Involvement of nitric oxide released from microglia-macrophages in pathological changes of cathepsin D-deficient mice

Cathepsin D (CD) deficiency has been shown to induce ceroid-lipofuscin storage in lysosomes of mouse CNS neuron (Koike et al., 2000). To understand the behavior of microglial cells corresponding to these neuronal changes, CD-deficient (CD-/-) mice, which die at approximately postnatal day (P) 25 by intestinal necrosis, were examined using morphological as well as biochemical approaches. Light and electron microscopic observations revealed that microglia showing large round cell bodies with few processes appeared in the cerebral cortex and thalamus after P16. At P24, microglia often encircled neurons that were occupied with autolysosomes, indicating increased phagocytic activity. These morphologically transformed microglia markedly expressed inducible nitric oxide synthase (iNOS), which was also detected in the intestine of the mice. To assess the role of microglial nitric oxide (NO) in neuropathological changes in CD-/- mice, l-N(G)-nitro-arginine methylester (l-NAME), a competitive NOS inhibitor, or S-methylisothiourea hemisulfate (SMT), an iNOS inhibitor, was administered intraperitoneally for 13 consecutive days. The total number of terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling-positive cells counted in the thalamus was found to be significantly decreased by chronic treatment of l-NAME or SMT, whereas neither the neuronal accumulation of ceroid-lipofuscin nor the microglial phagocytic activity was affected by these treatments. Moreover, the chronic treatment of l-NAME or SMT completely suppressed hemorrhage-necrotic changes in the small intestine of CD-/- mice, resulting in normal growth of the body weight of the mice. These results suggest that NO production via iNOS activity in microglia and peripheral macrophages contributes to secondary tissue damages such as neuronal apoptosis and intestinal necrosis, respectively.

Long-term results of local recurrence after breast conservation treatment for invasive breast cancer

PURPOSE

The outcome for women with a local failure after breast conservation treatment is not well described in the literature. Because local recurrence is a potentially salvageable event, this study was performed to evaluate the outcome of patients with local recurrence after breast conservation surgery and definitive radiation treatment.

METHODS AND MATERIALS

The study population consisted of 112 patients with ipsilateral breast tumor recurrence. There were 100 isolated local recurrences and 12 local-plus-regional recurrences. There were 93 invasive local recurrences and 19 DCIS (ductal carcinoma in situ) local recurrences. Local recurrences were detected by physical examination alone in 42 patients, mammography alone in 47 patients, and both modalities in 23 patients. All patients were initially treated with breast conservation treatment with or without systemic therapy and subsequently treated at the time of local recurrence with salvage mastectomy with or without systemic therapy. The mean and median follow-up times after local recurrence were 49 and 44 months, respectively.

RESULTS

For the entire group of 112 patients, the overall survival at 10 years after local recurrence was 69%, the cause-specific survival was 71%, and the freedom from distant metastases was 47%. For the 93 patients with an invasive local recurrence, the overall survival at 10 years was 64%, cause-specific survival was 67%, and freedom from distant metastases was 44%. For the 93 patients with an invasive local recurrence, interval from diagnosis to local recurrence (< or =2 years vs. 2.1-5 years vs. >5 years) predicted for overall survival at 5 years (65% vs. 84% vs. 89%; p = 0.03). Method of detection of local recurrence (physical examination vs. mammography vs. both methods) also predicted for 5-year overall survival (73% vs. 91% vs. 93%, respectively; p = 0.04). On multivariable analysis, interval from diagnosis to local recurrence was an independent predictor of overall survival (p = 0.03). Method of detection of local recurrence (physical examination vs. mammography vs. both methods) was borderline in predicting for 5-year cause-specific survival (73% vs. 91% vs. 93%, respectively; p = 0.06). Similarly, interval from diagnosis to local recurrence (< or =2 years vs. 2.1-5 years vs. >5 years) was a borderline predictor of 5-year cause-specific survival (65% vs. 84% vs. 89%; p = 0.08). No factors that predicted for freedom from distant metastases were identified. There were three second locoregional failures on the chest wall. Two of the 19 patients with a DCIS local recurrence have died of metastatic breast cancer. Death was probably not related to their local recurrence, but rather a result of persistent risk from an invasive primary cancer.

