Analysis of immune reconstitution after autologous bone marrow transplantation in systemic sclerosis

OBJECTIVE: To analyze hematopoietic and immune reconstitution after autologous hematopoietic stem cell transplantation (HSCT) in 7 patients with systemic sclerosis (SSc). METHODS: Two groups of patients were retrospectively constituted according to whether they had a favorable clinical response (group A; n = 4) or no response or a relapse of disease (group B; n = 3) after HSCT. Immune reconstitution was analyzed every 3 months using lymphocyte immunophenotyping, alpha/beta T cell receptor (TCR) diversity analysis, and ex vivo thymic function analysis by quantification of TCR rearrangement excision circles (TRECs). RESULTS: Patients had similar characteristics at study entry, except for a lower modified Rodnan skin thickness score (P = 0.03) and a lower Health Assessment Questionnaire score (P = 0.05) in group A than in group B. The number of reinjected cells and the time to hematopoietic reconstitution were similar in both groups. The absolute numbers of CD19+ and CD20+ B cells were lower in group A than in normal controls (P < 0.05) and within the normal range in group B. Absolute numbers of T and natural killer lymphocytes were normal before HSCT. Numbers of CD3+ cells remained low thereafter. Numbers of CD8+ cells were back to normal 3 months after HSCT in both groups. B cell counts were low until 6 months after HSCT in group A and stayed in the normal range in group B. The CD3+ defect was sustained in group A, with an opposite trend and a faster CD4+ reconstitution profile in group B. The T cell repertoire was skewed before and until 1 year after HSCT, with shared expansions before and after transplant in a given individual. TREC values correlated negatively with C-reactive protein levels (r(s) = -0.41, P = 0.001) and positively with CD19+ (r(s) = 0.35, P = 0.001) and CD20+ (r(s) = 0.34, P = 0.002) lymphocyte counts. CONCLUSION: B and T lymphocyte populations remained disturbed for at least 1 year after HSCT in SSc patients, which may reflect the persistence of an underlying disease mechanism.     

Quadritherapy vs standard tritherapy immunosuppressant regimen after heart transplantation: A propensity score–matched cohort analysis

After heart transplant, adding everolimus (EVL) to standard immunosuppressive regimen mostly relies on converting calcineurin inhibitors (CNIs) into EVL. The aim of this study was to describe the effects of combining low‐dose EVL and CNIs in maintenance immunosuppression regimen (quadritherapy) and compare it with standard tritherapy associating standard‐dose CNIs, mycophenolate mofetil, and corticosteroids. In the 3‐year registry cohort of heart transplanted patients, those who received quadritherapy were compared with those who received tritherapy. EVL was added after 3 months posttransplant. Three analyses were performed to control for confounders: propensity score matching, multivariable survival, and inverse probability score weighting analyses. Among 213 patients who were included (75 with quadritherapy), propensity score matching selected 64 unique pairs of patients with similar characteristics. In the matched cohort (n = 128), quadritherapy was associated with fewer deaths (3 [4.7%] vs 17 [21.9%], P = .007) and biopsy‐proven acute rejections (15 [23.4%] vs 31 [48.4%], P = .002). These results were confirmed in the overall cohort (n = 213), after multivariable and inverse probability score weighting analyses. Renal function and donor‐specific HLA‐antibodies remained similar in both groups. Low‐dose combination quadritherapy was associated with fewer deaths and rejections, compared with standard immunosuppression tritherapy.     

Influence of bone marrow graft lymphocyte subsets on outcome after HLA-identical sibling transplants.

