Mesoporous silica particles as potential carriers for protein drug delivery: protein immobilization and the effect of displacer on γ-globulin release.

The adsorption of γ-globulin was evaluated with experiments with silica particles marketed as Syloid AL1-FP (SAL), XDP-3150 (SXDP), and 244FP (SFP). The influence of pH, pore sizes, and degree of surface porosity on the extent of γ-globulin immobilization was examined. Protein adsorption on these particles was largely related to their surface porosity and pore sizes. The adsorption capacity was established to be greater with mesoporous SFP and SXDP particles at 474 and 377 mg/g, respectively, when compared to significantly low-porosity SAL (16 mg/g). Additionally, γ-globulin immobilization was favored at pH closer to iso-electric point. A key aim of this work was to better understand and improve the limited reversibility of protein adsorption. Protein desorption was found to be lower in simulated intestinal fluid (SIF) in comparison to pH 7.4 phosphate buffer (PB). The use of displacer molecules (sodium dodecyl sulfate [SDS]/Tween 80/Pluronic F127 [PF127]) promoted protein desorption from the adsorbent surface by the exchange mechanism. The PF127 provided substantial release in both studied condition but the highest release of 83% of γ-globulin from SXDP was obtained with tween 80 in PB. The released protein was analyzed with circular dichroism (CD) spectroscopy which indicated that the secondary structure of desorbed γ-globulin was dependent on the pH and displacer molecule. The conformation largely remained unchanged when desorption was carried out in SIF but changed markedly in PB specially in the presence of SDS.

Immunoglobulin Abnormalities in Gaucher Disease: an Analysis of 278 Patients Included in the French Gaucher Disease Registry.

Gaucher disease (GD) is a rare lysosomal autosomal-recessive disorder due to deficiency of glucocerebrosidase; polyclonal gammopathy (PG) and/or monoclonal gammopathy (MG) can occur in this disease. We aimed to describe these immunoglobulin abnormalities in a large cohort of GD patients and to study the risk factors, clinical significance, and evolution. Data for patients enrolled in the French GD Registry were studied retrospectively. The risk factors of PG and/or MG developing and their association with clinical bone events and severe thrombocytopenia, two markers of GD severity, were assessed with multivariable Cox models and the effect of GD treatment on gammaglobulin levels with linear/logarithmic mixed models. Regression of MG and the occurrence of hematological malignancies were described. The 278 patients included (132 males, 47.5%) were followed up during a mean (SD) of 19 (14) years after GD diagnosis. PG occurred in 112/235 (47.7%) patients at GD diagnosis or during follow-up and MG in 59/187 (31.6%). Multivariable analysis retained age at GD diagnosis as the only independent risk factor for MG (> 30 vs. ≤30 years, HR 4.71, 95%CI [2.40-9.27]; p < 0.001). Risk of bone events or severe thrombocytopenia was not significantly associated with PG or MG. During follow-up, non-Hodgkin lymphoma developed in five patients and multiple myeloma in one. MG was observed in almost one third of patients with GD. Immunoglobulin abnormalities were not associated with the disease severity. However, prolonged surveillance of patients with GD is needed because hematologic malignancies may occur.

Oral management of a patient with down syndrome and agammaglobulinemia: a case report.

BACKGROUND: Down syndrome is characterized by a variety of dysmorphic features and congenital malformations, such as congenital heart disease, gastrointestinal disease, and other conditions like leukemia and autoimmune disorders. Patients with Down syndrome are highly prone to respiratory tract infections, which might be fatal to them. However, there are only few available data on patients diagnosed with Down syndrome and agammaglobulinemia. In this report, we describe a case of successful prevention of post-dental treatment complications (e.g., pneumonia and other bacterial infections) in a patient with Down syndrome and agammaglobulinemia. CASE PRESENTATION: A 43-year-old man with Down syndrome, untreated agammaglobulinemia, and a history of recurrent pneumonia, was referred to our clinic for tooth mobility. To reduce the risk of post-operative infections, gammaglobulin treatment and prophylactic administration of antibiotics was scheduled before the dental procedure. Furthermore, the dental treatment, which included a filling and extractions, was conducted under general anesthesia and with the supervision of a hematologist. The dental procedures were successfully performed without any post-operative infection, and the patient is undergoing follow-up care. CONCLUSIONS: The purpose of this case report was to recommend a close liaison between physicians and dentists who may encounter a similar case, and to emphasize the importance of improving oral health of immunodeficient patients to prevent infections caused by oral microbial flora.

