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.

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.

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.

Viral infections in patients with hematological malignancies.

Viral infections remain one of the most frequent complications in patients with hematological malignancies, especially in those receiving an allogeneic stem cell transplantation. Viral infections result from reactivation of latent infection rather than from acquisition of new infection. Infections caused by herpes viruses, including cytomegalovirus and Epstein-Barr virus, respiratory viruses and hepatitis B virus are frequently associated with high morbidity and mortality in the immunocompromised host. Major advances have been made primarily by the availability of rapid diagnostic tests and the introduction of potent antiviral compounds into clinical practice.

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.

Zygomycosis in Italy: a survey of FIMUA-ECMM (Federazione Italiana di Micopatologia Umana ed Animale and European Confederation of Medical Mycology).

The aims of the study were to analyze the clinical and epidemiological characteristics and treatments for patients who developed zygomycosis enrolled in Italy during the European Confederation of Medical Mycology of medical mycology survey. This prospective multicenter study was performed between 2004 and 2007 at 49 italian Departments. 60 cases of zygomycosis were enrolled: the median age was 59.5 years (range 1-87), with a prevalence of males (70%). The majority of cases were immunocompromised patients (42 cases, 70%), mainly hematological malignancies (37). Among non-immunocompromised (18 cases, 30%), the main category was represented by patients with penetrating trauma (7/18, 39%). The most common sites of infection were sinus (35%) with/without CNS involvement, lung alone (25%), skin (20%), but in 11 cases (18%) dissemination was observed. According to EORTC criteria, the diagnosis of zygomycosis was proven in 46 patients (77%) and in most of them it was made in vivo (40/46 patients, 87%); in the remaining 14 cases (23%) the diagnosis was probable. 51 patients received antifungal therapy and in 30 of them surgical debridement was also performed. The most commonly used antifungal drug was liposomal amphotericin B (L-AmB), administered in 44 patients: 36 of these patients (82%) responded to therapy. Altogether an attributable mortality rate of 32% (19/60) was registered, which was reduced to 18% in patients treated with L-AmB (8/44). Zygomycosis is a rare and aggressive filamentous fungal infection, still associated with a high mortality rate. This study indicates an inversion of this trend, with a better prognosis and significantly lower mortality than that reported in the literature. It is possible that new extensive, aggressive diagnostic and therapeutic procedures, such as the use of L-AmB and surgery, have improved the prognosis of these patients.

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.

Oral valganciclovir as preemptive therapy for cytomegalovirus infection post allogeneic stem cell transplantation.

UNLABELLED: Antiviral compounds including ganciclovir, foscarnet, and cidofovir are routinely used in the treatment of cytomegalovirus (CMV) infection and disease; however, these agents have a poor oral bioavailability and have the inconvenience and expense of intravenous administration. AIM OF THE STUDY: To evaluate the safety and efficacy of oral valganciclovir (VGCV) for preemptive treatment of CMV reactivation in the setting of allogeneic hematopoietic stem cell transplantation (HSCT). PATIENTS AND METHODS: We treated 15 patients receiving allogeneic HSCT from related (n=9) or unrelated (n=6) donors. In all patients, either the donor, host, or both were CMV Ig G positive pretransplant. Indication for therapy was preemptive treatment of CMV infection defined as one or two consecutive positive tests of pp65 antigenemia assay or CMV-polymerase chain reaction (PCR). VGCV was administered orally in a dosage of 900 mg b.i.d. for 2 weeks, followed by 450 mg b.i.d. for 2 additional weeks. RESULTS: Patients developed a positive CMV-PCR after a median of 52 days (range 37-427) post HSCT and a positive pp65 antigenemia after a median time of 74 days (range 37-427) post HSCT. Preemptive treatment with VGCV was started a median time of 56 days (range 37-429) after transplant. In all, 11 patients (73%) completed the 28 days of therapy with VGCV. All patients showed a complete clearance of the virus. The median time to achieve a negative CMV-PCR was 6 days (range 4-18). A relapse of CMV infection after VGCV preemptive therapy occurred in 6 patients (40%). No patient developed early or late CMV disease. Six patients (40%) presented hematological toxicity including neutropenia and/or thrombocytopenia that required drug discontinuation in 4 cases. CONCLUSION: VGCV administered as preemptive therapy for CMV infection in patients receiving an allogeneic HSCT showed promise for treating this frequent complication. Prospective randomized studies in this setting are mandatory to yield more definitive results.

Role of non-HLA genetic polymorphisms in graft-versus-host disease after haematopoietic stem cell transplantation.

Graft-versus-host disease (GvHD) is the main complication after haematopoietic stem cells transplantation (HSCT) and acute forms (aGvHD) occur in 20-40% of cases even after donor (D) and recipient (R) HLA matching, apparently because of D/R minor histocompatibility antigen (mHA) mismatches and cytokine polymorphisms. The genotype of cytokines and mHA of 77 haematological R following HSCT from HLA identical siblings were determined to detect genetic polymorphisms correlated with GvHD. We analysed TNFA (-863 C/A, -857 C/T and G/A at positions -574, -376, -308, -244, -238), IL-10 (-1082 G/A, -819 C/A, -592 C/T), IL-1B (T/C +3953), IL-1RA (VNTR), HA-1 (H/R allele) and CD-31 (C/G at codon 125, A/G at codon 563). Allele frequencies were in Hardy-Weinberg equilibrium and similar to those of 77 healthy controls. We observed positive correlations between a lower risk of clinically significant aGvHD and both the presence of -1082G -819C -592C IL-10 haplotype when both R and D are considered together and the absence of R IL-1RA allele 2. Furthermore, we observed an association between the absence of TNF-A -238 A allele and the risk of extensive chronic GvHD. mHA and cytokines genotyping would thus seem a valid source of information for the prior identification of recipients with a higher risk of aGvHD.

