Plasmapheresis adjusts inflammatory responses in potential kidney transplant recipients

Research priorities for therapeutic plasma exchange in critically ill patients

Therapeutic plasma exchange (TPE) is a therapeutic intervention that separates plasma from blood cells to remove pathological factors or to replenish deficient factors. The use of TPE is increasing over the last decades. However, despite a good theoretical rationale and biological plausibility for TPE as a therapy for numerous diseases or syndromes associated with critical illness, TPE in the intensive care unit (ICU) setting has not been studied extensively. A group of eighteen experts around the globe from different clinical backgrounds used a modified Delphi method to phrase key research questions related to "TPE in the critically ill patient". These questions focused on: (1) the pathophysiological role of the removal and replacement process, (2) optimal timing of treatment, (3) dosing and treatment regimes, (4) risk-benefit assumptions and (5) novel indications in need of exploration. For all five topics, the current understanding as well as gaps in knowledge and future directions were assessed. The content should stimulate future research in the field and novel clinical applications.

The efficacy of haemoperfusion combined with continuous venovenous haemodiafiltration in the treatment of severe viral encephalitis in children

BACKGROUND

This study investigated the efficacy of the integrated blood purification mode of early haemoperfusion (HP) combined with continuous venovenous haemodiafiltration (CVVHDF) in children with severe viral encephalitis, and evaluated the correlation of cerebrospinal fluid (CSF) neopterin (NPT) levels with prognosis.

METHODS

The records of children with viral encephalitis who received blood purification treatment in the authors' hospital from September 2019 to February 2022 were retrospectively analysed. According to the blood purification treatment mode, they were divided into the experimental group (HP + CVVHDF, 18 cases), control group A (CVVHDF only, 14 cases), and control group B (16 children with mild viral encephalitis who did not receive blood purification treatment). The correlation between the clinical features, severity of the disease and the extent of lesions on brain magnetic resonance imaging (MRI) and the CSF NPT levels was analysed.

RESULTS

The experimental group and control group A were comparable with respect to age, gender and hospital course (P > 0.05). There was no significant difference in speech and swallowing functions between the two groups after treatment (P > 0.05) and no significant difference in 7 and 14-day mortality (P > 0.05). The CSF NPT levels in the experimental group before treatment were significantly higher compared with control group B (P < 0.05). The extent of brain MRI lesions correlated positively with CSF NPT levels (P < 0.05). In the experimental group (14 cases), the serum NPT levels decreased after treatment, whereas the CSF NPT levels increased after treatment, and the differences were statistically significant (P < 0.05). Dysphagia and motor dysfunction correlated positively with CSF NPT levels (P < 0.05).

CONCLUSION

Early HP combined with CVVHDF in the treatment of severe viral encephalitis in children may be a better approach than CVVHDF only for improving prognosis. Higher CSF NPT levels indicated the likelihood of a more severe brain injury and a greater possibility of residual neurological dysfunction.

Translation: Expert Consensus on the Application of Artificial Liver Blood Purification System in the Treatment of Severe and Critical COVID-19

The prevention and treatment of COVID-19 nationwide has entered a tackling phase. Effective treatment of severe and critically ill patients is the key to reducing the fatality of the disease. The artificial liver blood purification system can remove inflammatory factors, alleviate the damage of the inflammatory response to the body, and has important value for the treatment of severe COVID-19. Led by Academician Lanjuan Li, based on the experience of treating patients across the country, integrating the opinions of experts from all over the country, the center summarized and formulated the consensus including the basic principles, treatment indications, relative contraindications, mode selection, monitoring indicators, and efficacy evaluation of artificial liver, which provides reference for treatment of severe COVID-19 patients.

Exosome microRNA signatures in patients with complex regional pain syndrome undergoing plasma exchange

Background

Therapeutic plasma exchange (PE) or plasmapheresis is an extracorporeal procedure employed to treat immunological disorders. Exosomes, nanosized vesicles of endosomal origin, mediate intercellular communication by transferring cargo proteins and nucleic acids and regulate many pathophysiological processes. Exosomal miRNAs are potential biomarkers due to their stability and dysregulation in diseases including complex regional pain syndrome (CRPS), a chronic pain disorder with persistent inflammation. A previous study showed that a subset of CRPS patients responded to PE.

Methods

As a proof-of-concept, we investigated the PE-induced exosomal miRNA changes in six CRPS patients. Plasma cytokine levels were measured by HPLC and correlated with miRNA expression. Luciferase assay following co-transfection of HEK293 cells with target 3′UTR constructs and miRNA mimics was used to evaluate miRNA mediated gene regulation of target mRNA. Transient transfection of THP-1 cells with miRNA mimics followed by estimation of target gene and protein expression was used to validate the findings.

