Nontuberculous mycobacterial infections in hematopoietic stem cell transplant recipients: characteristics of respiratory and catheter-related infections.

Over a 20-year period, 40 nontuberculous mycobacteria (NTM) were isolated from 6259 hematopoietic stem cell transplant (HSCT) recipients (0.64%), of which 28 were considered to have probable or definite infection (0.44%). Only 3 of 15 lower respiratory isolates obtained by bronchoalveolar lavage (BAL) and/or biopsy; (Mycobacterium avium complex [n = 2] and M. gordonae [n = 1]) caused definite or probable lower respiratory tract disease, whereas 12 of 15 were considered to cause possible lower respiratory tract disease according to Centers for Disease Control and Prevention definitions. The median time to diagnosis was 251 days following HSCT. All 3 patients with definite NTM disease were successfully treated with 3 antimicrobials for several months. Twenty-three patients had catheter-related infections, including exit site infection (n = 5), tunnel infection (n = 7), and catheter-related bacteremia (n = 11). All were caused by rapidly growing mycobacteria. The median time to diagnosis was 61 days following HSCT. All patients with catheter-related infections were successfully treated with an average of 2 antibiotics for a median of 3 weeks for exit site infection and 6 weeks for tunnel infection and catheter-related bacteremia. Soft tissue debridement was performed in all cases with tunnel infection. The catheter was removed in 21 of 23 patients with catheter-related infections. Two additional patients were diagnosed, one with lymphadenitis and one with skin lesion, due to NTM. In conclusion, NTM infections are infrequent in HSCT recipients and carry a good clinical prognosis. In the majority of lower NTM respiratory isolates obtained by BAL, a pathogenic role could not be established. However, lower respiratory tract disease can occur late after HSCT and should be considered if patients fail to respond to the treatment of concomitant infections or if evidence of tissue infection or concomitant bacteremia is present. Therapy should be performed with 2 to 3 antimicrobials, guided by antimicrobial susceptibilities, with additional surgical debridement in patients with tunnel infection.     

Fungal infections in hematopoietic stem cell transplant recipients.

Fungal infections have historically been, and remain important causes of transplant-related morbidity in recipients of hematopoietic stem cell transplant (HSCT). However, there have been notable changes in the epidemiology and outcomes of invasive fungal infections, induced by changes in the transplant procedures as well as supportive care. This review discusses invasive fungal infections in hematopoietic stem cell transplant recipients, with a focus on the host and the two most common infections, candidiasis and those caused by moulds.     

Adenoviral infections in hematopoietic stem cell transplantation.

Adenoviruses are lytic DNA viruses that are ubiquitous in human communities. In total, 51 different serotypes with varying tissue tropisms have been identified. Adenovirus infections, although frequent, are rarely fatal in immunocompetent individuals who have potent innate and adaptive immunity. But in immunosuppressed individuals, adenoviruses are a significant cause of morbidity and mortality, with limited treatment options. In particular, pediatric recipients of allogeneic hematopoietic stem cell transplantation frequently develop infections early in the posttransplantation period. Because the endogenous recovery of adenovirus-specific T cells has proven important in controlling infection, we explore the potential of adoptive T-cell immunotherapy as a therapeutic strategy. We discuss the advantages and limitations of T-cell therapy for the prophylaxis and treatment of adenovirus infection posttransplantation.     

PCR diagnostics and monitoring of adenoviral infections in hematopoietic stem cell transplantation recipients

After stem cell transplantation, human patients are prone to life-threatening opportunistic infections with a plethora of microorganisms. We report a retrospective study on 116 patients (98 children, 18 adults) who were transplanted in a pediatric bone marrow transplantation unit. Blood, urine and stool samples were collected and monitored for adenovirus (AdV) DNA using polymerase chain reaction (PCR) and real-time PCR (RT-PCR) on a regular basis. AdV DNA was detected in 52 (44.8%) patients, with mortality reaching 19% in this subgroup. Variables associated with adenovirus infection were transplantations from matched unrelated donors and older age of the recipient. An increased seasonal occurrence of adenoviral infections was observed in autumn and winter. Analysis of immune reconstitution showed a higher incidence of AdV infections during periods of low T-lymphocyte count. This study also showed a strong interaction between co-infections of AdV and BK polyomavirus in patients undergoing hematopoietic stem cell transplantations.     

