Inclusion of spleen in pediatric multivisceral transplantation.

Inclusion of the donor spleen may be beneficial for small children who receive multivisceral transplantation (MVT) because asplenia is associated with increased risk of bacterial sepsis. Beginning in 2003, the spleen was transplanted together with multivisceral transplantation in 17 children under daclizumab induction (spleen group). The results were compared to 23 children who received multivisceral transplantation without the spleen (control group) with the same immunosuppression regimen. Median age of 17 patients who received a spleen was 0.80 years (range 0.54-1.66). Platelet counts at 30 and 60 days posttransplant were significantly lower in the spleen group (average values: day 30: 399,000 vs 636,000, P = .015; day 60: 413,000 vs 622,000, P = .0056). WBC counts at 30 and 60 days posttransplant were also decreased in the spleen group but the difference was not statistically significant. Median rejection-free survival was 205 days in the spleen group and 101 days in the control group (P = NS). Median length of hospital stay was 39 days in the spleen group and 61 days in the control group. With a median follow-up of 398 days (spleen group) and 1232 days (control group), 3 of 17 (17%) in the spleen group developed graft versus host disease (GVHD), whereas 1 of 23 (4.5%) in control group did (P = NS). In one patient in each group, GVHD was fatal. No patient developed posttransplant lymphoproliferative disorder (PTLD) in the spleen group, whereas 4 of 23 (17%) in the control group developed PTLD. One-year patient survival was 84% in the spleen group and 86% in the control group. Recipients of the spleen as part of a multivisceral graft had significantly lower platelet counts. Rejection-free survival may be prolonged, but the risk of GVHD may be increased.

An association of lower serum citrulline levels within 30 days of acute rejection in patients following small intestine transplantation.

INTRODUCTION: In a prospective protocol we studied whether serum citrulline level within 30 days of an acute rejection was predictive of the episode. METHODS: An acute rejection episode was defined as the date of occurrence of any biopsy-proven rejection in which treatment was initiated until two successive biopsies showed no further rejection. We compared the mean citrulline level based on values determined within 30 days of the start of an acute rejection episode with the mean citrulline level measured on the same patient during a rejection-free period. Serum citrulline measurements were available immediately prior to the occurrence of rejection for 22 patients who experienced 37 episodes. RESULTS: For the 12 episodes of mild rejection, the mean serum citrulline level +/- SE (standard error) was 15.0 + 2.3 micromol/L prior to rejection and 18.8 +/- 2.4 micromol/L during the rejection-free periods. A paired t test of the mean differences was not significant (P = 17). For the 25 episodes of moderate or severe rejection, the mean serum citrulline level was 12.4 +/- 1.1 micromol/L before rejection and 18.8 +/- 2.0 micromol/L during the rejection-free periods. A paired t test of the mean difference was statistically significant (P = .002). CONCLUSIONS: Although further study of citrulline as a marker for the early detection of acute rejection episodes is needed, our hope is that its use will help to prevent some of these early episodes from evolving into full-blown moderate or severe grades of rejection.

Trends in serum citrulline and acute rejection among recipients of small bowel transplants.

A test for detecting acute cellular rejection (ACR) of small intestinal transplants (ITx) would be a major advance. Small preliminary studies suggest that serum citrulline levels correlate with ACR. The results for a group of 26 isolated intestinal and multivisceral transplant recipients are summarized here. Serum citrulline concentrations were determined by ion exchange chromatography and compared to biopsy-based grade of ACR. Other factors considered included patient and donor age and sex, ischemia time, and serum creatinine. Straight-line fits were employed to describe how each patient's citrulline levels changed over time. Estimated times to achieve normal citrulline (>or=30 micromol/L) ranged from 1 to 730 days posttransplant for 21 patients demonstrating increasing citrulline levels over time. Using stepwise linear regression, patients' ranks for time required to achieve normal citrulline levels were the only independent predictors of both maximum ACR (P <.0001) and average ACR (P =.0059) after 14 days posttransplant. The rate and direction of change in citrulline over time may be an indicator of the risk of acute rejection. We plan to further examine the use of citrulline as a marker for rejection in larger prospective studies.

Study of the development and evolution of neointestine in a rat model.

