Impact of allogeneic stem cell transplantation on thyroid function.

PURPOSE: Primary hypothyroidism is a main endocrine complication after allogeneic stem cells transplantation (allo-SCT) in children, but in adults data on post-SCT hypothyroidism are limited. The aims of this observational, cross-sectional study were to assess the prevalence of hypothyroidism in adult allo-SCT recipients according to time from transplantation, and to identify risk factors. METHODS: One hundred and eighty-six patients (M 104; F 82; median age 53.4 years) who underwent allo-SCT between January 2010 and December 2017 were enrolled and divided into three groups, according to time from allo-SCT (1-3 years; 3-5 years; > 5 years). Pre-transplant TSH and fT4 levels were available for all patients. After transplantation, TSH, fT4 and anti-thyroperoxidase antibodies (TPO-Ab) were evaluated. RESULTS: After a follow-up of 3.7 years, 34 (18.3%) patients developed hypothyroidism, with higher prevalence in females (p < 0.001) and in patients who received matched unrelated donor grafts (p < 0.05). No difference in prevalence was found at different time points. Patients who developed hypothyroidism showed higher rate of TPO-Ab positivity (p < 0.05) and higher pre-transplant TSH levels (median 2.34 µU/ml) compared to those with preserved thyroid function (median 1.53 µU/ml; p < 0.001). Multivariable analysis identified higher pre-transplant TSH levels as a positive predictor of hypothyroidism (p < 0.005). The ROC curve analysis identified a pre-SCT TSH cutoff of 1.84 µU/ml, which can predict hypothyroidism with sensitivity 74.1% and specificity 67.2%. CONCLUSIONS: About one out of four patients developed hypothyroidism after allo-SCT, with a greater incidence in females. Pre-transplant TSH levels seem to predict the onset of post-SCT hypothyroidism.

Fungal infections of the central nervous system and paranasal sinuses in onco-haematologic patients. Epidemiological study reporting the diagnostic-therapeutic approach and outcome in 89 cases.

Invasive fungal infections (IFI) of the Central Nervous System (IFI-CNS) and Paranasal Sinuses (IFI-PS) are rare, life-threatening infections in haematologic patients, and their management remains a challenge despite the availability of new diagnostic techniques and novel antifungal agents. In addition, analyses of large cohorts of patients focusing on these rare IFI are still lacking. Between January 2010 and December 2016, 89 consecutive cases of Proven (53) or Probable (36) IFI-CNS (71/89) and IFI-PS (18/89) were collected in 34 haematological centres. The median age was 40 years (range 5-79); acute leukaemia was the most common underlying disease (69%) and 29% of cases received a previous allogeneic stem cell transplant. Aspergillus spp. were the most common pathogens (69%), followed by mucormycetes (22%), Cryptococcus spp. (4%) and Fusarium spp. (2%). The lung was the primary focus of fungal infection (48% of cases). The nervous system biopsy was performed in 10% of IFI-CNS, and a sinus biopsy was performed in 56% of IFI-PS (P = 0.03). The Galactomannan test on cerebrospinal fluid has been performed in 42% of IFI-CNS (30/71), and it was positive in 67%. Eighty-four pts received a first-line antifungal therapy with Amphotericine B in 58% of cases, Voriconazole in 31% and both in 11%. Moreover, 58% of patients received 2 or more lines of therapy and 38% were treated with a combination of 2 or more antifungal drugs. The median duration of antifungal therapy was 60 days (range 5-835). A surgical intervention was performed in 26% of cases but only 10% of IFI-CNS underwent neurosurgical intervention. The overall response rate to antifungal therapy (complete or partial response) was 57%, and 1-year overall survival was 32% without significant differences between IFI-CNS and IFI-PS. The overall mortality was 69% but the IFI attributable mortality was 33%. Mortality of IFI-CNS/PS remains high but, compared to previous historical data, it seems to be reduced probably due to the availability of newer antifungal drugs. The results arising from this large contemporary cohort of cases may allow a more effective diagnostic and therapeutic management of these very rare IFI complications in haematologic patients.