OBJECTIVE: The aim of this study was to analyze bone marrow lymphocyte subsets and CD34 cell dose and their influence on the outcomes of bone marrow transplantation. MATERIALS AND METHODS: Forty-eight patients (median age 30 years, range 5-54) receiving HLA-identical sibling bone marrow transplantation for hematologic malignancies were analyzed. RESULTS: Median number (range) of nucleated cells and CD34+ cells infused were 2.4 (0.4-6.0) x 10(8)/kg and 3.5 (0.5-13.0) x 10(6)/kg, respectively. Probability of neutrophil recovery was 97%. In a multivariate analysis, time to neutrophil recovery was shortened when a higher number of CD3/CD8 cells was infused (> or =1.0 x 10(7)/kg) (hazard ratio [HR] = 2.13, p = 0.018); when the patient was female or had negative cytomegalovirus serology (HR = 2.03, p = 0.03; HR = 0.41, p = 0.009; respectively). The incidence of grade II to IV acute graft-vs-host disease (GVHD) was 47%. Infusion of >1 x 10(7) CD4 infused/kg increased the risk of acute GVHD (HR = 2.86, p = 0.03). Nineteen of 40 patients at risk experienced chronic GVHD, the risk of which was increased by diagnosis of chronic leukemia (p = 0.03), <2.0 x 10(8) nucleated cells infused/kg (p = 0.05), and a low number of all lymphocyte subsets, except CD19. Estimated 3-year survival rate was 54%. Risk of death was increased in patients receiving <3.5 x 10(6)CD34 infused/kg (HR = 0.37, p = 0.02). Only six patients relapsed. CONCLUSIONS: A high cell dose of CD3/CD8 is associated with faster neutrophil recovery, whereas a high cell dose of CD4+ cells increases the incidence of acute GVHD. A high number of nucleated cells and CD34+ cells infused was associated with decreased risk of chronic GVHD and improved survival, respectively.     

Face transplantation: A longitudinal histological study focusing on chronic active and mucosal rejection in a series with long-term follow-up

The 2007 Banff working classification of skin-containing Tissue Allograft Pathology addressed only acute T cell–mediated rejection in skin. We report the longitudinal long-term histological follow-up of six face transplant recipients, focusing on chronic and mucosal rejection. We identified three patterns suggestive of chronic rejection (lichen planus-like, vitiligo-like and scleroderma-like). Four patients presented lichen planus-like and vitiligo-like chronic rejection at 52 ± 17 months posttransplant with severe concomitant acute T cell–mediated rejection. After lichen planus-like rejection, two patients developed scleroderma-like alterations. Graft vasculopathy with C4d deposits and de novo DSA led to subsequent graft loss in one patient. Chronic active rejection was frequent and similar patterns were noted in mucosae. Concordance between 124 paired skin and mucosal biopsies acute rejection grades was low (κ = 0.2, p = .005) but most grade 0/I mucosal rejections were associated with grade 0/I skin rejections. We defined discordant (grade≥II mucosal rejection and grade 0/I skin rejection) (n = 55 [70%]) and concordant (grade≥II rejection in both biopsies) groups. Mucosal biopsies of the discordant group displayed lower intra-epithelial GranzymeB/FoxP3 ratios suggesting a less aggressive phenotype (p = .08). The grading system for acute rejection in mucosa may require phenotyping. Whether discordant infiltrates reflect a latent allo-immune reaction leading to chronic rejection remains an open question.     

Long-term immune deficiency after allogeneic stem cell transplantation: B-cell deficiency is associated with late infections

Immune reconstitution was analyzed in 140 consecutive patients who were 2-year disease-free and who underwent myeloablative allogeneic transplantation. A CD4 and CD8 defect was observed involving naive, terminally differentiated, memory and competent cells and above limits values for activated subsets. Natural killer cells normalize at six months while we observed expansion of CD19⁺/CD5⁺ B cells after three months and a persisting defect of memory B cells. Chronic graft-versus-host disease did not influence significantly those parameters for CD8 subsets while the naïve and competent CD4 subsets were strongly affected. But the most profound impact of chronic graft-versus-host disease was on B-cell subsets, especially on the memory B population. The cumulative incidence of late severe infections was low (14% at four years). Using Cox’s models, only low B-cell counts at 12 (P=0.02) and 24 (P=0.001) months were associated with the hazard of developing late infection, in particular if patients did not develop chronic graft-versus-host disease.     

