RhIg for the prevention Rh immunization and IVIg for the treatment of affected neonates.

Rhesus D (RhD) negative pregnant women carrying an RhD positive fetus are at risk of developing anti-D during or after pregnancy. Anti-d-immunoglobulin (RhIg), which is mainly produced from special plasma donated in a few countries for the whole world, is able to prevent an anti-D alloimmunization. Through the introduction of ante- and postnatal anti-d-prophylaxis into clinical routine, the frequency of hemolytic disease of fetus and newborn decreased considerably. Postnatal prophylaxis from the beginning in the 1960s has been applied only to women who delivered an RhD positive newborn. Because the fetal RhD status can be determined with high sensitivity and accuracy from the mother's peripheral blood, targeted antenatal anti-d-prophylaxis is becoming a new standard procedure in more and more countries. Phototherapy and exchange transfusion are still the main pillars for the treatment of RhD hemolytic disease of the newborn. The efficacy of IVIg in the management of these neonates is not conclusive and cannot be recommended until a larger randomized, double-blind, placebo-controlled study is performed.

New insights into IVIg mechanisms and alternatives in autoimmune and inflammatory diseases.

PURPOSE OF REVIEW: Intravenous immunoglobulin (IVIg) is an effective treatment for an increasing number of autoimmune and inflammatory conditions. However, IVIg continues to be limited by problems of potential shortages and cost. A number of mechanisms have been described for IVIg, which have been captured in newly emergent IVIg mimetic and IVIg alternative therapies. This review discusses the recent developments in IVIg mimetics and alternatives. RECENT FINDINGS: Newly emergent IVIg mimetics and alternatives capture major proposed mechanisms of IVIg, including FcγR blockade, FcRn inhibition, complement inhibition, immune complex mimetics and sialylated IgG. Many of these emergent therapies have promising preclinical and clinical trial results. SUMMARY: Significant research has been undertaken into the mechanism of IVIg in the treatment of autoimmune and inflammatory disease. Understanding the major IVIg mechanisms has allowed for rational development of IVIg mimetics and alternatives for several IVIg-treatable diseases.

Bovine IgG Prevents Experimental Infection With RSV and Facilitates Human T Cell Responses to RSV.

Respiratory syncytial virus (RSV) infections represent a major burden of disease in infants and are the second most prevalent cause of death worldwide. Human milk immunoglobulins provide protection against RSV. However, many infants depend on processed bovine milk-based nutrition, which lacks intact immunoglobulins. We investigated the potential of bovine antibodies to neutralize human RSV and facilitate-cell immune activation. We show cow's milk IgG (bIgG) and Intravenous Immunoglobulin (IVIG) have a similar RSV neutralization capacity, even though bIgG has a lower pre-F to post-F binding ratio compared to human IVIG, with the majority of bIgG binding to pre-F. RSV is better neutralized with human IVIG. Consequently, we enriched RSV specific T cells by culturing human PBMC with a mixture of RSV peptides, and used these T cells to study the effect of bIgG and IVIG on the activation of pre-F-pecific T cells. bIgG facilitated in vitro T cell activation in a similar manner as IVIG. Moreover, bIgG was able to mediate T cell activation and internalization of pathogens, which are prerequisites for inducing an adaptive viral response. Using in vivo mouse experiments, we showed that bIgG is able to bind the murine activating IgG Fc Receptors (FcγR), but not the inhibiting FcγRII. Intranasal administration of the monoclonal antibody palivizumab, but also of bIgG and IVIG prevented RSV infection in mice. The concentration of bIgG needed to prevent infection was ~5-fold higher compared to IVIG. In conclusion, the data presented here indicate that functionally active bIgG facilitates adaptive antiviral T cell responses and prevents RSV infection in vitro and in vivo.

Toxic Epidermal Necrolysis and Steven-Johnson Syndrome: A Comprehensive Review.