Successful management of chronic disseminated candidiasis in hematologic patients treated with high-dose liposomal amphotericin B: a retrospective study of the SEIFEM registry.

PURPOSE: Chronic disseminated candidiasis (CDC) is a complication of Candida infection in immunocompromised patients, involving the liver and spleen, and rarely other organs. The aim of the study is to identify the best antifungal drug for hematologic immunocompromised patients with CDC. METHODS: In this multicentric retrospective study, the charts of 20 patients with CDC following cytotoxic agent protocols for hematological malignancies, diagnosed from 2003 to 2013, were analyzed. The response to systemic antifungal therapy within 90 days from CDC diagnosis and the possible delay in chemotherapy plan, due to the infection, were evaluated. RESULTS: Six patients were treated with high-dose (HD; 5 mg/kg/daily) liposomal amphotericin B (L-AmB), whereas three received standard-dose (SD) L-AmB (3 mg/kg/daily). Azoles were given to six patients; the remaining five were treated with echinocandins. All patients treated with HD L-AmB (6/6-100 %) achieved complete resolution of CDC; one of them had to interrupt the chemotherapy program for the infection. In the SD L-AmB group, treatment failed in the 100 % of cases and one patient had to delay chemotherapy for the infection. Of the six patients who received azoles, two achieved complete resolution of the infection, four experienced treatment failure, and only three performed chemotherapy as planned. Echinocandins treatment resulted in complete resolution of the infection in 2/5 cases, partial response in 2/5 cases, and failure in one case. In this group, 3/5 patients completed chemotherapy as planned. CONCLUSIONS: This study shows that HD L-AmB was particularly effective against CDC in hematologic patients, allowing most patients to continue cytotoxic agent program.

Multicentre surveillance study on feasibility, safety and efficacy of antifungal combination therapy for proven or probable invasive fungal diseases in haematological patients: the SEIFEM real-life combo study.

UNLABELLED: This multicentre observational study evaluated the feasibility, efficacy and toxicity of antifungal combination therapy (combo) as treatment of proven or probable invasive fungal diseases (IFDs) in patients with haematological malignancies. Between January 2005 and January 2010, 84 cases of IFDs (39 proven and 45 probable) treated with combo were collected in 20 Hematological Italian Centres, in patients who underwent chemotherapy or allogeneic haematopoietic stem cell transplantation for haematological diseases. Median age of patients was 34 years (range 1-73) and 37% had less than 18 years. Acute leukaemia was the most common underlying haematological disease (68/84; 81%). The phase of treatment was as follows: first induction in 21/84 (25%), consolidation phase in 18/84 (21%) and reinduction/salvage in 45/84 (54%). The main site of infection was lung with or without other sites. The principal fungal pathogens were as follows: Aspergillus sp. 68 cases (81%), Candida sp. six cases (8%), Zygomycetes four cases (5%) and Fusarium sp. four cases (5%). The most used combo was caspofungin+voriconazole 35/84 (42%), caspofungin + liposomal amphotericin B (L-AmB) 20/84 (24%) and L-AmB+voriconazole 15/84 (18%). The median duration of combo was 19 days (range 3-180). The overall response rate (ORR) was 73% (61/84 responders) without significant differences between the combo regimens. The most important factor that significantly influenced the response was granulocyte (PMN) recovery (P 0.009). Only one patient discontinued therapy (voriconazole-related neurotoxicity) and 22% experienced mild and reversible adverse events (hypokalaemia, ALT/AST increase and creatinine increase). The IFDs-attributable mortality was 17%. This study indicates that combo was both well tolerated and effective in haematological patients. The most used combo regimens were caspofungin + voriconazole (ORR 80%) and caspofungin + L-AmB (ORR 70%). The ORR was 73% and the mortality IFD related was 17%. PMN recovery during combo predicts a favourable outcome. CLINICAL TRIALS REGISTRATION: NCT00906633.

The reversed halo sign as the initial radiographic sign of pulmonary zygomycosis.