Adenoviral infections and a prospective trial of cidofovir in pediatric hematopoietic stem cell transplantation.

Adenoviral (ADV) infections are increasingly recognized as a cause of morbidity and mortality in pediatric hematopoietic stem cell transplantation (HSCT). We reviewed our experience with ADV infections in HSCT patients hospitalized for transplantation at Childrens Hospital Los Angeles January 1998 through December 1998. ADV was detected in 47% of patients, with recipients of HSCT from alternative donors (matched unrelated, unrelated cord, and mismatched related donors) being more frequently culture positive than recipients of HSCT from matched siblings (62% versus 27%, P = .04). Detection of ADV from 2 or more sites was associated with organ injury, eg, hemorrhagic cystitis, enteritis, and hepatitis. Because of the high incidence of ADV culture-positive patients and the lack of effective anti-ADV therapy, we initiated a prospective trial to evaluate cidofovir (CDV) in the treatment of ADV infections in HSCT recipients. Eight patients were enrolled on a dosage schedule of 1 mg/kg 3 times weekly. AD of these patients eventually achieved long-term viral suppression and clinical improvement, although 6 patients needed prolonged CDV therapy for up to 8 months before CDV could be stopped without ADV recurrence. We did not observe dose-limiting nephrotoxicity, and the discontinuation of the drug was not required in any patients. Prospective controlled trials to further define the role of CDV in the treatment of ADV infections in HSCT patients are warranted.     

Risk factors for molecular detection of adenovirus in pediatric hematopoietic stem cell transplantation recipients

Adenovirus (AdV) infections are a major cause of morbidity and mortality in patients undergoing hematopoietic stem cell transplantation (HSCT). To evaluate the use of molecular AdV testing in HSCT at our institution and identify risk factors for AdV viremia and disease, we performed a retrospective cohort study of all HSCT recipients who had undergone AdV polymerase chain reaction testing over a 2-year period. Two cohorts were identified: cohort 1, comprising patients testing positive for AdV (n = 7) and cohort 2, comprising patients testing negative (n = 36). Overall patient characteristics were not statistically significantly different between the 2 cohorts. A comparison of cohort 1 and cohort 2 identified the following medication exposures as risk factors influencing AdV status: preparatory regimens using fludarabine (relative risk [RR], 8.73; 95% confidence interval [CI], 1.18-64.27; P = .006), melphalan (RR, 3.47; 95% CI, 0.76-15.94: P = .08), and/or cyclophosphamide (RR, 0.18; 95% CI, 0.02-1.4; P = .05), and GVHD prophylaxis with methylprednisone (RR, 3.73; 95% CI, 1.01-13.9; P = .04). AdV-positive patients had higher grades of GVHD and?higher?rates of GVHD of the gastrointestinal tract (RR, 4; 95% CI, 1.18-13.5; P = .03) compared with AdV-negative patients. Four of the 7 AdV-positive patients had concomitant clinical manifestations of disease, including pneumonia, diarrhea, and/or disseminated disease. Clinical outcomes in symptomatic patients included resolution of disease in 2 patients and death in 2 patients. All 7 AdV-positive patients received antiviral therapy, including 1 patient with severe disseminated disease that resolved after administration of liposomal cidofovir. Our study at a large pediatric HSCT center provides important preliminary data for the development of a prospective trial destined to identify specific HCST patient subpopulations that might benefit most from molecular screening and early preemptive therapy.     

Coccidioidomycosis in hematopoietic stem cell transplant recipients.

