A rare multisystemic disorder with chronic kidney disease: Karyomegalic interstitial nephritis due to homozygous FAN1 c.2260C>T variant.

Karyomegalic interstitial nephritis (KIN) is a rare entity associated with biallelic FAN1 (FANCD2/FANCI-Associated Nuclease 1) gene variants. In FAN1-related KIN, abnormal liver function tests and respiratory involvement are common, in addition to chronic kidney disease. Karyomegalic changes have also been reported in many other organs in patients with FAN1-related KIN in various studies. We report the case of a 35-year-old male with chronic kidney disease of unknown aetiology, concurrent recurrent upper and lower respiratory tract infections, and elevated liver function test results with unidentified aetiology. The patient's family history was remarkable for consanguineous parent marriage and history of kidney transplantation in his aunt. A kidney biopsy was performed, which was consistent with KIN. Clinical exome sequencing revealed a homozygous nonsense variant NM_014967.5 (FAN1): c. 2260C > T (p.Arg754Ter). According to the American College of Medical Genetics (ACMG) criteria, this variant is pathogenic and, to the best of our knowledge, has not been previously reported, homozygously. Therefore, the histopathological and clinical diagnoses of KIN were confirmed by genetic studies in our patient. This case report expands the genetic spectrum of FAN1-related KIN, and briefly reviews the current literature data.

Baseline systemic inflammatory indices and clinicopathological features to predict the outcome of acute tubulointerstitial nephritis : A single-center retrospective study.

BACKGROUND: Acute tubulointerstitial nephritis (AIN) is an immune-mediated disorder that can cause acute kidney injury (AKI). We aimed to investigate the characteristics of patients with AIN and predictive factors for treatment response. MATERIAL AND METHODS: In this study, thirty-one patients diagnosed with AIN on kidney biopsy between 2006 and 2021 were included. Baseline clinical, histopathological, and laboratory findings, including complete blood count (CBC), creatinine, erythrocyte sedimentation rate, C­reactive protein, C3, C4, systemic immune inflammation index (SII), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and urinalysis were evaluated. Treatment response, mortality, and creatinine levels at the time of last follow-up were also noted. RESULTS: The median age was 46 years and 80.6% were female. Median baseline creatinine and proteinuria levels were 4.1 mg/dL and 0.84 gram/day. The median follow-up period was 14 months and 93.5% received immunosuppressives. End-stage kidney disease (ESKD) developed in five patients (16.1%). Renal recovery (creatinine < 1.4 mg/dL) was observed in 17 patients (54.8%). Higher degrees of interstitial fibrosis, tubular atrophy, granuloma formation, global glomerulosclerosis, and higher baseline hemoglobin levels, in addition to a longer interval between first symptom to initiation of immunosuppressives were associated with renal nonrecovery, statistically. Also, patients who progressed to ESKD had higher baseline hemoglobin (p = 0.033) and lymphocyte (p = 0.044) and lower PLR levels (p = 0.016), as well as higher degrees of global glomerulosclerosis (p = 0.014), interstitial fibrosis (p = 0.042), and tubular atrophy (p = 0.030). CONCLUSION: Treatment response rates are low for AIN, which may lead to ESKD. Besides chronicity in histopathology specimens, higher baseline hemoglobin levels and lower platelet-to-lymphocyte ratio might be prognostic. Further studies should be conducted on new markers for AIN.

LIM Zinc Finger Domain Containing 1 Risk Genotype of Recipient Is Associated with Renal Tubular Inflammation in Kidney Transplantation.