[The Effect of Intravenous Gamma-globulin Reagents on the Measurement Results of (1➔3)-ß-D-glucan].

Serum (1→3) beta-D-glucan (BG) measurement is a useful test for systemic mycoses, and often used. On the other hand, various factors, including administration of intravenous immunoglobulins (IVIG) may cause false-positives. In the present study, we measured BG concentration of seven IVIG preparations with three lots respectively. BG levels varied with individual IVIG preparations (<3.0 - >300 pg/mL), and contamination from manufacturing processes was suspected. With serum BG concentration of clinical specimens obtained in Niigata University Medical & Dental Hospital, the difference between before and after administration of IVIG were calculated. The false-positive rate of BG due to IVIG administration was 9.8 %, and the positive predective value was reduced to 37.5%. Above all, administration of IVIG can complicate the BG test's interpretation, and caution is required.

Henry K. Beecher and the Oversight of Research in Children.

Henry K. Beecher was a pioneer of research ethics and a prominent whistleblower with regard to ethically problematic studies. Most of his work focused on research in adults, not children, but he did speculate about the implications of his ethical concerns for research in minors. This paper reviews Beecher's response to Krugman's studies of hepatitis at the Willowbrook State School and the debate that Beecher's article stimulated between Ramsey and McCormick. That debate shaped the terms that were used in current federal regulations for research in children. The paper then speculates about whether Beecher would have approved of our current regulatory system.

[X-linked agammaglobulinemia in adults. Clinical evolution]. / Agammaglobulinemia ligada al cromosoma X en adultos. Evolución clínica.

X-linked agammaglobulinemia (XLA) is characterized by absent or severely reduced B cells, low or undetectable immunoglobulin levels and clinically by extracellular bacterial infections which mainly compromise the respiratory tract as well as recurrent diarrheas. The mainstay of treatment is gammaglobulin replacement therapy, which allows most patients to reach adulthood with high quality of life. We analyzed the clinical features of 14 patients over 18 years of age with XLA diagnosis that received treatment in our unit from the year 2003, the date the first patient was derived, until 2015. The average age at which patients were referred was 20.4 years old; age at the last consult was 25.5. The average follow-up time was 59.8 months. Previously to being diagnosed all patients had suffered infections, most frequently respiratory. After diagnosis all were started on intravenous gammaglobulin replacement treatment and in spite of infections being reduced in severity and frequency, there were cases of severe disease with long term sequelae. At the beginning of our follow-up 35.7% presented impaired respiratory function with only one case being severe. In no cases during this period did the respiratory function worsen, nor were there severe clinical complications. Three patients were switched to subcutaneous immunoglobulin treatment with good tolerance. The number of XLA cases is increasing, as most reach the second decade of life without serious complications and remain free of severe infectious disease and further impairment of their respiratory functions with the treatment.

[Clinical effect of gamma globulin pulse therapy for abdominal Henoch-Schönlein purpura in children].

OBJECTIVE: To study the clinical effect of high-dose gamma globulin pulse therapy for abdominal Henoch-Schönlein purpura (HSP). METHODS: Thirty-three children with abdominal HSP were randomly assigned to dexamethasone group (15 children) and gamma globulin group (18 children). The children in the dexamethasone group were treated with dexamethasone and conventional treatment, and those in the gamma globulin group were treated with high-dose gamma globulin pulse therapy in addition to the conventional treatment. Clinical outcome and recurrence rate were observed in both groups. RESULTS: Compared with the dexamethasone group, the gamma globulin group had a significantly shorter onset time of rash, a significantly shorter time to complete regression of rash, a significantly shorter time to abdominal pain remission, and a significantly shorter time to disappearance of bloody stool, as well as comparable time to vomiting remission and length of hospital stay. The gamma globulin group had a significantly higher response rate than the dexamethasone group (95% vs 65%; P<0.05) and a significantly lower recurrence rate within 6 months than the dexamethasone group (5.6% vs 33.3%; P<0.05). CONCLUSIONS: High-dose gamma globulin pulse therapy has a marked clinical effect in the treatment of abdominal HSP. It is safe and reliable and has a low recurrence rate, and therefore, it holds promise for clinical application.

