Lipoprotein glomerulopathy with markedly increased arterial stiffness successfully treated with a combination of fenofibrate and losartan: a case report.

BACKGROUND: Lipoprotein glomerulopathy (LPG) is a apolipoprotein E (ApoE)-related glomerular disease and has been associated with type III hyperlipidemia. Without appropriate treatment, chronic kidney disease (CKD) caused by LPG progresses, and approximately half of the patients develop end-stage kidney disease within 1-27 years of disease onset. However, few studies have highlighted the clinical course of cardiovascular diseases (CVDs) in patients with LPG. Herein, we report the first case of LPG in which the CVD risk was assessed using arterial stiffness. CASE PRESENTATION: A 32-year-old Japanese man was referred to our hospital due to persistent proteinuria. Kidney biopsy showed markedly dilated capillary lumens containing pale-stained thrombi, which stained positively with Oil Red O. Electron microscopy revealed the presence of thrombi in the capillary lumen with low electron density and vacuoles of various sizes in part of the thrombi. Toluidine blue and Sudan IV stains were used to stain the thin sections of Epon-embedded tissue samples for electron microscopy. Sudan IV-positive droplets were observed in the capillary lumens, vascular walls, and cytoplasm of tubular cells. Increased serum ApoE concentration was observed. Liquid chromatography-tandem mass spectrometry of laser-microdissected glomeruli from paraffin sections revealed an increase in ApoE. Direct deoxyribonucleic acid sequencing of ApoE revealed a heterozygous ApoE Sendai mutation (Arg145Pro). The patient was finally diagnosed with LPG with heterozygosity for ApoE-Sendai mutation (Arg145Pro). Notably, at the time of diagnosis, he had markedly increased arterial stiffness for his age. Arterial stiffness was measured using brachial-ankle pulse wave velocity (baPWV), which was equivalent to that of a 56-year-old man. After three months of treatment with fenofibrate and losartan, a significant reduction in proteinuria was achieved along with an improvement in baPWV. Furthermore, these effects were maintained despite the lack of decrease in serum ApoE levels. CONCLUSION: Herein, we report the case of a patient with LPG with markedly increased arterial stiffness at the time of diagnosis, in whom combination therapy with fenofibrate and losartan successfully improved proteinuria and arterial stiffness. To the best of our knowledge, this is the first case report of LPG in which CVD risk was assessed using arterial stiffness.

Peripheral Blood Absolute Lymphocyte Count as a Predictor of Cytomegalovirus Infection in Kidney Transplant Recipients.

BACKGROUND: Cytomegalovirus viremia and infection have been reported to increase the risks for acute graft rejection and mortality in kidney transplant recipients. Previous studies demonstrated that a lower absolute lymphocyte count in peripheral blood is associated with cytomegalovirus infection. The aim of this study was to investigate whether absolute lymphocyte count could predict cytomegalovirus infection in kidney transplant recipients. METHODS: From January 2010 to October 2021, 48 living kidney transplant recipients in whom both donor and recipient were positive for immunoglobulin G of cytomegalovirus were included in this retrospective study. The primary outcome was defined as cytomegalovirus infection occurring ≥28 days after kidney transplantation. All recipients were followed for 1 year after kidney transplantation. The diagnostic accuracy of absolute lymphocyte count on day 28 post-transplantation for cytomegalovirus infection was analyzed using receiver operating characteristic curves. A Cox proportional hazards model was used to calculate hazard ratios for the incidence of cytomegalovirus infection. RESULTS: There were 13 patients (27%) with cytomegalovirus infection. The sensitivity and specificity for cytomegalovirus infection were 62% and 71%, respectively; the negative predictive value was 83% when an absolute lymphocyte count of 1100 cells/µL on day 28 post-transplantation was used as the cutoff. The incidence of cytomegalovirus infection was significantly higher when the absolute lymphocyte count was <1100 cells/µL on day 28 post-transplantation (hazard ratio, 3.32; 95% CI, 1.08-10.2). CONCLUSION: Absolute lymphocyte count is an inexpensive and easy test that can effectively predict cytomegalovirus infection. Further validation is needed to confirm its utility.