The implantation of fragmented rat intestinal epithelium into the omentum of syngeneic animals results in the formation of a cyst containing neointestine. The purpose of our project was to study the evolution of this neointestine-containing cyst over time. Harvested jejunum and ileum of neonatal DA rats (6 to 8 days old) was digested with collagenase type XI and dispase at room temperature. The resulting organoid units, containing clusters of intestinal epithelium with stem cells were seeded onto a polyglactin polymer mesh (100000 units per mesh). The absorbable mesh was implanted in the omentum or peritoneal wall of an adult syngeneic animal. Animals were sacrificed at weekly intervals to harvest the neointestinal cysts. The lumen of the neointestine cysts was full of mucous while the wall of the cyst was covered by intestinal mucosa. H&E staining of the cyst demonstrated the morphology of intestinal epithelium; PAS staining identified goblet cells. The size of the cyst was maximal between 4 and 8 weeks postimplantation tending to regress thereafter. Neointestinal cysts are a consistent finding after implantation of intestinal epithelium organoids into the omentum or peritoneal wall in the rat model. The cysts reach a maximal size at 4 to 8 weeks postimplantation, tending to regress thereafter.

Unmasking of acquired autoimmune C1-inhibitor deficiency by an angiotensin-converting enzyme inhibitor.

BACKGROUND: A majority of angioedema arise from unknown etiologies. Angioedema may also arise from medications or deficiency of C1-esterase inhibitor (C1-INH); either of these may lead to recurrent, sometimes life-threatening attacks of subcutaneous or submucosal edema if the angioedema involves the tongue, throat, or larynx. We describe a patient with unknown acquired C1-INH deficiency, who experienced only mild attacks of angioedema before treatment with an angiotensin-converting enzyme (ACE) inhibitor. This therapy led to life-threatening respiratory distress. OBJECTIVE: To investigate this patient's life-threatening angioedema. METHODS: Serum protein electrophoresis and immunofixation were performed. The titer of anti-C1-inhibitor autoantibody was determined by ELISA, and the specificity of the autoantibody demonstrated by using purified C1-INH to block binding in the ELISA. Finally, fractions from the immunoelectrophoresis gel were tested for C1-INH autoantibody by ELISA. RESULTS: Complement activation was documented by reduced C1-INH, C1q, and C4, and the patient was found to have an autoantibody of IgG2 isotype specific for C1-INH. After discontinuation of the ACE inhibitor, he continued to have decreased C1-INH and positive C1-INH autoantibodies. CONCLUSIONS: This case describes a patient who had a history of mild facial and extremity swelling with abdominal symptoms before ACE inhibitor treatment; this medication resulted in life-threatening respiratory distress. The use of the ACE inhibitor may have unmasked this patient's acquired autoimmune C1-INH deficiency.

Murine model of atopic dermatitis associated with food hypersensitivity.

BACKGROUND: Atopic dermatitis (AD) is an eczematous skin eruption that generally begins in early infancy and affects up to 12% of the population. The cause of this disorder is not fully understood, although it is frequently the first sign of atopic disease and is characterized by an elevated serum IgE level, eosinophilia, and histologic tissue changes characterized early by spongiosis and a CD4(+) T(H)2 cellular infiltrate. Hypersensitivity to foods has been implicated as one causative factor in up to 40% of children with moderate-to-severe AD. OBJECTIVE: The purpose of this study was to establish a murine model of food-induced AD. METHODS: Female C3H/HeJ mice were sensitized orally to cow's milk or peanut with a cholera toxin adjuvant and then subjected to low-grade allergen exposure. Histologic examination of skin lesions, allergen-specific serum Ig levels, and allergen-induced T-cell proliferation and cytokine production were examined. RESULTS: An eczematous eruption developed in approximately one third of mice after low-grade exposure to milk or peanut proteins. Peripheral blood eosinophilia and elevated serum IgE levels were noted. Histologic examination of the lesional skin revealed spongiosis and a cellular infiltrate consisting of CD4(+) lymphocytes, eosinophils, and mast cells. IL-5 and IL-13 mRNA expression was elevated only in the skin of mice with the eczematous eruption. Treatment of the eruption with topical corticosteroids led to decreased pruritus and resolution of the cutaneous eruption. CONCLUSION: This eczematous eruption resembles AD in human subjects and should provide a useful model for studying immunopathogenic mechanisms of food hypersensitivity in AD.

A murine model of IgE-mediated cow's milk hypersensitivity.