[Clinical efficacy of different doses of gamma globulin combined with glucocorticoid in treatment of moderate/severe acute Guillain-Barré syndrome in children: a comparative analysis].

OBJECTIVE: To investigate the clinical efficacy and safety of intravenous injection of low-dose versus high-dose gamma globulin combined with glucocorticoid pulse therapy in the treatment of children with moderate/severe acute Guillain-Barré syndrome (GBS). METHODS: A total of 100 children with moderate/severe acute GBS were randomly assigned to low-dose group (n=48) and high-dose group (n=52). The children in the low-dose and high-dose groups were treated with 0.2 g/(kg · d) and 0.4 g/(kg · d) gamma globulin respectively combined with methylprednisolone. The two groups were compared in terms of the time to improvements of symptoms after treatment, serum levels of inflammatory factors, proportion of children undergoing invasive ventilation, treatment response rate, and adverse events. RESULTS: After 5 days of treatment, the low- and high-dose groups had significant reductions in serum levels of tumor necrosis factor-α, interleukin-6, and C-reactive protein, and there were no significant differences in the reductions of these markers between the two groups. There were no significant differences between the two groups in the time to recovery of respiratory muscle paralysis, time to an improvement in muscle strength of one grade, time to recovery of sensory disturbance, and length of hospital stay. There was no significant difference in the treatment response rate between the low- and high-dose groups (90% vs 92%). There were also no significant differences in the incidence rates of pyrexia, headache, nausea, and palpitation between the two groups. CONCLUSIONS: Low-dose versus high-dose gamma globulin combined with methylprednisolone pulse therapy have comparable clinical efficacy and safety in the treatment of children with moderate/severe acute GBS.

Post-exposure passive immunisation for preventing rubella and congenital rubella syndrome.