CONCLUSIONS

This analysis provides long-term data after salvage treatment for patients who experience local recurrence after breast conservation treatment. The variables of method of detection and interval from diagnosis to local recurrence are identified as having prognostic significance for overall and cause-specific survival. In view of the potential for long-term survival, aggressive attempt at salvage treatment is warranted for the patient with local recurrence after breast conservation treatment. Second local recurrence after salvage mastectomy is an uncommon event. Although DCIS local recurrences may not in themselves cause an increase in the risk of mortality, the risk from the primary invasive cancer persists.

Allogeneic bone marrow transplantation-mediated transfer of specific immunity against Toxocara canis associated with excessive IgE

A girl with myelodysplastic syndrome (RAEB-T) received HLA-identical bone marrow from her younger brother after myeloablative treatment with busulfan and cyclophosphamide. After bone marrow transplantation, fever, exanthema, pruritus, and a pulmonary infiltrate were treated symptomatically. Bacterial cultures remained negative. Leukocyte engraftment began on day 10, and all blood cell populations proved to be of donor origin on FISH analysis. Increasing IgE levels (21 000 U/ml) on day 14 after BMT, positive RAST, specific IgG-antibodies, and missing Toxocara (T.) canis antigens in the recipient indicated donor-derived seroconversion. Before BMT, the recipient had been negative for T. canis in routine parasitological screening, and the donor proved to be positive for T. canis antibody by ELISA. This report suggests that the transfer of IgE immunity in the absence of detectable antigens may be responsible for IgE-mediated symptoms consistent with toxocara infection and confirms the need for parasite screening in donor medical examinations.

The chemical biology of Ras lipidation

In this review, we summarize the successful interplay between three disciplines, organic synthesis, biophysics and cell biology, in the study of protein lipidation and its relevance to targeting of proteins to the plasma membrane of cells in molecular detail. Highlighting the example of the Ras proteins, we show how the development of new synthetic methodologies paved the road to the synthesis of lipidated peptides and--by a combination of chemical and molecular biological techniques--lipidated proteins as molecular tools. We further give an overview of the results of the biophysical properties and biological activities of the molecules synthesized by means of this interdisciplinary approach. This successful combination of different disciplines led to a better understanding of the selective targeting of Ras and related lipoproteins to the plasma membrane.

Cathepsin S regulates the expression of cathepsin L and the turnover of gamma-interferon-inducible lysosomal thiol reductase in B lymphocytes

Loading of antigenic peptide fragments on major histocompatibility complex class II molecules is essential for generation of CD4(+) T cell responses and occurs after cathepsin-mediated degradation of the invariant chain chaperone molecule. Cathepsins are expressed differentially in antigen presenting cells, and mice deficient in cathepsin S or cathepsin L exhibit severely impaired antigen presentation in peripheral lymphoid organs and the thymus, respectively. To determine whether these defects are due solely to the block in invariant chain cleavage, we used cathepsin-deficient B cells to examine the role of cathepsins S and B in the degradation of other molecules important in the class II presentation pathway. Our data indicate that neither cathepsin S nor B is critical for H-2M degradation or processing of precursor gamma-interferon-inducible lysosomal thiol reductase (GILT) to a mature thiol reductase, but suggest a role for cathepsin S in the turnover of mature GILT and in regulating levels of mature cathepsin L protein in B cells. Despite the presence of mature cathepsin L protein, no enzyme activity could be detected in B cells or dendritic cells. These experiments suggest a novel mechanism by which these functionally important enzymes may be regulated.

Comparison of outcomes of unrelated bone marrow and umbilical cord blood transplants in children with acute leukemia