Zygomycosis is an emerging fungal infection that is associated with high mortality in hematological patients and stem cell transplantation (SCT) recipients. Radiology--computed tomography (CT) imaging in particular--facilitates the detection of lung involvement at an early stage of the infection. The reversed halo sign (RHS) has previously been reported in cryptogenetic organizing pneumonia and, more recently, as a manifestation of pulmonary zygomycosis. Here we describe a case of histologically proven zygomycosis due to Rhizopus microsporus in a SCT recipient. A chest CT scan performed on day +6 due to persistent fever unresponsive to antibiotics revealed the presence of the RHS, i.e., a focal ground-glass opacity mass surrounded by a solid ring of consolidation. The patient was treated with a combination of liposomal amphotericin B, caspofungin, and deferasirox, but subsequently developed a large pneumothorax and died on day +49 due to progressive infection. This case supports earlier observations that RHS may be an early radiological sign of zygomycosis, facilitating an aggressive diagnostic strategy.

Blood stream infections after allogeneic stem cell transplantation: a single-center experience with the use of levofloxacin prophylaxis.

Blood stream infections (BSIs) remain one of the major causes of morbidity and mortality for patients receiving an allogeneic hematopoietic stem cell transplantation (HSCT). In the present study, we evaluated the incidence and characteristics of BSI within 1 year after allogeneic HSCT in 269 consecutive adult patients who received antibacterial prophylaxis with levofloxacin. Cumulative incidence of BSI was 12% (95% confidence interval, 8-16%). Bacteria were responsible for 30 out of the 32 BSI, while fungi were responsible for 2 episodes of BSI. The median onset of BSI was day 8 (range 1-328 days) post transplant, and 66% of BSI occurred before neutrophil recovery. Gram-positive organisms accounted for 60% (n=18) of bacteremia, and gram-negative isolates for 40% (n=12) of the cases. Coagulase-negative staphylococci were the most commonly isolated gram-positive pathogens (53% of the cases), while Escherichia coli was the most commonly isolated gram-negative bacteria (58% of the cases). Candida albicans and Candida guillermondii were isolated from patients with candidemia. Resistance to fluoroquinolones (FQ) was common with 13% of gram-positive isolates being susceptible to FQ, while 50% of the gram-negative rods were susceptible to FQ. Crude mortality and mortality attributable to BSI were both 3% (1 of 32). In conclusion, our data suggest that despite the emergence of antibiotic resistance, FQ prophylaxis may be considered an appealing approach in allogeneic HSCT recipients and is also worth evaluating in randomized studies.

Efficacy of caspofungin as secondary prophylaxis in patients undergoing allogeneic stem cell transplantation with prior pulmonary and/or systemic fungal infection.

Transplanted patients with a history of invasive fungal infection (IFI) are at high risk of developing relapse and fatal complications. Eighteen patients affected by hematological malignancies and a previous IFI were submitted to allogeneic stem cell transplantation, using Caspofungin as a secondary prophylaxis. Patients had a probable or proven fungal infection and 16 had a pulmonary localization. No side effects were recorded during treatment with Caspofungin. Compared to pre-transplant evaluation, stability or improvement of the previous IFI was observed in 16 of the 18 patients at day 30, in 13 of the 15 evaluable patients at day 180 and in 11 of the 11 evaluable patients at day 360 post transplant. In particular, all the six patients with a proven fungal infection were alive, with a stable or improved IFI after 1 year from transplant. At a maximum follow-up of 31 months, eight patients died for disease progression or transplant-related complications, but only two had evidence of fungal progression. Secondary prophylaxis with Caspofungin may represent a suitable approach to limit IFI relapse or progression, allowing patients with hematological malignancies to adhere to the planned therapeutic program.

Usefulness of sequential Aspergillus galactomannan antigen detection combined with early radiologic evaluation for diagnosis of invasive pulmonary aspergillosis in patients undergoing allogeneic stem cell transplantation.