BACKGROUND: Control of rubella is desired because infection in early pregnancy can result in miscarriage, foetal death or congenital abnormality. Primary studies examining the effectiveness of immunoglobulins for post-exposure prophylaxis of rubella have small sample sizes and varying results. National public health recommendations suggest a degree of effectiveness. OBJECTIVES: To assess the effectiveness of intramuscular injection or intravenous infusion of polyclonal immunoglobulins of human sera or plasma origin for preventing rubella and congenital rubella syndrome when administered to exposed susceptible people before the onset of disease. SEARCH METHODS: We searched CENTRAL (2014, Issue 7), MEDLINE (1946 to August week 2, 2014), EMBASE (1974 to August 2014), CINAHL (1981 to August 2014), LILACS (1982 to August 2014) and Web of Science (1955 to August 2014). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry on 16 October 2014. We searched the reference lists of relevant retrieved reviews and studies and identified national public health guidelines. SELECTION CRITERIA: For the outcome 'preventing cases of rubella', we included randomised controlled trials (RCTs) and quasi-RCTs. We found several studies addressing this outcome where the design was a controlled clinical trial (CCT) (with exposure to rubella virus controlled by the investigators) but the method of allocation of participants to groups was not reported. We found an alternative report of one of these studies that indicated participants were assigned to groups randomly. We therefore included such studies as meeting criteria for RCTs or quasi-RCTs and undertook sensitivity analyses. For the outcomes, 'congenital rubella infection' and 'congenital rubella syndrome', we included RCTs, quasi-RCTs and prospective controlled (cohort) studies. Participants were necessarily susceptible and exposed to rubella. Polyclonal immunoglobulins derived from human sera or plasma must have been administered intramuscularly or intravenously as the only intervention in at least one group. DATA COLLECTION AND ANALYSIS: We used the standard methodological procedures expected by The Cochrane Collaboration. MAIN RESULTS: We included 12 studies (430 participants) in the review: seven RCTs and five CCTs where it was not clear whether participants were randomly allocated to groups. We did not include any unpublished studies. Participants included children and adults of both sexes. Only one study included pregnant women. All studies were conducted in high-income countries.The quality of the 11 studies in the initial meta-analysis was moderate, although we classified no study as having a low risk of bias on all criteria.We included 11 studies in the initial meta-analysis of gamma-globulin (concentrated polyclonal immunoglobulins) versus control (saline or no treatment) for rubella cases. The result favoured the intervention group (risk ratio (RR) 0.61, 95% confidence interval (CI) 0.45 to 0.83) but was heterogenous (Chi² test = 36.59, df = 10 (P value < 0.0001); I² statistic = 73%). Heterogeneity was explained by subgrouping studies according to the estimated volume of gamma-globulin administered per pound of bodyweight and then removing those studies where the intervention was administered more than five days after participant exposure to rubella (post hoc analysis). The test of subgroup differences demonstrated heterogeneity between subgroups according to our protocol definition (P value < 0.1; I² statistic > 60%) and there appeared to be greater effectiveness of the intervention when a greater volume of gamma-globulin was administered ('0.027 to 0.037 ml/lb' RR 1.60 (95% CI 0.57 to 4.52); '0.1 to 0.15 ml/lb' RR 0.53 (95% CI 0.29 to 0.99); '0.2 to 0.5 ml/lb' RR 0.20 (95% CI 0.04 to 1.00)).None of the studies reported the outcome 'congenital rubella infection'. One included study reported on congenital rubella syndrome, with no cases among participants who were fewer than nine weeks pregnant at enrolment and who were randomised to one of two gamma-globulin groups ('high' or 'low' rubella titre). However, the study did not report how congenital rubella syndrome was measured and did not report the length of follow-up according to intervention group. This study did not include a non-treatment group.No included study measured adverse events. AUTHORS' CONCLUSIONS: Compared to no treatment, polyclonal immunoglobulins seem to be of benefit for preventing rubella. The available evidence suggests that this intervention may be of benefit up to five days after exposure, and that effectiveness is dependent on dose. Considering the attack rate for rubella cases in the control group of the highest volume gamma-globulin subgroup (333 per 1000), the absolute risk reduction (calculated from the RR) for this volume of gamma-globulin was 266 (95% CI 0 to 320) and the number needed to treat to benefit is four (95% CI 3 to incalculable).The included studies did not measure rubella-specific antibodies in the immunoglobulin products used in a standard way and thus estimation of the dose of rubella-specific antibodies in international units administered was not possible. As the concentration of rubella-specific antibodies in today's polyclonal immunoglobulin products may vary from those products used in the studies in the review, the volume required per pound of bodyweight to produce similar results may also vary.There is insufficient evidence to make direct conclusions about the effectiveness of polyclonal immunoglobulins for preventing congenital rubella syndrome. This is an area requiring further research.

Anti-N-methyl-D-aspartate receptor encephalitis associated with an ovarian teratoma: two cases report and anesthesia considerations.

BACKGROUND: Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an immune-mediated syndrome caused by the production of anti-NMDAR receptor antibodies. The syndrome characterised by psychosis, seizures, sleep disorders, hallucinations and short-term memory loss. Ovarian teratoma is the confirmed tumour associated with anti-NMDAR antibodies. The patients with anti-NMDAR encephalitis complicated by ovarian teratoma require surgical treatment under general anesthesia. NMDARs are important targets of many anesthetic drugs. The perioperative management and complications of anti-NMDAR encephalitis, including hypoventilation, paroxysmal sympathetic hyperactivity (PSH) and epilepsy, are challenging for ansthesiologists. CASE PRESENTATION: This report described two female patients who presented for resection of the ovarian teratoma, they had confirmed anti-NMDAR encephalitis accompanied by ovarian teratoma. Two patients received gamma globulin treatments and the resection of the ovarian teratoma under total intravenous anesthesia. They were recovered and discharged on the 20(th) and 46(th) postoperative day respectively. CONCLUSIONS: There is insufficient evidence about the perioperative management, monitoring and anesthesia management of anti-NMDAR encephalitis. This report was based on the consideration that controversial anesthetics that likely act on NMDARs should be avoided. Additionally, BIS monitoring should to be prudently applied in anti-NMDAR encephalitis because of abnormal electric encephalography (EEG). Anesthesiologists must be careful with regard to central ventilation dysfunctions and PSH due to anti-NMDAR encephalitis.

Post-exposure passive immunisation for preventing measles.