Coccidioidomycosis is an endemic fungal infection of the desert southwestern United States that can cause devastating disseminated infection in immunocompromised persons. Clinical coccidioidomycosis, which is caused by Coccidioides species, has been well characterized in patients who have had solid organ transplants, but it has rarely been described in patients who have received a hematopoietic stem cell transplant (HSCT). We report the experience of 121 consecutive HSCT recipients at a single tertiary care institution in an endemic area. One patient had fatal disseminated coccidioidomycosis after receiving an allogeneic transplant, and 2 patients had pulmonary infection before successful autologous HSCT; 1 of these 2 had a reactivation of coccidioidal infection after HSCT but was treated and survived. Coccidioidomycosis was not commonly identified in HSCT recipients, even in the endemic area. A prospective evaluation is required to address the optimal use of coccidioidal serologic tests, antifungal protocols, and secondary prophylaxis in these patients.     

Renal pathology in hematopoietic cell transplantation recipients.

Hematopoietic cell transplantation-associated renal injury may be related to a combination of factors including chemotherapy, radiation, infection, immunosuppressive agents, ischemia, and graft-versus-host disease. Renal biopsy specimens from hematopoietic cell transplant recipients at two institutions (Stanford University Medical Center and Oregon Health & Science University) were reviewed in correlation with clinical data. Fifteen cases were identified (post hematopoietic cell transplant time 0.7-14.5 years), including six with autologous hematopoietic cell transplant. Indications for renal biopsy included proteinuria (n=13; nephrotic range in 8), increased serum creatinine (n=10), or both (n=6). Many patients had multiple pathologic findings on renal biopsy. Membranous glomerulonephritis was the most common diagnosis (n=7), including two patients with autologous hematopoietic cell transplant and five with evidence of chronic graft-versus-host disease elsewhere. Four membranous glomerulonephritis patients achieved sustained remission with rituximab therapy. Other glomerular pathology included focal segmental glomerulosclerosis (n=1) and minimal change disease (n=1). Evidence of thrombotic microangiopathy was common (in isolation or combined with other pathology), as was acute tubular necrosis and tubulointerstitial nephritis. Of 14 patients with follow-up (2-64 months, mean 19 months), 6 had chronic renal insufficiency (serum creatinine >1.5 mg/dl), 2 had end stage renal disease, and 6 had essentially normal renal function. Our retrospective study shows that renal dysfunction in hematopoietic cell transplant recipients is often multifactorial, and biopsy may reveal treatable causes. Membranous glomerulonephritis is seen in autologous and allogeneic hematopoietic cell transplant recipients, and may respond to anti-B-cell therapy, which has implications regarding pathogenesis and relationship to graft-versus-host disease.     

Mycobacterial infections in adult recipients of allogeneic hematopoietic stem cell transplantation: A cohort study in a high endemic area

BackgroundMycobacterial infections are important and potentially life-threatening complications after organ transplantations. Notably, for the recipients of allogeneic hematopoietic stem cell transplantation (HSCT), there are a few supporting results to explore post-transplant mycobacterial infections. Taiwan is a high endemic area of the infection. We aim to investigate the incidence, risk factors, and survival of post-transplant mycobacterial infections, including mycobacterium tuberculosis (MTB) and non-tuberculous mycobacterium (NTM).MethodsWe included 422 adult patients undergoing allogeneic HSCT at an Asian tertiary medical center between January 2003 and December 2014. A total 26 subjects developed post-transplant mycobacterial infections. Risk factors, clinical features, and survival for post-transplant mycobacterial infections were collected and analyzed.ResultsPost-transplant mycobacterial infections occurred in 26 (6.2%) of 422 HSCT patients. Two-year cumulative incidences in MTB and NTM were 1.4% and 5.4%. In the multivariate analysis, being age >45 years (adjusted HR 2.21, 95% CI 1.01–4.83) and extensive chronic graft-versus-host disease (cGVHD) (adjusted HR 4.95, 95% CI 2.14–11.46) were identified as independent risk factors of infections. There was a trend as a risk factors in relapsed patients (P = 0.088). For patients with cGVHD, there was a significant difference of post-transplant survival between mycobacterial infections and none (P = 0.036). Pneumonia contributed most to mortality (n = 11, 42.3%).ConclusionMycobacterial infections are worth to note in a high endemic area. Once a high-risk group is identified, much effort is required to target new approaches for prevention, early detection and treatment of infections.     