BACKGROUND: Early diagnosis of invasive pulmonary aspergillosis (IPA) is important as prompt treatment with antifungal drugs may increase patient survival. Our study investigated the efficiency of routine testing of the Aspergillus galactomannan antigen (AGA) test in combination with chest CT scans for IPA diagnosis. PATIENTS AND METHODS: From February 2002 to June 2004, 74 hemato-oncologic patients undergoing allogeneic stem cell transplantation were prospectively studied with serum AGA twice weekly from admission until death or discharge and weekly afterward when possible. Chest CT scans were performed when fever of unknown origin had lasted beyond 3 days of antibacterial therapy. RESULTS: Seven patients were classified with possible IPA and two patients, proven IPA. Fourteen patients showed positive results for AGA (OD index>or=1.0 on two subsequent sera). The sensitivity and specificity of the test were 100% and 93%, respectively; the positive and negative predictive values were 64% and 100%, respectively. All patients with possible/proven IPA showed abnormal CT signs; in four cases, imaging signs followed AGA positivity (median 5 days), whereas in five cases they preceded serologic positivity (median, 8 days). In the nine patients with IPA, antifungal therapy was promptly instituted, including lipid formulations of amphotericin B (n=5) or caspofungin (n=4). In only two of the nine patients (22%) with IPA, the primary cause of death was fungal infection. CONCLUSIONS: The combination of AGA detection and early chest CT scans might be considered useful tools to detect minimal changes of IPA. Based on these findings, aggressive antifungal therapy should be initiated.

Second allogeneic bone marrow transplantation in acute leukemia: a multicenter study from the Gruppo Italiano Trapianto Di Midollo Osseo (GITMO).

Thirty-eight second allogeneic bone marrow transplants (BMT) for acute leukemia relapsed after first BMT were performed in 13 Italian centers between 1987 and 1994. Twenty-one patients had acute myelogenous leukemia (AML), 17 acute lymphoblastic leukemia (ALL); at second BMT 24 patients were in complete remission (CR) and 14 in relapse. The median time to relapse after first BMT was 10 months (range 1-70). Grade II or greater acute graft-versus-host disease (GVHD) after second transplant occurred in 34.2% of patients and a chronic GVHD in 31.5% of patients. Twenty-four patients died: seven from early transplant-related mortality (TRM), 13 from relapse and four from late toxicity. As of 31 July 1996, at a median follow-up of 47 months (range 22-85), there are 14 survivors. The three-year probability of TRM, relapse and event-free survival (EFS) is 28%, 40% and 42% respectively. In 20 of 27 evaluable patients, remission duration after second BMT was longer than after the first BMT. A diagnosis of AML was correlated with a better outcome. These data support the usefulness of second allograft in selected patients with AML relapsing after a first BMT.

Analysis of immune reconstitution in children undergoing cord blood transplantation.

OBJECTIVE: The aim of this study was to investigate and compare immune reconstitution in allogeneic cord blood transplantation (CBT) and bone marrow transplantation (BMT) recipients. MATERIALS AND METHODS: Twenty-three children underwent CBT from either human leukocyte antigen-identical siblings (11 cases) or unrelated donors (12 cases) were enrolled in the study, together with 23 matched children receiving BMT. Patients were analyzed 2-3 and 12-15 months after transplant. Recovery of T-, B-, and NK-lymphocyte subsets, proliferative in vitro response to mitogens, as well as cytotoxic activities, were investigated. RESULTS: CBT recipients showed a marked increase in the number of B lymphocytes as compared with patients who underwent BMT (p < 0.001). The absolute number of CD3(+) and CD8(+) T cells, as well as the proliferative response to T-cell mitogens, recovered with time after transplantation, irrespective of the source of stem cells used. Recipients of unrelated CBT had a better recovery of CD4(+) T lymphocytes (p < 0.01). Among patients experiencing acute graft-versus-host disease (GVHD), children given CBT had a much greater production of CD4(+) CD45RA(+) T cells than BMT recipients (p < 0.005). Recovery of NK cell number and innate cytotoxic activities was fast, irrespective of the source of stem cells used. CONCLUSIONS: Despite the much lower number of lymphocytes transferred with the graft, recovery of lymphocyte number and function toward normal in CBT recipients was rapid and comparable to that observed after transplantation of bone marrow progenitors. This prompt immune recovery possibly was favored by the reduced incidence and severity of GVHD observed in children who underwent CBT.

Current epidemiology and antimicrobial resistance data for bacterial bloodstream infections in patients with hematologic malignancies: an Italian multicentre prospective survey.