Results

Comparison of miRNAs in exosomes from the serum of three responders and three poor-responders showed that 17 miRNAs differed significantly before and after therapy. Of these, poor responders had lower exosomal hsa-miR-338-5p. We show that miR-338-5p can bind to the interleukin 6 (IL-6) 3′ untranslated region and can regulate IL-6 mRNA and protein levels in vitro. PE resulted in a significant reduction of IL-6 in CRPS patients.

Conclusions

We propose that lower pretreatment levels of miR-338-5p in poor responders are linked to IL-6 levels and inflammation in CRPS. Our data suggests the feasibility of exploring exosomal miRNAs as a strategy in patient stratification for maximizing therapeutic outcome of PE.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-1833-3) contains supplementary material, which is available to authorized users.

Failure to remove de novo donor-specific HLA antibodies is influenced by antibody properties and identifies kidney recipients with late antibody-mediated rejection destined to graft loss - a retrospective study

Current research is focusing on identifying bioclinical parameters for risk stratification of renal allograft loss, largely due to antibody-mediated rejection (AMR). We retrospectively investigated graft outcome predictors in 24 unsensitized pediatric kidney recipients developing HLA de novo donor-specific antibodies (dnDSAs), and treated for late AMR with plasmapheresis + low-dose IVIG + Rituximab or high-dose IVIG + Rituximab. Renal function and DSA properties were assessed before and longitudinally post treatment. The estimated GFR (eGFR) decline after treatment was dependent on a negative % eGFR variation in the year preceding treatment (P = 0.021) but not on eGFR at treatment (P = 0.74). At a median follow-up of 36 months from AMR diagnosis, 10 patients lost their graft. Altered eGFR (P < 0.001) and presence of C3d-binding DSAs (P = 0.005) at treatment, and failure to remove DSAs (P = 0.01) were negatively associated with graft survival in the univariable analysis. Given the relevance of DSA removal for therapeutic success, we analyzed antibody properties dictating resistance to anti-humoral treatment. In the multivariable analysis, C3d-binding ability (P < 0.05), but not C1q-binding, and high mean fluorescence intensity (P < 0.05) were independent factors characterizing DSAs scarcely susceptible to removal. The poor prognosis of late AMR is related to deterioration of graft function prior to treatment and failure to remove C3d binding and/or high-MFI DSAs.

ABO desensitization affects cellular immunity and infection control after renal transplantation

The impact of ABO desensitization on overall immunity, infectious control, and alloreactivity remains unknown. We compared 35 ABO-incompatible kidney transplant recipients (KTRs) to a control of 62 ABO compatible KTRs. Samples were collected before, at +1, +2, +3, +6, and +12 months post-transplantation. CMV-, BKV-specific, and alloreactive T cells were measured using an interferon-γ ELISPOT assay. The extent of immunosuppression was quantified by enumeration of lymphocyte subpopulations and cytokines. No differences were observed for 5-year allograft survival and function between both groups (P > 0.05). However, ABO-incompatible KTRs were more likely to develop CMV infection, BKV-associated nephropathy, and severe sepsis (P = 0.001). Interestingly, ABO-incompatible KTRs with poor HLA-match showed the highest rates of infections and inferior allograft function (P < 0.05). CD3+, CD4+ T-cell counts, interferon-γ and IL-10 levels were lower in ABO-incompatible KTRs early post-transplantation (P < 0.05). Likewise, ABO-incompatible KTRs showed impaired BKV- and CMV-specific T-cell immunity (P < 0.05). ABO-incompatible KTRs showed lower frequencies of alloreactive T cells (P < 0.05). Our data suggest T-cell depletion due to ABO desensitization, which may contribute to the increased risk of T-cell-dependent infections. Elimination of B cells serving as antigen-presenting cells, thereby causing impaired T-cell activation, plays a significant role in both impaired infection control and reduced alloreactive T-cell activation.

Treatment of antibody-mediated rejection including immunoadsorption during first year after renal transplantation--Clinical results and regulation of endothelial progenitor cells

OBJECTIVE

Antibody-mediated rejection (AMR) is associated with poor allograft survival. Therefore, effective treatment strategies are required. Extracorporeal strategies are increasingly included in treatment of antibody-mediated rejection to eliminate the detrimental alloantibodies. Yet, other mechanisms contributing to the beneficial effect of apheresis besides the removal of antibodies are under consideration.

METHODS

We retrospectively analyzed data of 427 transplant patients from 2006 to 2013 with special focus on occurrence, treatment - always including immunoadsorption - and 12-months outcome of antibody-mediated rejection. Besides, we prospectively monitored how the number and phenotype of endothelial progenitor cells in four patients experiencing antibody-mediated rejection changed during the treatment course of 6-20 sessions of immunoadsorption in comparison to seven patients subjected to immunoadsorption because of preparation for ABO-incompatible transplantation.

