Two acute kidney injury episodes after ICI therapy: a case report

A 74-year-old Japanese male with lung squamous cell carcinoma received his first dose of immune checkpoint inhibitors (ICIs): ipilimumab and nivolumab. He developed acute kidney injury (AKI) and was admitted to our department. We diagnosed kidney immune-related adverse effects (irAE), and a kidney biopsy revealed acute tubulointerstitial nephritis. We started oral prednisolone (PSL) and his AKI immediately improved. The patient maintained stable findings after PSL was tapered off. However, seven months after the ICI administration, he developed rapid progressive glomerular nephritis and was admitted to our department again. The second kidney biopsy showed findings consistent with anti-glomerular basement membrane glomerulonephritis. Although the patient was treated with pulse methylprednisolone followed by oral PSL and plasma exchange, he became dependent on maintenance hemodialysis. To our knowledge, no case report has described two different types of biopsy-proven nephritis. In cases of suspected relapsing kidney irAEs, both a relapse of previous nephritis and the development of another type of nephritis should be considered.

Tissue-resident memory T cells break tolerance to renal autoantigens and orchestrate immune-mediated nephritis

Immune-mediated nephritis is a leading cause of acute kidney injury and chronic kidney disease. While the role of B cells and antibodies has been extensively investigated in the past, the advent of immune-checkpoint inhibitors has led to a reappraisal of the role of T cells in renal immunology. However, it remains elusive how T cells with specificity for renal autoantigens are activated and participate in immune-mediated nephritis. Here, we followed the fate and function of pathogen-activated autoreactive CD8 T cells that are specific for a renal autoantigen. We demonstrate that recently activated splenic CD8 T cells developed a hybrid phenotype in the context of renal autoantigen cross-presentation, combining hallmarks of activation and T cell dysfunction. While circulating memory T cells rapidly disappeared, tissue-resident memory T cells emerged and persisted within the kidney, orchestrating immune-mediated nephritis. Notably, T cells infiltrating kidneys of patients with interstitial nephritis also expressed key markers of tissue residency. This study unveils how a tissue-specific immune response can dissociate from its systemic counterpart driving a compartmentalized immune response in the kidneys of mice and man. Consequently, targeting tissue-resident memory T cells emerges as a promising strategy to control immune-mediated kidney disease.

Heterogeneity-induced NGF-NGFR communication inefficiency promotes mitotic spindle disorganization in exhausted T cells through PREX1 suppression to impair the anti-tumor immunotherapy with PD-1 mAb in hepatocellular carcinoma

BACKGROUND

The mechanism of decreased T cells infiltrating tumor tissues in hepatocellular carcinoma is poorly understood.

METHODS

Cells were separated from the single-cell RNA-sequence dataset of hepatocellular carcinoma patients (GSE149614) for cell-cell communication. Flow cytometry, EDU staining, H3-Ser28 staining, confocal immunofluorescence staining, western blotting and naked microsubcutaneous tumors were performed for the mechanism of NGF-NGFR promoting proliferation.

RESULTS

The present study has revealed that during the process of T-cell infiltration from adjacent tissues to tumor tissues, an inefficiency in NGF-NGFR communication occurs in the tumor tissues. Importantly, NGF secreted by tumor cells interacts with NGFR present on the membranes of the infiltrated T cells, thereby promoting the proliferation through the activation of mitotic spindle signals. Mechanistically, the mediation of mitotic spindle signal activation promoting proliferation is executed by HDAC1-mediated inhibition of unclear trans-localization of PREX1. Furthermore, PD-1 mAb acts synergistically with the NGF-NGFR communication to suppress tumor progression in both mouse models and HCC patients. Additionally, NGF-NGFR communication was positively correlates with the PD-1/PDL-1 expression. However, expressions of NGF and NGFR are low in tumor tissues, which is responsible for the invasive clinicopathological features and the disappointing prognosis in HCC patients.

CONCLUSION

Inefficiency in NGF-NGFR communication impairs PD-1 mAb immunotherapy and could thus be utilized as a novel therapeutic target in the treatment of HCC patients in clinical practice.

