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Analysis of non-histocompatibility leucocyte antigen (HLA) functional genomics, together with conventional risk factors in haematopoietic stem cell transplantation (HSCT) can lead to predicting outcome in HLA-matched sibling transplant recipients. Polymorphisms of cytokine genes including tumour necrosis factor alpha, interleukin-10, interferon gamma and interleukin (IL)-6, associate with more severe acute graft-versus-host disease (aGvHD). Donor genotype for IL-1 receptor antagonist (IL-1Ra) has been associated with reduced aGvHD severity. Other genotypes (patient IL-1Ra, IL-6 and donor IL-1 alpha) have been associated with chronic GvHD, or overall survival (Vitamin D receptor and oestrogen receptor). Polymorphisms within genes associated with host defence/inflammatory responses (mannose binding lectin genes, myeloperoxidase genes and the FC gamma receptors) have been associated with infections. Polymorphisms of pharmacogenes, such as methylenetetrahydrofolate-reductase, have been associated with aGvHD and other post-transplant complications. The NOD2 gene polymorphism, associated with Crohn's disease, has been shown to be associated with risk of gut GvHD. The majority of the studies have been carried out in single centre HLA-matched sibling cohorts and in relatively few matched unrelated donor transplants. This review gives an overall perspective of the current field of non-HLA genetics with regard to HSCT outcome, clinical relevance and potential application of the results to clinical management of HSCT.

The interleukin-1 (IL-1) family of cytokines is widely involved in inflammatory processes and diseases with an inflammatory component. Polymorphisms of the IL-1alpha, IL-1beta and IL-1Ra genes have been implicated in a number of autoimmune or inflammatory conditions, with polymorphism of the IL-1Ra gene showing association with severity of graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation (BMT). We compared the clinical outcomes (GVHD and survival) of 115 patients after human leucocyte antigen (HLA)-identical sibling allogeneic BMT with their genotype for two polymorphisms present in the IL-1alpha gene, which have been implicated in immune-related pathology. Possession of allele 2 of the IL-1alpha-889 polymorphism and allele 2 of the IL-1alpha variable number tandem repeat (VNTR) polymorphism in the donor genotype was associated with the occurrence of chronic, but not acute GVHD. A local normal population was also genotyped for these polymorphisms, and subsequent analysis identified conserved haplotypes in this gene region. Haplotypes containing allele 2 at both IL-1alpha-889 and IL-1alpha VNTR loci were extremely uncommon, suggesting that both risk alleles would be inherited independently. Both loci could therefore function as independent disease association markers. The polymorphisms of the IL-1alpha gene could be used to predict chronic GVHD in HLA-matched sibling transplants alongside clinical risk factors.

Recent studies have shown that CD38 expressed as a percentage of the antigen positivity can predict prognosis and disease progression in patients with B-cell chronic lymphocytic leukaemia (B-CLL). The present study showed that quantification of CD38 expressed as antibody-binding capacity (ABC) improves the prognostic value of the percentage of CD38 positivity in B-CLL. In a cohort of 81 patients with B-CLL, a level of CD38 expression of > or = 30% and an ABC value of 250 proved statistically valid cut-off points to predict disease progression (% CD38: P=0.0027; ABC: P < 0.0001). There was a positive and significant correlation between the percentage of CD38 expression and ABC (r=0.7; P < 0.0001). There was a better discrimination of survival using ABC rather than percentage CD38 positivity (P < 0.0001 compared with P=0.0027). Only ABC predicted for survival in patients under 60 years of age (P=0.0076) or with stage A disease (P=0.0195). Both percentage CD38 and ABC discriminated between time to first treatment for all patients but only ABC predicted time to treatment for stage A patients (P=0.0004). In conclusion, CD38 positivity is an important prognostic factor in B-CLL. However, quantification of CD38 is superior to the percentage positivity and should be used clinically in conjunction with other variables of predictive value to identify B-CLL patients that are likely to progress.

Interleukin 1 (IL-1) is involved in various autoimmune and inflammatory diseases. IL-1 receptor antagonist (IL-1Ra) is the naturally occurring antagonist to IL-1alpha and -1beta. Polymorphisms of IL-1beta have been associated with variations in IL-1beta production (nucleotides +3953 and -511). A variable number tandem repeat (VNTR) polymorphism in the IL-1Ra gene has been associated (allele 2) with increased IL-1Ra production. We examined these polymorphisms in human leucocyte antigen (HLA)-matched allogeneic bone marrow transplant patients and donors. IL-1Ra VNTR (allele 2) in the donor genotype was more frequent with milder acute graft-versus-host disease (aGvHD) grades 0-II (29 out of 59 transplants) than severe GvHD grades III-IV (2 out of 18 transplants) (P = 0.0032). This association was confirmed in a subgroup with cyclosporine monotherapy prophylaxis: donor possession of allele 2 was again associated with milder aGvHD, grades 0-II (19 out of 38 transplants), than grades III-IV (1 out of 14) (P = 0.0042) transplants. No association was found between the IL-1beta -511 or IL-1beta +3953 polymorphism and severity of GvHD. Recipient IL-1Ra VNTR genotype (allele 2) showed a strong trend towards association with aGvHD severity (P = 0.0697). Thus, the donor genotype for the IL-1Ra polymorphism has an apparent protective role against acute GvHD following transplantation and may be an additional factor for individual risk assessment for complications, including GvHD, post transplant.

Human peripheral blood mononuclear cell cultures (PBMC) stimulated with Sendai virus or K562 cells produce a mixture of interferons. Temperature and pH stability characteristics and reactions with monospecific antibodies indicate that PBMC cultures from adults produce interferons alpha and gamma in approximately equal proportions. PBMC cultures from children produce lower levels of interferons with a higher proportion of type alpha. The ability of PBMC cultures from children with acute lymphoblastic leukaemia (ALL) to produce interferon was determined. Little or no gamma interferon was induced by either Sendai virus or K562 cells. Cultures from some children with ALL produced alpha interferon but mean levels were significantly lower than from normal children. A group of older children with ALL who had completed their course of therapy and were off treatment produced levels of interferon indistinguishable from those of normal children. This in vitro deficit, possibly induced by chemotherapy, may reflect an in vivo deficit and may contribute to the impaired handling of viruses seen in children being treated for ALL.

Fifteen children with acute lymphoblastic leukaemia (ALL) in remission receiving maintenance chemotherapy and 12 ALL patients off treatment and in remission were tested for natural killer (NK) cell activity in vitro. Compared with a control population the children with ALL receiving maintenance chemotherapy had low levels of NK cell activity. This effect was not due to a specific reduction in NK cell numbers since proportions of mononuclear cells detected by the monoclonal antibodies HNK-1 (Leu-7) and Leu-11a were normal. Furthermore NK cell activity in patients could only be partially increased by pre-incubation of effector cells with interferon (alpha IFN). These studies confirm the lack of NK cell activity in children with ALL and show that this phenomenon is directly related to functional NK cell impairment. Our study has further shown that this effect is transient since ALL patients off treatment and in remission showed normal levels and augmentation of NK cell activity.