Efficacy and cytokine modulating effects of tacrolimus in systemic lupus erythematosus: a review

State of the art: the treatment of systemic lupus erythematosus

PURPOSE OF REVIEW

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease with dysregulated cells in the immune system. The disease affects organs like kidneys, nervous system, joints, and skin. To manage SLE effectively, novel treatments targeting immune system components have been developed. This review investigates the therapeutic potential of existing targeted therapies and explores future innovative approaches for well tolerated, personalized treatment.

RECENT FINDINGS

SLE treatment involves cytokine targets and specific immunologic pathways, with even small molecules involved.

SUMMARY

The advanced therapeutic options in SLE management give clinicians more tools to control disease activity according to personalized medicine.

Dupilumab-induced psoriasiform dermatitis in two pediatric cardiac transplant patients

Dupilumab is an interleukin-4 receptor antagonist important in the treatment of refractory atopic dermatitis (AD), particularly among pediatric patients. Two boys with a history of AD and cardiac transplant who developed psoriasiform dermatitis in response to dupilumab therapy are reported. These patients paradoxically developed an immune-mediated adverse drug reaction despite taking systemic immunosuppressive agents. While the literature suggests possible pathomechanisms for psoriasiform dermatitis despite immunosuppression, further research is necessary to better characterize this unique and unexpected phenomenon.

Comparison of efficacy of continuous mycophenolate mofetil with sequential cyclophosphamide and tacrolimus as maintenance therapy for lupus nephritis

OBJECTIVES

To evaluate the renal response to mycophenolate mofetil (MMF) as maintenance therapy for lupus nephritis (LN) in Japanese patients, we compared the efficacy of MMF and the sequential use of monthly intravenous cyclophosphamide (IVCY) followed by tacrolimus (TAC).

METHODS

We examined 14 patients with LN who were treated with continuous MMF as induction and maintenance therapies (MMF group) and 10 patients with LN who received monthly IVCY as induction therapy followed by maintenance therapy with TAC (IVCY-TAC group). We assessed the therapeutic effects of each treatment regimen on renal manifestations and serological findings over a 36-month period after treatment initiation.

RESULTS

Mean urine protein-to-creatinine ratios in the MMF and IVCY-TAC groups significantly decreased from 2.75 to 0.11 g/gCr and from 3.26 to 0.22 g/gCr, respectively. Significant improvements in serum immunological variables (serum complement C3 or C4 levels and the anti-double-stranded DNA antibody titer) and reductions in the SLE disease activity index and daily prednisolone dosages were observed in both groups during induction therapy and were maintained during maintenance therapy. Efficacy was similar between the MMF and IVCY-TAC groups.

CONCLUSION

MMF has potential as an effective treatment for renal manifestations in Japanese patients throughout induction and maintenance therapies for LN, as an alternative to conventional IVCY-TAC therapy, and as a glucocorticoid-sparing agent.

A Case Report of Drug Interactions Between Nirmatrelvir/Ritonavir and Tacrolimus in a Patient With Systemic Lupus Erythematosus

Nirmatrelvir/ritonavir is a treatment for COVID-19 consisting of nirmatrelvir, which has anti-SARS-CoV-2 activity, and ritonavir, a booster to maintain blood levels. Ritonavir is known to be a potent inhibitor of cytochrome P450 3A (CYP3A), and interactions with CYP3A-metabolized drugs, such as the immunosuppressant tacrolimus, can be problematic. Ritonavir's inhibition of CYP3A is irreversible due to covalent binding, and its inhibitory effects are expected to persist until replaced by new CYP3A. Here, we report a case where the combination of nirmatrelvir/ritonavir and tacrolimus resulted in toxic tacrolimus blood levels. A patient on tacrolimus for systemic lupus erythematosus (SLE) developed COVID-19 and was prescribed nirmatrelvir/ritonavir. After starting the combination of nirmatrelvir/ritonavir and tacrolimus, the patient's tacrolimus blood levels became abnormally high, leading to the discontinuation of these drugs due to symptoms of tacrolimus toxicity. Even after ritonavir blood levels had fallen below the detection limit, the decline in tacrolimus blood levels was delayed. The CYP3A inhibition of ritonavir persists even when its blood concentration decreases, emphasizing the need for careful consideration of concomitant medications before starting nirmatrelvir/ritonavir therapy. Adjustments or discontinuation may be necessary.