BACKGROUND: Measles outbreaks continue to occur in countries with high vaccination coverage. Passive immunisation is generally considered to prevent measles in someone who is not immune and has been exposed to infection. Estimates of effectiveness have varied and no minimum effective dose has been determined. OBJECTIVES: To assess the effectiveness and safety of intramuscular injection or intravenous infusion of immunoglobulins (passive immunisation) for preventing measles when administered to exposed susceptible people before the onset of symptoms. SEARCH METHODS: We searched CENTRAL (2013, Issue 7), MEDLINE (1946 to July week 5, 2013), CINAHL (1981 to August 2013) and EMBASE (1974 to August 2013). SELECTION CRITERIA: We included randomised controlled trials (RCTs), quasi-RCTs and prospective, controlled (cohort) studies if: participants were susceptible and exposed to measles, polyclonal immunoglobulins derived from human sera or plasma were administered intramuscularly or intravenously as the only intervention in at least one group and the number of subsequent measles cases was measured. We excluded studies of other sources of immunoglobulins. DATA COLLECTION AND ANALYSIS: Two authors independently extracted data and critically appraised the included studies. We attempted to contact study authors for missing information. We described the results of studies not included in meta-analyses. MAIN RESULTS: We included one RCT, two quasi-RCTs and 10 cohort studies (3925 participants). No studies were rated as low risk of bias for all criteria. Critical appraisal was constrained by a lack of information in most studies. The overall quality of the evidence was moderate.Seven studies (1432 participants) assessed cases of measles after immunoglobulin versus no treatment. Heterogeneity was explained by subgrouping according to the blood product used as an approximation of dose of immunoglobulin. When given within seven days of exposure, immunoglobulins were effective at preventing measles: gamma globulin (risk ratio (RR) 0.17, 95% confidence interval (CI) 0.08 to 0.36), convalescent serum (RR 0.21, 95% CI 0.15 to 0.29 to RR 0.49, 95% CI 0.44 to 0.54) and adult serum (RR 0.52, 95% CI 0.45 to 0.59). The differences in the effectiveness of different blood products were supported by studies not included in the meta-analysis and by two studies (702 participants) that found gamma globulin more effective than serum (RR 0.56, 95% CI 0.46 to 0.69).Based on three studies (893 participants) immunoglobulin was effective at preventing death due to measles compared to no treatment (RR 0.24, 95% CI 0.13 to 0.44).Two studies included measles vaccine alone among the intervention groups. Meta-analysis could not be undertaken. Both studies suggested the vaccine was more effective than gamma globulin.No serious adverse events were observed in any of the included studies, although reporting of adverse events was poor overall. Non-serious adverse events included transient fever, rash, muscle stiffness, local redness and induration. AUTHORS' CONCLUSIONS: Passive immunisation within seven days of exposure is effective at preventing measles, with the risk for non-immune people up to 83% less than if no treatment is given. Given an attack rate of 45 per 1000 (per the control group of the most recent included study), gamma globulin compared to no treatment has an absolute risk reduction (ARR) of 37 per 1000 and a number needed to treat to benefit (NNTB) of 27. Given an attack rate of 759 per 1000 (per the attack rate of the other included study assessing gamma globulin), the ARR of gamma globulin compared to no treatment is 629 and the NNTB is two.It seems the dose of immunoglobulin administered impacts on effectiveness. A minimum effective dose of measles-specific antibodies could not be identified.Passive immunisation is effective at preventing deaths from measles, reducing the risk by 76% compared to no treatment. Whether the benefits of passive immunisation vary among subgroups of non-immune exposed people could not be determined.Due to a paucity of evidence comparing vaccine to passive immunisation, no firm conclusions can be drawn regarding relative effectiveness.The included studies were not specifically designed to detect adverse events.Future research should consider the effectiveness of passive immunisation for preventing measles in high-risk populations such as pregnant women, immunocompromised people and infants. Further efforts should be made to determine the minimum effective dose of measles-specific antibodies for post-exposure prophylaxis and the relative effectiveness of vaccine compared to immunoglobulin.

[Strategies for avoiding hepatitis B infection recurrence following liver transplantation]. / Estrategias para evitar la recidiva viral B después del trasplante hepático.