Novel Complement C5 Small-interfering RNA Lipid Nanoparticle Prolongs Graft Survival in a Hypersensitized Rat Kidney Transplant Model.

BACKGROUND: Prophylaxis of antibody-mediated rejection (AMR) caused by donor-specific antibodies remains challenging. Given the critical roles of complement activity in antibody-mediated graft injury, we developed a lipid nanoparticle (LNP) formulation of small-interfering RNA against complement C5 (C5 siRNA-LNP) and investigated whether C5 siRNA-LNP could downregulate the complement activity and act as an effective treatment for AMR. METHODS: Lewis recipient rats were sensitized by skin grafting from Brown Norway donor rats. Kidney transplantation was performed at 4 wk post-skin grafting.C5 siRNA- or control siRNA-LNP was administered intravenously, and the weekly injections were continued until the study's conclusion. Cyclosporin (CsA) and/or deoxyspergualin (DSG) were used as adjunctive immunosuppressants. Complement activity was evaluated using hemolysis assays. The deposition of C5b9 in the grafts was evaluated using immunohistochemical analysis on day 7 posttransplantation. RESULTS: C5 siRNA-LNP completely suppressed C5 expression and complement activity (hemolytic activity ≤ 20%) 7 d postadministration. C5 siRNA-LNP in combination with CsA and DSG (median survival time: 56.0 d) prolonged graft survival compared with control siRNA-LNP in combination with CsA and DSG (median survival time: 21.0 d; P = 0.0012; log-rank test). Immunohistochemical analysis of the grafts revealed that downregulation of C5 expression was associated with a reduction in C5b9-positive area ( P = 0.0141, Steel-Dwass test). CONCLUSIONS: C5 siRNA-LNP combined with immunosuppressants CsA and DSG downregulated C5 activity and significantly prolonged graft survival compared with control siRNA-LNP with CsA and DSG. Downregulation of C5 expression using C5 siRNA-LNP may be an effective therapeutic approach for AMR.

Long-Term Humoral Response After a Second Dose of SARS-CoV-2 mRNA Vaccine in Japanese Kidney Transplant Recipients.

Background: The mortality rate due to COVID-19 in kidney transplant recipients (KTRs) is 16.8 to 32%. Vaccination against COVID-19 is expected to contribute to the prevention of infection, severe disease, and mortality; however, it has been reported that the humoral response to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccine in KTRs is poor. Vaccination strategies against COVID-19 vary from country to country, and in Japan, the third dose is given 6 months after the second dose. Few studies have evaluated long-term humoral responses after the second dose of SARS-CoV-2 mRNA vaccine. In addition, the superiority of BNT162b2 vaccine and mRNA-1,273 vaccine in KTRs regarding humoral response is controversial. Methods: Ninety-four KTRs were administered a second dose of the BNT162b2 or mRNA-1,273 vaccines, and anti-spike (anti-S) and anti-nucleocapsid (anti-N) SARS-CoV-2 antibody levels were measured 5 months (149.2 ± 45.5 days) later. The cutoff value of anti-S antibodies was defined ≥50 AU/ml and 1.4 Index for anti-N antibodies. The primary outcome was the rate of seropositivity, and factors associated with an appropriate humoral response were assessed by univariate and multivariate analysis. Results: Of 94 KTRs, only 45 (47.9%) patients were positive for anti-S antibodies. The median anti-S SARS-CoV-2 IgG antibody titers was 35.3 (Interquartile range 3.8 to 159.7). Anti-N SARS-CoV-2 IgG antibodies in all patients were < 1.4 Index. Response to SARS-CoV-2 mRNA vaccines were 43.2 and 65% for BNT162b2 and mRNA-1,273, respectively (p = 0.152). In comparison with high-dose, low-dose of mycophenolic acid was a robust factor associated with an adequate humoral response. Conclusion: The long-term humoral response after a second dose of SARS-CoV-2 mRNA vaccine in Japanese KTRs was poor. In comparison with high-dose, low-dose mycophenolic acid was related to an appropriate humoral response. Five months is too long to wait for a 3rd dose after 2nd dose of SARS-CoV-2 vaccine in KTRs. In this cohort, there was no statistical difference in humoral response to the BNT162b2 and mRNA-1,273 vaccines. Additional large observational studies and meta-analyses are needed to clarify the factors related to an appropriate humoral immune response to COVID-19 vaccination.