Induction of liver transplant immune tolerance in an outbred rat strain model using tacrolimus

BACKGROUND

Orthotopic liver transplantation is the only option for patients with end-stage liver disease and hepatocellular carcinoma. Post-transplant immunosuppressive therapy is important to prevent graft failure. We investigated the effectiveness of tacrolimus (FK506) and their mechanisms for liver transplant immune tolerance in an outbred rat LT model.

RESULTS

To investigate the therapeutic effect of the FK506 on outbred rat LT model, FK506 and postoperative therapy were administered subcutaneously once or twice daily to transplanted rats. Histopathological and immunohistochemical analyses were conducted for all groups. The regulation of inflammatory cytokine signaling in the spleen was analyzed by flow cytometry. FK506 attenuated allograft rejection and increased survival in rat orthotopic liver transplantation models. The FK506-treated group had reduced serum levels of alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase. Furthermore, FK506 decreased the expression of inflammatory cytokines and the activation of pathogenic Th1 and Th17 cells in the liver.

CONCLUSIONS

Taken together, we revealed that FK506 ameliorated strong allograft rejection in outbred liver transplantation model by anti-inflammatory effect and inhibitory peroperty of pathogenic T cells.

Efficacy and steroid-sparing effect of tacrolimus in patients with autoimmune cytopenia

The aim of this study was to evaluate the efficacy, safety, and steroid-sparing effect of tacrolimus in patients with autoimmune cytopenia, including immune thrombocytopenia (ITP), autoimmune hemolytic anemia (AIHA), and Evans syndrome (ES). Patients in the tacrolimus group were treated with tacrolimus in combination with steroids, and the control group received only steroids. Of the 318 patients finally enrolled, 87 (27.4%) were males, with a median age of 45 (14-90) years. The tacrolimus group comprised 144 patients, including 120 ITP, 19 AIHA, and 5 ES patients, and the control group comprised 174 patients, including 141 ITP, 25 AIHA, and 8 ES patients. The optimal ORR of the tacrolimus group was comparable to that of the control group, and the optimal CRR was higher (p < 0.05). Patients receiving tacrolimus had a decreased relapse rate and prolonged relapse-free survival (p < 0.05) compared with the controls for both the whole cohort and the ITP and AIHA subgroups. Compared with the control group, the tacrolimus group had a lower cumulative steroid dosage and earlier discontinuation of steroids (p < 0.05), which resulted in a decreased incidence of steroid-related adverse events (p < 0.05) although the total side effects were similar between the two groups. Similar drug expenses were observed between the tacrolimus and control groups at the 18-month follow-up. In conclusion, the early addition of tacrolimus had a similar ORR, better CRR, lower relapse rate, and prolonged relapse-free survival compared to steroids alone, with reduced steroid-related adverse events.

Pyoderma Gangrenosum: An Updated Literature Review on Established and Emerging Pharmacological Treatments

Pyoderma gangrenosum is a rare inflammatory skin disease classified within the group of neutrophilic dermatoses and clinically characterized by painful, rapidly evolving cutaneous ulcers with undermined, irregular, erythematous-violaceous edges. Pyoderma gangrenosum pathogenesis is complex and involves a profound dysregulation of components of both innate and adaptive immunity in genetically predisposed individuals, with the follicular unit increasingly recognized as the putative initial target. T helper 17/T helper 1-skewed inflammation and exaggerated inflammasome activation lead to a dysregulated neutrophil-dominant milieu with high levels of tumor necrosis factor-α, interleukin (IL)-1β, IL-1α, IL-8, IL-12, IL-15, IL-17, IL-23, and IL-36. Low-evidence studies and a lack of validated diagnostic and response criteria have hindered the discovery and validation of new effective treatments for pyoderma gangrenosum. We review established and emerging treatments for pyoderma gangrenosum. A therapeutic algorithm based on available evidence is also provided. For emerging treatments, we review target molecules and their role in the pathogenesis of pyoderma gangrenosum.

