Chemotherapy for a secondary malignancy nearly restores complete chimerism in an SCID-patient after HSCT.

For patients with inborn errors of immunity (IEI) and other inborn diseases, mixed donor chimerism is a well-accepted outcome of hematopoietic stem cell transplantation (HSCT). Cytoreductive chemotherapy for a secondary malignancy is a potential challenge for the stability of the graft function after HSCT. We report on a boy with X-SCID who developed Ewing sarcoma ten years after HSCT which was successfully treated with cytoreductive chemotherapy, surgery and local radiation. Surprisingly, this treatment had a positive impact on mixed chimerism with an increase of donor-cell proportions from 40% for neutrophils and 75% for non-T-mononuclear cells (MNCs) to >90% for both. T-cell counts remained stable with 100% of donor origin. This is -to our knowledge- the first report on the impact of cytoreductive chemotherapy on post-HSCT mixed chimerism and provides an important first impression for future patients.

Spectrum of diabetes mellitus in patients with Shwachman-Diamond syndrome: case report and review of the literature.

BACKGROUND: Shwachman-Diamond syndrome (SDS) is a rare congenital disorder caused by mutations in the SBDS gene and characterized by exocrine pancreatic deficiency, hematologic dysfunction, and skeletal growth failure. Although the hematologic features and characteristics of the somatic disorders commonly associated with SDS are well known, emerging data from case reports and patient registries suggest that SDS may also be associated with an increased risk of diabetes mellitus. However, currently available data on SDS-associated diabetes are limited and do not allow conclusions regarding prevalence and incidence rates, clinical course, and outcomes. CASE PRESENTATION: Here we report the case of a 5-year-old girl with SDS who underwent bone marrow transplantation at the age of 3 months and developed autoantibody-positive type 1 diabetes mellitus at the age of 1.8 years. The manifestation and course of diabetes development were mild, complicated by concurrent spontaneous episodes of hypoglycemia even before the onset of antidiabetic treatment. Currently, adequate metabolic control can be achieved by dietary intervention. CONCLUSIONS: Considering that the SBDS protein regulates mitosis and ribosomal biosynthesis and that its suppression may cause immunologic instability and chronic inflammation, this case provides insight into the phenotype of rare Shwachman-Diamond syndrome-associated diabetes mellitus, which may be characterized by significant age-dependent differences in clinical course.

Matched Family Donor Lymphocyte Infusions as First Cellular Therapy for Patients with Severe Primary T Cell Deficiencies.

Patients with primary immunodeficiencies caused by severe defects in T cell immunity are at risk of acquiring life-threatening infections. Cellular therapies are necessary to establish normal T cell function and to allow for long-term survival. This is most commonly achieved by hematopoietic stem cell transplantation (HSCT), but the outcome of this procedure is impaired if active infections are present at the time of HSCT. Donor lymphocyte infusions (DLIs) are a well-established therapeutic strategy following HSCT to treat viral infections, improve donor cell engraftment, or achieve graft-versus-leukemia activity in malignant disease. Here we present a cohort of 6 patients with primary T cell deficiencies who received transfusions of unselected mature donor lymphocytes prior and not directly related to allogeneic HSCT. DLIs obtained from the peripheral blood of HLA-identical (10/10) family donors were transfused without prior conditioning to treat or prevent life-threatening infections. All patients are alive with a follow-up of 0.5 to 16.5 years after the initial T cell administration. Additional cellular therapies were administered in 5 of 6 patients at 0.8 to 15 months after the first DLI. Mild cutaneous graft-versus-host disease (GVHD, stage ≤2) was observed in 3 of 6 patients and resolved spontaneously. We provide evidence that unselected HLA-identical DLIs can effectively prevent or contribute to overcome infections with a limited risk for GVHD in T cell deficient patients. The T cell system established by this readily available source can provide T cell function for years and can serve as a bridge to additional cellular therapies or, in specific conditions, as definite treatment.

Stem cell transplantation for osteopetrosis in patients beyond the age of 5 years.