Non-myeloablative hematopoietic stem cell transplantation.

Conventional approaches to allogeneic stem cell transplantation have used toxic high-dose conditioning therapy in attempts to eradicate underlying diseases and achieve allogeneic engraftment. Preclinical studies and clinical observations have shown that to achieve engraftment conditioning regimens could be markedly reduced in intensity with reduction in treatment toxicities. The use of potent pre- and postgrafting immunosuppression facilitated stable mixed hematopoietic chimerism in a preclinical canine model. The initial clinical experiences with attenuated conditioning regimens have shown promise as a modality to achieve human stem cell transplantation with an improved safety profile. This may allow offering potentially curative hematopoietic stem cell transplantation (HSCT) to a more representative patient population (older and sicker) who are currently not eligible for such therapy. Obtaining a state of mixed hematopoietic chimerism could prove curative of the disease phenotype of various nonmalignant disturbances of the hematopoietic and immune systems. On the other hand, patients with hematopoietic malignancy will likely require conversion to full donor hematopoeisis by virtue of graft-versus-host (GVH) reactions directed against both recipient hematopoiesis and underlying malignancy. The infusion of additional donor lymphocytes has been proposed by many groups to augment graft versus tumor responses, but most likely more specific strategies will need to be developed to improve efficacy and avoid nonspecific GVH reactions.     

Oral chronic graft-versus-host disease in pediatric patients after hematopoietic stem cell transplantation.

Chronic graft-versus-host disease (cGVHD) is a serious and potentially life-threatening complication of hematopoietic stem cell transplantation. This study, which is the largest single-center series of oral disease in pediatric patients with cGVHD, describes the oral findings in 49 consecutive patients seen in a pediatric multidisciplinary cGVHD clinic. All consecutive patients seen at the multidisciplinary pediatric hematopoietic stem cell transplantation/cGVHD clinic at the Dana-Farber Cancer Institute (Boston, MA) from July 2001 through October 2003 were included in this study. Subjective and objective assessments of mucosal, salivary gland, and sclerotic pathology were performed for each patient, and specific therapy was initiated when indicated. Oral mucosal cGVHD was identified in 22 (45%) of 49 patients. Only 4 (8%) of 49 patients reported mouth pain, and all patients reported being able to eat well. All patients who required specific therapy for their oral mucosal cGVHD (45%) were already taking at least 1 immunomodulatory agent; however, efficacy of treatment was difficult to assess because of inconsistent follow-up periods. Subjective and objective salivary gland and sclerotic disease were observed far less often. Oral mucosal pathology is common in these patients, and appropriate diagnosis and management of oral lesions is critical to reduce patient morbidity and to improve quality of life. The apparent lack of salivary gland involvement was notable. Developing validated age-appropriate evaluation strategies and identifying effective treatment guidelines will be invaluable in the future management of these patients.     

Cidofovir for cytomegalovirus reactivation in pediatric patients after hematopoietic stem cell transplantation.