Diminished PD-L1 regulation along with dysregulated T lymphocyte subsets and chemokine in ANCA-associated vasculitis

ANCA-associated vasculitis (AAV) is a life-threatening disease characterized by small vessel inflammation and pathogenic self-directed antibodies. Programmed death-ligand 1 receptor (PD-1) and programmed cell death ligand-1 (PD-L1) are immune checkpoint molecules crucial for maintaining tolerance and immune homeostasis. After checkpoint inhibition therapy, development of various autoimmune diseases and immune-related adverse events (irAEs) have been observed. Here, we investigated the immunomodulatory roles of neutrophils through the expression of immune checkpoint molecule (PD-L1), migratory molecules (CXCR2), chemotactic chemokines (CXCL5) and other important molecules (BAFF and HMGB1) in development of AAV. We also scrutinized the immune mechanism responsible for development of pauci-immune crescentic GN (PICGN). We demonstrate for the first time that the frequency of PD-L1 expressing neutrophils was significantly reduced in AAV patients compared to healthy controls and correlated negatively with disease severity (BVASv3). Further, in renal biopsy, reduced PD-L1 immune checkpoint expression provides a microenvironment that unleashes uncontrolled activated CD4 + T cells, B cells, neutrophils and macrophages and ultimately causes engulfment of immune complexes leading to PICGN. Furthermore, during remission, reduced neutrophils PD-L1 and CXCR2 expression, increased neutrophils CXCL5 expression and increased peripheral effector memory T cells and increased HMGB1 and BAFF levels in serum, demonstrate the propensity for the persistence of sub-clinical inflammation, which could explain relapse, in this group of diseases.

Current therapeutic strategies and perspectives in refractory ITP: What have we learned recently?

Immune thrombocytopenia (ITP) is an acquired autoimmune bleeding disorder featured by increased platelet destruction and deficient megakaryocyte maturation. First-line treatments include corticosteroids, intravenous immunoglobulin and intravenous anti-D immunoglobulin. Second-line treatments consist of rituximab, thrombopoietin receptor agonists and splenectomy. Although most patients benefit from these treatments, an individualized treatment approach is warranted due to the large heterogeneity among ITP patients. In addition, ITP patients may relapse and there remains a subset of patients who become refractory to treatments. The management of these refractory patients is still a challenge. This review aims to summarize emerging therapeutic approaches for refractory ITP in several categories according to their different targets, including macrophages, platelets/megakaryocytes, T cells, B cells, and endothelial cells. Moreover, current management strategies and combination regimens of refractory ITP are also discussed.

The Programmed Death-1 Pathway Counter-Regulates Inflammation-Induced Osteoclast Activity in Clinical and Experimental Settings

Objective

The programmed death-1 (PD-1) pathway is essential for maintaining self-tolerance and plays an important role in autoimmunity, including rheumatoid arthritis (RA). Here, we investigated how membrane-bound and soluble (s)PD-1 influence bone homeostasis during chronic inflammation, exemplified in RA.

Methods

Bone mineral density and bone microstructure were examined in PD-1 and PD-L1 knockout (KO) mice and compared with wild-type (WT) mice. Receptor activator of nuclear factor kappa-B ligand (RANKL) was measured in serum, and the expression examined on activated bone marrow cells. Osteoclast formation was examined in cells from murine spleen and bone marrow and from human synovial fluid cells. sPD-1 was measured in chronic and early (e)RA patients and correlated to markers of disease activity and radiographic scores.

Results

PD-1 and PD-L1 KO mice showed signs of osteoporosis. This was supported by a significantly reduced trabecular bone volume fraction and deteriorated microstructure, as well as increased osteoclast formation and an increased RANKL/OPG ratio. The recombinant form of sPD-1 decreased osteoclast formation in vitro, but was closely associated with disease activity markers in eRA patients. Sustained elevated sPD-1 levels indicated ongoing inflammation and were associated with increased radiographic progression.