Role of Fractalkine-CX3CR1 Axis in Acute Rejection of Mouse Heart Allografts Subjected to Ischemia Reperfusion Injury.

Transplantation outcomes are affected by the increase in rejection associated with ischemia reperfusion injury (IRI). Fractalkine (FKN), a chemokine for recruitment of CX3CR1+ leukocytes, contributes to the pathogenesis of various inflammatory diseases. Herein, we evaluated the importance of the FKN-CX3CR1 axis during IRI-related rejections using a mouse heterotopic heart transplantation model. FKN expression and graft survival was compared between wild-type C57BL/6 recipients transplanted with BALB/c hearts preserved for 8 (WT-IRI) and 0.5 h (WT-control) at 4°C. Graft survival of WT-IRI was shorter than that of WT-control. FKN was expressed on the vascular endothelium in WT-IRI allografts, but minimally in WT-control. The role of the FKN-CX3CR1 axis in IRI-related rejection was directly investigated using the transplant model with CX3CR1-deficient recipients (CX3CR1 KO-IRI) or treatment with anti-mouse FKN monoclonal antibodies. Graft survival of CX3CR1 KO-IRI was longer than that of WT-IRI; antibody treatment prolonged graft survival. The contribution of CX3CR1+ monocytes to IRI-related rejection was evaluated by adoptive transfer to CX3CR1 KO-IRI. Adoptive transfer of CX3CR1+ monocytes attenuated the effect of prolonged graft survival in CX3CR1 KO-IRI. Overall, the FKN-CX3CR1 axis plays a major role during IRI-related rejection; its blockade has the potential to improve the outcomes of deceased donor transplantation.

Interstitial fibroblasts in donor kidneys predict late posttransplant anemia.

BACKGROUND: Posttransplant anemia (PTA) is associated with the progression of kidney disease and mortality in kidney transplant recipients. Although the main causes of PTA are recipient factors, donor factors have not been fully investigated. In this study we investigated the association of donor pathological findings with the incidence of PTA in kidney transplant recipients after 3 years of transplantation. METHODS: We conducted a retrospective cohort study at a single university hospital. A total of 50 consecutive adult recipients and donors were enrolled. To assess the structure of interstitial lesions, immunohistochemical staining of interstitial fibrosis and fibroblasts were assessed in 0-h biopsies for quantitative analysis. RESULTS: The incidence of PTA in this cohort was 30%. The mean hemoglobin (Hb) was 11.6 ± 0.8 g/dL in patients with PTA and 14.3 ± 1.5 g/dL in patients without PTA. An inverse association was observed in biopsies between interstitial fibrosis area and interstitial fibroblast area (P < 0.01) and each pathological finding was examined for its association with PTA incidence after multivariate adjustment. For the interstitial fibrosis area, the odds ratio (OR) was 1.94 [95% confidence interval (CI) 1.26-2.99; P < 0.01]. For the interstitial fibroblast area, the OR was 0.01 (95% CI 0.00-0.16; P < 0.01). Receiver operating characteristics curve analysis indicated that the interstitial fibroblast area had high predictive power for the incidence of PTA. CONCLUSIONS: The presence of interstitial fibroblasts in donor kidneys may play an important role in predicting the incidence of PTA.

A Case of Transplant Nephrectomy due to Chronic Graft Intolerance Syndrome.