BACKGROUND: Homozygosity for LIMS1 rs893403-GG genotype is linked to an increased risk of allograft rejection after kidney transplantation. Ischemia-reperfusion of the kidney allograft leads to long term infiltration of activated and effector-memory T lymphocytes and resulting in rejection and long-term fibrosis. However, the genotype, LIMS1 expression under ischemic conditions and the long-term histopathological relationships remain ill-defined. METHODS: We examined the impact of the recipient's LIMS1-rs893403 genotype with transplant kidney histopathology. The association of the LIMS1-rs893403 genotype and LIMS1 and GCC2 mRNA expression in ischemic donor kidneys were also examined. Recipients who underwent transplant kidney biopsy were genotyped for the LIMS1-rs893403 variant and associated deletion. Histopathological findings were compared between recipients with LIMS1 risk and non-risk genotypes. Real-time PCR and immunofluorescence staining for LIMS1 and GCC2 expression were performed in non-utilized donor kidneys. RESULTS: Demographic, clinical, and treatment characteristics and the histopathological diagnosis were similar between recipients with rs893403 GG and AA/AG genotype. The Banff tubulitis score was higher in GG recipients (n = 24) compared to AA/AG (n = 86) recipients (1.42 ± 0.65 vs. 1.12 ± 0.66, p = 0.03). Ischemic kidneys with GG showed higher LIMS1 and GCC2 mRNA expression than kidneys with AG. Kidneys with rs893403-GG had higher tubular LIMS1 and GCC2 immunohistochemical staining compared to kidneys with rs893403-AG. CONCLUSIONS: Our data supports the role of the LIMS1 locus in kidney transplant rejection, particularly in lymphocyte infiltration into the internal aspect of the tubular basement membranes. Increased LIMS1 and GCC2 expression in ischemic donor kidneys with the GG genotype require further studies.

Immunosuppressive treatment results in patients with primary IgA nephropathy in Turkiye; the data from TSN-GOLD working group.

BACKGROUND: Immunoglobulin A (IgA) nephropathy (IgAN) treatment consists of maximal supportive care and, for high-risk individuals, immunosuppressive treatment (IST). There are conflicting results regarding IST. Therefore, we aimed to investigate IST results among IgAN patients in Turkiye. METHOD: The data of 1656 IgAN patients in the Primary Glomerular Diseases Study of the Turkish Society of Nephrology Glomerular Diseases Study Group were analyzed. A total of 408 primary IgAN patients treated with IST (65.4% male, mean age 38.4 ± 12.5 years, follow-up 30 (3-218) months) were included and divided into two groups according to treatment protocols (isolated corticosteroid [CS] 70.6% and combined IST 29.4%). Treatment responses, associated factors were analyzed. RESULTS: Remission (66.7% partial, 33.7% complete) was achieved in 74.7% of patients. Baseline systolic blood pressure, mean arterial pressure, and proteinuria levels were lower in responsives. Remission was achieved at significantly higher rates in the CS group (78% vs. 66.7%, p = 0.016). Partial remission was the prominent remission type. The remission rate was significantly higher among patients with segmental sclerosis compared to those without (60.4% vs. 49%, p = 0.047). In the multivariate analysis, MEST-C S1 (HR 1.43, 95% CI 1.08-1.89, p = 0.013), MEST-C T1 (HR 0.68, 95% CI 0.51-0.91, p = 0.008) and combined IST (HR 0.66, 95% CI 0.49-0.91, p = 0.009) were found to be significant regarding remission. CONCLUSION: CS can significantly improve remission in high-risk Turkish IgAN patients, despite the reliance on non-quantitative endpoints for favorable renal outcomes. Key predictors of remission include baseline proteinuria and specific histological markers. It is crucial to carefully weigh the risks and benefits of immunosuppressive therapy for these patients.

Clinical and histopathological characteristics of primary focal segmental glomerulosclerosis in Turkish adults.