BACKGROUND: Cidofovir (CDV) is a nucleotide analogue with broad antiviral activity. This drug has a very favorable pharmacokinetic profile that enables intermittent dosing, but the potential for nephrotoxicity has hitherto restricted its use in stem cell transplant recipients. Data on pediatric patients are limited. OBJECTIVES: To report the efficacy and toxicity of CDV in a group of pediatric patients with cytomegalovirus (CMV) reactivation after allogeneic stem cell transplantation. STUDY DESIGN: Prospective evaluation of safety and efficacy of CDV used pre-emptively for CMV reactivation in 10 out of 30 children who underwent allogeneic hematopoietic stem cell transplantation from January 2000 to December 2001. In all the patients but one, CDV was used as second-line therapy (after foscarnet or ganciclovir) of CMV reactivation. RESULTS: Overall, 12 courses of CDV were administered with a median 5 doses per course, range 1-6 (two patients were treated twice). Considering the first CDV treatment episode, 8 out of 10 patients had positive CMV antigenemia assay when they started CDV. Five of eight antigenemic patients responded completely while three were switched to foscarnet or ganciclovir, respectively, due to increasing (one) or persistent CMV antigenemia (two). Overall, the therapy with CDV was well tolerated, but it was withdrawn in one patient due to a two-fold increase in the baseline creatinine level. This patient concurrently had a high tacrolimus blood level. CONCLUSION: Safety is the major concern regarding the use of CDV but the adoption of probenicid, intravenous hydration and anti-emetic therapy improved its tolerability profile. Our data suggest that CDV has an acceptable toxicity and would deserve further controlled studies in the setting of pre-emptive therapy for CMV.     

抗CD20单抗在致敏受者造血干细胞移植中应用的实验研究

目的： 寻找促进异基因造血干细胞在致敏受者植入的策略研究,探讨抗CD20单抗在致敏受者造血干细胞移植的作用。方法：分别于移植前第14 d及第7 d予BALB/c小鼠输注C57BL/6小鼠的脾细胞建立致敏模型。实验组于移植前第11 d经尾静脉输注抗CD20单抗（美罗华）2 mg/mouse,对照组于移植前第11 d予输注RPMI-1640培养液 0.2 mL/mouse。于第0 d（移植当天）取部分小鼠分离得血清及脾细胞,并检测供者反应性抗体及CD19＋B细胞;部分小鼠予［60Co］致死量照射,4 h后予1×107 C57BL/6小鼠骨髓细胞进行移植,观察生存情况及血常规恢复情况。结果：实验组与对照组血清细胞毒性指数分别为（37.00±3.46）％和（51.80±3.49）％,差异显著（P<0.01）;2组的脾细胞CD19＋B细胞百分比分别为（17.32±3.02）％和（34.26±2.87）％,差异显著（P<0.01）。照射移植后2组受者均于14 d左右全部死亡,生存中位数分别为第13 d及第11 d,Log-rank检验2组间的差别无显著（P>0.05）。濒死动物血常规结果示三系减少,提示受者死于造血衰竭。结论：抗CD20单抗能杀伤受者B细胞,降低致敏程度,但实验中该单抗并不能有效促进异基因造血干细胞在致敏受者的植入。     

Cytomegalovirus enteritis among hematopoietic stem cell transplant recipients.

Cytomegalovirus (CMV) is a cause of enteritis associated with hematopoietic stem cell transplantation (HSCT), but the natural history is rarely studied and hence poorly understood. CMV infection at this end-organ site is notably less frequent than is pneumonitis. To evaluate the spectrum of CMV enteritis after HSCT, we reviewed the database spanning 11.5 years of 2240 University of Minnesota transplantation patients for cases of gastrointestinal CMV. We identified 46 case-patients. The incidence of CMV enteritis at 2 years following HSCT averaged 2% over the 11.5-year study interval. The median time to diagnosis of CMV enteritis after HSCT was 91 days (range, 17-527 days). The methods used in diagnosis included histopathology (58%) and virology (61%). Viremia was detected in two thirds of patients with CMV prior to the diagnosis of enteritis. Most treatment regimens included ganciclovir. The overall survival rate was 35% at 2 years following the onset of enteritis.     

