementation was not effective in improving the inflammatory profile of patients on hemodialysis, as indicated by the IL-1β and hs-CRP levels.

End-stage renal disease as a risk factor for epiglottitis: a population-based cohort study in Taiwan

OBJECTIVES

Patients with uremia are prone to infection; however, end-stage renal disease (ESRD) as a risk factor for acute epiglottitis warrants study. We investigated the risk of severe epiglottitis requiring hospitalisation in patients with ESRD.

SETTING

We conducted a retrospective matched cohort study by using the claims data of Taiwan's National Health Insurance Research Database.

PARTICIPANTS

We identified an ESRD cohort with 87 908 patients newly diagnosed in 2000-2013 and underwent dialysis. The non-ESRD cohort comprised patients who had not received a diagnosis of ESRD, and they were matches to the ESRD cohort (1:1) by sex, age, residence urbanisation level, monthly income, and diabetes and hypertension status.

PRIMARY AND SECONDARY OUTCOME MEASURES

The cumulative incidence of epiglottitis at the end of 2013 was analysed with Kaplan-Meier methods and log-rank tests. The HR of epiglottitis was calculated using the Cox proportional hazards model after adjustment for confounding factors.

RESULTS

The overall epiglottitis incidence rate was 94% greater in the ESRD cohort than in the non-ESRD cohort (10.3 vs 5.3 cases per 100 000 person-years, p=0.002), with an adjusted HR of 1.89 (95% CI: 1.23 to 2.91, p=0.004). In the log-rank analysis, compared with the non-ESRD group, the epiglottitis cumulative incidence was significantly higher in the ESRD group (p=0.003). Epiglottitis did not exhibit an association with higher rates of airway interventions, intensive care unit admissions or longer hospitalisation in patients with ESRD than in controls.

CONCLUSIONS

This nationwide matched cohort study indicated that ESRD patients should be monitored for the risk of severe epiglottitis requiring hospitalisation.

Kidney Failure Associates With T Cell Exhaustion and Imbalanced Follicular Helper T Cells

Individuals with kidney failure are at increased risk of cardiovascular events, as well as infections and malignancies, but the associated immunological abnormalities are unclear. We hypothesized that the uremic milieu triggers a chronic inflammatory state that, while accelerating atherosclerosis, promotes T cell exhaustion, impairing effective clearance of pathogens and tumor cells. Clinical and demographic data were collected from 78 patients with chronic kidney disease (CKD) (n = 42) or end-stage kidney disease (ESKD) (n = 36) and from 18 healthy controls (HC). Serum cytokines were analyzed by Luminex. Immunophenotype of T cells was performed by flow cytometry on peripheral blood mononuclear cells. ESKD patients had significantly higher serum levels of IFN-γ, TNF-α, sCD40L, GM-CSF, IL-4, IL-8, MCP-1, and MIP-1β than CKD and HC. After mitogen stimulation, both CD4+ and CD8+ T cells in ESKD group demonstrated a pro-inflammatory phenotype with increased IFN-γ and TNF-α, whereas both CKD and ESKD patients had higher IL-2 levels. CKD and ESKD were associated with increased frequency of exhausted CD4+ T cells (CD4+KLRG1+PD1+CD57-) and CD8+ T cells (CD8+KLRG1+PD1+CD57-), as well as anergic CD4+ T cells (CD4+KLRG1-PD1+CD57-) and CD8+ T cells (CD8+KLRG1-PD1+CD57-). Although total percentage of follicular helper T cell (TFH) was similar amongst groups, ESKD had reduced frequency of TFH1 (CCR6-CXCR3+CXCR5+PD1+CD4+CD8-), but increased TFH2 (CCR6-CXCR3-CXCR5+PD1+CD4+CD8-), and plasmablasts (CD3-CD56-CD19+CD27highCD38highCD138-). In conclusion, kidney failure is associated with pro-inflammatory markers, exhausted T cell phenotype, and upregulated TFH2, especially in ESKD. These immunological changes may account, at least in part, for the increased cardiovascular risk in these patients and their susceptibility to infections and malignancies.