The data regarding primary FSGS (pFSGS) from different parts of the world differ. While the prevalence of pFSGS has been increasing in Western countries like the USA, it follows an inconsistent trend in Europe and Asia and a decreasing trend in Far Eastern countries such as China in the last two decades. There are undetermined factors to explain those national and geographic discrepancies. Herein, we aimed to reveal the current prevalence with clinical and histopathological characteristics of pFSGS in Turkish adults. This study includes the biopsy-proven pFSGS patients data recorded between 2009 and 2019, obtained from the national multicenter primary glomerulonephritis registry system of the Turkish Society of Nephrology Glomerular Diseases (TSN-GOLD) database. 850 of the 3875 primer glomerulonephritis patients(21.9%) have pFSGS. The mean age is 40.5 ± 14.2 and 435 (51.2%) of patients are male. Nephrotic syndrome is the most common biopsy indication (59.2%). 32.6% of patients have hematuria, 15.2% have leukocyturia and 7.8% have both. Serum creatinine, albumin, and proteinuria are 1.0 mg/dL (IQR = 0.7-1.4) mg/dl, 3.4 ± 0.9 g/dl, 3400 mg/day(IQR, 1774-5740), respectively. Females have lower mean arterial pressure (- 2.2 mmHg), higher eGFR (+ 10.0 mL/min/1.73 m2), and BMI (+ 1.6 kg/m2) than males. Thickened basal membrane(76.6%) and mesangial proliferation (53.5%) on light microscopy are the major findings after segmental sclerosis. IgM (32.7%) and C3 (32.9%) depositions are the most common findings on immunofluorescence microscopy. IgM positivity is related to lower eGFR, serum albumin, and higher proteinuria. The prevalence of pFSGS is stable although slightly increasing in Turkish adults. The characteristics of the patients are similar to those seen in Western countries.

Concurrent Cobalamin C and Plasminogen Deficiencies in a Patient with Chronic Thrombotic Microangiopathy.

BACKGROUND: Although most patients with atypical hemolytic uremic syndrome (aHUS) have variants in genes participating in alternative complement pathways, rare variants in non-complement pathway-related genes, including DGKE, INF2, MMACHC, PLG, and THBD, have also been described. CASE PRESENTATION: We report an 18-year-old male patient with renal biopsy-proven chronic thrombotic microangiopathy that raised suspicion of aHUS. Whole-exome sequencing revealed a novel pathogenic homozygous MMACHC c.484G>T (p.Gly162Trp) variant. Subsequently, clinical and laboratory findings confirmed cobalamin C (Cbl C) deficiency. Also, homozygous missense c.1112C>T PLG (p.Thr371Ile) variant was detected (it had been reported as a variant of unknown significance). However, the low serum plasminogen (PLG) activity proved the pathogenicity of c.1112C>T. Hence, the patient was diagnosed with concurrent Cbl C and PLG deficiencies. Segregation analysis revealed that the mother and father had the same heterozygous PLG and MMACHC variants. PLG variants have generally been described in aHUS patients concomitant with complement gene variants in the literature; therefore, the association between aHUS and PLG variants is controversial. The possible contribution of PLG deficiency to thrombotic microangiopathy was also discussed in this case. CONCLUSION: Non-complement-mediated aHUS is an exceptional disorder. A limited number of genes are involved in this entity. To our knowledge, this is the first aHUS patient diagnosed with both Cbl C and PLG deficiencies in the literature.

Thromboembolic complications after COVID-19 in kidney transplant recipients.

AIM: Increased venous thrombosis and arterial embolism rates are observed in the general population during or after COVID-19. Data regarding the kidney transplant population are scarce. In this study, we aim to investigate the thrombotic complications and risk factors associated with thrombotic complications in kidney transplant patients. METHODS: This retrospective observational study included adult kidney transplant recipients diagnosed with COVID-19 between March 2020 and June 2022. The endpoint was the occurrence of thromboembolic events. RESULTS: Four hundred and sixty-nine patients were followed for a median of 10.8 months after COVID-19. Forty patients (8.5%) died. Thromboembolic complications developed in 51 (11.9%) of the surviving patients. Twenty-four patients with thromboembolic events were receiving prophylactic anticoagulation before the event. The patients with mild, moderate, and severe COVID-19 were 292, 129, and 48, respectively. Patients with moderate COVID-19 had a significantly higher percentage of thromboembolic complications than patients with mild COVID-19. Older age, prior heart disease, and moderate COVID-19 were significantly associated with thromboembolic events. The incidence of thromboembolic events after COVID-19 is 10.9 per 100 patient-year. CONCLUSION: Thromboembolic complications were observed at increased rates in kidney transplant recipients after COVID-19. Therefore, prospective and cohort studies for post-COVID-19 complications regarding the treatment modalities are urgently needed.