We report a case of graft intolerance syndrome in which transplant nephrectomy was performed 11 years after kidney transplantation. A 46-year-old man was admitted to our hospital in February 2018 with a mild fever, left lower abdominal pain, and gross hematuria with enlargement of the transplanted kidney. Urinary tract infection was ruled out. Because the symptoms developed after the immunosuppressants had been stopped after kidney graft loss, graft intolerance syndrome was suspected. He had lost his graft in 2016 and had stopped all immunosuppressants since January of 2017. Immunosuppressive therapy was intensified, and steroid half-pulse therapy was added for 3 days. After the steroid pulse therapy, the C-reactive protein (CRP) decreased from 6.47 mg/dL to 0.76 mg/dL, but there was little improvement in the symptoms, and the CRP then increased to 4.44 mg/dL. Transplant nephrectomy was performed in March 2018. Postoperatively, the symptoms disappeared without the administration of immunosuppressants, and the CRP decreased. Pathologically, the resected kidney graft showed persistent active allograft rejection with severe endarteritis, transplant glomerulopathy, and diffuse interstitial fibrosis. Massive thrombi occluded the large arteries, and there was extensive hemorrhagic cortical necrosis. Transplant nephrectomy is uncommon in patients >6 months after transplantation. However, even if more time has passed since transplantation, as in this case, transplant nephrectomy may be a valid option in some cases of severe graft intolerance syndrome.

Association Between Galactose-Deficient IgA1 Derived From the Tonsils and Recurrence of IgA Nephropathy in Patients Who Underwent Kidney Transplantation.

Background: Recurrence of IgA nephropathy (IgAN) in the transplanted kidney is associated with graft survival, but no specific treatment is available. Tonsillectomy (TE) reportedly arrests the progression of IgAN in the native kidney. Thus, we conducted a single-center retrospective cohort study to evaluate the effect of TE prior to IgAN recurrence. Methods: Of the 36 patients with biopsy-proven IgAN who underwent kidney transplantation, 27 were included in this study. Nine patients underwent TE at 1 year after kidney transplantation (group 1), and the remaining 18 did not undergo TE (group 2). Results: The rate of histological IgAN recurrence was significantly lower in group 1 than in group 2 (11.1 vs. 55.6%, log-rank p = 0.046). In addition, half of the recurrent patients in group 2 exhibited active lesions, compared to none in group 1. Serum Gd-IgA1 levels decreased after TE in group 1, whereas they remained stable or increased slightly in group 2. In the recurrent cases, IgA and Gd-IgA1 were found in the germinal center in addition to the mantle zone of tonsils. Finally, mesangial IgA and Gd-IgA1 immunoreactivity was reduced after TE in some cases. Conclusion: Our data suggest that TE at 1 year after kidney transplantation might be associated with the reduced rate of histological IgAN recurrence. TE arrested or reduced serum Gd-IgA1 and mesangial Gd-IgA1 immunoreactivity. Therefore, we generated a hypothesis that serum Gd-IgA1 derived from the tonsils may play a pivotal role in the pathogenesis of IgAN. Based on these findings, we need to conduct verification in a prospective randomized controlled trial.

Combination therapy of an iNKT cell ligand and CD40-CD154 blockade establishes islet allograft acceptance in nonmyeloablative bone marrow transplant recipients.

AIMS: Islet transplantation is an effective therapeutic option for type 1 diabetes. Although maintenance immunosuppression therapy is required to prevent allogeneic rejection and recurrence of autoimmunity, long-term allograft survival has not yet been achieved partly because of its adverse effects. The induction of donor-specific immunotolerance is a promising approach for long-term allograft survival without maintenance immunosuppression therapy. We previously reported that combination therapy using a liposomal ligand for invariant natural killer T cells, RGI-2001, and anti-CD154 antibody established mixed hematopoietic chimerism for the induction of donor-specific immunotolerance. This study investigated whether the protocol could promote islet allograft acceptance in experimental diabetes. METHODS: Streptozotocin-induced diabetic BALB/c mice were transplanted with bone marrow cells from C57BL/6 donors and received combination therapy of RGI-2001 and anti-CD154 antibody after 3-Gy total body irradiation. 3 Weeks after bone marrow transplantation, islets isolated from C57BL/6 donors were transplanted under the kidney capsule. RESULTS: Mixed chimerism was established in diabetic mice receiving the tolerance induction protocol. After islet transplantation, blood glucose levels improved and normoglycemia persisted for over 100 days. Hyperglycemia recurred after islet grafts were removed. Histopathological examinations showed insulin-positive staining and absence of cellular infiltration in the islet grafts. T cells of recipients showed donor-specific hyporesponsiveness, and anti-donor antibodies were not detected. CONCLUSIONS: The tolerance induction protocol with combination therapy of RGI-2001 and anti-CD154 antibody promoted islet allograft acceptance in a mouse diabetic model. This protocol may be clinically applied to islet transplantation for type 1 diabetes mellitus.