RESULTS

24 patients were diagnosed with acute AMR and treated with immunoadsorption resulting in patient and allograft survival of 100% and 87.5%, respectively. In patients with antibody-mediated rejection, the endothelial progenitor cell number after successful immunoadsorption therapy was always transiently decreased and the adhesive and migratory ability improved. This regulation of circulating endothelial precursor cells was not seen in patients undergoing repetitive immunoadsorptions before ABO-incompatible transplantation.

CONCLUSION

Combined therapy with immunoadsorption allows a successful treatment of AMR. Treatment seems to be associated with a transient regulation of circulating endothelial precursor cells.

Efficacy of plasmapheresis on donor-specific antibody reduction by HLA specificity in post-kidney transplant recipients

BACKGROUND

Donor-specific antibodies (DSAs) to HLA antigens can cause acute antibody-mediated rejection (AMR) after kidney transplantation (Txp). Therapeutic plasma exchange (TPE) has been used for AMR treatment; however, DSA reduction rates are inconsistent. We investigated DSA reduction rates by HLA specificity and clinical outcome.

STUDY DESIGN AND METHODS

Sixty-four courses of TPE for 56 kidney Txp recipients with high DSA were investigated. Dates of TPE procedures and Txp, patients' age, sex, race, creatinine (Cr), and mean fluorescent intensity (MFI) of DSA were retrieved. MFI reduction rate after one to three TPE and four to six TPE procedures were calculated by HLA DSA specificity in each patient, and the mean reduction rates were compared. The relationship of TPE treatment, MFI or Cr improvement rate, and graft age was also investigated.

RESULTS

Patients received a mean 6.0 TPE procedures. Most received intravenous immunoglobulin after TPE and immunosuppressives. Forty-two cases (65.6%) had DSA to HLA Class I and 54 cases (84.4%) to Class II, including 32 cases (50.0%) to both. Mean MFI reduction rates after one to three TPE and four to six TPE procedures were 25.7 and 37.1% in HLA Class I, 25.1 and 34.2% in Class II, and 14.3 and 19.9% in DR51-53. The mean Cr improvements at the end of TPE and 3 and 6 months after TPE were 3.41, -0.37, and -0.72%, respectively.

CONCLUSION

Six TPE procedures decreased DSA more than three TPE procedures, but reduction rate was lower by the second three TPE procedures than the first three TPE procedures. Although the mean Cr improvement was minimal, the treatment has good potential to stop further deterioration of kidney function. Better Cr improvement rate is correlated with the graft age.

Evaluation of plasma exchange and continuous veno-venous hemofiltration for the treatment of severe avian influenza A (H7N9): a cohort study

Avian influenza A (H7N9) is a severe disease with high mortality. Hypercytokinemia is thought to play an important role in the pathogenesis. This study was to investigate the efficiency of plasma exchange (PE) + continuous veno-venous hemofiltration (CVVH) on the removal of inflammatory mediators and their benefits in the management of fluid overload and metabolic disturbance. In total, 40 H7N9-infected patients were admitted to our hospital. Sixteen critically ill H7N9-infected patients received combination of PE and CVVH. Data from these 16 patients were collected and analyzed. The effects of PE + CVVH on plasma cytokine/chemokine levels and clinical outcomes were examined. H7N9-infected patients had increased plasma levels compared to healthy controls. After 3 h of PE + CVVH treatment, the cytokine/chemokine levels descended remarkably to lower levels and were maintained thereafter. PE + CVVH also benefited the management of fluid, cardiovascular dysfunction and metabolic disturbance. Of the 16 critically ill patients who received PE + CVVH, 10 patients survived. PE + CVVH decreased the plasma cytokine/chemokine levels significantly. PE + CVVH were also beneficial to the management of severe avian influenza A (H7N9).

Desensitization for solid organ and hematopoietic stem cell transplantation

Desensitization protocols are being used worldwide to enable kidney transplantation across immunologic barriers, i.e. antibody to donor HLA or ABO antigens, which were once thought to be absolute contraindications to transplantation. Desensitization protocols are also being applied to permit transplantation of HLA mismatched hematopoietic stem cells to patients with antibody to donor HLA, to enhance the opportunity for transplantation of non-renal organs, and to treat antibody-mediated rejection. Although desensitization for organ transplantation carries an increased risk of antibody-mediated rejection, ultimately these transplants extend and enhance the quality of life for solid organ recipients, and desensitization that permits transplantation of hematopoietic stem cells is life saving for patients with limited donor options. Complex patient factors and variability in treatment protocols have made it difficult to identify, precisely, the mechanisms underlying the downregulation of donor-specific antibodies. The mechanisms underlying desensitization may differ among the various protocols in use, although there are likely to be some common features. However, it is likely that desensitization achieves a sort of immune detente by first reducing the immunologic barrier and then by creating an environment in which an autoregulatory process restricts the immune response to the allograft.