Long-term Effects of Gastric Acid Prophylaxis in Kidney Transplant Recipients.

Objectives: Prophylactic acid suppression with proton pump inhibitors or H2 receptor antagonists is often administered after kidney transplantation. The Association of proton pump inhibitors or H2 receptor antagonists with acute rejection, hypomagnesemia, and graft loss in kidney transplant recipients is not well established. Material and Methods: We performed a retrospective cohort study of 302 kidney transplant recipients at one center (57% male; mean age 35.5±11.2 years) with more than 6 months post-transplant follow-up. Recipients were grouped according to gastric acid prophylaxis: only proton pump inhibitors (n=179), only H2 receptor antagonists (n=42), proton pump inhibitors and H2 receptor antagonists (n=55), and nonusers (n=26). The primary outcome was biopsy-proven acute rejection. Graft loss and hypomagnesemia were defined as secondary outcomes. Results: Nonusers were younger and mostly under steroid-free immunosuppression compared to other study groups (p=0.030 and p=0.009, respectively). The primary outcome was similar across study groups (p=0.266). Kaplan-Meier analyses also demonstrated similar 10-year graft survival rates: 95.5% for proton pump inhibitors, 97.6% for H2 receptor antagonists, 100% for proton pump inhibitors/H2 receptor antagonists, and 96.2% for nonusers (p=0.275). Conclusions: The use of proton pump inhibitors is not associated with acute rejection or graft loss but may cause mild hypomagnesemia in kidney transplant recipients.

Diagnostic yield and safety of percutaneous native kidney biopsy in pregnancy: 20-years of single-center experience.

BACKGROUND: Percutaneous kidney biopsy is a fundamental procedure in nephrology. Although pregnancy is not a contraindication, a careful risk-benefit assessment is mandatory in pregnancy. We aimed to evaluate safety and diagnostic accuracy of percutaneous kidney biopsy in pregnancy in a single-center retrospective study. METHODS: Percutaneous kidney biopsy was performed in 19 pregnant patients. Demographics, estimated glomerular filtration rates, serum albumin levels, and proteinuria levels at the time of biopsy were evaluated. Biopsy-related complications, diagnoses, and treatments during the follow-up were analyzed. In addition, delivery success, preeclampsia, early delivery, low birth weight rates, and long-term outcomes of the patients were retrieved and analyzed. RESULTS: Mean patient age was 27 (range 16-41) years. Median gestational week at kidney biopsy was 20th. All but one biopsies were diagnostic. Median gestational week of delivery was 35 (range 23-39) gestational weeks. Preterm delivery (< 37 gestational weeks) and low birth weight (< 2500 mg) occurred in 73.7% and 52.6% of cases, respectively. Median weight at birth was 2500 mg. The incidence of preeclampsia was 57.9%. Overall 89.5% of the children survived. Median post-biopsy follow-up was 64 months. Maternal mortality was not observed during the follow-up period. End stage kidney disease developed in one patient. The results of percutaneous kidney biopsy led to therapeutic decisions in 73.7% of cases. CONCLUSIONS: Although percutaneous kidney biopsy is not frequently performed during pregnancy, it is relatively safe and usually diagnostic, and may guide further follow-up.

Baseline inflammation indexes and neutrophil-to-LDH ratio for prediction of the first mobilization failure without plerixafor-based regimens in multiple myeloma and lymphoma patients: A single-center retrospective study.