Osteopetrosis (OP) is a rare disease caused by defective osteoclast differentiation or function. Hematopoietic stem cell transplantation (HSCT) is the only curative treatment available in the infantile "malignant" form of OP. Improved clinical and genetic diagnosis of OP has seen the emergence of a cohort of patients with less severe and heterogeneous clinical presentations. This intermediate form of OP does not call for urgent intervention, but patients accumulate debilitating skeletal complications over years and decades, which are severe enough to require curative treatment and may also require intermittent transfusion of blood products. Here we present data from 7 patients with intermediate OP caused by mutations in TCIRG1 (n = 2), CLCN7 (n = 2), RANK (n = 1), SNX10 (n = 1), and CA2 (n = 1), who were transplanted between the ages of 5 to 30 years (mean, 15; median, 12). Donors were matched siblings or family (n = 4), matched unrelated (n = 2), or HLA haploidentical family donors (n = 1). Conditioning was fludarabine and treosulfan based. All 6 patients transplanted from matched donors are currently alive with a follow-up period between 1 and 8 years at time of publication (median, 4 years) and have demonstrated a significant improvement in symptoms and quality of life. Patients with intermediate OP should be considered for HSCT.

Therapy with low-dose azacitidine for MDS in children and young adults: a retrospective analysis of the EWOG-MDS study group.

Low-dose azacitidine is efficient and safe in the therapy of malignant myeloid disorders in adults but data in children are lacking. We present a retrospective analysis of 24 children and young adults with myelodysplastic syndrome (MDS) who received azacitidine at the time of first diagnosis or relapse after allotransplant (2 children were treated with azacitidine both initially and for relapse). Diagnoses were refractory cytopenia of childhood (N = 4), advanced primary MDS (N = 9) and secondary MDS (N = 11). The median duration of treatment was four cycles. Azacitidine was well tolerated, but cytopenias led to dose reduction in five cases. Treatment was discontinued in one child because of impaired renal function. Sixteen MDS patients were treated with azacitidine at first diagnosis. One complete clinical remission was observed and one child showed complete marrow remission; six children experienced stable disease with haematological improvement. Ten children received azacitidine for relapsed MDS after transplant: of these, seven experienced stable disease for 2-30 cycles (median 3), including one patient with haematological improvement for seven cycles. In summary, azacitidine is effective in some children with MDS and appears to be a non-toxic option in palliative situations to prolong survival.

Unmistakable Morphology? Infantile Malignant Osteopetrosis Resembling Juvenile Myelomonocytic Leukemia in Infants.

The initial clinical and hematologic presentation of infantile malignant osteopetrosis may be indistinguishable from that of juvenile myelomonocytic leukemia in infants. Timely radiographic imaging, however, allows straightforward delineation of these 2 severe diseases and facilitates immediate initiation of appropriate therapy.

Hematopoietic stem cell transplantation in children and young adults with secondary myelodysplastic syndrome and acute myelogenous leukemia after aplastic anemia.

Secondary myelodysplastic syndrome and acute myelogenous leukemia (sMDS/sAML) are the most serious secondary events occurring after immunosuppressive therapy in patients with aplastic anemia. Here we evaluate the outcome of hematopoietic stem cell transplantation (HSCT) in 17 children and young adults with sMDS/sAML after childhood aplastic anemia. The median interval between the diagnosis of aplastic anemia and the development of sMDS/sAML was 2.9 years (range, 1.2 to 13.0 years). At a median age of 13.1 years (range, 4.4 to 26.7 years), patients underwent HSCT with bone marrow (n = 6) or peripheral blood stem cell (n = 11) grafts from HLA-matched sibling donors (n = 2), mismatched family donors (n = 2), or unrelated donors (n = 13). Monosomy 7 was detected in 13 patients. The preparative regimen consisted of busulfan, cyclophosphamide, and melphalan in 11 patients and other agents in 6 patients. All patients achieved neutrophil engraftment. The cumulative incidence of grade II-IV acute graft-versus-host disease (GVHD) was 47%, and that of chronic GVHD was 70%. Relapse occurred in 1 patient. The major cause of death was transplant-related complication (n = 9). Overall survival and event-free survival at 5 years after HSCT were both 41%. In summary, this study indicates that HSCT is a curative therapy for some patients with sMDS/sAML after aplastic anemia. Future efforts should focus on reducing transplantation-related mortality.

Morphological differentiation of severe aplastic anaemia from hypocellular refractory cytopenia of childhood: reproducibility of histopathological diagnostic criteria.