Cognitive Function in Kidney Transplantation

Purpose of the review

Cognitive impairment is common in kidney transplant recipients and affects quality of life, graft survival, morbidity, and mortality. In this review article we discuss the epidemiology, diagnosis, pathophysiology and future directions for cognitive impairment in kidney transplantation. We describe the potential role of pre-transplant cognition, immunosuppression and peri-transplant factors in post -transplant cognitive impairment.

Recent Findings

A majority of patients with kidney transplant have cognitive impairment. Cognitive impairment affects both pre-transplant evaluation and post-transplant outcomes. Failure to identify patients with cognitive impairment can withhold appropriate care and timely intervention.

Summary

Cognitive impairment is common in kidney transplant and affects outcomes. Studies addressing modifiable risk factors and possible interventions to slow cognitive decline in patients with kidney disease are needed.

Population pharmacokinetics model and initial dose optimization of tacrolimus in children and adolescents with lupus nephritis based on real-world data

The present study aimed to establish a population pharmacokinetics model of tacrolimus and further optimize the initial dosing regimen of tacrolimus in pediatric and adolescent patients with lupus nephritis (LN). Pediatric and adolescent patients with LN were recruited between August 2014 and September 2019 at the Children's Hospital of Fudan University (Shanghai, China). Relevant information was used to set up a population pharmacokinetics model with a Nonlinear Mixed Effect Model and the initial dosage regimen was simulated with the Monte Carlo method. Body weight and co-administration of wuzhi capsule were indicated to influence tacrolimus clearance in pediatric and adolescent patients with LN, and at the same body weight, the rate of tacrolimus clearance in patients without vs. with co-administration of wuzhi capsule was 1:0.71. In addition, in patients who were not administered wuzhi capsule, an initial dosage regimen of 0.15 mg/kg/day was recommended for a body weight of 10-23 kg and 0.10 mg/kg/day for 23-60 kg; in patients who were administered wuzhi capsule, an initial dosage regimen of 0.10 mg/kg/day was recommended for a body weight of 10-23 kg and 0.05 mg/kg/day for 23-60 kg. To the best of our knowledge, the present study was the first to establish a population pharmacokinetics model of tacrolimus in order to determine the optimal initial dosage regimen of tacrolimus in pediatric and adolescent patients with LN.

Meta-analysis of cognitive functioning in patients following kidney transplantation

Background

There is mixed evidence regarding the nature of cognitive function in patients who have undergone renal transplantation. The aim of this meta-analysis was to examine which cognitive domains are impacted following kidney transplantation and how performance compares with non-transplanted patients or healthy controls/normative data.

Method

A systematic search was conducted using keywords within three databases (Embase, MEDLINE and PsychINFO), yielding 458 unique studies, 10 of which met the inclusion criteria. Neuropsychological tests were grouped into nine cognitive domains and three separate analyses were undertaken within each domain: (i) within subjects pre- versus post-transplant, (ii) transplanted versus non-transplanted patients and (iii) transplanted versus healthy matched controls and standardized normative data.

Results

Transplanted patients showed moderate to large improvements in the domains of general cognitive status (g = 0.526), information and motor speed (g = 0.558), spatial reasoning (g = 0.376), verbal memory (g = 0.759) and visual memory (g = 0.690) when compared with their pre-operative scores. Test scores in the same five domains were significantly better in post-transplanted patients when compared with dialysis-dependant or conservatively managed chronic kidney disease patients. However, post-transplanted patients’ performance was significantly low compared with that of healthy controls (and standardized normative data) in the domains of executive functioning (g = −0.283), verbal fluency (g = −0.657) and language (g = −0.573).