BACKGROUND: Cow's milk allergy (CMA) is one of the leading causes of food allergy in children. Understanding the mechanisms involved in the development of CMA has been hampered by the lack of suitable animal models. OBJECTIVE: We sought to develop a mouse model of IgE-mediated cow's milk hypersensitivity (CMH) that mimics the clinical features of immediate CMA in humans. METHODS: Three-week-old C3H/HeJ mice were sensitized by intragastric administration of cow's milk (CM) plus cholera toxin and boosted 5 times at weekly intervals. RESULTS: CM-specific IgE antibody levels were significantly increased at 3 weeks and peaked at 6 weeks after the initial feeding. Intragastric challenge with CM at week 6 elicited systemic anaphylaxis accompanied by vascular leakage, significantly increased plasma histamine, and increased intestinal permeability to casein. Histologic examination of intestinal tissue revealed marked vascular congestion, edema, and sloughing of enterocytes. The role of IgE in mediating CMH was confirmed by abrogation of passive cutaneous anaphylaxis reactions by heat inactivation of immune sera. Development of IgE-mediated CMH in this model is likely to be TH2 cell mediated because in vitro stimulation of spleen cells from mice allergic to CM induced significant increases in the levels of IL-4 and IL-5, but not IFN-gamma. CONCLUSION: This model should provide a useful tool for evaluating the immunopathogenic mechanisms involved in CMA and for exploring new therapeutic approaches.

Esophageal obstruction after incomplete removal of a percutaneous endoscopic gastrostomy tube.

This two-year-old boy presented with a two-day history of vomiting and fever. He was diagnosed with acute otitis media four days before this incident. Repeated questioning revealed removal of a percutaneous enterostomy tube two weeks earlier with failure to pass the internal bumper in his stool. The child was in no distress, except for repeated emesis and drooling. A chest x-ray revealed a foreign body in the esophagus, and the patient underwent removal of the percutaneous endoscopic gastrostomy plastic bumper by endoscopy without incident.

Control of IgE responses. V. Oral administration of a synthetic derivative of the inner bacterial cell wall (SDZ 280.636) to sensitized mice induces isotype specific suppression of peak hapten specific IgE antibody forming cell responses, serum IgE levels and immediate hypersensitivity responses.

SDZ 280.636, a nontoxic diacyl glycerol derivative of muramyl dipeptide (MDP), a component of the inner bacterial cell wall, which is suitable for use in man, suppressed hapten specific IgE antibody forming cell (AFC) responses in spleen, serum levels of hapten specific IgE and hapten specific immediate hypersensitivity (i.h.) responses in skin, when fed to mice at the peak of a hapten specific IgE AFC response. In addition, serum levels of IL-6 appeared increased while IFN gamma was decreased. To induce these IgE responses, BALB/c mice were injected i.p. with BPO-KLH (benzylpenicilloyl-keyhole limpet hemocyanin) (10 micrograms) in aluminum hydroxide gel (alum) on days 0, 21 and 42. Mice were fed (gavage) with either MDP or SDZ 280.636 (1.0 or 10 mg/kg) on day 44, or on days 44, 46 and 48, and killed on days 46 or 50. Numbers of BPO specific AFC in spleen, and serum levels of BPO specific immunoglobulins (IgG1, IgE and IgA) were determined (ELISPOT assay, ELISA). In addition, BPO specific IH responses were measured in these animals. Mice were injected in the right pinna with BPO-BSA (0.1 microgram) and in the left pinna with an equal volume of saline (0.05 ml). At 2 hr, pinnae were measured using a micrometer caliper. We found that 1 feeding with either MDP or SDZ 280.636 abrogated IgE AFC responses and dramatically suppressed serum levels of IgE, both in isotype specific fashion, and suppressed IH responses (> 50%). 3 feedings with SDZ 280.636 also abrogated IgE AFC responses and further decreased serum levels of IgE. In contrast to SDZ 280.636, 3 treatments with MDP had opposite effects in that IgE AFC responses and serum levels of IgE dramatically increased. A single treatment with SDZ 280.636 appeared to increase serum levels of IL-6 up to three fold, while IFN gamma levels decreased. Our data suggest that SDZ 280.636 may be useful in the therapeutic and prophylactic management of human atopic disease such as allergic rhinitis, asthma, and other atopic diseases.

IgE-bearing cells and epsilon-specific mRNA in lymphoid organs of two children with AIDS.

To characterize the cellular basis of IgE responses in HIV-positive (HIV+) children, we obtained central (bone marrow [BM], thymus) and peripheral (Peyer's patches [PP], mesenteric [MLN], and other lymph nodes [OLN], spleen), lymphoid organs from two children with AIDS (females, 2 and 8 years old), and from a non-HIV-infected trauma victim (female, 5 years old) at autopsy. PP were obtained from one of the HIV+ children (2 yr old) and from the non-infected child, but no PP were detected in small intestine of the 8-yr-old HIV+ child. Numbers of lymphocytes bearing surface IgE, CD19, CD3, CD4, and CD8 in lymphoid organs were determined (flow cytometry) and evaluated for expression of epsilon-specific (E) mRNA (RT-PCR). Thymus and MLN of the HIV+ child without PP contained high numbers of IgE+ (34% and 41%, respectively) and CD19+ (32% and 28%, respectively) cells; IgE+ cells were not found in any other organ. In contrast, in the HIV+ child with PP, IgE+ cells were detected in all organs, except BM. The thymus of this child contained fewer CD19+ cells (7%). However, in both HIV+ children, all lymphoid organs, including thymus, contained E mRNA. Because numbers of IgE+ cells often far exceeded numbers of CD19+ B cells, and because CD8+ T cells predominated in all organs, some of the IgE+ cells were probably CD8+ T cells with cytophilic IgE and may include IgE-specific regulatory and/or memory T cells. IgE responses were not detected in the healthy trauma victim nor were B cells found in thymus. The data suggest that during HIV infection, IgE+ B cells may be found in thymus and that synthesis of IgE may occur in all lymphoid organs except BM.