Hepatitis B is currently an excellent indication for liver transplantation due to the highly effective strategies of prophylaxis and treatment for recurrent hepatitis B infection. The combined administration of low-dose hepatitis B hyperimmune gamma globulin and a nucleoside/nucleotide analogue with a high genetic barrier to resistance, such as entecavir (except for patients with lamivudine resistance) or tenofovir, represents the standard for the prophylaxis of recurrent hepatitis B infection and is used in most centers. The drawbacks of long-term administration of hyperimmune gamma globulin have led to research on regimens in which this agent is withdrawn after a certain amount of time in combination treatment, a strategy that appears to be safe in patients with undetectable viremia at the time of liver transplantation if the patients adhere to the treatment. In recent years, there has also been research into regimens of gamma-globulin-free prophylaxis, based only on the administration of oral antiviral drugs, which appear to be safe if antivirals with a high genetic barrier to resistance are used. Hepatitis B prophylaxis should be maintained indefinitely; therefore, the total withdrawal of prophylaxis is not an accepted strategy at present in daily clinical practice if not in the context of a clinical trial.

IL-21 receptor is critical for the development of memory B cell responses.

Development of long-term humoral immunity, characterized by the formation of long-lived plasma cells (PCs) in the bone marrow and memory B cells, is a critical component of protective immunity to pathogens, and as such it is the major goal of vaccination. However, the mechanisms involved in the generation of long-term humoral immunity remain poorly understood. In this study, we used IL-21R-deficient (IL-21R.KO) mice to examine the role of the IL-21 pathway in the development of the B cell memory response. Primary IgG serum Ab responses to the T cell-dependent Ag 4-hydroxy-3-nitrophenylacetyl (NP) hapten conjugated to chicken γ globulin were delayed in IL-21R.KO mice, but reached normal titers within 3 to 4 wk of immunization. IL-21R.KO mice formed germinal centers and generated normal numbers of PCs in their bone marrow. Additionally, memory B cell formation was similar in wild-type and IL-21R.KO mice. However, NP-specific memory B cells and PCs failed to expand following secondary immunization of IL-21R.KO mice, and consequently, secondary IgG Ab responses to NP hapten conjugated to chicken γ globulin were significantly impaired. These results identify the IL-21 pathway as a critical component of the memory B cell response.

The role of anti-IgA antibodies in causing adverse reactions to gamma globulin infusion in immunodeficient patients: a comprehensive review of the literature.

Anaphylactic reactions to immunoglobulin infusions in immunodeficient patients with undetectable IgA have been attributed in several reports to IgG or IgE anti-IgA antibodies. However, other reports have not supported an association between such antibodies and the development of severe reactions. We have reviewed the articles reporting reactions to immunoglobulin products in IgA-deficient patients, as well as those describing the presence of such antibodies in the absence of reactions to infusions. A variety of factors might influence the association of adverse reactions with anti-IgA antibodies, including the serum concentration and isotype (IgG or IgE) of the anti-IgA antibody, its specificity (class or subclass specific), the method of measurement, and the IgA content of the gamma globulin infusion and its route of administration. The role of anti-IgA antibodies in causing anaphylaxis in IgA-deficient patients receiving gamma globulin therapy is still controversial. Larger (multicenter) studies are needed to further evaluate this association.

The immunopathogenesis of immune thrombocytopenia: T cells still take center-stage.

PURPOSE OF REVIEW: Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder in which T and B cells recognize platelet antigens and initiate antiplatelet destructive mechanisms such as peripheral Fc receptor-mediated phagocytosis in the spleen or megakaryocyte destruction/inhibition within the bone marrow. The purpose of this review is to report on the ITP pathophysiology literature published from January 2011 to early in 2012. RECENT FINDINGS: The underlying stimulus of platelet autoimmunity is not known; however, in 2011, as in previous years, there has been a significant contribution of published studies addressing the pathophysiology of ITP. At least half of the 2011 ITP pathophysiology literature was associated with T-cell dysregulation particularly with respect to T-helper 17 cell and related cytokine and genetic studies. There were also studies related to B-cell responses, human spleen cells and the potential role of oxidative stress in ITP. With respect to therapeutic research, the mechanisms of action of intravenous gammaglobulin relating to Fc inhibitory receptors and sialylation have been challenged. SUMMARY: The overall landscape of pathophysiological research into ITP still is overwhelmed by studies on abnormal T-cell responses and these studies are beginning to clarify the underlying immune mechanisms that are responsible for the disorder.

Epistasis: the key to understanding immunological disease?