Conclusions

Two key issues arise from this review. First, domain-specific cognitive improvement occurs in patients after successful transplantation. Nevertheless, transplanted patients still performed significantly below healthy controls in some domains. Second, there are important shortcomings in existing studies; the length of follow-up is typically short and only limited neuropsychological test batteries are employed. These factors are important in order to support the recovery of cognitive function among patients following renal transplant.

Low-Dose Tacrolimus Prevents Dysregulated Peri-Conceptional Ovarian and Systemic Immune Cellular Homeostasis in Subjects with PCOS

Polycystic ovary syndrome (PCOS) is characterized by failure of ovulation and is associated with obesity and chronic inflammation. Recent evidence suggests that anomalous activation of ovarian macrophages and numerical and functional deficits in the Th17 (CD4+IL17A+) and the CD4+CD25+CD127^low Tregs plays crucial role in PCOS. We have shown that the pre-pregnancy use of tacrolimus prevents adverse reproductive outcomes in a mouse model of PCOS. Here we used the HFD-NONcNZO mice to test a hypothesized beneficial use of tacrolimus relative to metformin in favorably influencing the ovarian and systemic immune milieux conducive to gestational success in subjects with PCOS. Compared to normative controls, our data revealed an aberrant peri-conceptional suppression of the CD4⁺CD25⁺CD127^low Tregs together with an overexpression of the Th17 T cells and lack of coordinated activation of ovarian macrophages in untreated HFD-dNONcNZO mice. Significant variances in treatment outcomes favoured the use of tacrolimus over metformin in treated mice. Consistent with the human fertility studies, this investigation reveals a beneficial systemic use of tacrolimus (0.1 mg/kg) in promoting early pregnancy in individuals with PCOS and suggests the need for further research into the selective inhibition of IL17A as a plausibly alternative immunotherapeutic approach in the clinical management of infertile individuals with PCOS.

Efficacy of mycophenolate mofetil in Japanese patients with systemic lupus erythematosus

OBJECTIVES

To assess the renal and non-renal efficacy of mycophenolate mofetil (MMF) in Japanese patients with systemic lupus erythematosus (SLE).

METHODS

We conducted a retrospective study to assess the renal and non-renal efficacies of MMF in Japanese patients with systemic lupus erythematosus (SLE). We analyzed 14 patients with lupus nephritis (LN) who were given MMF, and 13 patients who received monthly intravenous cyclophosphamide (IVCY) as induction therapy, and a further 19 patients without LN who were treated with MMF, and 13 patients who took tacrolimus (TAC) to reduce glucocorticoid dosages. We assessed the therapeutic effects of each therapeutic regime on renal and non-renal disease manifestations over a six-month period after treatment initiation.

RESULTS

Median urine protein to creatinine ratios in the MMF and IVCY groups significantly decreased from 2.2 to 0.7 g/gCr and from 3.3 to 0.5 g/gCr, respectively. Significant improvements in serum immunological variables (serum complements C3 and C4 and the anti-double stranded DNA antibody) and reductions in the SLE disease activity index (SLEDAI) and daily prednisolone dosages were observed in each group with LN. MMF and TAC significantly improved SLEDAI and serum immunological variables and reduced daily prednisolone dosages in patients without LN.

CONCLUSION

The present results demonstrated that MMF might be an effective treatment for renal and non-renal manifestations in Japanese patients with SLE and has potential as a good therapeutic alternative and steroid-sparing agent.