In order to compare the outcomes of unrelated umbilical cord blood transplants (UCBTs) or bone marrow transplants, 541 children with acute leukemia (AL) transplanted with umbilical cord blood (n = 99), T-cell-depleted unrelated bone marrow transplants (T-UBMT) (n = 180), or nonmanipulated (UBMT) (n = 262), were analyzed in a retrospective multicenter study. Comparisons were performed after adjustment for patient, disease, and transplant variables. The major difference between the 3 groups was the higher number in the UCBT group of HLA mismatches (defined by serology for class I and molecular typing for DRB1). The donor was HLA mismatched in 92% of UCBTs, in 18% of UBMTs, and in 43% of T-UBMTs (P <.001). Other significant differences were observed in pretransplant disease characteristics, preparative regimens, graft-versus-host disease (GVHD) prophylaxis, and number of cells infused. Nonadjusted estimates of 2-year survival and event-free survival rates were 49% and 43%, respectively, in the UBMT group, 41% and 37% in the T-UBMT group, and 35% and 31% in the UCBT group. After adjustment, differences in outcomes appeared in the first 100 days after the transplantation. Compared with UBMT recipients, UCBT recipients had delayed hematopoietic recovery (Hazard ratio [HR] = 0.37; 95% confidence interval [95CI]: 0.27-0.52; P <.001), increased 100 day transplant-related mortality (HR = 2.13; 95CI: 1.20-3.76; P <.01) and decreased acute graft-versus-host disease (aGVHD) (HR = 0.50; 95CI: 0.34-0.73; P <.001). T-UBMT recipients had decreased aGVHD (HR = 0.25; 95CI: 0.17-0.36; P <.0001) and increased risk of relapse (HR = 1.96; 95CI: 1.11-3.45; P =.02). After day 100 posttransplant, the 3 groups achieved similar results in terms of relapse. Chronic GVHD was decreased after T-UBMT (HR = 0.21; 95CI: 0.11-0.37; P <.0001) and UCBT (HR = 0.24; 95CI: 0.01-0.66; P =.002), and overall mortality was higher in T-UBMT recipients (HR = 1.39; 95CI: 0.97-1.99; P <.07). In conclusion, the use of UCBT, as a source of hematopoietic stem cells, is a reasonable option for children with AL lacking an acceptably matched unrelated marrow donor.

Towards specific functions of lysosomal cysteine peptidases: phenotypes of mice deficient for cathepsin B or cathepsin L

The lysosomal cysteine peptidases cathepsin B and cathepsin L are abundant and ubiquitously expressed members of the papain family, and both enzymes contribute to the terminal degradation of proteins in the lysosome. However, there is accumulating evidence for specific functions of lysosomal proteases in health and disease. The generation of 'knock out' mouse strains that are deficient in lysosomal proteases provides a valuable tool for evaluation of existing hypotheses and gaining new insights into the in vivo functions of these proteases. In this minireview, we summarise and discuss the findings obtained by analysis of mice that are devoid of cathepsin B or cathepsin L. In brief, cathepsin L appears to be critically involved in epidermal homeostasis, regulation of the hair cycle, and MHC class II-mediated antigen presentation in cortical epithelial cells of the thymus. Cathepsin B plays a major role in pathological trypsinogen activation in the early course of experimental pancreatitis and contributes significantly to TNF-alpha induced hepatocyte apoptosis.

A multi-institutional analysis of laparoscopic orchidopexy

OBJECTIVE

To combine and analyse the results from centres with a large experience of laparoscopy for the impalpable testis with small series, to determine the expected success rate for laparoscopic orchidopexy.

METHODS

A questionnaire was distributed to participating paediatric urologists; each contributor retrospectively reviewed the clinical charts for their cases of therapeutic laparoscopy for an impalpable testis, detailing 36 variables for each patient. The data were collated centrally into a computerized database. For inclusion, the testis was intra-abdominal (including 'peeping' at the internal ring) at laparoscopic examination, was not managed through an open approach and did not undergo orchidectomy. Three surgical groups were assessed, with success defined as lack of atrophy and intrascrotal position: group 1, primary laparoscopic orchidopexy; group 2, a one-stage Fowler-Stephens (F-S) orchidopexy; and group 3, a two-stage F-S orchidopexy.

RESULTS

Data were gathered from 10 centres in the USA, covering the period 1990-1999; 252 patients representing 310 testes were included and overall, 15.2% were lost to follow-up. There was no significant difference between success rates in the larger and smaller series. Atrophy occurred in 2.2% of 178 testes, 22.2% of 27 testes and 10.3% of 58 testes in groups 1-3, respectively. Testes were not in a satisfactory scrotal position in 0.6%, 7.4% and 1.7% of groups 1-3, respectively. The mean follow-up for each group was 7.7, 8.6 and 20.0 months, respectively. The overall success for all groups was 92.8% (97.2% group 1; 74.1% group 2; 87.9% group 3), with an atrophy rate of 6.1%.

CONCLUSION

Laparoscopic orchidopexy for the intra-abdominal testis, in both large and small series, can be expected to have a success rate higher than that historically ascribed to open orchidopexy. Within this series, single-stage F-S laparoscopic orchidopexy resulted in a significantly higher atrophy rate than the two-stage repair. However, when considering both F-S approaches, the laparoscopic approach gave greater success than previously reported for the same open approaches. Despite the weaknesses inherent in a retrospective unrandomized study, we conclude that laparoscopic orchidopexy is, if not the procedure of choice, an acceptable and successful approach to the impalpable undescended testicle.