Conclusion

The PD-1 pathway is closely associated with bone homeostasis, and lacking members of this pathway causes a deteriorated bone structure. The immunological balance in the microenvironment determines how the PD-1 pathway regulates osteoclast formation. In eRA patients, sPD-1 may serve as a biomarker, reflecting residual but clinically silent disease activity and radiographic progression.

Role of the PD-1/PD-L1 Signaling in Multiple Sclerosis and Experimental Autoimmune Encephalomyelitis: Recent Insights and Future Directions

Multiple sclerosis (MS) is an autoimmunity-related chronic demyelination disease of the central nervous system (CNS), causing young disability. Currently, highly specific immunotherapies for MS are still lacking. Programmed cell death 1 (PD-1) is an immunosuppressive co-stimulatory molecule, which is expressed on activated T lymphocytes, B lymphocytes, natural killer cells, and other immune cells. PD-L1, the ligand of PD-1, is expressed on T lymphocytes, B lymphocytes, dendritic cells, and macrophages. PD-1/PD-L1 delivers negative regulatory signals to immune cells, maintaining immune tolerance and inhibiting autoimmunity. This review comprehensively summarizes current insights into the role of PD-1/PD-L1 signaling in MS and its animal model experimental autoimmune encephalomyelitis (EAE). The potentiality of PD-1/PD-L1 as biomarkers or therapeutic targets for MS will also be discussed.

The Antitumor Activity of CAR-T-PD1 Cells Enhanced by HPV16mE7-Pulsed and SOCS1-Silenced DCs in Cervical Cancer Models

Background

Genetically T cells modified with cancer-specific chimeric antigen receptors (CARs) showed great promise in mediate tumor regression, especially in patients with advanced leukemia. However, the therapeutic effect against solid tumors is not as prominent as anticipated to exhibit potent antitumor efficacy. The underlying mechanism maybe attributed to the inhibitory co-stimulatory pathways such as (PD1/PDL1), which provide tumor cells an escape mechanism from immunosurveillance. Therefore, by exchanging the transmembrane and cytoplasmic tail of PD1 with positive costimulatory molecules, such as CD28 and 4–1BB signaling domains (PD1-CD28-4-1BB, PD1-CAR), the T cell-negative co-stimulatory PD1/PDL1 signal pathway was thus converted into a positive one. This study aimed to investigate whether the genetically modified CAR-T-PD1 cells activated by SOCS1 silenced DCs have enhanced anti-neoplastic potential in vitro/in vivo.

Methods

In order to enhance the antigenicity and reduce transformation activity, a modified HPV16 E7 (HPV16mE7) was employed to load on dendritic cells (DCs) with SOCS1 silenced to improve its antitumor efficiency and targeting ability against cervical cancer. The CAR-T-PD1 cells activated by the generated DCs were transfused into murine models bearing tumor of CaSki cells that expressing PDL1 and HPV16 E6/E7 for in vitro/in vivo antitumor activity assay.

Results

The data showed that DC-activated CAR-T-PD1 cells significantly increased the secretion of IL-2, IFN-γ and TNF-α, whilst enhanced cytotoxic activity, suppressed tumor growth and prolong the survival time compared with the controls.

Conclusion

These results indicated that the genetically engineered T cells activated by DCs had improved antitumor efficiency and targeting ability. Furthermore, it was suggested that it may have important implications for the improvement of T cell immunotherapy against cervical cancer.

Immune Checkpoints, a Novel Class of Therapeutic Targets for Autoimmune Diseases

Autoimmune diseases, such as multiple sclerosis and type-1 diabetes, are the outcomes of a failure of immune tolerance. Immune tolerance is sustained through interplays between two inter-dependent clusters of immune activities: immune stimulation and immune regulation. The mechanisms of immune regulation are exploited as therapeutic targets for the treatment of autoimmune diseases. One of these mechanisms is immune checkpoints (ICPs). The roles of ICPs in maintaining immune tolerance and hence suppressing autoimmunity were revealed in animal models and validated by the clinical successes of ICP-targeted therapeutics for autoimmune diseases. Recently, these roles were highlighted by the clinical discovery that the blockade of ICPs causes autoimmune disorders. Given the crucial roles of ICPs in immune tolerance, it is plausible to leverage ICPs as a group of therapeutic targets to restore immune tolerance and treat autoimmune diseases. In this review, we first summarize working mechanisms of ICPs, particularly those that have been utilized for therapeutic development. Then, we recount the agents and approaches that were developed to target ICPs and treat autoimmune disorders. These agents take forms of fusion proteins, antibodies, nucleic acids, and cells. We also review and discuss safety information for these therapeutics. We wrap up this review by providing prospects for the development of ICP-targeting therapeutics. In summary, the ever-increasing studies and results of ICP-targeting of therapeutics underscore their tremendous potential to become a powerful class of medicine for autoimmune diseases.

