Booster Dose of SARS-CoV-2 mRNA Vaccine in Kidney Transplanted Patients Induces Wuhan-Hu-1 Specific Neutralizing Antibodies and T Cell Activation but Lower Response against Omicron Variant

Kidney transplanted recipients (KTR) are at high risk of severe SARS-CoV-2 infection due to immunosuppressive therapy. Although several studies reported antibody production in KTR after vaccination, data related to immunity to the Omicron (B.1.1.529) variant are sparse. Herein, we analyzed anti-SARS-CoV-2 immune response in seven KTR and eight healthy controls after the second and third dose of the mRNA vaccine (BNT162b2). A significant increase in neutralizing antibody (nAb) titers were detected against pseudoviruses expressing the Wuhan-Hu-1 spike (S) protein after the third dose in both groups, although nAbs in KTR were lower than controls. nAbs against pseudoviruses expressing the Omicron S protein were low in both groups, with no increase after the 3rd dose in KTR. Reactivity of CD4⁺ T cells after boosting was observed when cells were challenged with Wuhan-Hu-1 S peptides, while Omicron S peptides were less effective in both groups. IFN-γ production was detected in KTR in response to ancestral S peptides, confirming antigen-specific T cell activation. Our study demonstrates that the 3rd mRNA dose induces T cell response against Wuhan-Hu-1 spike peptides in KTR, and an increment in the humoral immunity. Instead, humoral and cellular immunity to Omicron variant immunogenic peptides were low in both KTR and healthy vaccinated subjects.

[Acute severe respiratory distress in chronic haemodialytic patients affected by SARS-CoV-2 pneumonia: prevalence and associated factors. A single-centre experience from Cardarelli Hospital in Naples (Italy)]

Background: SARS‑CoV‑2-induced severe acute respiratory syndrome is associated with high mortality in the general population; however, the data on chronic haemodialysis (HD) patients are currently scarce. Methods: We performed a retrospective analysis to evaluate the onset of acute respiratory distress syndrome (ARDS) in patients with SARS‑CoV‑2-induced interstitial pneumonia diagnosed by PCR test and detected by high resolution computed tomography (HRCT). For each patient, we calculated a CT score between 0 and 24, based on the severity of pneumonia. The primary outcome was the onset of ARDS, detected by P/F ratio >200. We included 57/90 HD patients (age: 66.5 ±13.4 years, 61.4 % males, 42.1% diabetics, 52.6% CV disease) treated at the Cardarelli Hospital in Naples (Italy) from 1st September 2020 to 31st March 2021. All patients were treated with intermittent HD. Results: Patients who experienced ARDS had a more severe pneumonia (CT score: 15 [C.I.95%:10-21] in ARDS patients vs 7 [C.I.95%: 1-16] in no ARDS; P=0.015). Logistic regression showed that the CT score was the main factor associated with the onset of ARDS (1.12; 95% c.i.: 1.00-1.25), independently from age, gender, diabetes, chronic obstructive pulmonary disease, and prior CV disease. Thirty-day mortality was much greater in ARDS patients (83,3%) than in no-ARDS (19.3%). Conclusions: This retrospective analysis highlights that HD patients affected by SARS-CoV-2 pneumonia show an increased risk of developing ARDS, dependent on the severity of CT at presentation. This underlines once again the need for prevention strategies, in primis the vaccination campaign, for these frail patients.

Quality of life of hemodialysis patients in Central and Southern Italy: cross-sectional comparison between Hemodiafiltration with endogenous reinfusion (HFR) and Bicarbonate Hemodialysis

INTRODUCTION

in hemodialysis (HD) patients, poor health-related quality of life (HR-QoL) is prevalent and associated with adverse outcomes. HR-QoL is strictly linked to nutritional status of HD patients. Hemodiafiltration with endogenous reinfusion (HFR) is an alternative dialysis technique that combines diffusion, convection and absorption. It reduces burden of inflammation and malnutrition and this effect may cause beneficial effect on HR-QoL. However no data on HR-QoL in HFR is currently available.

METHODS

we designed a cross-sectional multicentre study in order to compare the HR-QoL in patients treated with HFR versus Bicarbonate HD (BHD). We enrolled adult patients HFR treated for at least 6 months, with life expectancy greater than six months and without overt cognitive deficit. The recruited patients in HFR were matched for age, gender, dialytic vintage and performance in activities of daily living (Barthel index) with BHD treated patients. SF-36 questionnaire for the assessment of HR-QoL was administered.

RESULTS

one hundred fourteen patients (57 HFR vs 57 BHD) were enrolled (age 65.413.5 years; dialysis vintage 5.4 (3.3-10.3) years; 53% males) from 18 dialysis non-profit centres in central and southern Italy. As result of matching, no difference in age, gender, dialytic age and Barthel index was found between HFR and BHD patients. In HFR patients we observed better values of physical component score (PCS) of SF-36 than BHD patients (P=0.048), whereas no significant difference emerged in the mental component score (P=0.698). In particular HFR patients were associated with higher Physical Functioning (P=0.045) and Role Physical (P=0.027).