IgE against HIV proteins in clinically healthy children with HIV disease.

Elevated serum Ige was detected in 26% (7 of 30) of children with HIV infection. The majority of children with elevated IgE were of one ethnic group (Puerto Rican) (4 of 7), compared with only 9% (2 of 23) in the normal to low IgE group (p = 0.02). Most of the children with elevated IgE had decreased circulating CD4+ T cells (5 of 7 or 71%); but none had opportunistic infections, and none failed to thrive. Although similar numbers of children with normal to low IgE had decreased circulating CD4+ T cells (19 of 23 or 83%), this group had opportunistic infections (6 of 23 or 26%) and failure to thrive (7 of 30 or 30%). There was no difference in incidence of allergic symptoms between groups. IgE antibody against HIV protein was detected by Western blot technique in the sera of three children with elevated serum IgE. Thus we have identified a group of children with HIV infection and elevated serum IgE of predominantly one ethnic group, who are without opportunistic infections or failure to thrive, some of whom produce HIV-specific IgE. This suggests that IgE may play a protective (perhaps late compensatory) role in HIV disease in genetically predisposed individuals.

Acute promyelocytic leukemia and pregnancy. A case report.

BACKGROUND: Acute promyelocytic leukemia (APL) is an uncommon form of acute myeloid leukemia usually associated with disseminated intravascular coagulation (DIC). Pregnancy in patients with APL requires special consideration to maximize the probability of survival of both mother and fetus. METHODS: A patient with APL diagnosed during pregnancy who developed DIC is described. Obstetric and oncologic management of this difficult patient is discussed, and a pertinent literature review of pregnancy in APL is presented. RESULTS: Of 23 pregnancies in patients with APL reported in the literature (including the present patient), 19 yielded live births, including 8 of 12 who received chemotherapy during late pregnancy and all 3 patients who received all-trans-retinoic acid (ATRA) during late pregnancy. Chemotherapy or ATRA induced complete remission in 72% of treated patients. CONCLUSIONS: Proper management of pregnant patients with APL usually results in a live birth and complete remission of the mother's leukemia, despite the potentially devastating consequences of DIC, which is present at diagnosis in most patients.

Regulation of hapten-specific memory IgE responses induced in vitro. Requirement for both Thy-1+ AsGM1+ and Thy-1+ AsGM1- cells and for IFN-alpha and IL-4.

The roles of Thy-1+ and AsGM1+ spleen cells and cytokines (IL-4, IL-5, IL-6, IFN-alpha, and IFN-gamma) in regulation of hapten-specific memory IgE antibody-forming cell (AFC) responses induced in vitro were examined. BALB/c mice, injected i.p. with benzylpenicilloyl-keyhole limpet hemocyanin (BPO-KLH) (10 micrograms) on days 0 and 21, were killed on day 60 or day 120. Numbers of BPO-specific IgGI, IgE, and IgA AFC in spleen were determined by enzyme-linked immunosorbent spot assay after 0 to 6 days of culture +/- BPO-KLH. BPO-specific AFC of all isotypes were detected in spleen on day 60, but not on day 120. Day 60 AFC responses did not persist in culture in that no AFC were detected by day 2 of culture +/- BPO-KLH. When either day 60 or day 120 cells were cultured for 3 days with BPO-KLH, BPO-specific AFC responses were induced, and peaked on day 5, with similar numbers of AFC of each isotype induced with day 60 and day 120 cells. On day 60, spleen contained two subsets of Thy-1+ cells: AsGM1- (approximately 32% of total cells) and AsGM1+ (approximately 4%). Depletion and reconstitution experiments established that both subsets were required for induction of BPO-specific IgE AFC responses. Cytokines could not substitute for the Thy-1(+)-depleted cells. However, when unfractionated day 60 cells were cultured with cytokines or anti-cytokine antibodies, BPO-specific IgE AFC responses induced were both IFN-alpha and IL-4 dependent; either increased or decreased by IFN-gamma, depending on its concentration, and unaffected by IL-5 or IL-6.