Oral busulfan pharmacokinetics and engraftment in children with Hurler syndrome and other inherited metabolic storage diseases undergoing hematopoietic cell transplantation

Allogeneic hematopoietic cell transplantation (HCT) is the only treatment for selected inherited metabolic storage diseases (IMSD); a significant shortcoming is failure to achieve donor-derived engraftment. This study was undertaken to determine whether busulfan pharmacokinetics (BU PK) are altered in children with IMSD and whether BU concentrations are important in achieving engraftment. BU samples were obtained from 39 IMSD children, including 20 children with Hurler syndrome, undergoing HCT. Patients received oral BU (40 mg/m(2)/dose x 8 doses), cyclophosphamide (60 mg/kg/day x 2 doses) and TBI (750 cGy in one fraction) as a preparative regimen. Median (range) oral clearance corrected for bioavailability (Cl/F in ml/min/kg), area under the curve (AUC in ng min/ml) and BU plasma concentration (Cp in ng/ml) with the fourth dose were 5.2 (2.1-11.4), 318 294 (112 893-640 995) and 950 (314-1780), respectively. Children < 3 years of age had lower AUC and Cp but higher Cl/F (P < or = 0.03). BU Cp (P = 0.06) or marrow cell dose (P = 0.32) was not different in Hurler syndrome compared to other IMSD. A median BU Cp of 959 and 831 ng/ml was achieved in children with full and failed early engraftment, respectively. There was no difference in early and late engraftment between children with Hurler and other IMSD. In conclusion, we found no significant association between engraftment, marrow cell dose and BU exposure when combined with CY and TBI in children with IMSD.

Measurement of CP-violating asymmetries in B0 decays to CP eigenstates

We present measurements of time-dependent CP-violating asymmetries in neutral B decays to several CP eigenstates. The measurement uses a data sample of 23x10(6) Upsilon(4S)-->BbarB decays collected by the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we find events in which one neutral B meson is fully reconstructed in a CP eigenstate containing charmonium and the flavor of the other neutral B meson is determined from its decay products. The amplitude of the CP-violating asymmetry, which in the standard model is proportional to sin2beta, is derived from the decay time distributions in such events. The result is sin2beta = 0.34+/-0.20 (stat)+/-0.05 (syst).

Antidepressant treatment and neural plasticity

The use of psychopharmacologic agents in children is complicated by several factors. One important neurobiologic consideration is the relationship of the effect of the medication to ongoing brain development. Although available data are inadequate to address this issue directly, a review of ancillary data suggests that there are theoretical reasons to exercise prudence in prescribing psychopharmacologic agents. For example, the effects of serotonin on neuronal plasticity suggest that agents that can alter serotonergic function may alter neuronal wiring. Although this can occur in any brain, it may be of particular importance in a developing nervous system. The consequences of these induced changes are not clear. Animal studies on the effect of long-term antidepressant administration in immature pups may begin to answer some of the clinical concerns of these observations.

Serial granulocytapheresisunder daily administration of rHuG-CSF: effects on peripheral blood counts, collection efficiency, and yield

BACKGROUND

An option for treatment of severe infections in neutropenic patients is the transfusion of granulocytes from donors stimulated with rHuG-CSF. The schedule of rHuG-CSF-stimulated granulocyte donations and the quality of the components remain controversial. This study was done with the intention of ensuring daily granulocyte support with therapeutic cell numbers, while keeping the patients' allogeneic exposure as low as possible.

STUDY DESIGN AND METHODS

Granulocyte collection with multiple consecutive leukapheresis procedures under daily rHuG-CSF administration and with hydroxyethyl starch as sedimenting agent were prospectively studied. Complete blood counts of the donors, collection yield, and efficiency were analyzed.

RESULTS

Products (n = 259) from 76 donors were examined. The median peripheral blood WBC and neutrophil counts were 28.1 g per L and 24.1 g per L, respectively, and they were significantly higher on Day 5 of collections than on Days 1 to 3. Platelet counts and Hb levels decreased steadily. Collection yields increased over time from 4.9 to 6.7 x 10(10) neutrophils. Side effects of cytokines and aphereses did not exceed World Health Organization grade II status.