Autoimmune/inflammatory syndrome induced by adjuvants-ASIA-related to biomaterials: analysis of 45 cases and comprehensive review of the literature

Systemic autoimmune or granulomatous disorders related to biomaterials of human use have rarely been described. The aim of this study was to report cases of autoimmune/inflammatory syndrome induced by adjuvants (ASIA) related to biomaterial injections and prostheses, mainly silicone, hyaluronic acid, acrylamides and methacrylate compounds in a Spanish patient cohort. This study is a retrospective analysis of clinical, laboratory, histopathological and follow-up data of 45 cases of patients suffering from late-onset, non-infectious inflammatory/autoimmune disorders related to bioimplants. Late onset was defined as 3 months or more post injection. Data were obtained through a further non-systematic but comprehensive review of the literature. Forty-five cases of late-onset adverse reactions related to biomaterial injections or prostheses were reviewed. All cases had systemic complaints that could be categorised as ASIA. In all but four patients, inflammatory features at the implantation site preceded distant or systemic manifestations. Abnormal blood tests were common. Localised inflammatory nodules and panniculitis in 40/45 (88.88%) evolved into a variety of disorders, viz., primary biliary cirrhosis, Sjögren's syndrome, sarcoidosis, human adjuvant disease, vasculitis, inflammatory bowel syndrome and inflammatory polyradiculopathy. Five (11.11%) cases presented primarily with systemic autoimmune disorders. Biomaterials and prostheses can provoke late-onset systemic autoimmune disorders fulfilling ASIA criteria, or present primarily local/regional inflammatory reactions that may eventually evolve into systemic autoimmune and/or granulomatous disorders which fall under ASIA.

Changes in the blood level, efficacy, and safety of tacrolimus in pregnancy and the lactation period in patients with systemic lupus erythematosus

OBJECTIVES

We investigated the efficacy and safety of tacrolimus (TAC) by monitoring its serum concentration for mothers and infants in pregnant patients with systemic lupus erythematosus (SLE).

METHODS

We measured trough concentrations of TAC in 25 pregnant patients with SLE to assess influence of TAC on the disease activity. Additionally, we measured the concentrations of TAC in umbilical arterial blood, breast milk, and breastfed infants to investigate the safety of TAC for the mothers and infants.

RESULTS

The trough concentrations of TAC in the mothers significantly decreased in the second trimester as compared with those before pregnancy. However, the decrease in the trough concentrations of TAC did not lead to the deterioration of SLE. When examined, the doses of TAC were significantly lower in the second trimester and postpartum in the deteriorating group than those in the non-deteriorating group. There were no adverse events by TAC in mothers and fetuses. The concentrations of TAC in the umbilical cord blood were lower than those in the maternal blood. The relative infant dose in breastfed infants of TAC was < 1%. The level of TAC in infant bloods was below detectable limits.

CONCLUSION

These findings suggest that TAC is one of the most effective and safest immunosuppressive drugs for use in pregnant patients with SLE.

Induction Therapy for Lupus Nephritis: the Highlights

PURPOSE OF REVIEW

Lupus nephritis is a frequent complication of systemic lupus erythematosus and is more common and severe in children. This is a disease of the immune system characterized by T cell, B cell, and complement activation, as well as immune complex formation and deposition. The introduction of steroids and later cyclophosphamide transformed lupus nephritis from a fatal to a treatable condition. However, the standard therapies currently used for treatment carry significant toxicity and chronic kidney disease still remains a far too frequent outcome. To address these issues, we will review current and emerging induction therapies in LN.

RECENT FINDINGS

Several clinical trials have been undertaken to test more effective and safer drugs, often targeting mechanistic disease pathways. At present, it is difficult to identify an induction regimen that is more effective and less toxic than the standard of care; however, we believe continuing efforts in drug development will bring breakthrough agents to clinics.