Suppression of human IgE antibody forming cell responses by IL-6.

To study the effects of cytokines on human IgE antibody forming cells (AFCs), log phase U266 myeloma cells (3 x 10(3)/ml), which secrete immunoglobulin E (IgE), were cultured for 0-24 h with and without cytokine or with or without antibodies against various cytokines. The numbers of IgE AFCs were determined in ELISPOT assay. We found that interleukin-6 (IL-6) suppressed (to 95%) whereas anti-IL-6 increased (to 148%) the numbers of IgE AFCs and that both worked in a dose-dependent fashion. IL-4 and interferon-gamma (IFN-gamma) also suppressed IgE AFC responses in a dose-dependent fashion. However, antibodies to these cytokines had no effect. In contrast, IFN-alpha increased (to fourfold) the numbers of IgE AFCs in a dose-dependent fashion. The data are the first to show a suppressive effect of IL-6 on human IgE responses and may also suggest a role for IL-6 in the treatment of atopic disease.

Cytokine-induced suppression and potentiation of hapten-specific immediate hypersensitivity responses.

The ability of subcutaneously (s.c.) injected cytokines (IL-4, IL-5, IL-6, IFN alpha, IFN gamma, GMCSF) to regulate the induction of hapten-specific immediate hypersensitivity (IH) responses was studied in BPO-KLH (benzylpenicilloyl-keyhole limpet hemocyanin) sensitized BALB/c mice at the peak of a hapten-specific IgE antibody forming cell (AFC) response. To induce IH responses, mice were injected in the right pinna with either BPO-BSA (benzylpenicilloyl-bovine serum albumin), BPO-KLH (0.01-1.0 micrograms/ml) or mcAb anti-IgE (0.001 - 1.0 micrograms/ml); and in the left pinna with an equal volume of saline (0.05 ml). Pinnae were measured 5 min to 4 hr later using a micrometer caliper. Treatment of mice with IL-4 or IFN gamma dramatically suppressed the induction of IH responses in dose dependent fashion. In contrast, treatment of mice with IL-6 and IFN alpha increased these responses in dose dependent fashion, while GMCSF and IL-5 had no effect. The suppression obtained with IL-4 and IFN gamma, and the increases seen with IL-6 and IFN alpha, were transient since these cytokines, as well as GMCSF and IL-5, had no effect on IH responses elicited 21 days after the peak of BPO-specific IgE AFC responses. The data suggest that cytokine mediated effects on IH responses occur via changes in serum levels of BPO-specific IgG1 or IgE, through direct or indirect effects of cytokines on mast cells or other cell types, or by affecting the ability of BPO-specific homocytotropic antibodies to bind to mast cell surfaces.

Control of IgE responses. III. IL-6 and IFN-alpha are isotype-specific regulators of peak BPO-specific IgE antibody-forming cell responses in mice.

The ability of cytokines (IL-4, IL-5, IL-6, IFN-alpha, IFN-gamma, TNF-alpha, GmCSF) to regulate peak benzylpenicilloyl (BPO)-specific IgE antibody-forming cell (AFC) responses was investigated. These responses were induced in BALB/c mice by ip injection of BPO-keyhole limpet hemocyanin (BPO-KLH; 10 micrograms) in aluminum hydroxide gel on Days 0, 21, and 42. On Day 44, or on Days 43, 44, and 45, mice were injected sc with varying doses of cytokine or anti-cytokine antibody. On Day 46, the numbers of BPO-specific AFC (IgM, IgG1, IgE and IgA) in spleen were determined ex vivo in enzyme-linked immunosorbent spot assay. Among the cytokines tested, only IL-6 suppressed BPO-specific IgE AFC responses in an isotype-specific fashion (60-90%). However, treatment of mice with anti-IL-6 also suppressed these responses, suggesting that IL-6 can either suppress or increase peak antigen specific IgE responses, depending upon its concentration. Among the cytokines tested, only IFN-alpha increased BPO-specific IgE AFC responses in an isotype-specific fashion. Since treatment with anti-IFN-alpha suppressed these responses, it appears that IFN-alpha is required to maintain peak antigen-specific IgE AFC responses. IL-4 or IFN-gamma nonspecifically suppressed responses of all isotypes. Treatment with anti-IL-4 also suppressed IgE responses, suggesting that this cytokine is required to maintain peak antigen specific IgE responses. Treatment with anti-IFN-gamma increased IgE responses, indicating that IFN-gamma suppresses peak antigen-specific IgE responses.