A prospective cohort study was conducted in nine hematology wards at tertiary care centres or at university hospitals located throughout Italy from January 2009 to December 2012. All of the cases of bacterial bloodstream infection (BBSI) occurring in adult patients with hematologic malignancies were included. A total of 668 bacterial isolates were recovered in 575 BBSI episodes. Overall, the susceptibility rates of Gram-negative bacteria were 59.1% to ceftazidime, 20.1% to ciprofloxacin, 79.1% to meropenem, 85.2% to amikacin, 69.2% to gentamicin and 69.8% to piperacillin/tazobactam. Resistance to third-generation cephalosporins was found in 98/265 (36.9%) of Enterobacteriaceae isolates. Among Klebsiella pneumoniae strains, 15/43 (34.9%) were resistant to carbapenems. Of 66 Pseudomonas aeruginosa isolates, 46 (69.7%) were multidrug resistant. Overall, the susceptibility rates of Gram-positive bacteria were 97.4% to vancomycin and 94.2% to teicoplanin. Among the monomicrobial cases of BBSI, the 21-day mortality rate was significantly higher for those caused by Gram-negative bacteria compared to those caused by Gram-positive bacteria (47/278, 16.9% vs. 12/212, 5.6%; p < 0.001). Among Gram-negative bacteria, the mortality rate was significantly higher for BBSI caused by K. pneumoniae, P. aeruginosa, and Acinetobacter baumannii. Our results confirm the recently reported shift of prevalence from Gram-positive to Gram-negative bacteria as causative agents of BBSIs among patients with hematologic malignancies and highlight a worrisome increasing frequency in antimicrobial resistance among Gram-negative bacteria.

Rebound thymic hyperplasia following high dose chemotherapy and allogeneic BMT.

We describe a child with acute lymphoblastic leukemia who showed mediastinal widening 8 months after allogeneic BMT. Total thymectomy was carried out by the transcervical approach. Histologic examination showed only thymic hyperplasia. The immunohistologic investigation revealed a normal distribution of thymic cell elements, without evidence of clonal proliferation of lymphocytic subpopulations. This case supports the hypothesis that thymic hyperplasia following chemotherapy may be merely a rebound phenomenon. The patient had an uneventful postoperative recovery and remains in remission more than 1 year after BMT.

ABMT for early isolated extramedullary relapse of childhood ALL.

From July 1987 to July 1991, 12 children underwent AMBT following high-dose cytarabine (HD Ara-C) plus 14.4 Gy hyperfractionated total body irradiation (hyfr-TBI) for early isolated extramedullary relapse of ALL, while in first BM remission. No patient received intrathecal prophylaxis following AMBT. One patient died on day +5 due to sepsis and three patients, two of them transplanted in second and third CNS relapse, respectively, died from BM relapse occurring 1.5, 4 and 5 months after AMBT. Eight of the 12 survive disease-free with a median follow-up of 24 months (range 14-62 months). The toxicity of HD Ara-C plus hyfr-TBI was acceptable and well controlled with supportive therapy. These results suggest that ABMT following HD Ara-C plus hyfr-TBI may eradicate leukemia from extramedullary sites of ALL relapse.

Cytotoxic T lymphocyte precursor frequency as a predictor of acute graft-versus-host disease in bone marrow transplantation from HLA-identical siblings.

The measurement of precursor frequencies of donor anti-recipient cytotoxic T lymphocytes (CTL-p) has been shown to predict the incidence and the severity of acute graft-versus-host disease (aGVHD) in unrelated donor bone marrow transplantation (BMT). In HLA-identical sibling BMT, where aGVHD is most likely caused by minor histocompatibility antigen mismatches, this assay did not appear to be sensitive enough to provide similar predictive information. In this study, the CTL-p frequencies and the incidence and severity of aGVHD in 51 onco-hematological patients transplanted from HLA-identical siblings were compared. Sibling donors were selected on the basis of HLA identity using serological typing for HLA-A, B, C antigens, whereas HLA-DRB was tested by molecular analysis. Sibling identity was also confirmed by DNA heteroduplex analyses. Fifteen out of 21 (71%) patients with high precursor frequency (>1:100 x 10(3)) and 12 out of 30 (40%) with low precursor frequency (<1:100 x 10(3)) experienced clinically significant (II-IV) aGVHD. A significant correlation (P = 0.04) between CTL-p frequency and severe aGVHD was demonstrated. Moreover there was a positive trend for a high frequency response according to an increasing grade of aGVHD, which was statistically significant (P = 0.04). In our experience the CTL-p assay is a helpful predictive test for aGVHD in HLA-identical sibling BMT, indicating high risk patients possibly requiring additional prophylaxis.