Significance: Toxic epidermal necrolysis (TEN) and Steven-Johnson syndrome (SJS) are potentially fatal acute mucocutaneous vesiculobullous disorders. Evidence to date suggests that outcomes for patients with both TEN and SJS are largely dependent on stopping the causative agent, followed by supportive care and appropriate wound management in a specialized burns unit. These are life-threatening conditions characterized by widespread full-thickness cutaneous and mucosal necrosis. This article outlines the approach to holistic management of such patients, in a specialized unit, highlighting various practical aspects of wound care to prevent complications such as infection, mucosal and adhesions, and ocular scaring. Recent Advances: There is improved understanding of pain and morbidity with regard to the type and frequency of dressing changes. More modern dressings, such as nanocrystalline, are currently favored as they may be kept in situ for longer periods. The most recent evidence on systemic agents, such as corticosteroids and cyclosporine, and novel treatments, are also discussed. Critical Issues: Following cessation of the culprit trigger, management in a specialized burns unit is the most important management step. It is now understood that a multidisciplinary team is essential in the care of these patients. Following admission of such patients, dermatology, ear, nose, and throat surgery, ophthalmology, urology, colorectal surgery, and gynecology should all be consulted to prevent disease sequelae. Future Directions: Looking forward, research is aimed at achieving prospective data on the efficacy of systemic immunomodulating agents and dressing types. Tertiary centers with burns units should develop policies for such patients to ensure that the relevant teams are consulted promptly to avoid mucocutaneous complications.

KMP01D Demonstrates Beneficial Anti-inflammatory Effects on Immune Cells: An ex vivo Preclinical Study of Patients With Colorectal Cancer.

Background: Colorectal cancer (CRC) is frequently associated with dysbiosis of the gut microbiome which, together with a compromised gut barrier, can result in perioperative endotoxin leakage into the circulation. Constant local and systemic inflammatory activity is suggested to facilitate metastases formation. Previous studies have pointed to the capacity of a colostrum preparation to neutralize endotoxins within the gastrointestinal tract which could ameliorate associated inflammatory responses and tumor recurrence in affected patients. This study aimed to examine the effects of the colostrum preparation, KMP01D, on the inflammatory activity of patient-derived immune cells. Methods: The effects of KMP01D on pro-/anti-inflammatory cytokine responses and apoptosis were examined ex vivo using immune cells from CRC patients (stages I-IV, n = 48). The expression of CD14, CD68, Toll-like receptor (TLR)4, and insulin-like growth factor (IGF)-1 was also analyzed. Results: KMP01D increased interleukin (IL)-10 and IL-13 anti-inflammatory cytokine expression in patient-derived peripheral blood mononuclear cells (PBMCs). Interestingly, KMP01D also decreased the secretion of IL-1ß, IL-6, interferon (IFN)-γ, tumor necrosis factor (TNF)-α, IL-12 inflammatory cytokines, and IGF-1 in these cells. Moreover, CD14 and TLR4 expression involved in endotoxin signaling was downregulated in PBMCs and tumor-derived cells. Apoptosis of immune cells and tumor-derived cells was likewise enhanced with KMP01D. Addition of vitamin D3 as a cofactor demonstrated enhanced anti-inflammatory effects. Conclusions: KMP01D demonstrated beneficial ex vivo effects on inflammatory cytokine responses in PBMCs and enhanced apoptosis of immune cells from CRC patients. In line with previous clinical trials, we present new evidence endorsing KMP01D as a treatment strategy to regulate stage-dependent local and systemic inflammation in CRC patients.

Engineering of Fc Multimers as a Protein Therapy for Autoimmune Disease.

The success of Intravenous Immunoglobulin in treating autoimmune and inflammatory processes such as immune thrombocytopenia purpura and Kawasaki disease has led to renewed interest in developing recombinant molecules capable of recapitulating these therapeutic effects. The anti-inflammatory properties of IVIG are, in part, due to the Fc region of the IgG molecule, which interacts with activating or inhibitory Fcγ receptors (FcγRs), the neonatal Fc Receptor, non-canonical FcRs expressed by immune cells and complement proteins. In most cases, Fc interactions with these cognate receptors are dependent upon avidity-avidity which naturally occurs when polyclonal antibodies recognize unique antigens on a given target. The functional consequences of these avid interactions include antibody dependent cell-mediated cytotoxicity, antibody dependent cell phagocytosis, degranulation, direct killing, and/or complement activation-all of which are associated with long-term immunomodulatory effects. Many of these immunologic effects can be recapitulated using recombinant or non-recombinant approaches to induce Fc multimerization, affording the potential to develop a new class of therapeutics. In this review, we discuss the history of tolerance induction by immune complexes that has led to the therapeutic development of artificial Fc bearing immune aggregates and recombinant Fc multimers. The contribution of structure, aggregation and N-glycosylation to human IgG: FcγR interactions and the functional effect(s) of these interactions are reviewed. Understanding the mechanisms by which Fc multimers induce tolerance and attempts to engineer Fc multimers to target specific FcγRs and/or specific effector functions in autoimmune disorders is explored in detail.