Successful treatment with clarithromycin and/or tacrolimus for two patients with polymyalgia rheumatica

Polymyalgia rheumatica (PMR) is an inflammatory rheumatic disease in the elderly. Glucocorticoids (GCs) remain the mainstay of treatment. GC therapy usually dramatically improves the clinical picture, but approximately one-third of patients experience disease recurrence when the dose is reduced. Moreover, long-term use of GCs causes adverse reactions. Macrolide antibiotics have anti-inflammatory action. Several recent studies have reported the successful treatment of rheumatoid arthritis (RA) and PMR treated using clarithromycin (CAM), a macrolide, because of its anti-inflammatory action. Tacrolimus (TAC) has been indicated as a treatment for RA in patients who failed to respond to methotrexate. Recently, a case of RA was successfully treated using CAM and TAC according to one report. Reported here are two cases of PMR treated using CAM and/or TAC. Case 1: A 73-year-old man suffering from PMR was successfully treated with prednisolone (PSL) and CAM. Because his muscle pain disappeared, CAM was discontinued. However, the pain returned after that discontinuation, so CAM was successfully administered again. Case 2: An 83-year-old man suffering from PMR was successfully treated with PSL and CAM. Because muscle pain disappeared, the CAM dosage was halved. The pain returned after the dosage was reduced, so the CAM dosage was successfully resumed and the PSL dosage was reduced. When the PSL dosage was reduced, muscle pain recurred. Because the PSL and CAM dosages were not successfully increased, TAC was also administered and was found to be effective at treating muscle pain. These two cases suggest that CAM and/or TAC are effective at treating PMR.

Rational design of a Kv1.3 channel-blocking antibody as a selective immunosuppressant

A variable region fusion strategy was used to generate an immunosuppressive antibody based on a novel "stalk-knob" structural motif in the ultralong complementary-determining region (CDR) of a bovine antibody. The potent Kv1.3 channel inhibitory peptides Moka1-toxin and Vm24-toxin were grafted into different CDRs of the humanized antibodies BVK and Synagis (Syn) using both β-sheet and coiled-coil linkers. Structure-activity relationship efforts led to generation of the fusion protein Syn-Vm24-CDR3L, which demonstrated excellent selectivity and potency against effector human memory T cells (subnanomolar to picomolar EC₅₀ values). This fusion antibody also had significantly improved plasma half-life and serum stability in rodents compared with the parent Vm24 peptide. Finally, this fusion protein showed potent in vivo efficacy in the delayed type hypersensitivity in rats. These results illustrate the utility of antibody CDR fusions as a general and effective strategy to generate long-acting functional antibodies, and may lead to a selective immunosuppressive antibody for the treatment of autoimmune diseases.

Pro: The use of calcineurin inhibitors in the treatment of lupus nephritis

Renal disease in systemic lupus erythematosus (SLE) carries significant morbidity and mortality. Cyclophosphamide (CYC)- and mycophenolate mofetil (MMF)-based induction regimens are not ideal in terms of efficacy and toxicity. The adverse effects of CYC, such as infection risk, infertility, urotoxicity and oncogenicity, limit its use in lupus nephritis. Although MMF is non-inferior to CYC as induction therapy and has reduced gonadal toxicity and oncogenic potential, meta-analyses of clinical trials do not show a lower rate of infective and gastrointestinal complications. Tacrolimus (TAC) has recently been shown to have equal efficacy to either MMF or CYC for inducing remission of lupus nephritis. A low-dose combination of MMF and TAC appears to be more effective than intravenous CYC pulses in Chinese patients, and has potential to replace the more toxic CYC regimens in high-risk subgroups. TAC may be considered as another non-CYC alternative for induction therapy of lupus nephritis and in those with refractory disease or intolerance to CYC or MMF. TAC has no negative effect on fertility in younger women, and unlike MMF and CYC, it is safe in pregnancy. However, TAC has a narrow therapeutic window and drug level monitoring is required to ensure drug exposure and minimize acute toxicities. Current evidence for the efficacy of TAC in lupus nephritis is limited to 6 months and the incidence of renal flare after discontinuation of therapy or switching to azathioprine appears to be higher than other induction agents. Long-term data and the incidence of chronic nephrotoxicity of TAC as maintenance therapy in lupus nephritis are currently lacking and further prospective trials are needed to address these issues.