BACKGROUND: Many factors were identified for mobilization failure (MF) in autologous hematopoietic stem-cell transplantation. To our knowledge, this is the first study to investigate the efficacy of baseline inflammation indexes and neutrophil-to-lactate dehydrogenase (LDH) ratio to predict MF in multiple myeloma (MM) and lymphoma. METHODS: A total of 240 patients with lymphoma or MM hospitalized between January 2014 and June 2022 for the first stem cell mobilization were included in this retrospective single-center study. We evaluated the impact of baseline demographic, clinical, and laboratory data (before granulocyte colony-stimulating factor and chemotherapy implementation), including neutrophil, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio, monocyte-to-lymphocyte ratio, systemic immune-inflammation index (SII), systemic inflammatory response index (SIRI), neutrophil-to-C-reactive protein, and neutrophil-to-LDH ratios on MF. RESULTS: A total of 240 patients were divided into successful (214 patients, 89.16%) and poor mobilizers (26 patients, 10.84%). Poor mobilizers had lower neutrophil, NLR, SII, and neutrophil-to-LDH ratios (P values were .001, .022, .001, and .001, respectively). Among these markers, only the neutrophil-to-LDH ratio was statistically low in both poor mobilizer MM and lymphoma patients. Receiving operator characteristic curve analysis was performed to evaluate neutrophil, SII, and neutrophil-to-LDH ratios for MF. Neutrophil-to-LDH ratio had the highest specificity (93.93%, for ≤9.904 cut-off) compared to the other two variables. Multivariate logistic regression analysis showed that neutrophil-to-LDH ratio ≤ 9.904 (cut-off) (odds ratio: 7.116, P = .001), neutrophil counts ≤3300/mm3 (cut-off) (odds ratio: 3.248, P = .021), and lymphoma diagnosis (odds ratio: 2.674, P = .039) were independent risks for MF. CONCLUSION: The neutrophil-to-LDH ratio could be a novel marker in lymphoma and MM patients to predict the first MF. New studies should be conducted for the optimization of this index.

Temporary hypothyroidism in severe crush syndrome: a potential novel entity.

BACKGROUND: Thyroid hormone synthesis is a complex process in the human body. Although the thyroid gland is essential for thyroid hormone synthesis, skeletal muscles also have crucial roles in thyroid hormone metabolism due to the deiodinase activities of the muscle cells. Hypothyroidism-related myopathy is a well-known entity. However, systemic effects of acute myopathies, such as rhabdomyolysis, on thyroid hormone metabolism have not to date been fully clarified. METHODS: Fifty-three earthquake victims were evaluated retrospectively. We investigated the thyroid function tests (TFTs) among patients with creatine kinase (CK) levels higher than 10.000 U/L at admission. Fifteen patients had CK levels higher than 10.000 U/L and 12 of them had data of TFTs, including thyroid stimulating hormone (TSH), free T4 (FT4), and free T3 (FT3) during hospitalization. These patients were evaluated. RESULTS: TSH levels were increased in all seven patients who required HD due to severe crush syndrome. Decreased FT4 levels were detected in 71.4% of them. None of the five non-HD patients had increased TSH levels or reduced FT4 levels. During follow-up, all patients survived. Renal and thyroid functions were normalized during follow-up without thyroxin replacement in patients with no prior history of hypothyroidism. Moreover, TFTs were normalized in two patients with history of hypothyroidism under thyroxine treatment without dose adjustments. CONCLUSIONS: In severe forms of crush syndrome, temporary hypothyroidism might be seen. The exact mechanism underlying this entity is not well-known. Further clinical and experimental trials should be conducted to illuminate the mechanism of disrupted thyroid hormonogenesis in crush syndrome victims.

Outcomes of kidney transplantation in patients with congenital anomalies of the kidney and urinary tract: a propensity-score-matched analysis with case-control design.

BACKGROUND: We compared long-term outcomes after kidney transplantation (KTx) in patients with and without congenital anomalies of the kidney and urinary tract (CAKUT). METHODS: KTx recipients (KTRs) with CAKUT in 1980-2016 were identified; their hard copy and electronic medical records were reviewed and compared to a propensity-score-matched control group (non-CAKUT) from the same period. The primary outcomes were graft loss or death with a functioning graft; secondary outcomes included posttransplant urinary tract infections (UTIs) and biopsy-proven rejection (BPR). RESULTS: : We identified 169 KTRs with CAKUT and 169 matched controls. Median follow-up was 132 (IQR: 75.0-170.0) months. UTIs were more common in CAKUT patients compared to non-CAKUT group (20.7% vs 10.7%; p = 0.01). Rates of BPR were similar between the two groups. In Kaplan-Meier analysis, 10-year graft survival rates were significantly higher in the CAKUT group than in the non-CAKUT group (87.6% vs 69.2%; p < 0.001), while patient survival rates were similar. In multivariate Cox regression analyses, CAKUT (HR: 0.469; 95% CI: 0.320-0.687; p < 0.001) and PRA positivity before transplantation (HR: 3.756; 95% CI: 1.507-9.364; p = 0.005) predicted graft loss. DISCUSSION: Graft survival in KTRs with CAKUT appears superior to KTRs without CAKUT. Transplant centers should develop multidisciplinary educational and social working groups to support and encourage CAKUT patients with kidney failure to seek for transplants.

