[Interdisciplinary AWMF guideline for the diagnostics of primary immunodeficiency]. / Interdisziplinäre AWMF-Leitlinie zur Diagnostik von primären Immundefekten (S2k).

BACKGROUND: Primary immunodeficiencies are potentially life-threatening diseases. Over the last years, the clinical phenotype and the molecular basis of an increasing number of immunological defects have been characterized. However, in daily practice primary immunodeficiencies are still often diagnosed too late. Considering that an early diagnosis may reduce morbidity and mortality of affected patients, an interdisciplinary guideline for the diagnosis of primary immunodeficiencies was developed on behalf of the Arbeitsgemeinschaft Pädiatrische Immunologie (API) and the Deutsche Gesellschaft für Immunologie (DGfI). METHODS: The guideline is based on expert opinion and on knowledge from other guidelines and recommendations from Germany and other countries, supplemented by data from studies that support the postulated key messages (level of evidence III). With the contribution of 20 representatives, belonging to 14 different medical societies and associations, a consensus-based guideline with a representative group of developers and a structured consensus process was created (S2k). Under the moderation of a representative of the Association of the Scientific Medical Societies in Germany (AWMF) the nominal group process took place in April 2011. RESULTS: The postulated key messages were discussed and voted on following a structured consensus procedure. In particular, modified warning signs for primary immunodeficiencies were formulated and immunological emergency situations were defined.

Myeloid antigen co-expression in childhood acute lymphoblastic leukaemia: relationship with in vitro drug resistance.

Contradictory data have been reported about the prognostic value of myeloid antigen co-expression (My+) in childhood acute lymphoblastic leukaemia (ALL). In the present study the methyl thiazol tetrazoliumbromide (MTT) assay was used to compare the in vitro cytotoxicity of 14 drugs between 60 My+ (CD13+ and/or CD33+) and 107 My- ALL children at initial diagnosis. P-glycoprotein (P-gp), multidrug resistance-associated protein (MRP), major vault protein/lung resistance protein (LRP) and the intracellular daunorubicin concentration were studied by flow cytometry. My+ ALL samples were significantly more resistant, i.e. between 1.1- and 2.9-fold, to daunorubicin, doxorubicin, idarubicin, mitoxantrone, vincristine, 6-thioguanine, 6-mercaptopurine, teniposide, etoposide and ifosfamide compared with My- ALL samples. My- and My+ ALL did not significantly differ in sensitivity to prednisolone, dexamethasone, L-asparaginase and cytarabine. Comparable results were found when only common and preB ALL cases were analysed. Drug resistance in My+ ALL was not related to increased expression of P-gp, MRP or LRP compared with My- ALL (ratio My+/My-:P-gp 0.8, MRP 1.0, LRP 1.1). Accumulation and retention of daunorubicin did not significantly differ between My- and My+ ALL cells (ratio My+/My-: accumulation 1.2, retention 1.3). Therefore the nature of drug resistance in My+ ALL remains unknown. The lack of prognostic value for My+ in childhood ALL may be explained by the responsiveness of My+ ALL to glucocorticoids, L-asparaginase and cytarabine. In addition, the currently intensive treatment regimens may apply drug doses which are simply high enough to overcome the mild resistance to anthracyclines, mitoxantrone, vincristine, thiopurines, epipodophyllotoxins and ifosfamide in childhood My+ ALL.

Slow progression of juvenile metachromatic leukodystrophy 6 years after bone marrow transplantation.

Metachromatic leukodystrophy refers to a group of genetic neurologic diseases caused by deficiencies of the enzyme arylsulfatase A and the resulting accumulation of sulfatides in white matter. Bone marrow transplantation has been advocated as a treatment in an attempt to correct the enzyme deficiency. Such a transplant was performed in 1991 in a 16-year-old girl with a form of late juvenile metachromatic leukodystrophy caused by a homozygous P426L mutation in the arylsulfatase A gene. Engraftment was prompt and resulted in constant enzymatic normalization of circulating lymphocytes. The elevated urinary excretion of sulfatides remained unaffected. Clinical findings up until transplantation consisted of gait disturbances, impairment of cognitive functioning, and deterioration in school performance over several years. During a 6-year follow-up period, the patient's condition was subject to major fluctuations but, on the whole, findings showed slow neurologic and neurophysiologic deterioration. The clinical course observed after bone marrow transplantation probably more or less reflects the natural course expected in this form of late-onset metachromatic leukodystrophy.

A classification based on T cell selection-related phenotypes identifies a subgroup of childhood T-ALL with favorable outcome in the COALL studies.