Con: Cyclophosphamide for the treatment of lupus nephritis

Kidney involvement is a major determinant for morbidity and mortality in patients with systemic lupus erythematosus. The treatment target of lupus renal disease is to induce and maintain remission and to minimize disease or treatment-related comorbidities. Cyclophosphamide (CYC), in conjunction with glucocorticoids, has conventionally been used for the initial treatment of lupus nephritis. However, the major concerns of CYC are its toxicities, such as infertility, urotoxicity and oncogenicity, which are particularly relevant in women of childbearing age. As a result, maintenance therapy of lupus nephritis with an extended course of CYC pulses has largely been replaced by other immunosuppressive agents such as mycophenolate mofetil (MMF) and azathioprine. Recent randomized controlled trials have demonstrated non-inferiority of MMF to pulse CYC as induction therapy of lupus nephritis. Although MMF as induction-maintenance therapy has been increasingly used in lupus nephritis, its efficacy in the long-term preservation of renal function remains to be elucidated. MMF is not necessarily less toxic than CYC. Meta-analyses of clinical trials show similar incidence of infective complications and gastrointestinal adverse events in both MMF- and CYC-based regimens. However, considering the reduction in gonadal toxicity and the risk of oncogenicity, MMF may be used as first-line therapy of lupus nephritis. Tacrolimus (TAC) has recently been shown to be equivalent to either MMF or CYC for inducing remission of lupus nephritis and may be considered as another non-CYC alternative. Combined low-dose MMF and TAC appears to be more effective than CYC pulses in Chinese patients with lupus nephritis and has the potential to replace the more toxic CYC regimens in high-risk patients. Currently, CYC still plays an important role in the management of lupus nephritis patients with impaired or rapidly deteriorating renal function, crescentic glomerulonephritis or as salvage therapy for recalcitrant disease.

Towards new avenues in the management of lupus glomerulonephritis

Renal involvement in systemic lupus erythematosus (SLE) carries substantial morbidity and mortality. Conventional immunosuppressive agents (cyclophosphamide and azathioprine) have suboptimal efficacy and substantial toxicity. Mycophenolate mofetil has emerged as an alternative agent for both induction and maintenance therapy in lupus nephritis because of its reduced gonadal toxicity, despite its failure to demonstrate superiority over cyclophosphamide in pivotal studies. The calcineurin inhibitor tacrolimus has equivalent efficacy to cyclophosphamide and mycophenolate mofetil for inducing remission of lupus nephritis. Although rituximab has shown promise in refractory lupus nephritis, combining rituximab with mycophenolate mofetil as initial therapy offers no additional benefit. Considerable interethnic variation is evident in the efficacy and tolerability of the various immunosuppressive regimens, which necessitates individualized treatment and comparison of the efficacy of new regimens across different ethnic groups. For example, low-dose combinations of tacrolimus and mycophenolate mofetil seem to be more effective than pulse cyclophosphamide as induction therapy in Chinese patients. The same regimen has also been used successfully to treat refractory proliferative and membranous lupus nephritis in patients of various ethnic groups. Finally, novel serum and urinary biomarkers are being validated for diagnosis, prognostic stratification and early recognition of flares in lupus nephritis.

Tacrolimus Protects Podocytes from Injury in Lupus Nephritis Partly by Stabilizing the Cytoskeleton and Inhibiting Podocyte Apoptosis

Objective

Several studies have reported that tacrolimus (TAC) significantly reduced proteinuria in lupus nephritis (LN) patients and mouse models. However, the mechanism for this effect remains undetermined. This study explored the mechanism of how TAC protects podocytes from injury to identify new targets for protecting renal function.