Impact of activated invariant natural killer T cells on the expansion of regulatory T cell precursors in murine thymocytes in vitro.

Tolerance induction is a goal of clinical transplantation to prevent graft rejection without the lifelong use of immunosuppressive drugs. In a series of mouse studies, we previously reported that the establishment of mixed chimerism by treatment with a ligand for invariant natural killer T (iNKT) cells with CD40 signal blockade makes it possible to prevent allograft rejection without immunosuppressants, and this approach fails in thymectomized recipient mice. In this study, we showed that iNKT cells in murine thymocyte cultures are indispensable for the expansion of CD4+CD25+Foxp3+ regulatory T (Treg) cells as well as CD4+CD25+Foxp3- cells, which contained precursor Tregs (preTregs). After the culture of BALB/c mouse-derived thymocytes in the presence of α-galactosylceramide (α-GalCer), a representative ligand for iNKT cells, the ratio of CD4+CD25+Foxp3- preTregs to total CD4+CD8- T cells was much higher than that of CD4+CD25+Foxp3+ Treg cells, regardless of anti-CD40 L mAb treatment. The proliferation of CD4+CD25+Foxp3- cells, but not Treg cells, was significantly augmented, and the stability of Treg cells was not affected by α-GalCer. The expansion of thymocyte-derived Tregs was not inhibited by cytokine neutralization. However, in vitro thymus-derived CD4+CD25+Foxp3- cells expressed Foxp3 after IL-2 stimulation in a dose-dependent manner. These results collectively suggest that in vitro thymus-derived Treg cell expansion by α-GalCer treatment was caused by the proliferation of CD4+CD25+Foxp3- preTregs but not existing Treg cells.

Evaluation of the impact of conventional immunosuppressant on the establishment of murine transplantation tolerance - an experimental study.

Regulatory T cells (Tregs) play a significant role in immune tolerance. Since Treg function deeply depends on Interleukin-2 signaling, calcineurin inhibitors could affect their suppressive potentials, whereas mammalian target of rapamycin (mTOR) inhibitors may have less impact, as mTOR signaling is not fundamental to Treg proliferation. We previously reported a novel mixed hematopoietic chimerism induction regimen that promotes Treg proliferation by stimulating invariant natural killer T cells under CD40 blockade. Here, we use a mouse model to show the impact of tacrolimus (TAC) or everolimus (EVL) on the establishment of chimerism and Treg proliferation in the regimen. In the immunosuppressive drug-dosing phase, peripheral blood chimerism was comparably enhanced by both TAC and EVL. After dosing was discontinued, TAC-treated mice showed gradual graft rejection, whereas EVL-treated mice sustained long-term robust chimerism. Tregs of TAC-treated mice showed lower expression of both Ki67 and cytotoxic T lymphocyte antigen-4 (CTLA-4), and lower suppressive activity in vitro than those of EVL-treated mice, indicating that TAC negatively impacted the regimen by interfering with Treg proliferation and activation. Our results suggest that the usage of calcineurin inhibitors should be avoided if utilizing the regimen to induce Tregs in vivo for the establishment of mixed hematopoietic chimerism.

Long-term survival in Japanese renal transplant recipients with Alport syndrome: a retrospective study.