CONCLUSION

Repetitive daily rHuG-CSF administration-even under daily leukapheresis procedures-results in a continuing increase in WBC and neutrophil levels and thus leads to increased collection yields. Side effects are tolerable, although Hb and platelet levels should be monitored closely.

Observing proteases in living cells

The lysosomal cysteine protease cathepsin B has been implicated in tumor progression and metastasis in part due to its altered trafficking. In order to analyze the trafficking of cathepsin B in living cells, we utilized enhanced green fluorescent protein (EGFP) fused to various cathepsin B constructs for transfecting two cell lines: an invasive human breast adenocarcinoma cell line (BT20) and a cathepsin B deficient mouse embryonic fibroblast cell line (MEF T -/-). The cells were transiently transfected with four cathepsin B-EGFP fusion constructs: full-length preprocathepsin B-EGFP, cathepsin B preregion-EGFP, cathepsin B prepro region-EGFP, and cathepsin B prepro region-EGFP with a mutation of the glycosylation site in the pro region. The full length construct showed vesicular distribution throughout the cells in both cell lines. In both BT20 and MEF T -/- cells, preregion-EGFP was localized in a ring tightly associated with the cell nucleus, suggesting distribution to the endoplasmic reticulum. The distribution of the prepro region-EGFP construct was similar except that it also included some patchy areas adjacent to the nucleus. This suggested that the cathepsin B prepro region-EGFP might have entered the Golgi. Distribution of the mutated cathepsin B prepro region-EGFP was similar to that of wild-type prepro region-EGFP in the MEF T -/-. In the invasive BT20 cells, however, the mutated prepro region-EGFP showed a vesicular distribution throughout the cytoplasm and in cell processes. This distribution is similar to that of endogenous cathepsin B in these cells. Our results suggest that: 1) tumor cells have an alternative mechanism for trafficking of cathepsin B which is independent of the mannose-6-phosphate receptor pathway, and 2) the pro region of cathepsin B may contain the sorting sequence necessary for its trafficking via this pathway.

Ceramide as an activator lipid of cathepsin D

We have identified the aspartic protease cathepsin D as a novel intracellular target protein for the lipid second messenger ceramide. Ceramide specifically binds to and induces CTSD proteolytic activity. A-SMase deficient cells derived from Niemann-Pick patients show decreased CTSD activity that was reconstituted by transfection with A-SMase cDNA. Ceramide accumulation in cells derived from A-ceramidase defective Farber patients correlates with enhanced CTSD activity. These findings suggest that A-SMase-derived ceramide targets endolysosomal CTSD.

Trans-complex formation by proteolipid channels in the terminal phase of membrane fusion

SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) and Rab-GTPases, together with their cofactors, mediate the attachment step in the membrane fusion of vesicles. But how bilayer mixing--the subsequent core process of fusion--is catalysed remains unclear. Ca2+/calmodulin controls this terminal process in many intracellular fusion events. Here we identify V0, the membrane-integral sector of the vacuolar H+-ATPase, as a target of calmodulin on yeast vacuoles. Between docking and bilayer fusion, V0 sectors from opposing membranes form complexes. V0 trans-complex formation occurs downstream from trans-SNARE pairing, and depends on both the Rab-GTPase Ypt7 and calmodulin. The maintenance of existing complexes and completion of fusion are independent of trans-SNARE pairs. Reconstituted proteolipids form sealed channels, which can expand to form aqueous pores in a Ca2+/calmodulin-dependent fashion. V0 trans-complexes may therefore form a continuous, proteolipid-lined channel at the fusion site. We propose that radial expansion of such a protein pore may be a mechanism for intracellular membrane fusion.

Ovine and Human Placental IgG inhibit Human Natural Killer Cell Cytotoxicity in vitro

To determine the effect of ovine and human placental IgG on human Natural Killer (NK) cell cytotoxicity in vitro placental IgG was eluted at acidic pH and purified by ion exchange and subsequently by affinity chromatography on protein G and protein A sepharose columns. These antibodies were analysed for presense of IgG by immuno-electrophoresis and relative purity determined by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS PAGE). The effect of these antibodies on human NK cell cytotoxicity was investigated by slChromium Release Assay using human K562 cells as targets and human peripheral blood lymphocytes as effector cells. Both ovine and human placental IgG inhibited human NK cell cytotoxicity in a dose dependent manner. Placental IgG may down-regulate the cytotoxic effects of NK cells in vivo by competitively excluding the binding of NK cells to their respective targets on the trophoblast. Alternatively, these antibodies may themselves be toxic to NK cells. Either way, the presence of these antibodies on the placental trophoblast may prevent the binding of NK cells and subsequent immunological rejection of the fetal allograft. Also, ovine placental IgG may be functionally similar to its human counterpart and may therefore be suitable as a model for the study of maternal fetal interaction during pregnancy in humans.