Epistasis is fast becoming central to the understanding of the complex relationship between genotype and phenotype observed in autoimmune disease. A study in this issue of the European Journal of Immunology uses in-depth analysis of genome-wide mapping by polymorphic microsatellite markers to shed light on the genomic control of autoimmunity and self-tolerance.

Susceptibility loci for the defective foreign protein-induced tolerance in New Zealand Black mice: implication of epistatic effects of Fcgr2b and Slam family genes.

In contrast to normal mice, autoimmune-prone New Zealand Black (NZB) mice are defective in susceptibility to tolerance induced by deaggregated bovine γ globulin (DBGG). To examine whether this defect is related to the loss of self-tolerance in autoimmunity, susceptibility loci for this defect were examined by genome-wide analysis using the F(2) intercross of nonautoimmune C57BL/6 (B6) and NZB mice. One NZB locus on the telomeric chromosome 1, designated Dit (Defective immune tolerance)-1, showed a highly significant linkage. This locus overlapped with a locus containing susceptibility genes for autoimmune disease, namely Fcgr2b and Slam family genes. To investigate the involvement of these genes in the defective tolerance to DBGG, we took advantage of two lines of Fcgr2b-deficient B6 congenic mice: one carries autoimmune-type, and the other carries B6-type, Slam family genes. Defective tolerance was observed only in Fcgr2b-deficient mice with autoimmune-type Slam family genes, indicating that epistatic effects of both genes are involved. Thus, common genetic mechanisms may underlie the defect in foreign protein antigen-induced tolerance and the loss of self-tolerance in NZB mouse-related autoimmune diseases.

A role for lysosomal-associated protein transmembrane 5 in the negative regulation of surface B cell receptor levels and B cell activation.

Mechanisms by which cell surface levels of the BCR are regulated remain largely unknown. We found that B cells lacking the lysosomal-associated protein transmembrane 5 (LAPTM5) expressed higher levels of cell surface BCR than did wild-type (WT) B cells after Ag stimulation in vitro and in vivo. In addition, LAPTM5-deficient mice contained an increased frequency of Ag-specific B cells and produced greater amounts of Abs than did WT mice after immunization with a T-dependent Ag. Adoptive transfer of LAPTM5-deficient B cells with WT T cells into RAG1-deficient mice revealed that the increased surface BCR levels and the enhanced B cell activation and Ab production were due to a B cell intrinsic defect. As they aged, the LAPTM5-deficient mice had increased titers of serum IgM and autoantibodies and immune complex deposition in the kidney. Immunofluorescent and biochemical analysis revealed that LAPTM5 physically interacted with the BCR complex and promoted its degradation in the lysosomal compartment in mouse B cells. These results demonstrate a role for LAPTM5 in the negative regulation of cell surface BCR levels and B cell activation.

Acute cerebellar infarction associated with intravenous gammaglobulin treatment in idiopathic thrombocytopenic purpura.

Intravenous immunoglobulins (IVIGs) are used for a variety of immunologic and hematologic disorders. Hemorheologic alteration or the rapid increase of platelet counts by IVIG administration can cause thrombotic adverse events. We present a 58-year-old woman with a previous diagnosis of idiopathic thrombocytopenic purpura who developed cerebellar infarction immediately after IVIG treatment. We discuss a possible role of IVIG in cerebral ischemia and management strategies.

[Successful treatment with rituximab in two cases of IgM-monoclonal gammopathy of undetermined significance (MGUS) neuropathy].

A 66-year-old male was hospitalized with muscle weakness and gait disturbance. Examination revealed IgM 3,407 mg/dl (IgM, κ-type M protein) and he was diagnosed as having IgM-MGUS neuropathy. He suffered from paralysis of respiratory muscles and required a respirator support. Plasmapheresis and intravenous immunoglobulin were performed and he was weaned from the respirator. Rituximab given as 8 weekly infusions improved gait disturbance. A 71-year-old male was hospitalized with lumbago, numbness of lower extremities and gait disturbance. Examination revealed IgM 1,553 mg/dl (IgM, λ-type M protein) and he was diagnosed with IgM-MGUS neuropathy. Rituximab given as 8 weekly infusions improved gait disturbance. It was concluded that rituximab is a well-tolerated treatment that may be effective in some patients with IgM-MGUS neuropathy.