BACKGROUND: Patients with Alport syndrome (AS) develop progressive kidney dysfunction due to a hereditary type IV collagen deficiency. Survival of the kidney allograft in patients with AS is reportedly excellent because AS does not recur. However, several studies have implied that the type IV collagen in the GBM originates from podocytes recruited from the recipient's bone marrow-derived cells, suggesting the possibility of AS recurrence. Limited data are available regarding AS recurrence and graft survival in the Japanese population; the vast majority were obtained from living related kidney transplantation (LRKTx). METHODS: In this retrospective study, twenty-one patients with AS were compared with 41 matched patients without AS from 1984 to 2015 at two centers using propensity scores. Nineteen of the 21 patients with AS underwent LRKTx. The mean post-transplant follow-up period was 83 months in the AS group and 110 months in the control group. Histopathological AS recurrence was assessed by immunoreactivity of α5 (type IV collagen) antibody and electron microscopy. RESULTS: The graft survival rate was equivalent between patients with and without AS (86.7% vs. 77.1% and 69.3% vs. 64.2% at 5 and 10 years; p = 0.16, log-rank test). Immunoreactivity to α5 antibody showed strong linear positivity with no focal defect in six patients. Electron microscopy showed no GBM abnormalities in two patients who were exhibiting long-term kidney allograft survival. CONCLUSIONS: We confirmed that α5 and the GBM structure were histopathologically maintained in the long term after kidney transplantation. The patient and graft survival rates were equivalent between Japanese patients with and without AS.

Antibody-mediated rejection due to anti-HLA-DQ antibody after pregnancy and delivery in a female kidney transplant recipient.

Herein, we report a case of antibody-mediated rejection (ABMR) due to anti-HLA-DQ antibody after pregnancy and delivery in a female kidney transplant recipient. A 34-year-old female recipient was admitted at 2 years after delivery for an examination of an elevated serum creatinine (S-Cr) level. The patient had received a living kidney transplantation from her mother at 22 years of age, and her kidney graft function was almost stable. The episode biopsy showed peritubular capillaritis and transplant capillaropathy with C4d immunoreactivity in the peritubular capillaries. Additional examination revealed expression of a donor-specific antibody (DSA) against HLA-DQ5, leading to the diagnosis of chronic active ABMR. Intravenous immunoglobulin, plasma exchange, and rituximab were administered, and her S-Cr level was maintained stable. This case demonstrates a possible relationship between pregnancy/delivery and development of ABMR due to a de novo DSA in a female kidney transplant recipient.

Clinicopathological study of de novo membranous nephropathy of 'stage 0' after kidney transplantation.

AIM: De novo membranous nephropathy (dnMN) contributes to graft failure, but the pathophysiology of the disease remains poorly understood. We defined cases exhibiting granular Immunoglobulin G (IgG) immunofluorescence staining but lacking dense deposits on electron microscopy as being of 'dnMN stage 0'; we studied the associated clinicopathological features. METHODS: We studied 4653 allograft biopsy specimens (from 1747 cases treated in the Department of Urology, Tokyo Women's Medical University) and found 42 cases of allograft membranous nephropathy, of which 28 (1.6%) were diagnosed as dnMN. Of these, five cases (0.06%) fulfilled the criteria for dnMN stage 0. RESULTS: All five cases were diagnosed based on biopsies indicating increased serum levels of creatinine. Proteinuria status varied from negative to 2+. The median period from transplantation to allograft biopsy was 4068 days. Four of the five cases exhibited suspicious antibody-mediated rejection together with dnMN. The glomerular capillaries of all cases were C4d-positive, as were the peritubular capillaries of three of the four ABO-compatible transplants. In terms of IgG subclass, IgG1 and IgG3 predominated in all cases, and phospholipase A2 receptor status (evaluated via immunoreactivity) was negative in all cases. We examined two cases by immunoelectron microscopy using anti-IgG and anti-C4d antibodies. We found subendothelial and intramembranous deposits expressing both IgG and C4d, corresponding to positivity in immunofluorescence analysis. CONCLUSION: We confirmed the existence of dnMN stage 0 by focusing on granular IgG immunofluorescence positivity.