Efficacy and Safety of Sofosbuvir and Ledipasvir for Hepatitis C in Kidney Transplant Recipients: A Single-center Retrospective Observational Study

Background: Treatment using direct-acting antivirals provides high rates of sustained virologic response and a favorable safety profile for patients with chronic hepatitis C virus infection. However, data on the efficacy of direct-acting antivirals in kidney transplant recipients are still limited. Aims: To evaluate the safety and efficacy of fixed-dose sofosbuvir/ledipasvir combination in kidney transplant recipients. Study Design: Retrospective, observational, single-center study. Methods: Data of 29 kidney transplant recipients who received a fixed-dose safety and efficacy of fixed-dose sofosbuvir/ledipasvir combination for 12 or 24 weeks with or without ribavirin were analyzed. The primary outcome was SVR12, which was defined as undetectable HCV-RNA levels 12 weeks after the treatment. Secondary outcomes were graft function, proteinuria, and calcineurin inhibitor trough level variability. Results: The predominant hepatitis C virus genotype was 1b (n = 19, 65.6%). All patients achieved SVR12. No graft failures nor deaths were reported during the study period. Throughout and after the treatment, the levels of aspartate aminotransferase [21 (range: 18-29.5) to 16 (range: 14-20) U/l, p < 0.001] and alanine aminotransferase [22 (range: 15-34) to 14 (range: 12-17.5) U/l, p < 0.001] improved significantly, unlike bilirubin, hemoglobin, and platelet levels. Renal function remained stable. Dose adjustments for calcineurin inhibitors were required. Serious adverse events were not observed. Conclusion: Safety and efficacy of fixed-dose sofosbuvir/ledipasvir combination was effective and safe in kidney transplant recipients with hepatitis C virus. However, cautious monitoring of trough levels of calcineurin inhibitorss is needed due to potential drug-drug interactions during the treatment episode.

Propensity score-matched analysis of long-term outcomes for living kidney donation in alternative complement pathway diseases: a pilot study.

BACKGROUND: Atypical hemolytic syndrome (aHUS) and C3 glomerulopathy (C3G) are complement-mediated rare diseases with excessive activation of the alternative pathway. Data to guide the evaluation of living-donor candidates for aHUS and C3G are very limited. The outcomes of living donors to recipients with aHUS and C3G (Complement disease-living donor group) were compared with a control group to improve our understanding of the clinical course and outcomes of living donation in this context. METHODS: Complement disease-living donor group [n = 28; aHUS(53.6%), C3G(46.4%)] and propensity score-matched control-living donor group (n = 28) were retrospectively identified from 4 centers (2003-2021) and followed for major cardiac events (MACE), de novo hypertension, thrombotic microangiopathy (TMA), cancer, death, estimated glomerular filtration rate (eGFR) and proteinuria after donation. RESULTS: None of the donors for recipients with complement-related kidney diseases experienced MACE or TMA whereas two donors in the control group developed MACE (7.1%) after 8 (IQR, 2.6-12.8) years (p = 0.15). New-onset hypertension was similar between complement disease and control donor groups (21.4% vs 25%, respectively, p = 0.75). There were no differences between study groups regarding last eGFR and proteinuria levels (p = 0.11 and p = 0.70, respectively). One related donor for a recipient with complement-related kidney disease developed gastric cancer and another related donor developed a brain tumor and died in the 4th year after donation (2, 7.1% vs none, p = 0.15). No recipient had donor-specific human leukocyte antigen antibodies at the time of transplantation. Median follow-up period of transplant recipients was 5 years (IQR, 3-7). Eleven (39.3%) recipients [aHUS (n = 3) and C3G (n = 8)] lost their allografts during the follow-up period. Causes of allograft loss were chronic antibody-mediated rejection in 6 recipients and recurrence of C3G in 5. Last serum creatinine and last eGFR of the remaining patients on follow up were 1.03 ± 038 mg/dL and 73.2 ± 19.9 m/min/1.73 m2 for aHUS patients and 1.30 ± 0.23 mg/dL and 56.4 ± 5.5 m/min/1.73 m2 for C3G patients. CONCLUSION: The present study highlights the importance and complexity of living related-donor kidney transplant for patients with complement-related kidney disorders and motivates the need for further research to determine the optimal risk-assessment for living donor candidates to recipients with aHUS and C3G.