Imidovanadium(v) complexes as reaction partners for kinetically stabilized phosphaalkynes: synthesis of 1,2,4-azaphosphavanada(v)-cyclobutenes, 1,3,5-triphosphabenzenes, and 1H-1,2,4-azadiphospholes

Cycloaddition reactions of the kinetically stabilized phosphaalkynes 1 with the imidovanadium(v) trihalides 9 furnish the 1,2,4-azaphosphavanada(v)cyclobutenes 10. The stability of these novel metallacyclic compounds depends solely on the substitutents of the imido unit. Thus, the imidovanadium(v) species 9 with tertiary alkyl groups on the N atom form stable addition products with 1 while in the cases of compounds 9 with a lower degree of substitution at N (primary and secondary alkyl groups) the primarily formed adducts 10 undergo irreversible decomposition to afford the 1H-1,2,4-azadiphospholes 13. Reactions of an excess of the phosphaaalkyne 1 with the vanadium complexes 9 furnish the corresponding triphosphabenzenes 8 in good yields (36-68%). A catalytic reaction course has been demonstrated for the all-tert-butyl system 1a/9a in which the metallacyclic species 10a serves as the catalytically active species. Poisoning of the catalyst leads to a second reaction pathway, which results in formation of the azatetraphosphaquadricyclanes 16. By means of the stepwise use of different phosphaalkynes 1a,b this methodology provides the first access to the differently substituted triphosphabenzenes through cyclotrimerization.

Exonic variants of the GABA(B) receptor gene and panic disorder

The enhancement of GABAergic neurotransmission has been closely linked to antipanic drug efficacy. This is the first study to investigate a putative association of exonic sequence variants of the human GABA(B) receptor 1 (GABA(B)R1) gene and susceptibility to panic disorder. Three DNA sequence variants in exons 1a1, 7 and 11 were assessed by polymerase chain reaction-based restriction fragment length polymorphism in a case-control study among patients with panic disorder with and without agoraphobia (DSM III-R criteria) and blood donors. There was no indication of an increased vulnerability to panic disorder or agoraphobia with respect to the allelic variants under study.

Molecular organization, expression and chromosomal localization of the mouse pronapsin gene

Napsins have been identified only very recently as new aspartic proteinases of the pepsin family. Isolation, sequencing and functional analysis of the mouse genomic locus indicates that the organization of the pronapsin gene into nine exons is identical to that of other mammalian aspartic proteinase precursors, including pepsinogen. However, the additional C-terminal residues, which are a distinguishing feature of napsins, are encoded within exon 9 and not within an additional exon. Quantitation of pronapsin mRNA using RT-PCR indicates that the gene is transcribed in lung, kidney and spleen but not in heart. Regulation of gene expression was not influenced by the extent of CpG methylation but depended on the recognition of potential binding motifs in the promoter region by specific transcription factors such as YY-1. The single copy of the mouse pronapsin gene was located on chromosome 7. In humans, there are two pronapsin genes and, based on the mouse information, preliminary structures were deduced for these from sequences in the human genome databases. They appear to be located together on chromosome 19.

Successful stem cell transplantation following orthotopic liver transplantation from the same haploidentical family donor in a girl with hemophagocytic lymphohistiocytosis

The case of a 4-month-old girl with familial hemophagocytic lymphohistiocytosis is described. The patient underwent stem cell transplantation from her haploidentical mother 2 months after receiving a living-related liver transplant from the same donor for acute hepatic failure. Conditioning regimen consisted of 16 mg/kg busulfan, 200 mg/kg cyclophosphamide, 10 mg/kg thiothepa, and antithymocyte globulin. Myeloid engraftment occurred on day +10, but CD3(+) cells of recipient origin remained. To convert the T-cell chimerism, the patient received donor lymphocyte infusion on day +43, and subsequently the allelic pattern changed to complete donor genotype on day +57. Four months after stem cell transplantation the patient is disease free, with complete donor chimerism in bone marrow and stable hepatic graft function without any immunosuppressive therapy. (Blood. 2000;96:3997-3999)