Recurrence of native kidney disease after kidney transplantation.

The extent of recurrence of original kidney disease after kidney transplantation has been underestimated for several reasons. First, the duration of observation varies among studies. Second, the criteria used to schedule protocol and episode biopsies differ among institutions. And third, diagnostic modalities used for early detection of recurrent original kidney disease also vary. Thus, rates of graft loss attributable to a recurrence of original kidney disease vary among institutions and are often underestimated. However, the recurrence of original disease is often thought to be less important than chronic rejection followed by loss of a functioning allograft. It is important to note that recent data have shown that in patients with certain limited primary kidney diseases (e.g., membranous proliferative glomerulonephritis [MPGN], IgA nephritis [IgAN], focal segmental glomerulonephritis [FSGS], and membranous nephropathy [MN]), the predominant (60%) cause of graft loss is the recurrence of original kidney disease. In addition, the rate of 5-year graft survival in patients with recurrent original kidney disease averages 45%. Thus, research must address the recurrence of original kidney disease. Here we focus on this recurrence and discuss diagnoses, preventive strategies, treatments, and future research directions.

Clinicopathological features and outcomes of kidney allografts in plasma cell-rich acute rejection: A case series.

Plasma cell-rich acute rejection (PCAR) is a rare type of acute rejection in renal transplantation. Despite aggressive immunotherapy, approximately 40-60% of patients develop graft loss within 1 year after an episode of PCAR. However, the reason for this outcome remains obscure. This study retrospectively identified six patients with PCAR diagnosed between 2009 and 2015 at a single university hospital. Clinicopathological data were collected. Five of the six patients were male, and mean age at the onset of PCAR was 49.0 ±14.5 years. None of the patients showed overall poor adherence to medication. Mean time to diagnosis was 302 ±234 days post-transplantation. All patients had preceding or concurrent viral infection. Four patients developed PCAR alone and two patients developed PCAR with antibody-mediated rejection. One of the six patients showed both severe tubulointerstitial and microvascular inflammation (total of Banff tubulitis 't' + interstitial inflammation 'i' + glomerulitis 'g' + peritubular capillaritis 'ptc' scores >10). This patient had progressive worsening of graft function and re-initiated dialysis at 74 months after a PCAR episode. In addition, three of the six patients had long-term recurrence of PCAR. With the recurrence of PCAR, patients with both moderate tubulointerstitial and microvascular inflammation (total of Banff 't' + 'i' + 'g' + 'ptc' scores >6) had progressive worsening of graft function. In summary, the present results suggest that concurrent moderate to severe tubulointerstitial and microvascular inflammation may lead to poor outcomes of graft function after a PCAR episode.

Successful treatment of recurrent immunoglobulin a nephropathy using steroid pulse therapy plus tonsillectomy 10 years after kidney transplantation: a case presentation.

BACKGROUND: Both prevention and treatment of recurrent immunoglobulin A nephropathy (IgAN) in kidney transplant recipients are important since recurrent IgAN seems to affect long-term graft survival. We present here a case of recurrent IgAN that was successfully treated using steroid pulse therapy plus tonsillectomy 10 years after kidney transplantation. CASE PRESENTATION: A 46-year-old male was admitted for an episode biopsy with a serum creatinine level of 1.8 mg/dl and proteinuria (0.7 g/day). Histological features showed recurrent IgAN (only focal segmental mesangial proliferation) and severe arteriolar hyalinosis partly associated with calcineurin inhibitor toxicity, with limited interstitial fibrosis and tubular atrophy (5%) (IF/TA) 8 years after transplantation. Sodium restriction and conversion from cyclosporine to tacrolimus successfully reduced his proteinuria to the level of 0.15 g/day. However, 2 years later, his proteinuria increased again (1.0 g/day) and a second episode biopsy showed global mesangial proliferation with glomerular endocapillary and extracapillary proliferation accompanied by progressive IF/TA (20%). The steroid pulse therapy plus tonsillectomy successfully decreased his proteinuria and he achieved clinical remission 3 years after this treatment. CONCLUSION: This case, presented with a review of relevant literature, demonstrates the difficulty and importance of the treatment of recurrent IgAN and calcineurin inhibitor arteriolopathy, especially in long-term kidney allograft management.