AIMS: To evaluate the reproducibility and reliability of the histomorphological criteria differentiating severe aplastic anaemia (SAA) and hypoplastic refractory cytopenia of childhood (RCC), the most frequently acquired hypocellular bone marrow conditions of childhood. METHODS AND RESULTS: We performed a double-blind interobserver study of 100 different cases of SAA and RCC among seven haematopathologists of the European Working Group of MDS in Childhood (EWOG-MDS) and the German SAA study. Cases with foci of typical myelodysplastic syndrome (MDS) morphology, such as patchy erythropoiesis with defective maturation, in an otherwise highly hypocellular or adipocytic bone marrow were classified as having RCC. Bone marrow samples without a patchy distribution, few scattered myeloid cells or haematopoietic aplasia were diagnosed as SAA. In only four of 100 cases did the reference pathologists not reach agreement regarding classification as SAA or RCC. The kappa index was 0.79. CONCLUSIONS: Our results show that the vast majority of SAA and RCC cases can be reliably differentiated by morphological means alone. A clear differentiation between SAA and RCC at presentation is mandatory for optimizing therapy strategies, and might be responsible for the fact that, in the German childhood SAA study, the probability of developing clonal disease after immunosuppressive therapy has dropped to 3%.

Sequential acquisition of IgH and TCR rearrangements during the preleukemic phase of acute lymphoblastic leukemia in an adolescent patient.

Acute lymphoblastic leukemia (ALL) can be preceded by a prodromal phase of bone marrow failure. In serial trephine biopsies in a girl with acquired bone marrow hypoplasia, we have identified a monoclonal B-cell precursor population characterized by a clone-specific IgH-FR3 gene rearrangement. Progression to ALL more than 4 months later was accompanied by acquisition of an additional T-cell receptor rearrangement. Thus, hypoplastic pre- and overt leukemia share a common clonal origin. Prospective biobanking and extended molecular analysis can help to better understand the nature and sequence of genetic events during progression of a covert (pre)leukemic clone.

Germline CBL mutations cause developmental abnormalities and predispose to juvenile myelomonocytic leukemia.

CBL encodes a member of the Cbl family of proteins, which functions as an E3 ubiquitin ligase. We describe a dominant developmental disorder resulting from germline missense CBL mutations, which is characterized by impaired growth, developmental delay, cryptorchidism and a predisposition to juvenile myelomonocytic leukemia (JMML). Some individuals experienced spontaneous regression of their JMML but developed vasculitis later in life. Importantly, JMML specimens from affected children show loss of the normal CBL allele through acquired isodisomy. Consistent with these genetic data, the common p.371Y>H altered Cbl protein induces cytokine-independent growth and constitutive phosphorylation of ERK, AKT and S6 only in hematopoietic cells in which normal Cbl expression is reduced by RNA interference. We conclude that germline CBL mutations have developmental, tumorigenic and functional consequences that resemble disorders that are caused by hyperactive Ras/Raf/MEK/ERK signaling and include neurofibromatosis type 1, Noonan syndrome, Costello syndrome, cardiofaciocutaneous syndrome and Legius syndrome.

Developing skeletal muscle cells express functional muscarinic acetylcholine receptors coupled to different intracellular signaling systems.

This study analyzed the expression of muscarinic acetylcholine receptors (mAChRs) in the rat cultured skeletal muscle cells and their coupling to G protein, phospholipase C and adenylyl cyclase (AC). Our results showed the presence of a homogeneous population of [(3)H]methyl-quinuclidinyl benzilate-binding sites in the membrane fraction from the rat cultured muscle (K(D) = 0.4 nM, B(max) = 8.9 fmol mg protein(-1)). Specific muscarinic binding sites were also detected in denervated diaphragm muscles from adult rats and in myoblasts isolated from newborn rats. Activation of mAChRs with carbachol induced specific [(35)S]GTPgammaS binding to cultured muscle membranes and potentiated the forskolin-dependent stimulation of AC. These effects were totally inhibited by 0.1-1 microM atropine. In addition, mAChRs were able to stimulate generation of diacylglycerol (DAG) in response to acetylcholine, carbachol or selective mAChR agonist oxotremorine-M. The carbachol-dependent increase in DAG was inhibited in a concentration-dependent manner by mAChR antagonists atropine, pirenzepine and 4-DAMP mustard. Finally, activation of these receptors was correlated with increased synthesis of acetylcholinesterase, via a PKC-dependent pathway. Taken together, these results indicate that expression of mAChRs, coupled to G protein and distinct intracellular signaling systems, is a characteristic of noninnervated skeletal muscle cells and may be responsible for trophic influences of acetylcholine during formation of the neuromuscular synapse.