Mycophenolate mofetil (MMF) as therapy for refractory chronic GVHD (cGVHD) in children receiving bone marrow transplantation.

Mycophenolate mofetil (MMF) is an alternative immunosuppressant which inhibits the proliferation of T and B lymphocytes. The purpose of the present study was to evaluate the safety and efficacy of MMF as salvage therapy for chronic GVHD (cGVHD) in children receiving allogeneic bone marrow transplantation. Fifteen children, 3-16 years of age, who had received grafts from HLA-compatible siblings (n = 8), partially matched related donors (n= 2) or matched unrelated donors (n = 5), developed extensive cGVHD which had proved unresponsive to standard immunosuppressive therapy. Patients were treated with MMF at the dose of 15-40 mg/kg/day in combination with other immunosuppressive therapy for a median of 4 months (range 1-15 months). The overall response rate (complete or partial response) was 60%. Thirteen percent had only minor responses, whereas 27% of patients had progressive disease. Best responses were seen in patients with GI tract (60% of complete responses) or mouth (33% of complete responses) cGVHD and skin involvement (43% of complete responses) that did not include sclerodermatous manifestations. Once MMF was started, improvements in the clinical manifestations of cGVHD allowed a significant reduction of steroids in 45% of patients and discontinuation in 27% of cases. Six patients (40%) experienced adverse events, with gastrointestinal symptoms predominating. Five patients experienced opportunistic infections. MMF was discontinued after 35-180 days in six patients for the following reasons: parents choice (n = 2), liver toxicity (n = 1), poor compliance (n = 2), and no response (n = 1). In conclusion, these preliminary results suggest that MMF in combination with other immunosuppressive agents may have a role to play in patients with cGVHD. Prospective clinical trials are needed to establish exact indications for therapy and dosage scheduling. Bone Marrow Transplantation (2000).

HLA-haploidentical umbilical cord blood stem cell transplantation in a child with advanced leukemia: clinical outcome and analysis of hematopoietic recovery.

Growing attention has been focused on cord blood as a source of transplantable hematopoietic stem cells. However, clinical experience is rather limited. In this study we describe a child with advanced acute lymphoblastic leukemia who received an HLA-haploidentical cord blood transplant. The patient was transplanted in third complete remission after conditioning with fractionated total body irradiation, thiotepa and cyclophosphamide. Forty-one milliliters of cryopreserved umbilical cord blood, containing 0.15 x 10(8) nucleated cells/kg and 0.25 x 10(4) CFU-GM/kg, were infused. Cyclosporine and prednisone were administered for graft-versus-host disease (GVHD) prophylaxis. The patient received G-CSF from day +1 to day +35, but no improvement in granulocyte counts was observed. Therefore, administration of GM-CSF was started on day +36 to day +59, which resulted in a significant increase in white blood cells and granulocyte counts. Sustained myeloid engraftment was evidenced by a granulocyte count > 0.5 x 10(9)/l by day +41. The presence of donor-derived cells could be documented in the peripheral blood and bone marrow of the patient by cytogenetic analysis, HLA phenotyping and DNA studies. Forty-one days after transplant, clonogenic bone marrow assays showed the presence of low frequencies of primitive hematopoietic progenitor cells (BFU-E = 19/10(5) and CFU-GM = 8/10(5)). The chimerism was complete and no host-derived cells could be detected. However, the engraftment was restricted to the myeloid lineage whereas lymphoid and megakaryocytic engraftments were inadequate. The immunophenotype of the patient's peripheral blood showed the presence of T lymphocytes expressing an immature phenotype (CD2+ CD3-) at day +21.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term persistence of hemopoietic chimerism following sex-mismatched bone marrow transplantation.