Successful Treatment of Plasma Cell-Rich Acute Rejection Using Pulse Steroid Therapy Alone: A Case Report.

Despite the recent development of immunosuppressive agents, plasma cell-rich acute rejection (PCAR) has remained refractory to treatment. Herein, we report an unusual case of PCAR that responded well to pulse steroid therapy alone. A 47-year-old man was admitted for a protocol biopsy three months after kidney transplantation, with a stable serum creatinine level of 1.6 mg/dL. Histological examination showed focal aggressive tubulointerstitial inflammatory cell infiltration of predominantly polyclonal mature plasma cells, leading to our diagnosis of PCAR. Three months following three consecutive days of high-dose methylprednisolone (mPSL) therapy, an allograft biopsy performed for therapy evaluation showed persistent PCAR. We readministered mPSL therapy and successfully resolved the PCAR. Although PCAR generally develops more than six months after transplantation, we diagnosed this case early, at three months after transplantation, with focally infiltrated PCAR. This case demonstrates the importance of early diagnosis and prompt treatment of PCAR to manage the development and severity of allograft rejection.

Helicobacter cinaedi bacteremia with cellulitis in a living-donor kidney transplant recipient identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry: a case report.

BACKGROUND: Helicobacter cinaedi causes bacteremia and cellulitis, mainly in immunocompromised patients. We report a rare case of H. cinaedi bacteremia with cellulitis in a living-donor kidney transplant recipient identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). A 54-year-old Asian man with IgA nephropathy underwent living-donor kidney transplantation 14 years previously. He was admitted to our hospital for evaluation of fever and multifocal cellulitis. H. cinaedi was isolated and identified from the patient's blood using matrix-assisted laser desorption ionization time-of-flight mass spectrometry and gyrase subunit B-targeted polymerase chain reaction assays. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry has proven over the years to be a rapid and accurate universal method for the identification of microorganisms. CONCLUSIONS: The combined use of these detection methods enabled the appropriate administration of 6 weeks of antibiotic therapy. The patient recovered completely, with no recurrence.

Recurrence and graft loss after renal transplantation in adults with IgA vasculitis.

BACKGROUND: IgA vasculitis, a rare condition resulting in end-stage renal disease, is a small-vessel vasculitis that affects the kidney in 49-83 % of adults. The reported recurrence rate of IgA vasculitis in renal transplant recipients is 11.5-60 %, leading to graft loss in 0-50 % of these patients. However, limited data are available on recurrence and graft loss after renal transplantation. METHODS: We evaluated renal transplant recipients seen from 1987 to 2015 at the Jikei University School of Medicine and the Department of Urology, Tokyo Women's Medical University. Using a 1:2 match, 21 patients with IgA vasculitis and 42 controls were selected. The mean post-transplant follow-up was 121 ± 69 months for IgA vasculitis and 147 ± 66 months for the controls. RESULTS: The 15-year patient survival was 100 % in IgA vasculitis and 97.6 % in the controls (p = 0.22). The 5-, 10-, and 15-year graft survival rates were 95.2, 90.5, and 81 % in IgA vasculitis and 100, 90.5, and 88.1 % in the controls, respectively (p = 0.63). The recurrence rate was 28.6 % (6 of 21 cases) and half of them (3 of 6 cases) showed histological activity (ISKDC III). We treated them with methylprednisolone pulse therapy and/or tonsillectomy. None of the recurrence cases lost the allograft. CONCLUSION: The long-term patient and graft survival of IgA vasculitis in renal transplantation were comparable with the previous reports. The recurrence rate was 28.6 %, but none of the recurrent cases showed allograft loss in this study. We speculate that methylprednisolone pulse therapy and/or tonsillectomy prevent the progression of recurrent IgA vasculitis.