Spatial Distribution of Macrophage Subtypes Among Rejection Subtypes in Renal Transplant Biopsies by Dual Immunohistochemistry.

We performed dual immunohistochemistry for CD163/CD34 and CD68/CD34 in 108 renal transplant indication biopsies to investigate the presence and distribution of macrophages in various renal compartments. All Banff scores and diagnoses were revised according to the Banff 2019 classification. CD163 and CD68 positive cell counts (CD163pos and CD68pos) were evaluated in the interstitium, glomerular mesangium, and, within glomerular and peritubular capillaries. The diagnosis was antibody-mediated rejection (ABMR) in 38 (35.2%), T-cell mediated rejection (TCMR) in 24 (22.2%), mixed rejection in 30 (27.8%), and no rejection in 16 (14.8%). Banff lesion scores t , i , and ti were correlated with both CD163 and CD68 interstitial inflammation scores ( r > 0.30; P < 0.05). Glomerular total CD163pos was correlated to Banff lesion scores g and cg ( r > 0.30; P < 0.05). Glomerular total, mesangial, and intracapillary CD68pos were correlated with g ( r > 0.30; P < 0.05). Both glomerular total and peritubular capillary CD68pos were correlated with peritubular capillaritis ( r > 0.30; P < 0.05). Glomerular CD163pos were significantly higher in ABMR compared with no rejection, in mixed rejection compared with no rejection and TCMR. CD163pos in peritubular capillaries was significantly higher in mixed rejection compared with no rejection. Glomerular CD68pos was significantly higher in ABMR compared with no rejection. CD68pos per peritubular capillary was higher in mixed rejection, ABMR, and TCMR compared with no rejection. In conclusion, compared with CD68 positive macrophages, localization of CD163 positive macrophages in various renal compartments seems to be different among rejection subtypes and their glomerular infiltration seems to be more specific for the presence of ABMR component.

A comparison of methods of plasmapheresis for the treatment of late antibody mediated rejection in kidney transplant recipients.

INTRODUCTION: We compared the outcomes associated with plasma exchange (PE), double filtration plasmapheresis (DFPP), or immunoadsorption (IA) in the treatment of late antibody mediated rejection (AMR). METHODS: Sixty-nine kidney transplantation (KTx) recipients with late AMR were retrospectively categorized according to management with PE (n = 30), DFPP (n = 22) or IA (n = 17). Allograft loss was compared across treatment groups by Kaplan-Meier analysis and Cox regression. RESULTS: Study groups were similar regarding age, sex, donor type, kidney function, donor specific antibodies, and post-KTx follow-up time. Five-year graft survival trended higher with IA (70.6%) compared to PE (36.7%) and DFPP (27.3%) (p = 0.06). In multivariate Cox regression, baseline eGFR (HR per ml/min/1.73 m2 [95% CI]; 0.96 [0.94-0.99]), rituximab use (HR [95% CI]; 0.42 [0.21-0.84]), interstitial inflammation (i) (HR [95% CI]; 2.05 [1.13-3.69]), and transplant glomerulopathy (cg) (HR [95% CI]; 1.46 [1.13-1.87]) were associated with graft loss. CONCLUSION: These results motivate the need for continued assessment of rituximab and plasmapheresis in larger studies.