Dissociation of caspase-mediated events and programmed cell death induced via HLA-DR in follicular lymphoma

Human leukocyte antigens (HLA) class II antigen-mediated apoptosis has been documented in antigen-presenting cells and B lymphoproliferations. Characteristics of the apoptosis include rapidity and selectivity for mature cells. Follicular lymphomas are particularly refractory to apoptosis. The B-cell lymphoma Ramos shares characteristics of this subgroup and is insensitive to apoptosis via simple HLA-DR engagement. However, oligomerization of HLA-DR antigens induced caspase activation followed by phosphatidylserine externalization, activation of PKC-delta and cleavage of nuclear lamin B. Mitochondrial injury was also detected. However, inhibition of caspase activation simply delayed the apoptotic phenotype but neither protected against cell death nor prevented mitochondrial injury. The data in this report demonstrate that the requirements for the initiating signal (oligomerization versus engagement) as well as the molecular pathways varies between different B lymphoproliferations despite their common expression of HLA-DR. Finally, blockade of caspase activation in parallel with HLA-DR mAb stimulation could provide a potent autovaccination stimulus by leading to necrotic death of B-cell lymphomas.     

Prognostic value of pretransplantation host thymic function in HLA-identical sibling hematopoietic stem cell transplantation

Thymic function is critical for immune reconstitution after hematopoietic stem cell transplantation (HSCT). We evaluated recipient thymic function before HSCT by quantifying T-cell receptor excision circles (TRECs) in pretransplantation peripheral blood lymphocytes from 102 patients who received HSCs from an HLA-identical sibling for malignant (n = 87) or nonmalignant diseases (n = 15). Median TREC value before transplantation was 257 TRECs per 150,000 CD3+ cells (range, 0-42,746). We assessed 172 TRECs per 150,000 CD3+ cells as the most discriminating TREC value for survival in a first cohort of patients (n = 62). This cut-off was validated in a second independent prospective group of 40 patients. In the 102 patients, a TREC value greater than or equal to 172 was associated with a better survival (P < .000 01), a decreased incidence of grade II-IV acute graft-versus-host disease (GVHD; P = .017), chronic GVHD (P = .023), and bacterial (P = .003) and cytomegalovirus (CMV) infection (P = .024). In a multivariate analysis, low pretransplantation TREC values were associated with a higher incidence of CMV infection (hazard ratio [HR] = 2.0, P = .06) and severe bacterial infections (HR = 2.8, P = .036). Finally, high TREC values (HR = 6.6, P = .002) and ABO compatibility (HR = 2.7, P = .02) were associated with a better survival. Therefore, recipient host thymic function assessment could be helpful in predicting HSCT outcome and identifying patients who require a close immunologic monitoring.     

Kaposi's sarcoma-associated herpesvirus viremia is associated with the progression of classic and endemic Kaposi's sarcoma

In order to gain further insight on the role of Kaposi's sarcoma-associated herpesvirus (KSHV) in classic and endemic Kaposi's sarcoma (KS) pathogenesis, we aimed to determine (i) whether KSHV is detectable in peripheral blood mononuclear cells (PBMCs), (ii) which PBMCs subpopulation harbor the virus, (iii) which clinical, histologic, and immunologic parameters are associated with KSHV viremia in a population of classic and endemic KS. KSHV viremia and various immunologic parameters were screened on 81 patients. KSHV viremia was positive in 58% of the patients. KSHV was detected in B cells, T cells, and monocytes. CD34+ cells depleted in circulating endothelial cells (CECs) were never infected and 50% of the patients tested had CECs infected by KSHV. We observed a significant increase of IL-2 and IFN-gamma production by CD4 T cells and an increase of IFN-gamma production by CD8 T cells compared to control patients. KS progression (P = 0.001) and KS staging (P = 0.03) were significantly and independently associated with positive KSHV viremia. Our results show that there is no specific immunosuppression in classic or endemic KS. We showed that KSHV can be detected within CECs and that KSHV viremia could be an indicator of circulating mature or precursor spindle cells.