During T cell selection in the thymic cortex more than 90% of the thymocytes are eliminated by apoptosis. Based on this biology, we propose to define blasts of T cell acute lymphoblastic leukemia (ALL) with the phenotype of cortical thymocytes (CD1+ and/or CD4+ 8+) as selection-related (SR) and all other T-ALL immunophenotypes as non-selection-related (NSR). The COALL cooperative treatment studies for childhood ALL offer a tool to study the outcome in T-ALL subgroups as children with T-ALL are allocated uniformly to the high risk arm of the protocol. In the COALL-85, -89 and -92 protocols, 39/83 cases presented as SR and 44/83 cases as NSR. Five-year event-free survival of SR phenotype is significantly better compared to the NSR group (0.87 +/- 0.06 vs 0.66 +/- 0.07, log rank test, P = 0.01). T-ALL with SR phenotype is a distinct subgroup of leukemia with excellent prognosis under a high risk treatment protocol.

MLL/ENL fusion in congenital acute lymphoblastic leukemia with a unique t(11;18;19).

To elucidate the events leading to a unique complex translocation involving chromosomes 11, 18, and 19 in a congenital progenitor B-cell acute lymphoblastic leukemia, we have performed comprehensive cytogenetic and fluorescence in situ hybridization (FISH) analyses as well as molecular genetic studies on the DNA and RNA level. We were able to confirm the cytogenetic interpretation of this complex t(11;18;19)(q23;q22;p13.3) by chromosome painting. Involvement of the MLL gene on 11q23 became evident by Southern blot analysis as well as by FISH with a YAC clone containing the respective gene. Despite the fact that the additional signals of the split YAC clone were observed on the abnormal chromosome 18, reverse transcription polymerase chain reaction (RT-PCR) revealed a MLL/ENL hybrid mRNA, which is specific for a t(11;19)(q23;p13.3). This gene fusion most probably represents the critical part of this rearrangement. The transfer of the translocated part of the split YAC clone onto chromosome 18 indicates that the second break must have occurred in the vicinity of the first one, at a distance too close to be resolved by FISH. Whether this break took place within chromosome 11 or 19 sequences, up- or downstream of the MLL/ENL fusion, and whether this translocation results from a concerted simultaneous exchange of material or from two separate sequential events in consecutive cell generations remains open.

Allogeneic bone marrow transplantation for lysosomal storage diseases. The European Group for Bone Marrow Transplantation.

Patients with lysosomal storage disorders have visceral, skeletal, and neurological abnormalities and a limited life expectancy. Bone marrow transplantation has been used to correct the metabolic defects and leads to metabolic improvements in most patients. However, the long-term effect of such therapy is uncertain. We analysed the data from 63 patients transplanted for lysosomal storage diseases. The transplant-related mortality was 10% if an HLA-identical sibling marrow donor was available (n = 40) and 20-25% if mismatched tissue was used. Data on the effect of bone marrow transplantation on biochemical and clinical disease variables were available in 29 of the 63. 28 had a follow-up duration of 1.0-10.2 years; 1 patient died of disease progression in the first year after stable engraftment. 13 patients who had severe neurological symptoms at the time of transplantation showed disease progression. Engraftment of bone marrow in 5 patients with non-neuronopathic Gaucher's disease led to complete disappearance of symptoms. 11 patients had skeletal symptoms because of various mucopolysaccharidoses (MPSs). There was stabilisation of the skeletal lesions during the observation period of 1.4-6.4 years, but none of the patients showed significant regression of the skeletal symptoms. The visceral features (hepatosplenomegaly, cardiac hypertrophy, and upper airway obstruction) in these patients abated after transplantation. We could not evaluate the biochemical and clinical variables in 34 patients because of graft rejection, transplant-related mortality, or follow-up of less than 1 year. There were significant beneficial effects of bone marrow transplantation in patients with non-neuronopathic Gaucher's disease. Stabilisation of disease was observed in patients with MPS-I and MPS-II; this potential benefit needs to be confirmed by longer follow-up. Bone marrow transplantation was not effective if severe neurological symptoms were already present at the time of transplantation.

Atypical chronic myelogenous leukemia in a patient with trisomy 8 mosaicism syndrome.

A 17-year-old woman was admitted for bone marrow transplantation with the diagnosis of atypical Philadelphia-negative chronic myelogenous leukemia (aCML), cytogenetically characterized by trisomy 8 as the sole chromosome aberration. A striking feature was a congenital opacity of the right cornea. Chromosomal analysis of skin fibroblasts were performed and revealed a mosaic for trisomy 8. Commonly, a distinct clinical picture leads to the diagnosis of trisomy 8 mosaicism syndrome (T8ms), but an extreme phenotypic variability has been observed. To our knowledge the development of an aCML in a patient with T8ms has not been reported. A review of the literature revealed that an association to other hematological disorders had been described in two cases. The question of whether our patient's aCML was a random event or not is discussed. The patient is now 24 months post transplant and shows no evidence of disease. Her Karnofsky score is 100%. We conclude that it might be worthwhile to look for an associated constitutional trisomy 8 mosaicism in all patients with trisomy 8 leukemia.