CONCLUSIONS

HFR is associated with better physical component of HR-QoL than BHD, independently of age, gender, dialysis vintage and invalidity score. Whether these findings translate into a survival benefit must be investigated by longitudinal studies.

Best practices on pregnancy on dialysis: the Italian Study Group on Kidney and Pregnancy

BACKGROUND

Pregnancy during dialysis is increasingly being reported and represents a debated point in Nephrology. The small number of cases available in the literature makes evidence-based counselling difficult, also given the cultural sensitivity of this issue. Hence, the need for position statements to highlight the state of the art and propose the unresolved issues for general discussion.

METHODS

A systematic analysis of the literature (MESH, Emtree and free terms on pregnancy and dialysis) was conducted and expert opinions examined (Study Group on Kidney and Pregnancy; experts involved in the management of pregnancy in dialysis in Italy 2000-2013). Questions regarded: timing of dialysis start in pregnancy; mode of treatment, i.e. peritoneal dialysis (PD) versus haemodialysis (HD); treatment schedules (for both modes); obstetric surveillance; main support therapies (anaemia, calcium-phosphate parathormone; acidosis); counselling tips.

MAIN RESULTS

Timing of dialysis start is not clear, considering also the different support therapies; successful pregnancy is possible in both PD and HD; high efficiency and strict integration with residual kidney function are pivotal in both treatments, the blood urea nitrogen test being perhaps a useful marker in this context. To date, long-hour HD has provided the best results. Strict, personalized obstetric surveillance is warranted; therapies should be aimed at avoiding vitamin B12, folate and iron deficits, and at correcting anaemia; vitamin D and calcium administration is safe and recommended. Women on dialysis should be advised that pregnancy is possible, albeit rare, with both types of dialysis treatment, and that a success rate of over 75% may be achieved. High dialysis efficiency and frequent controls are needed to optimize outcomes.

Effect of hemodiafiltration with endogenous reinfusion on overt idiopathic chronic inflammation in maintenance hemodialysis patients: a multicenter longitudinal study

Chronic inflammation is widely diffuse in maintenance hemodialysis (MHD) patients and is associated with poor survival. Hemodiafiltration with endogenous reinfusion (HFR) is a dialysis technique, highly biocompatible, able to adsorb proinflammatory cytokines and to decrease amino acids and antioxidants loss. These features could be helpful in MHD patients affected by idiopathic chronic inflammation, but this issue remains to be elucidated. We performed a multicenter longitudinal study to assess the effect of the switching from bicarbonate HD to HFR in patients with serum C-reactive Protein (CRP) > 5 mg/L coupled with albumin <4.0 g/dL in the last 6 months. We enrolled 24/176 (14%) patients, of which 20 patients were assessed at 4 months and 18 completed the study. We excluded 11 patients with evident causes of inflammation. At baseline, serum levels of CRP (18.7[7.0-39.4] mg/L) and albumin (3.5[3.3-3.7] g/dL) were significantly correlated (r = -0.49; P = 0.028). The effect on CRP and albumin was almost evident in the first 4 months and remained stable until to eighth month. A strict correlation (R = -0.49; 0.040) between percentage change of CRP (-35%) and albumin (+14%) after 8 months of HFR. These effects were associated with the reduction of IL-6, IL-1β, and TNF-α and the increment of pre-albumin and leptin, whereas the serum levels of Branched Chain Amino Acid (BCAA) remained unchanged. In MHD patients affected by idiopathic chronic inflammation the switching from BHD to HFR is associated with improvement of inflammation. Whether these favorable effects may modify the outcomes of these high-risk patients needs to be confirmed by studies ad hoc.

[Hemodiafiltration with endogenous reinfusion in chronic inflammation: a possible therapeutic alternative?]

The patients under maintenance haemodialysis (HD) continue to have an unacceptably excess of mortality compared to general population, that may be explained by high prevalence of inflammation that significantly influences the survival of these patients. Indeed, chronic inflammation is very common in HD and it may cause malnutrition and progression of atherosclerotic disease by several pathogenetic mechanisms triggered by pro-inflammatory cytokines. Currently no pharmacological intervention is specifically targeted the idiopathic chronic inflammation. Hemodiafiltration with endogenous reinfusion (HFR) is a dialysis technique, highly biocompatible, that combines three depurative mechanisms: diffusion, convection and absorption. The ultrafiltrate is obtained from convective section of dialyzer (convection). It is regenerated by passing through the adsorbent macro-porous synthetic resin cartridge (absorption) and then it is reinfused into the second section of the filter (diffusion). This resin cartridge is able to absorb cytokines and other uremic toxins, whereas allows to pass nutrients and antioxidants, as amino acids and vitamins, with a consequent decrement of inflammation and oxidative stress. These characteristics suggest the use of HFR in HD patients affected by overt and idiopathic chronic inflammation. In these patients, we observed that the switching from Bic-HD to HFR allowed an improvement of inflammatory as testified by a significant decrement of serum levels of CRP IL-6, IL-1 and TNF- and a significant increase of albumin and pre-albumin. Whether these favorable effects may modify the outcomes of these high-risk patients, needs to be confirmed by studies ad-hoc.