Immune Dysfunction in Uremia 2020

Cardiovascular disease and infections are major causes for the high incidence of morbidity and mortality of patients with chronic kidney disease. Both complications are directly or indirectly associated with disturbed functions or altered apoptotic rates of polymorphonuclear leukocytes, monocytes, lymphocytes, and dendritic cells. Normal responses of immune cells can be reduced, leading to infectious diseases or pre-activated/primed, giving rise to inflammation and subsequently to cardiovascular disease. This review summarizes the impact of kidney dysfunction on the immune system. Renal failure results in disturbed renal metabolic activities with reduced renin, erythropoietin, and vitamin D production, which adversely affects the immune system. Decreased kidney function also leads to reduced glomerular filtration and the retention of uremic toxins. A large number of uremic toxins with detrimental effects on immune cells have been identified. Besides small water-soluble and protein-bound compounds originating from the intestinal microbiome, several molecules in the middle molecular range, e.g., immunoglobulin light chains, retinol-binding protein, the neuropeptides Met-enkephalin and neuropeptide Y, endothelin-1, and the adipokines leptin and resistin, adversely affect immune cells. Posttranslational modifications such as carbamoylation, advanced glycation products, and oxidative modifications contribute to uremic toxicity. Furthermore, high-density lipoprotein from uremic patients has an altered protein profile and thereby loses its anti-inflammatory properties.

Expansion of Group 2 Innate Lymphoid Cells in Patients with End-Stage Renal Disease and Their Clinical Significance

Group 2 innate lymphoid cells (ILC2s) play an important role in the control of tissue inflammation and homeostasis. However, the role of ILC2s in patients with end-stage renal disease (ESRD) has never been illustrated. In this study, we investigated ILC2s in ESRD patients and their clinical significance. Results showed that the frequencies and absolute numbers of ILC2s, not group 1 innate lymphoid cells or innate lymphoid cell precursors, were significantly elevated in the peripheral blood of ESRD patients when compared with those from healthy donor controls. Moreover, ILC2s from ESRD patients displayed enhanced type 2 cytokine production and cell proliferation. Plasma from ESRD patients significantly increased ILC2 levels and enhanced their effector function after in vitro treatment. The expression of phosphorylation of STAT5 in ILC2s, as well as the amounts of IL-2 in plasma, were increased in ESRD patients when compared with those from healthy donors. Clinically, ESRD patients with higher ILC2 frequencies displayed lower incidence of infectious complications during a mean of 21 month follow-up study. The proportions of ILC2s were negatively correlated with the prognostic biomarkers of chronic kidney disease, including serum parathyroid hormone, creatinine, and phosphorus, whereas they were positively correlated with serum calcium. These observations indicate that ILC2s may play a protective role in ESRD.

Lymphopenia and lymphocytosis in practical healthy people born and living in the North

Introduction

The purpose of this study was to elucidate the mechanisms of the formation of lymphopenia and lymphocytosis in healthy people, who are living and working in the Arctic region.

Materials and Methods

A total of 88 practically healthy people living and working in the Arctic region were examined. An analysis of the results was carried out, depending on the concentration of lymphocytes in the peripheral venous blood: group 1—with lymphopenia, the content of lymphocytes below 1.5 × 10⁹cl/L (21 people); group 2—with a normal lymphocyte content from 1.5 to 3.5 × 10⁹cl/L (47 people); and group 3—with lymphocytosis, lymphocytes in the peripheral blood of more than 3.5 × 10⁹cl/L (20 people).

Results

It has been established that the main mechanism for the formation of lymphopenia in a person living in the Arctic is the activation of the migration of functionally active lymphocytes in the tissue. The decrease in the number of circulating lymphocytes is a consequence of their redistribution from the circulating pool to the marginal one and an increase in the activity of adhesive molecules, in particular, the selectin ligand. It was revealed that an increase in the content of lymphocytes in the blood occurs upon the activation of the intracellular energy‐intensive mechanisms of lymphoproliferation with an increase in the consumption of intracellular ATP and the participation of the nuclear factor of activated T cells 1. It was shown that the restoration of the circulating pool of mature neutrophils is ensured by the principle of reverse regulation in response to neutropenia by stimulating granulocyte‐colony stimulating factor granulopoiesis.

Conclusions

The main mechanism for the formation of lymphopenia and lymphocytosis in healthy people was established.