Methods

MRL/lpr mice were given TAC at a dosage of 0.1 mg/kg per day by intragastric administration for 8 weeks. Urine and blood samples were collected. Kidney sections (2μm) were stained with hematoxylin-eosin (HE), periodic acid-Schiff base (PAS) and Masson's trichrome stain. Mouse podocyte cells (MPC5) were treated with TAC and/or TGF-β₁ for 48h. The mRNA levels and protein expression of synaptopodin and Wilms’ tumor 1 (WT1) were determined by real-time PCR, Western blotting and/or immunofluorescence, respectively. Flow cytometry was used to detect cell apoptosis with annexin V. Podocyte foot processes were observed under transmission electron microscopy. IgG and C3 deposition were assessed with immunofluorescence assays and confocal microscopy.

Results

Synaptopodin expression significantly decreased in MRL/lpr disease control mice, accompanied by increases in 24-h proteinuria, blood urea nitrogen, and serum creatinine. TAC, however, reduced proteinuria, improved renal function, attenuated renal pathology, restored synaptopodin expression and preserved podocyte numbers. In MPC5 cells, TGF-β₁ enhanced F-actin damage in podocytes and TAC stabilized it. TAC also decreased TGF-β₁-induced podocyte apoptosis in vitro and inhibited foot process fusion in MRL/lpr mice. In addition, our results also showed TAC inhibited glomerular deposition of IgG and C3.

Conclusion

This study demonstrated that TAC reduced proteinuria and preserved renal function in LN through protecting podocytes from injury partly by stabilizing podocyte actin cytoskeleton and inhibiting podocyte apoptosis.

Streptavidin suppresses T cell activation and inhibits IL-2 production and CD25 expression

Streptavidin is widely used as a detection tool in biology research because of its high affinity and specificity binding to biotin. Biotin-streptavidin system has also been explored for detection of infection and tumor in clinical medicine. Here, we show immunosuppressive property of streptavidin on T cell activation and proliferation. Upon CD3 and CD28 stimulation, CD4(+) T cells produce interleukin 2 (IL-2) and express IL-2 receptor α chain (CD25). Addition of streptavidin in T cell culture suppressed IL-2 synthesis and CD25 expression with no cytotoxicity. The immunosuppressive effect of streptavidin was reversed by excessive biotin. Conjugated to a single chain anti-CD7 variable fragment (scFvCD7), streptavidin was directly delivered to T cells and showed substantially more profound suppressive effect on T cell activation. These results suggest that streptavidin could potentially be used as a novel immunomodulator.

Current and emerging strategies for the treatment and management of systemic lupus erythematosus based on molecular signatures of acute and chronic inflammation

Lupus is a chronic, systemic inflammatory condition in which eicosanoids, cytokines, nitric oxide (NO), a deranged immune system, and genetics play a significant role. Our studies revealed that an imbalance in the pro- and antioxidants and NO and an alteration in the metabolism of essential fatty acids exist in lupus. The current strategy of management includes administration of nonsteroidal anti-inflammatory drugs such as hydroxychloroquine and immunosuppressive drugs such as corticosteroids. Investigational drugs include the following: 1) belimumab, a fully human monoclonal antibody that specifically recognizes and inhibits the biological activity of B-lymphocyte stimulator, also known as B-cell-activation factor of the TNF family; 2) stem cell transplantation; 3) rituximab, a chimeric monoclonal antibody against CD20, which is primarily found on the surface of B-cells and can therefore destroy B-cells; and 4) IL-27, which has potent anti-inflammatory actions. Our studies showed that a regimen of corticosteroids and cyclophosphamide, and methods designed to enhance endothelial NO synthesis and augment antioxidant defenses, led to induction of long-lasting remission of the disease. These results suggest that methods designed to modulate molecular signatures of the disease process and suppress inflammation could be of significant benefit in lupus. Some of these strategies could be vagal nerve stimulation, glucose-insulin infusion, and administration of lipoxins, resolvins, protectins, and nitrolipids by themselves or their stable synthetic analogs that are known to suppress inflammation and help in the resolution and healing of the inflammation-induced damage. These strategies are likely to be useful not only in lupus but also in other conditions, such as rheumatoid arthritis, scleroderma, ischemia-reperfusion injury to the myocardium, ischemic heart disease, and sepsis.