Persistent rhinovirus infection in pediatric hematopoietic stem cell transplant recipients with impaired cellular immunity

BackgroundHRV infections are generally self-limiting in healthy subjects, whereas in immunocompromised hosts HRV infections can lead to severe complications and persistent infections. The persistence of HRV shedding could be due to the inefficient immunological control of a single infectious episode.ObjectivesTo investigate the clinical, virologic and immunologic characteristics of pediatric HSCT recipients with HRV-PI infection.Study designDuring the period 2006–2012, eight hematopoietic stem cell transplant (HSCT) recipients presented with persistent rhinovirus infection (HRV-PI, ≥30 days). Viral load and T-CD4⁺, T-CD8⁺, B and NK lymphocyte counts at the onset of infection were compared with those of fourteen HSCT recipients with acute HRV infection (HRV-AI, ≤15 days).ResultsThe median duration of HRV positivity in patients with HRV-PI was 61 days (range 30–174 days) and phylogenetic analysis showed the persistence of a single HRV type in all patients (100%). In HSCT recipients with HRV-PI, T-CD4⁺, T-CD8⁺ and NK cell counts at the onset of infection were significantly lower than those observed in recipients with HRV-AI (p < 0.01), while B cell counts were similar in the two groups (p =  0.25). A decrease in HRV load was associated with a significant increase in T-CD4⁺, T-CD8⁺and NK lymphocyte counts in HRV-PI patients (p < 0.01).ConclusionsThis study suggests a role for cellular immunity in HRV clearance and highlights the importance of its recovery for the control of HRV infection in HSCT recipients.     

Adenovirus infection among pediatric patients with cancer and in pediatric recipients of hematopoietic stem cell: A multicenter nationwide study

The aim was to evaluate the incidence, clinical course, and outcome of adenoviral infection (AdVI) in pediatric patients diagnosed and treated due to cancer and in pediatric recipients of hematopoietic stem cell. Over a 72-month period, all-in 5599 children with cancer: 2441 patients with hematological malignancy (HM) and 3158 with solid tumors (ST), and 971 patients after transplantation: 741 after allogeneic (allo-HSCT) and 230 after autologous (auto-HSCT) were enrolled into the study. Among cancer patients, 67 episodes of AdVI appeared in 63 (1.1%) children, including 45 (1.8%) with HM and 18 (0.6%; P < .001) with ST. Within transplanted patients, AdVIs were responsible for 88 episodes in 81 (8.3%) children (P < .001), including 78 (10.5%) patients after allo-HSCT and 3 (1.3%) after auto-HSCT. Time to develop AdVI was short, especially after allo-HSCT. The most common clinical manifestation in cancer patients was enteritis diagnosed in 63 (94.0%) cases, while among HSCT recipient asymptomatic adenoviremia was found in 36 (40.9%) cases and the most common clinical manifestation was urinary tract infection. Cancer patients with disseminated disease, as well as HSCT recipients with either asymptomatic viremia or disseminated disease, received antiviral treatment. The most commonly used first-line therapy was cidofovir. None of the cancer patients died due to AdVI, while within HSCT recipients three patients developed disseminated adenoviral disease and died despite antiviral treatment. In cancer patients, AdVIs are rare and associated with very good prognosis even without specific treatment. However, in allo-HSCT recipients, disseminated disease with fatal outcome is more likely to occur.     

Survival after second hematopoietic stem cell transplantation for recurrent pediatric acute myeloid leukemia.