Molecular Mechanisms of Premature Aging in Hemodialysis: The Complex Interplay Between Innate and Adaptive Immune Dysfunction

Hemodialysis (HD) patient are known to be susceptible to a wide range of early and long-term complication such as chronic inflammation, infections, malnutrition, and cardiovascular disease that significantly affect the incidence of mortality. A large gap between the number of people with end-stage kidney disease (ESKD) and patients who received kidney transplantation has been identified. Therefore, there is a huge need to explore the underlying pathophysiology of HD complications in order to provide treatment guidelines. The immunological dysregulation, involving both the innate and adaptive response, plays a crucial role during the HD sessions and in chronic, maintenance treatments. Innate immune system mediators include the dysfunction of neutrophils, monocytes, and natural killer (NK) cells with signaling mediated by NOD-like receptor P3 (NLRP3) and Toll-like receptor 4 (TLR4); in addition, there is a significant activation of the complement system that is mediated by dialysis membrane-surfaces. These effectors induce a persistent, systemic, pro-inflammatory, and pro-coagulant milieu that has been described as inflammaging. The adaptive response, the imbalance in the CD4+/CD8+ T cell ratio, and the reduction of Th2 and regulatory T cells, together with an altered interaction with B lymphocyte by CD40/CD40L, have been mainly implicated in immune system dysfunction. Altogether, these observations suggest that intervention targeting the immune system in HD patients could improve morbidity and mortality. The purpose of this review is to expand our understanding on the role of immune dysfunction in both innate and adaptive response in patients undergoing hemodialysis treatment.

Chronic Kidney Disease-Associated Immune Dysfunctions: Impact of Protein-Bound Uremic Retention Solutes on Immune Cells

Regardless of the primary disease responsible for kidney failure, patients suffering from chronic kidney disease (CKD) have in common multiple impairments of both the innate and adaptive immune systems, the pathophysiology of which has long remained enigmatic. CKD-associated immune dysfunction includes chronic low-grade activation of monocytes and neutrophils, which induces endothelial damage and increases cardiovascular risk. Although innate immune effectors are activated during CKD, their anti-bacterial capacity is impaired, leading to increased susceptibility to extracellular bacterial infections. Finally, CKD patients are also characterized by profound alterations of cellular and humoral adaptive immune responses, which account for an increased risk for malignancies and viral infections. This review summarizes the recent emerging data that link the pathophysiology of CKD-associated immune dysfunctions with the accumulation of microbiota-derived metabolites, including indoxyl sulfate and p-cresyl sulfate, the two best characterized protein-bound uremic retention solutes.

Uremia-Associated Ageing of the Thymus and Adaptive Immune Responses

Progressive loss of renal function is associated with a series of changes of the adaptive immune system which collectively constitute premature immunological ageing. This phenomenon contributes significantly to the mortality and morbidity of end-stage renal disease (ESRD) patients. In this review, the effect of ESRD on the T cell part of the adaptive immune system is highlighted. Naïve T cell lymphopenia, in combination with the expansion of highly differentiated memory T cells, are the hallmarks of immunological ageing. The decreased production of newly formed T cells by the thymus is critically involved. This affects both the CD4 and CD8 T cell compartment and may contribute to the expansion of memory T cells. The expanding populations of memory T cells have a pro-inflammatory phenotype, add to low-grade inflammation already present in ESRD patients and destabilize atherosclerotic plaques. The effect of loss of renal function on the thymus is not reversed after restoring renal function by kidney transplantation and constitutes a long-term mortality risk factor. Promising results from animal experiments have shown that rejuvenation of the thymus is a possibility, although not yet applicable in humans.

Alterations in peripheral blood B cells in systemic lupus erythematosus patients with renal insufficiency

OBJECTIVE

Systemic lupus erythematosus (SLE) is one of the autoimmune diseases, believed to be closely related to hyperactivity of B cells, overproduction of autoantibodies and immune complex formation and deposition in affected tissue. The autoreactive inflammation leads to multiorgan damage with kidney dysfunction in the forefront. Studies on lupus nephritis (LN), affecting the majority of SLE patients, are mainly focused on cells causing local inflammation. The aim of our work was to detect alterations in more accessible peripheral blood B cells in the course of SLE focusing on the influence of renal insufficiency (RI) on those parameters.

METHODS

We performed a comprehensive flow cytometry analysis of B cell subpopulations, analyzed gene expression patterns with qPCR, and examined serum cytokine levels with multiplex cytokine/chemokine assay.

RESULTS

We discovered distribution of specific B cell subsets, especially CD38⁺ cells, plasmablasts, associated with the presence and severity of the disease. Changes in expression of MBD2, DNMT1 and APRIL genes were not only associated with activity of SLE but also were significantly changed in patients with RI.

CONCLUSIONS

All these results shed new light on the role of circulating B cells, their subpopulations, function, and activity in the SLE with kidney manifestation.