Fifty-eight samples of bone marrow (31), whole peripheral blood (8) and separated fractions of circulating mononuclear (11) and polymorphonuclear (8) cells from 18 male patients, transplanted for hematological diseases from related (14) or unrelated (4) female donors were analyzed for chimerism at subsequent intervals (range, 1-72 months) following bone marrow transplantation, by means of PCR amplification of the Y-chromosome-specific DYS14 sequence, revealed by a radiolabelled hybridization probe (dot blot technique, 0.01% sensitivity). Detection of male cells was positive in all but two of 52 samples collected within the third year after transplantation and negative in six samples collected from three patients after the third year. In the first year after transplantation, mixed chimerism was found in all patients, apparently with no correlation with graft-versus-host disease. Comparable results were found in fractions of mononuclear and polymorphonuclear cells, when analyzed separately. The persistence of very low levels of recipient cells in patients in continuous complete remission until the third year after transplantation, suggests the persistence of normal host hemopoiesis for a long period of time after the so-called myeloablative regimen. The progressive negativization, occurring in our patients between the second and the fourth year after transplantation, could signify the disappearance of residual host hemopoiesis or its decrease to below the detection level of this highly sensitive method.

Low incidence of GvHD and rejection after pharmacological ex vivo modulation of bone marrow in 2-3 antigens mismatched BMT.

2-3 antigens mismatched BMT were performed on 32 children without a matched sibling donor. In the light of previous in vitro studies, which suggested a role of Vincristine and Methilprednisolone ex vivo treatment in modulating alloreactivity of T cells, bone marrow was treated with such a pharmacological cocktail before being infused. Acute GVHD 2 degrees to 4 degrees degree occurred in 46% of cases, chronic GVHD in 28%, graft failure in 13%. There was no significant difference between 2- and 3-antigens mismatched BMT as far as GVHD and graft failure are concerned.

Allogeneic transplantation of peripheral blood progenitor cells in children: experience of two pediatric centers.

Between February 1995 and August 1997, 11 children (eight males, three females) aged 4-16 years (median 7 years) underwent allogeneic PBPC transplantation for treatment of hematological disorders. Seven patients with acute leukemia (n = 5 ALL, n = 1 AML) or lymphoma (n = 1) received primary allogeneic PBPC transplantation, four patients received a second allotransplantation for graft failure (n = 1 AML, n = 1 sickle cell anemia) or disease recurrence (n = 1 ALL, n = 1 MDS). Five donors were HLA-identical siblings, five were 0-1 antigen mismatched family members and one was a matched unrelated donor. Donors received G-CSF 10-12 microg/kg/day for 3-7 days, and underwent one or two leukaphereses. The median cell yield per donor expressed per kg of recipient body weight was as follows: mononucleated cells 10.8 x 10(8)/kg (range 4.7-21.2); CD34+ cells 8.6 x 10(6)/kg (range 3.2-22); CD3+ cells 3.7 x 10(8)/kg (range 2.7-7.5). All patients achieved an ANC >0.5 x 10(9)/l after a median of 12 days (11-18). An unsupported platelet count >50 x 10(9)/l was reached 15 days (13-21) after PBPC transplantation; four patients failed to reach this threshold. Acute GVHD (aGVHD) grades II to IV occurred in eight (73%) patients: seven of them experienced grade III-IV aGVHD. Seven patients evaluable for chronic GVHD (cGVHD) were scored as absent in five, limited in one and extensive in one patient. As of September 1997, six patients (55 %) were alive between 60 and 938 days post-transplant (median follow-up 274 days); four patients with malignancy were alive in CR after primary allotransplantation, two patients were alive after a second PBPC transplant. Five patients have died with the main causes of death being aGVHD (n = 3), ARDS (n = 1), relapse of the underlying disease (n = 1). In conclusion, despite the limited number of patients, these preliminary results indicate that PBPC may be considered as an alternative to bone marrow for allografting also in children.