Imbalance of T Lymphocyte Subsets in Adult Immune Thrombocytopenia

BACKGROUND

Primary immune thrombocytopenia (ITP) is defined as an acquired autoimmune disease characterized by isolated thrombocytopenia. This work is to further clarify the relationship between T cell immune dysfunction and the pathogenesis of ITP.

METHODS

37 adult patients with ITP were selected and were classified into newly diagnosed ITP (nITP, n = 13), persistent ITP (pITP, n = 6) and chronic ITP (cITP n = 18). The frequency of cytotoxic T lymphocytes (Tc1, Tc2, and Tc17) and helper T cells (Th1, Th2, and Th17), Tregs, and the expression of chemokine receptors and PD-1 on CD4+ T cells were investigated by flow cytometry. Plasma levels of T cell-related cytokines (IL-2, IL-4, IL-6, IL-10, TNF-α, IFN-γ, IL-17) were measured by cytometric beads array (CBA).

RESULTS

The percentage of Tc1 in cITP was greatly higher than nITP and healthy controls (p < 0.05, p < 0.01). The percentage of Treg in nITP and cITP groups was remarkably lower than those in healthy control group (p < 0.05, p < 0.001); and according to platelet count analysis (PLT<50x109/L or PLT>50x109/L), Treg cells in ITP group were significantly lower than those in healthy control group (p < 0.001, p < 0.05). The percentage of CD4+CXCR3+ of cITP was significantly higher than healthy controls and nITP (p < 0.01, p < 0.05). The percentage of CD4+CCR6+ in cITP was significantly higher than healthy controls and nITP (p < 0.001, p < 0.05). The expression of PD-1 in cITP patients was higher than healthy control (p < 0.05), but there was no significant difference among nITP, pITP and cITP (p = 0.25). The levels of IL-2, IFN-γ and TNFα in nITP group and cITP group were significantly higher than those in healthy control group (p < 0.01, p < 0.05; p < 0.01, p < 0.05; p < 0.05, p < 0.05), and the level of IL-10 in nITP group was significantly higher than that in pITP group (p < 0.05).

CONCLUSION

Our results suggest that T lymphocyte immune dysfunction does exist in adult ITP patients and plays an important role in the pathogenesis of ITP.

Immune regulation in renal inflammation

Renal inflammation, induced by autoantigen recognition or toxic drugs, leads to renal tissue injury and decline in kidney function. Recent studies have demonstrated the crucial role for regulatory T cells in suppressing pathogenic adaptive but also innate immune responses in the inflamed kidney. However, there is also evidence for other immune cell populations with immunosuppressive function in renal inflammation. This review summarizes mechanisms of immune cell regulation in immune-mediated glomerulonephritis and acute and chronic nephrotoxicity.

Co-inhibitory Receptor Signaling in T-Cell-Mediated Autoimmune Glomerulonephritis

