The diagnostic criteria for antibody-mediated rejection (AMR) are continuously evolving. Here we investigated the clinical and molecular significance of different Banff microvascular inflammation ...(MVI) scores in transplant kidney biopsies. A total of 356 patients with clinically indicated kidney transplant biopsies were classified into three groups based on MVI scores of 0, 1, 2, or more for Groups 1–3, respectively. Gene expression profiles were assessed using arrays on a representative subset of 93 patients. The incidence of donor-specific anti-HLA antibodies was increased from 25% in Group 1 to 36% in Group 2 and to 54% in Group 3. Acute and chronic AMR were significantly more frequent in Group 3 (15% and 35%) compared with the Group 2 (3% and 15%) and Group 1 (0% and 5%), respectively. Gene expression profiles showed increased interferon-γ and rejection-induced, cytotoxic and regulatory T-cell, natural killer cell–associated and donor-specific antibody (DSA)–selective transcripts in Group 3 compared with Groups 1 and 2. There was no significant difference in gene expression profiles between the Groups 1 and 2. Increased intragraft expression of DSA–selective transcripts was found in the biopsies of C4d− Group 3 patients. Thus, an MVI score of 2 or more was significantly associated with a histological diagnosis of acute and chronic antibody-mediated rejection. Hence, increased intragraft DSA–selective gene transcripts may be used as molecular markers for AMR, especially in C4d− biopsies.
This study investigated the mechanisms involved in development of donor-specific antibody (DSA) and/or C4d-negative transplant glomerulopathy (TGP) by allograft gene expression profiles using ...microarrays.
This cohort study was conducted in kidney transplant recipients. Patients were eligible for inclusion if they required a clinically indicated biopsy at any time point after their transplant. They were then classified according to their histopathology findings and DSA and C4d results. Eighteen chronic antibody-mediated rejection (CAMR), 14 DSA+/C4d- TGP, 25 DSA-/C4d- TGP, and 47 nonspecific interstitial fibrosis/tubular atrophy (IFTA) biopsy specimens were identified. In a subset of patients from the study population, biopsy specimens in each group and normal transplant kidney specimens were analyzed with Affymetrix Human Gene 1.0 ST Arrays.
The mean sum score of glomerulitis and peritubular capillaritis increased from 0.28±0.78 in IFTA specimens to 0.75±0.85 in DSA-/C4d- TGP specimens, 1.71±1.49 in DSA+/C4d-/TGP specimens, and 2.11±1.74 in CAMR specimens (P<0.001). During a median follow-up time of 2 (interquartile range, 1.4-2.8) years after biopsy, graft loss was highest in CAMR specimens (27.8%) compared to IFTA specimens (8.5%), DSA+/C4d- TGP specimens (14.3%), and DSA-/C4d- TGP specimens (16%) (P=0.01). With use of microarrays, comparison of the gene expression profiles of DSA-/C4d- TGP specimens with glomerulitis + peritubular capillaritis scores > 0 to normal and IFTA biopsy specimens revealed higher expression of quantitative cytotoxic T cell-associated transcripts (QCAT). However, both CAMR and DSA+/C4d- TGP specimens had higher expression of not only QCAT but also IFN-γ and rejection-induced, constitutive macrophage-associated, natural killer cell-associated, and DSA-selective transcripts. Endothelial cell-associated transcript expression was upregulated only in CAMR biopsy specimens.
These results suggested that DSA+/C4d- TGP biopsy specimens may be classified as CAMR. In contrast, DSA-/C4d- TGP specimens showed increased cytotoxic T cell-associated transcripts, suggesting T cell activation as a mechanism of injury.
COVID-19 in Patients with Kidney Disease Ajaimy, Maria; Melamed, Michal L
Clinical journal of the American Society of Nephrology,
08/2020, Letnik:
15, Številka:
8
Journal Article
Kidney allocation system allows blood type B candidates accept kidneys from A2/A2B donors. There is no mandate by UNOS on which the anti-A2 level is acceptable. We aimed to investigate the safety of ...kidney transplant in blood group B patients with anti-A2 titers ≤16.
We performed 41 A2-incompatible kidney transplants in blood group B recipients between May 2015 and September 2019. Clinical outcomes were compared with a control group of 75 blood group B recipients who received blood group compatible kidney transplantation at the same period.
