Anti-glutathione S-transferase T1 antibody-mediated rejection in C4d-positive renal allograft recipients.

BACKGROUND: Chronic humoral rejection is a progressive form of graft injury, with defined diagnostic criteria, the crucial one being the evidence of circulating anti-donor antibodies. These antibodies are mainly directed against human leucocyte antigens (HLA), but other targets have also been described. We previously reported that antibodies against the Glutathione S-transferase T1 (GSTT1) enzyme appear in recipients without the GSTT1 gene who receive a graft from a GSTT1-positive donor. The primary aim of this study was to analyse the role of GSTT1 in cases of antibody-mediated rejection (AMR) in the absence of anti-HLA antibodies. A second objective was to describe the distribution of the GSTT1 enzyme in the human kidney. METHODS: Four renal biopsies from four renal transplanted patients with declined renal function and circulating anti-donor GSTT1 antibodies were studied for C4d deposits in sections of paraffin-embedded tissue samples. Anti-donor-specific HLA and MICA antibody detection was done with the Luminex platform and anti-GSTT1 antibodies were tested by indirect immunofluorescence on rat tissues and ELISA assay. DNA of the patients was extracted for GSTT1 genotyping. RESULTS: Four patients with the GSTT1 donor/recipient mismatch developed anti-GSTT1 antibodies 32, 42, 48 and 60 months after the transplant. One patient also had donor-specific anti-HLA antibodies. Their biopsies showed pathologic lesions compatible with chronic antibody-mediated rejection (CAMR), along with positive C4d deposition in peritubular capillaries in three of them, being no valuable in the other case. CONCLUSION: This is the first study reporting an association between the appearance of chronic antibody-mediated renal allograft rejection and the occurrence of de novo production of anti-GSTT1 antibodies, in the absence of anti-HLA donor-specific antibodies. This fact suggests a potential role of the GSTT1 system in anti-graft immune response.

Disseminate and fatal cytomegalovirus disease with thymitis in a naive HIV-patient after early initiation of HAART: immune restoration disease?

We describe a naive HIV-infected patient who developed a Pneumocystis carinii pneumonia and disseminate and fatal cytomegalovirus disease within 3 months after initiation of HAART, suggesting due to coincidence in time, an immune restoration disease. We propose an alternative hypothesis.

Bone involvement and abcess formation by neutrophil-rich CD30+ anaplastic large-cell lymphoma mimicking skeletal infection in an AIDS patient.

Neutrophil-rich CD30+ anaplastic large-cell lymphoma (ALCL) is a rare pathological entity without distinct clinical behavior. Twelve cases of neutrophil-rich CD30+ anaplastic large-cell lymphoma (ALCL) have been reported, three of them were HIV-infected patients. All these reports stressed the presence of neutrophil infiltration as a new morphologic feature of CD30+ ALCL. Only one case of cutaneous involvement presented with microabscess formation. We describe a case of neutrophil-rich CD30+ ALCL in an AIDS patient with a clinical picture determined by the massive neutrophil infiltration of the tumor without necrosis nor local infection, but with the formation of abscesses.

Donor-specific antibodies against HLA, MICA, and GSTT1 in patients with allograft rejection and C4d deposition in renal biopsies.

BACKGROUND: Production of antibodies against donor-specific antigens is one of the central mechanisms of allograft rejection. This antibody-mediated rejection (AMR) is evidenced by the presence of circulating donor-specific antibodies and deposition of complement component C4d on renal endothelium. Although anti-human leukocyte antigen (HLA) antibodies account for a high proportion of AMR, in many cases anti-HLA antibodies cannot be demonstrated. In liver transplant, antibodies against glutathione-S-transferase T1 (GSTT1) expressed on the graft may induce an antibody response leading to a severe graft dysfunction. In addition, presence of antibodies against major-histocompatibility-complex class I chain-related gene A (MICA) has been associated with a poor graft survival in kidney transplantation. METHODS: Pre- and posttransplantation sera from 19 patients fulfilling the criteria for AMR including C4d deposition in renal biopsies were included. Donor-specific antibodies against HLA-I and -II and MICA were studied using Luminex. Anti-GSTT1 antibodies were analyzed by indirect immunofluorescence and by an ELISA method. A control group of 39 patients with graft dysfunction negative for C4d was also included. RESULTS: At the time of the biopsy, 4 (21%) patients had only anti-HLA class I antibodies; 3 (15.8%) had anti-GSTT1, 2 (10.5%) had anti-HLA-class II, and 2 (10.5%) had anti-MICA; four patients had combination of antibodies: HLA-I + MICA (n=1), HLA-I + GSTT1 (n=2), and GSTT1+MICA (n=1). No antibodies were found in 4 (21%) patients. In total, 6 (31.6%) C4d+ patients had anti-GSTT1 antibodies, whereas, among the 39 C4d-negative patients, only 3 (7.7%) had anti-GSTT1 antibodies (P=0.027). CONCLUSION: Besides anti-HLA antibodies, donor-specific antibodies against MICA and GSTT1 antigens could be responsible for the occurrence of antibody-mediated kidney graft rejection.

[Nephrotic syndrome in scleroderma]. / Síndrome nefrótico en esclerodermia.

The renal affectation is infrequent in scleroderma, unlike other collagen diseases. The appearance of nephrotic syndrome has been related to the drug use, specially the D-penicilamine, or rarely as a manifestation of secondary amilodosis, quite infrequent in scleroderma. We report a case of nephrotic syndrome in a patient with systemic scleroderma, produced by a membranous glomerulonephritis, exceptionally described in literature.