Autoimmune glomerulonephritis occurs as a consequence of autoantibodies and T-cell effector functions that target autoantigens. Co-signaling through cell surface receptors profoundly influences the optimal activation of T cells. The scope of this review is signaling mechanisms and the functional roles of representative T-cell co-inhibitory receptors in the regulation of autoimmune glomerulonephritis, along with current therapeutic challenges mainly on preclinical trials. Co-inhibitory receptors utilize both shared and unique signaling pathway, suggesting specialized functions that provide the rationale behind therapies for autoimmune glomerulonephritis by targeting these inhibitory receptors. These receptors largely suppress Th1 immunity, modify Th17 and Th2 immune response, and enhance Treg function. Anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA4) immunoglobulin (Ig), which is able to block both activating CD28 and inhibitory CTLA4 signaling, has been shown in preclinical and clinical investigations to have effects on glomerular disease. Other inhibitory receptors for treating glomerulonephritis have not been clinically tested, and efficacy of manipulating these pathways requires further preclinical investigation. While immune checkpoint inhibition using anti-CTLA4 antibodies and anti-programmed cell death 1 (PD-1)/PD-L1 antibodies has been approved for the treatment of several cancers, blockade of CTLA4 and PD-1/PD-L1 is associated with adverse effects that resemble autoimmune disorders, including systemic vasculitis. A renal autoimmune vasculitis model features an initial Th17 dominancy followed later by a Th1-dominant outcome and Treg cells that attenuate autoreactive T-cell function. Toward the development of effective therapies for T-cell-mediated autoimmune glomerulonephritis, it would be preferable to pay attention to the impact of the inhibitory pathways in immunological renal disease settings.

Synergism of PDL/PD1 and IL33/ST2 Axis in Tumor Immunology

When it comes to tumor immunology, understanding of molecular pathways is rather important. During oncogenesis, many molecules should be taken in consideration altogether in context of a single malignancy. It is of a great significance to determine whether these molecules act synergistically or contrary, whether to understand a malignant disease more thoroughly, or even more important, to reveal new approaches of therapy. In this review, we discuss whether and how IL-33/ST2 and PD-1/PDL axis involve in antitumor immunity.

The co-inhibitory molecule PD-L1 contributes to regulatory T cell-mediated protection in murine crescentic glomerulonephritis

Immune-mediated glomerular diseases like crescentic glomerulonephritis (cGN) are driven by inappropriately regulated cellular and humoral immune responses subsequently leading to renal tissue injury. Recent studies demonstrated the crucial role for regulatory T cells (Tregs) in suppressing pathogenic T-cell responses during nephrotoxic nephritis (NTN), a murine model of cGN. However, mechanisms of immune regulation in cGN are less clear. Here, we aim at investigating the role of the co-inhibitory PD-1/PD-L1 pathway in Treg-mediated suppression of renal inflammation. We demonstrated that Foxp3⁺ Tregs expressing PD-L1 infiltrate the kidney during NTN. Inhibition of PD-L1 signalling by using PD-L1^−/− mice or by blockage of PD-L1 in wildtype mice resulted in an increased Treg frequency in the inflamed kidney. However, mice lacking PD-L1 developed more severe NTN associated with an elevated pathogenic renal Th1 immune response, which was reversed by blockage of IFNγ in these mice. Interestingly, lack of PD-L1 altered the gene expression profile of Tregs in homeostasis and kidney inflammation. Functionally, Tregs from nephritic PD-L1^−/− mice had impaired suppressive capacity in vitro and failed to protect from NTN in vivo. Thus, PD-L1 displays a protective role in NTN, which is related to Treg-mediated suppression of the Th1 immune response.

Goodpasture's disease in a patient with advanced lung cancer treated with nivolumab: An autopsy case report

Nivolumab, an anti-programmed death-1 immune checkpoint inhibitor (ICI), is now widely used to treat numerous cancers. Although most adverse effects related to ICIs are controllable, fulminant immune-related adverse events can occur. A 74-year-old patient with non-small-cell lung cancer was treated with nivolumab as a second-line treatment. After 8 cycles, acute kidney injury with macroscopic hematuria appeared, followed by diffuse ground-glass opacities with hemoptysis. Since the clinical course suggested Goodpasture's disease, methylprednisolone pulse therapy and plasma exchange were started. Later, it was confirmed that the serum anti-glomerular basement membrane antibody was positive. However, the patient died 35 days after admission due to respiratory failure, and an autopsy showed crescentic glomerulonephritis and massive alveolar hemorrhage which were compatible with Goodpasture's disease. Our case provides a possible link between nivolumab and lethal Goodpasture's disease.