Recurrent acute myeloid leukemia (AML) after hematopoietic stem cell transplantation (HSCT) predicts a dismal prognosis. We sought to determine whether a second HSCT would result in long-term disease-free survival with acceptable toxicity. We evaluated the outcome of a second HSCT with a preparative regimen of cyclophosphamide and total body irradiation in pediatric patients with AML who relapsed after an initial HSCT with a busulfan and cyclophosphamide preparative regimen. Twenty-five patients aged 1.1 to 17.2 years (median, 4.1 years) with AML received a second HSCT for recurrent disease. All patients were conditioned with busulfan and cyclophosphamide for the first HSCT and with cyclophosphamide and total body irradiation for the second HSCT. Donor sources for the first HSCT were autologous (n = 11) or allogeneic (n = 14), whereas all donors for the second HSCT were allogeneic (12 matched related, 9 mismatched related, and 4 unrelated). Engraftment after the second HSCT occurred in all patients at median of 19.0 days (range, 11-32 days). The cumulative incidence of grade II to IV graft-versus-host disease was 76% after the second HSCT. Three patients died from regimen-related toxicity before day 100, 9 relapsed at a median of 5.4 months (range, 1.8-34.0 months), and 12 survived a median of 9.1 years (range, 7.0-14.4 years) after the second HSCT. The Kaplan-Meier estimates of survival at 100 days, 1 year, and 10 years were 88%, 56%, and 48%, respectively. The disease-free survival rate at 10 years was 44%. Multivariate Cox regression analysis suggested that patients who received a second HSCT in relapse had a relative risk of relapse of 7.8 (P =.02) compared with patients who underwent transplantation in remission. In addition, patients who received their second HSCT 相似文献   

Second hematopoietic stem cell transplantation in pediatric patients: overall survival and long-term follow-up.

Despite potent intensive conditioning regimens, hematopoietic stem cell transplantation (HSCT) may fail because of either relapse of the malignancy or the rejection of the graft. We report on 27 pediatric patients who received a second HSCT from an allogeneic donor for relapsed malignancy or graft failure. One-year, 5-year, and 10-year probabilities of survival for all patients were 53%, 36%, and 24%, respectively. Twenty patients received second HSCTs for relapsed malignancy, of whom 6 were alive and disease free at the time of this report. Seven patients received a second HSCT for graft failure, of whom 3 were alive and well as of this report. Twenty-five patients were tested for immune reconstitution following their second HSCT. Sixteen patients developed antigen-specific T-lymphocyte responses; the median time to development of antigen-specific responses was 13 months. There was no significant neurocognitive decline in patients tested 1 to 3 years following their second HSCT. Endocrine evaluations revealed deficiencies in growth hormone (7 patients), gonadal function (3 patients), and thyroid function (2 patients). Three patients developed significant abnormalities of tooth development, including absence of secondary teeth. These results show that a second HSCT offers curative therapy for selected pediatric patients whose first HSCT failed. Although toxicity is considerable following a second transplantation, the major causes of mortality continue to be relapse and infection.     

Immunogenomics of hematopoietic stem cell transplantation

Recipients of allogeneic hematopoietic stem cell transplantation (HSCT) incur the risk of graft-versus-host disease even when the donor is a sibling who shares the Major Histocompatibility Antigens. Therefore, even the perfect HLA match does not represent the optimal genetic match between donors and recipients in HSCT. In addition to the HLA complex other genetic systems operate and affect the outcome of HSCT. These include minor histocompatibility systems (Martin P. Applicability of matching for minor histocompatibility antigens in human bone marrow transplantation. In: Roopenian DC, Simpson E, editors. Minor histocompatibility antigens: From the laboratory to the clinic. Georgetown: Landis Bioscience; 2000. p. 97-103) (inducing bona fide allogeneic responses) as well as a series of functional polymorphisms in cytokines and chemokines and receptors genes (Transplantation 1997;64:553). Among the items affecting the outcome of HSCT the incidence and severity of infections have an important impact. Polymorphisms of genes controlling both arms of the immune responses to pathogens (innate versus cognate) are strong candidates for susceptibility factors to infection in allogeneic transplantation. These include the MHC alleles (HLA class I, class II, MIC) CD1, Toll and TLR genes MBP, MPO genes, ...). In addition to the NK alloreactivity induced by HLA class I epitopes mismatching (a common situation in HSCT) variations in the genotype of the KIR genes (Tissue Antigens 2001;57:358) may also be encountered between the donor and the recipient leading to potentially harmful or beneficial combinations. An integrated knowledge of the role and hierarchy of the most important genetic factors (MHC and non-MHC) will provide the rationale for a comprehensive matching in HSCT (Curr Opin Hematol 3 (1996) 416). This short review provides a panorama of this strategic issue for further development of HSCT.