Aarthi Shenoy

Increased Risk of Cervical Dysplasia in Long-Term Survivors of Allogeneic Stem Cell Transplantation—Implications for Screening and HPV Vaccination

As more women survive allogeneic stem cell transplantation (SCT), the development of genital human papilloma virus (HPV)-related squamous intraepithelial lesions (SIL) warrants study. Thirty-five of 38 females followed prospectively long-term after SCT for hematological malignancies (median: 7 years posttransplant) were adults and had cervical cytology testing. Acute graft-versus-host-disease (aGVHD) occurred in 9 and chronic (cGVHD) in 34 patients. Six (17%) continued receiving systemic immunosuppressive therapy (IST) for cGVHD >3 years after SCT. Of 15 (43%) with abnormal cytology, 12 (34%) patients had HPV-related SIL (median time to SIL 51 months, range: 22-108) including high-grade SIL in 7 (20%). Patients requiring continued IST had the highest risk (odds ratio [OR] 4.6, 95% confidence interval [CI] 1.1-16.4; P = .019). This high incidence of SIL in long-term SCT survivors underscores the importance of gynecologic assessment after transplantation, especially in those requiring IST. This may portend an increased risk of genital or other HPV-related malignancies.

Robust Expansion of Viral Antigen-specific Cd4+ and Cd8+ T Cells for Adoptive T Cell Therapy Using Gene-modified Activated T Cells as Antigen Presenting Cells

Cytomegalovirus (CMV) reactivation after stem cell transplantation can be treated with CMV-specific T cells, but current in vitro techniques using dendritic cells as antigen-presenting cells are time-consuming and expensive. To simplify the production of clinical grade CMV-specific T cells, we evaluated gene-modified activated T cells [antigen presenting T cells (T-APCs)] as a reliable and easily produced source of APCs to boost CD4+ and CD8+ T-cell responses against the immunodominant CMV antigen pp65. T-APCs expressing the full-length immunodominant CMV pp65 gene were used to stimulate the expansion of autologous T cells. After 10 to 14 days, the T cell lines were tested for antigen specificity by using the flow cytometric intracellular detection of interferon-γ after stimulation for 6 hours with a pp65 peptide library of 15-mers, overlapping by 11 amino acids. Under optimal conditions, this technique induced a median 766-fold and a 652-fold expansion of pp65-specific CD4+ and CD8+ responder cells, respectively, in 15 T cell lines. In 13 of 15 T cell lines, over 106 antigen-specific CD4+ plus CD8+ T cells were generated starting with only 5×106 peripheral blood mononuclear cells, representing an over 3-log increase. These data indicate that T-APCs efficiently boost pp65-specific CD4+ and CD8+ T cell numbers to clinically useful levels. The approach has the advantage of using a single leukocyte collection from the donor to generate large numbers of CMV-specific T cells within a total 3-week culture period using only one stimulation of antigen.

Prolonged Chronic Graft-versus-Host Disease is a Risk Factor for Thyroid Failure in Long-Term Survivors After Matched Sibling Donor Stem Cell Transplantation for Hematologic Malignancies

We studied thyroid function in 81 long-term survivors of allogeneic stem cell transplantation (allo-SCT), with a median follow-up of 84 months (range, 45 to 166 months). Median age at transplantation was 35 years (range, 6 to 66). Seventy-two of the patients received a total body irradiation (TBI)-containing conditioning regimen (n = 23, 12 Gy; n = 49, 13 Gy). Twenty-one of the patients (25.9%) had subclinical hypothyroidism, and 9 (11.1%) developed overt hypothyroidism at a median of 28 months (range, 3 to 78 months) after allo-SCT. Multivariate logistic regression analysis demonstrated that prolonged immunosuppressive therapy (IST) was significantly associated with subclinical hypothyroidism (odds ratio [OR] = 3.8) and overt hypothyroidism (OR = 2.6). Antithyroglobulin and thyroid peroxidase antibody were detected in 12 of 60 patients tested (20%). No correlation was found between the occurrence of thyroid antibodies and hypothyroidism (P = .13) or chronic graft-versus-host disease (cGVHD) (P = .55). In conclusion, thyroid dysfunction is relatively common after allo-SCT and is more likely to occur in patients receiving prolonged IST for cGVHD; however, thyroid dysfunction does not appear to be related to an antibody-mediated autoimmune process.