Analysis of PD-1 and Tim-3 expression on CD4+ T cells of patients with rheumatoid arthritis; negative association with DAS28

Expression of T cell immunoglobulin and mucin-domain containing-3 (Tim-3) and programmed cell death-1 (PD-1) was studied on CD4⁺ T cells of patients with rheumatoid arthritis (RA). Association of Tim-3 and PD-1 expression with disease activity of RA patients was also addressed. A total of 37 RA patients and 31 sex- and age-matched healthy controls were included in this study. Disease activity of RA patients was determined by Disease Activity Score of 28 joints scoring system (DAS28). A three-color flow cytometry method was applied to determine the frequency of Tim-3⁺/PD-1⁺/CD4⁺ T cells. To measure the cytokine production, peripheral blood mononuclear cells (PBMCs) were stimulated with PMA/ionomycin. Concentrations of IL-17, IL-10, IFN-γ, and TNF-α were measured in culture supernatants by ELISA. The frequency of PD-1⁺/CD4⁺ and Tim-3⁺/PD-1⁺/CD4⁺ T cells was significantly higher in patients with RA compared to that in controls (p = 0.0013 and p = 0.050, respectively). The percentage of Tim-3⁺/CD4⁺ T cells was similar in patients and controls (p = 0.4498). The RA patients have produced significant higher levels of TNF-α, IL-17, and IFN-γ than those of healthy controls (p = 0.0121, p = 0.0417, and p = 0.0478, respectively). Interestingly, an inverse correlation was found between the frequency of Tim-3⁺/CD4⁺ cells and DAS28 of RA patients (r = - 0.4696, p = 0.0493). Similarly, the percentage of Tim-3⁺/PD-1⁺/CD4⁺ T cells was also revealed an inverse correlation with DAS28 (r = - 0.5268, p = 0.0493). Moreover, significant positive correlations were detected between the concentrations of TNF-α (r = 0.6418, p = 0.0023) and IL-17 (r = 0.4683, p = 0.0373) with disease activity of RA patients. Our results indicate that Tim-3 and PD-1 are involved in immune dysregulation mechanisms of rheumatoid arthritis and could be considered as useful biomarkers for determination of disease activity and progression.

Percentages of PD-1+CD4+T cells and PD-L1+DCs are increased and sPD-1 level is elevated in patients with immune thrombocytopenia

The present study is to measure the expression of programmed death (PD)-1 / programmed death ligand-1 (PD-L1) negative costimulatory molecules, soluble format sPD-1 in patients with immune thrombocytopenia (ITP), and to investigate their correlation with the secretion of cytokines. A total of 35 patients with ITP were included in the present study. Twenty healthy subjects who received physical examination at our hospital were included as control group. Peripheral blood was collected from all ITP patients and healthy subjects. Flow cytometry was performed to determine the percentages of PD-1+CD4+T cells and PD-L1+DCs in ITP patients and healthy subjects. Enzyme-linked immunosorbent assay was performed to measure the concentrations of interferon (IFN)-γ, interleukin (IL)-17 and sPD-1 in peripheral blood from ITP patients and healthy subjects. Percentages of PD-1+CD4+T cells and PD-L1+DCs in peripheral blood from ITP patients before treatment were significantly higher than that from healthy subjects, but were not different from those after treatment. Serum concentrations of IFN-γ, IL-17 and sPD-1 in ITP patients before treatment were significantly higher than those in healthy subjects, and these concentrations were significantly reduced after treatment. The concentration of sPD-1 was positively correlated with the concentration of IFN-γ, and negatively correlated with platelet count. Percentages of PD-1+CD4+T cells and PD-L1+DCs in ITP patients are higher than those in healthy subjects, but elevated sPD-1 concentration in the blood blocks PD-1/PD-L1 signaling pathway, leading to unaffected Th cell function. Elevated concentrations of IFN-γ and IL-17 in the blood may participate in the occurrence and development of ITP.