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.

Infectious complications following nonmyeloablative allogeneic hematopoietic stem cell transplantation.

Nonmyeloablative hematopoietic stem cell transplantation (NST) has been explored in hematological malignancies and solid tumors in an attempt to minimize treatment-related toxicity. Whether this approach is associated with reduced risk of infectious complications is unclear. The aim of the current study was to evaluate the infectious complications in a series of 32 consecutive adult patients who received NST at our institution. Peripheral blood stem cell grafts (n=30) or marrow grafts (n=2) were infused from human leukocyte antibody (HLA)-matched sibling (n=30), partially matched related (n=1), or unrelated (n=1) donors. Neutropenia developed in two-thirds of patients and lasted 16 days. Acute graft-versus-host disease (GVHD) grade II to IV was observed in 25% of patients, whereas 35% of patients had signs of extensive chronic GVHD. Twenty-two patients (69%) had at least one significant infectious episode. Bacteremia occurred in 19% of patients (n=5 gram-positive, n=1 gram-negative microorganisms). Cytomegalovirus (CMV) infection was observed in 10 out of 28 (36%) evaluable patients; 4 of these had recurrent or persistent CMV antigenemia requiring a second-line treatment, but eventually the viremia cleared. No patients experienced CMV disease. Fungal infections were documented in five (16%) patients, comprising invasive fungal infections in two cases and mucosal fungal infections in three. Four patients died of transplant-related causes, and three of these died before day +100. Infection was considered the primary cause of death in one patient (pulmonary aspergillosis) and contributed to death in another two. The actuarial probability of nonrelapse mortality at 100 days was 10% (95% confidence interval, 3-26%). Our preliminary results suggest that NST is associated to a low incidence of bacteremia or fungal and viral infections. Whether these findings would translate into an improved overall survival needs to be confirmed in larger prospective studies.

Impact of marrow unrelated donor search duration on outcome of children with acute lymphoblastic leukemia in second remission.

We analyzed the outcome of 167 consecutive children with second CR acute lymphoblastic leukemia (ALL), for whom an unrelated donor (UD) search was activated between 1989 and 1998 at a median time of 2 months after relapse. A suitable donor was identified for 70 patients at 1 year and 6.5 months before and after 1995 from search activation, respectively; a further leukemia relapse occurred during the search in 94 children at a median of 4 months after search activation, 36 of whom underwent UD (14) or other types of transplant (22), beyond second CR, while 58 died of progressive disease. Of 73 patients not experiencing a second relapse, 64 underwent UD (46) or other types of transplant (18), while nine proceeded with chemotherapy, and only four of them survived. The 3-year disease-free survival (DFS) from second CR for the 167 patients is 15.1%, whereas 3-year DFS after transplant for the 60 UD and 40 alternative donor transplanted children is 31.6 and 25.4%, respectively. In conclusion, a further relapse is the main factor adversely affecting outcome of children with second CR ALL. Thus, for these patients, the search should be activated early after relapse and either a UD or an alternative transplant should be performed as early as possible.

Transplant-related toxicity and mortality: an AIEOP prospective study in 636 pediatric patients transplanted for acute leukemia.

Hematopoietic stem cell transplantation can cure high-risk acute leukemia (AL), but the occurrence of non-leukemic death is still high. The AIEOP conducted a prospective study in order to assess incidence and relationships of early toxicity and transplant-related mortality (TRM) in a pediatric population. Between 1990 and 1997 toxicities reported in eight organs (central nervous system, heart, lungs, liver, gut, kidneys, bladder, mucosa) were classified into three grades (mild, moderate, severe) and prospectively registered for 636 consecutive children who underwent autologous (216) or allogeneic (420) transplantation, either from an HLA compatible related (294), or alternative (126) donor in 13 AIEOP transplant centers. Overall, 47% of the patients are alive in CR (3-year EFS: 45.2%, s.e.: 2.1), 19% died in CR at a median of 60 days (90-day TRM: 14.3%, s.e.: 1.4), 34% relapsed. Toxicity of any organ, but mucosa and gut, was positively correlated with early death; moderate and severe toxicity to heart, lungs, liver and kidneys significantly increased early TRM, with estimated relative risks of 9.1, 5.5, 2.7 and 2.8, respectively, as compared to absent or mild toxicity. Patients with grade III-IV aGVHD experienced more than double (56% vs. 19%) TRM than patients with grade 0-II aGVHD. A higher cumulative toxicity score, estimating the impact of toxicity on TRM, was significantly associated with transplantation from an alternative donor. Quantitative assessment allowed us to describe the extent to which 'grade' of toxicity and 'type' of involved organs were related to mortality and pre-transplant characteristics and yielded a prognostic score potentially useful to compare different conditioning regimens and predict probability of early death.