Evolution of the donor T-cell repertoire in recipients in the second decade after allogeneic stem cell transplantation

After allogeneic stem cell transplantation (SCT), T lymphocyte function is reestablished from the donors postthymic T cells and through thymic T-cell neogenesis. The immune repertoire and its relation to that of the donor have not been characterized in detail in long-term adult SCT survivors. We studied 21 healthy patients in their second decade after a myeloablative SCT for hematologic malignancy (median follow-up, 12 years). Immune profiles were compared with donor samples cryopreserved at transplant and beyond 10 years from SCT. Only one recipient was on continuing immunosuppression. Compared with the donor at transplant, there was no significant difference in CD4, CD8, natural killer, and B-cell blood counts. However, compared with donors, recipients had significantly fewer naive T cells, lower T-cell receptor excision circle levels, fewer CD4 central memory cells, more effector CD8(+) cells, and more regulatory T cells. TCR repertoire analysis showed no significant difference in complexity of TCRVβ spectratype between recipients and donors, although spectratype profiles had diverged with both gain and loss of donor repertoire peaks in the recipient. In conclusion, long-term allogeneic SCT survivors have subtle defects in their immune profile consistent with defective thymic function but compatible with normal health. This study is registered at http://www.clinicaltrials.gov as NCT00106925.

Lamivudine Prophylaxis and Hepatitis B Vaccination for Prevention of Hepatitis B Virus Reverse Seroconversion in Long-Term Survivors after Allogeneic Stem Cell Transplantation

The reactivation of resolved hepatitis B virus (HBV) infection is termed reverse seroconversion (RS). HBV-RS is a complication after allogeneic stem cell transplantation (SCT) in patients exposed to hepatitis B virus [1-4]. Recently, Onozawa et al [1] reported that HBV vaccination is effective in the prevention of HBV-RS after SCT, but there are limited data about RS of hepatitis B in long-term SCT survivors. At our institute, 15 of 103 patients with hematologic disorders (14 leukemia or myelodysplastic syndrome [MDS], 1 severe apalstic anemia [AA]) receiving SCT from an HLA identical sibling and surviving 3 or more years, had a pretransplant resolved HBV infection (negative HBsAg, positive anti-HBs and anti-HBc antibodies). Twelve (median age 39.5 years) had received total body irradiation (TBI)-based myeloablative SCT followed by a T cell-depleted peripheral blood stem cell transplantation (PBSCT), and 3 (median age 13 years) received a reduced-intensity regimen (RIC) of fludarabine (Flu) and cyclophosphamide (Cy), followed by PBSCT. All received cyclosporine (CsA) as graft-versus-host disease (GVHD) prophylaxis. Eight developed acute GVHD (aGVHD), and 12 developed chronic GVHD (cGVHD), 8 of whom continued immunosuppressive therapy (IST) 3 years or more after SCT. Serologic HBV markers were followed serially (median follow-up 59 months; range: 40-113). The probability of developing HBV-RS posttransplant in recipients with resolved pretransplant HBV infection was 30%. Five patients, 3 of whom had received lamivudine, developed RS with reappearance of HBsAg, 21-101 (median 31) months after SCT. Three developed clinical hepatitis, which was successfully treated with lamivudine with a decrease of HBV viral load after additional antiviral drugs in one. Of the 10 patients who did not have RS, 6 were vaccinated with HBV around 1 year posttransplant and 5 also received lamivudine prophylaxis starting 3 months posttransplant and continuing until anti-HBs antibody