The PD-1/PD-L1 Inhibitory Pathway is Altered in Primary Glomerulonephritides

The pathogenesis of primary proliferative and non-proliferative glomerulonephritides (PGN and NPGN) is still not fully understood, however, current evidence suggests that most cases of PGN and NPGN are the results of immunologic response to different etiologic agents that activates various biological processes leading to glomerular inflammation and injury. Programmed cell death protein 1 (PD-1) is the major inhibitory receptor regulating T cell exhaustion. The aim of this study was to evaluate the frequencies of PD-1-positive and PD-ligand 1 (PD-L1)-positive T and B lymphocytes in patients with NPGN and PGN in relation to clinical parameters for the first time. The study included peripheral blood (PB) samples from 20 newly diagnosed PGN and NPGN patients. The control group comprised of 20 healthy age- and sex-matched subjects. The viable PB lymphocytes underwent labelling with fluorochrome-conjugated monoclonal antibodies anti-PD-1 and anti-PD-L1, and were analyzed using a flow cytometer. The frequencies of CD4+/PD1+ T lymphocytes, CD8+/PD1+ T lymphocytes, and CD19+/PD-1+ B lymphocytes in the PGN group exceeded values obtained both in the NPGN group, and the control group. Alteration of PD-1/PD-L1 pathway may be involved in poorer prognosis, as patients with PGN are characterized by higher frequencies of PD-1-positive and PD-L1-positive T and B lymphocytes than patients with NPGN. Our results suggest that deregulation of PD-1/PD-L1 axis may contribute to the PGN and NPGN pathogenesis. High percentages of lymphocytes with PD-1 and PD-L1 expression may be related to the continuous T-cell activation and development of glomerular inflammation and injury.

What is new in the management of rapidly progressive glomerulonephritis?

Rapidly progressive glomerulonephritis (RPGN) results from severe crescentic damage to glomeruli and leads to irreversible kidney failure if not diagnosed and managed in a timely fashion. Traditional treatment has relied on glucocorticoids and cyclophosphamide, with additional plasmapheresis for certain conditions. Here we describe updates in the management of RPGN, according to the underlying renal pathology. However, there remains a paucity of trials that have enrolled patients with more advanced renal disease, dialysis dependence or with RPGN, and we are therefore still reliant on extrapolation of data from studies of patients with a less severe form of disease. In addition, reporting bias results in publication of cases or cohorts showing benefit for newer agents in advanced disease or RPGN, but it remains unclear how many unsuccessful outcomes in these circumstances take place. Since clinical trials specifically in RPGN are unlikely, use of biologic registries or combination of sufficient sized cohort series may provide indications of benefit outside of a clinical trial setting and should be encouraged, in order to provide some evidence for the efficacy of therapeutic regimens in RPGN and advanced renal disease.

Immunotherapeutic strategies in autoimmune uveitis

Autoimmune uveitis is an organ-specific disorder characterized by irreversible lesions to the eye that predominantly affect people in their most productive years and is among the leading causes of visual deficit and blindness. Currently available therapies are effective in the treatment of a wide spectrum of uveitis, but are often associated with severe side effects. Here, we review ongoing research with promising immunomodulatory therapeutic strategies, describing their specific features, interactions and the responses triggered by the targeted immune molecules that aim to minimize clinical complications and the likelihood of disease relapse. We first review the main features of the disease, diagnostic tools, and traditional forms of therapy, as well as the animal models predominantly used to understand the pathogenesis and test the novel intervention approaches aiming to control the acute immune and inflammatory responses and to dampen chronic responses. Both exploratory research and clinical trials have targeted either the blockade of effector pathways or of their companion co-stimulatory molecules. Examples of targets are T cell receptors (CD3), their co-stimulatory receptors (CD28, CTLA-4) and corresponding ligands (B7-1 and B7-2, also known as CD80 and CD86), and cytokines like IL-2 and their receptors. Here, we summarize the available evidence on effectiveness of these treatments in human and experimental uveitis and highlight a novel CD28 antagonist monovalent Fab′ antibody, FR104, which has shown preclinical efficacy suppressing effector T cells while enhancing regulatory T cell function and immune tolerance in a humanized graft-versus-host disease (GVHD) mice model and is currently being tested in a mouse autoimmune uveitis model with encouraging results.