Of the 41 recipients, 85% were male, 48% African American, with a median age of 53 (20-73) y. Thirty-eight (93%) were deceased-donor and 3 (7%) were living-donor kidney transplant recipients. Pretransplant anti-A2 IgG titers were 2 in 16, 4 in 9, 8 in 6, and 16 in 5 and too weak to titer in 5 recipients. Eight patients had pretransplant donor-specific antibodies. During a median follow-up of 32.6 mo (6-57.3) patient and graft survival were 100% and 92% in the A2-incompatible kidney transplant group, and 91% and 92% in the blood group compatible group, respectively. Twelve A2-incompatible recipients underwent a 21 clinically indicated kidney biopsies at a median 28 d (6-390) after transplantation. None of the patients developed acute antibody-mediated rejection and 2 patients (5%) had acute T-cell-mediated rejection. Interestingly, peritubular capillary C4d positivity was seen in 7 biopsies which did not have any findings of acute rejection or microvascular inflammation but not in any of the rejection-free biopsies in the control group. C4d positivity was persistent in 5 of those patients who had follow-up biopsies.
A2-incompatible transplantation is safe in patients with anti-A2 titers ≤16 with excellent short-term kidney allograft outcomes. C4d positivity is frequent in allograft biopsies without acute rejection.
Covid-19 and Kidney Transplantation Akalin, Enver; Azzi, Yorg; Bartash, Rachel ...
The New England journal of medicine,
06/2020, Letnik:
382, Številka:
25
Journal Article
Recenzirano
Odprti dostop
A cohort of 36 consecutive kidney-transplant recipients had less fever, lower CD3, CD4, and CD8 cell counts, more rapid clinical deterioration, and a higher mortality than the general population of ...patients with Covid-19.
We investigated the prevalence and clinical outcomes of COVID-19 in recipients of kidney transplants in the Bronx, New York, one of the epicenters of the pandemic. Between March 16 and June 2, 2020, ...132 kidney transplant recipients tested positive by SARS-CoV-2 RT-PCR. From May 3 to July 29, 2020, 912 kidney transplant recipients were screened for SARS-CoV-2 IgG antibodies during routine clinic visits, of which 16.6% tested positive. Fifty-five of the 152 patients had previously tested positive by RT-PCR, while the remaining 97 did not have significant symptoms and had not been previously tested by RT-PCR. The prevalence of SARS-CoV-2 infection was 23.4% in the 975 patients tested by either RT-PCR or SARS-CoV-2 IgG. Older patients and patients with higher serum creatinine levels were more likely diagnosed by RT-PCR compared to SARS-CoV-2 IgG. Sixty-nine RT-PCR positive patients were screened for SARS-CoV-2 IgG antibodies at a median of 44 days post-diagnosis (Inter Quartile Range 31-58) and 80% were positive. Overall mortality was 20.5% but significantly higher (37.8%) in the patients who required hospitalization. Twenty-three percent of the hospitalized patients required kidney replacement therapy and 6.3% lost their allografts. In multivariable analysis, older age, receipt of deceased-donor transplantation, lack of influenza vaccination in the previous year and higher serum interleukine-6 levels were associated with mortality. Thus, 42% of patients with a kidney transplant and with COVID-19 were diagnosed on antibody testing without significant clinical symptoms; 80% of patients with positive RT-PCR developed SARS-CoV-2 IgG and mortality was high among patients requiring hospitalization.
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BACKGROUNDWith the development of all oral, interferon-free directly acting antiviral (DAA) medications, treatment of hepatitis C virus (HCV) infection in renal transplant recipients is possible, but ...limited data exists on its safety and efficacy.
METHODSWe performed a retrospective cohort analysis of patients transplanted at our center with HCV who have been started on DAAs. Primary endpoints included sustained virologic response as defined as negative viral load at 12 weeks postcompletion of therapy and allograft function.
RESULTSA total of 31 patients met inclusion criteria. The most commonly used regimen was sofosbuvir and ledipasvir (n = 21). Of the treated patients, 100% had undetectable viral load at the completion of therapy. Of the 31 patients treated, 30 (97%) achieved sustained virologic response. Both graft and patient survivals at most recent follow-up was 100%. There was no significant change in glomerular filtration rate (GFR) before or after therapy (64.2 ± 16.5 mL/min per body surface area before vs. 58.9 ± 17.5 mL/min per body surface area after therapy; P = 0.22); however, 3 patients now have GFR less than 20. A total of 6 (19.3%) of 31 patients had worsening proteinuria during or shortly after therapy. Patients with more than 500 mg/g of proteinuria at the start of treatment were significantly more likely to develop worsening proteinuria than those with less than 500 mg/g of proteinuria at the start of therapy (P < 0.001). Retrospective review of 20 untreated HCV patients did not demonstrate worsening allograft function and proteinuria during a median follow-up time of 1386 days (range, 332–6254).
CONCLUSIONSOur preliminary data demonstrate that DAAs can be used safely and effectively in patients after kidney transplantation. Patients with proteinuria or lower GFR should be monitored more closely.