Anti-HLA antibodies with complementary and synergistic interaction geometries promote classical complement activation on platelets.

High titers of HLA antibodies are associated with platelet refractoriness, causing poor platelet increments after transfusions in a subset of patients with HLA antibodies. Currently, we do not know the biological mechanisms that explain the variability in clinical responses in HLA alloimmunized patients receiving platelet transfusions. Previously we showed that a subset of anti-HLA IgG-antibodies induces FcγRIIa-dependent platelet activation and enhanced phagocytosis. Here, we investigated whether anti-HLA IgG can induce complement activation on platelets. We found that a subset of anti-HLA IgG induced complement activation via the classical pathway, causing C4b and C3b deposition and formation of the membrane-attack complex. This resulted in permeabilization of platelet membranes and increased calcium influx. Complement activation also caused enhanced α-granule release, as measured by CD62P surface exposure. Blocking studies revealed that platelet activation was caused by FcγRIIa-dependent signaling as well as HLA antibody induced complement activation. Synergistic complement activation employing combinations of monoclonal IgGs suggested that assembly of oligomeric IgG complexes strongly promoted complement activation through binding of IgGs to different antigenic determinants on HLA. In agreement with this, we observed that preventing anti-HLA-IgG hexamer formation using an IgG-Fc:Fc blocking peptide, completely inhibited C3b and C4b deposition. Our results show that HLA antibodies can induce complement activation on platelets including membrane attack complex formation, pore formation and calcium influx. We propose that these events can contribute to fast platelet clearance in vivo in patients refractory to platelet transfusions with HLA alloantibodies, who may benefit from functional-platelet matching and treatment with complement inhibitors.

IqYmune® is an effective maintenance treatment for multifocal motor neuropathy: A randomised, double-blind, multi-center cross-over non-inferiority study vs Kiovig®-The LIME Study.

Intravenous immunoglobulin (IVIg) is the gold-standard for maintenance treatment of multifocal motor neuropathy (MMN). This phase III, randomised, double-blind, multi-centre, active-control, crossover study, aimed to evaluate the non-inferiority of IqYmune® relative to Kiovig®, primarily based on efficacy criteria. Twenty-two adult MMN patients, treated with any brand of IVIg (except Kiovig® or IqYmune®) at a stable maintenance dose within the range of 1 to 2 g/kg every 4 to 8 weeks, were randomised to receive either Kiovig® followed by IqYmune®, or IqYmune® followed by Kiovig®. Each product was administered for 24 weeks. The primary endpoint was the difference between IqYmune® and Kiovig® in mean assessments of modified Medical Research Council (MMRC) 10 sum score (strength of 5 upper-limb and 5 lower-limb muscle groups, on both sides, giving a score from 0 to 100) during the evaluation period (non-inferiority margin of Δ = 2). A linear mixed model analysis demonstrated the non-inferiority of IqYmune® relative to Kiovig®, independently of the covariates (value at baseline, treatment period, and treatment sequence). The estimated "IqYmune® - Kiovig®" difference was -0.01, with a 95% confidence interval (CI) -0.51 to 0.48. The number of adverse reactions (ARs) and the percentage of patients affected were similar for the two products: 39 ARs in 10 patients with IqYmune® vs 32 ARs in 11 patients with Kiovig®. No thromboembolic events nor haemolysis nor renal impairment were observed. In this first clinical trial comparing two IVIg brands for maintenance treatment of MMN, efficacy and tolerability of both brands were similar.

Preimplantation factor inhibits circulating natural killer cell cytotoxicity and reduces CD69 expression: implications for recurrent pregnancy loss therapy.

Embryo-secreted preimplantation factor (PIF) is necessary for, and its concentration correlates with, embryo development in humans by promoting implantation and trophoblast invasion. Synthetic PIF (sPIF) modulates systemic immunity and is effective in autoimmune disease models. sPIF binds monocytes and activated T and B cells, leading to immune tolerance without suppression. This study examined the effect of sPIF on natural killer (NK) cell cytotoxicity in 107 consecutive nonselected, nonpregnant patients with recurrent pregnancy loss (RPL) and 26 infertile IVF patients (controls). The effects of sPIF, intravenous gamma immunoglobulin (Ig), Intralipid and scrambled PIF (PIFscr; negative control) on NK cell cytotoxicity to peripheral-blood cells were compared by flow cytometry of labelled-K562 cell cytolysis. The effects of sPIF and PIFscr on whole-blood NKCD69+ expression were also compared. In patients with RPL, sPIF inhibited NK cell cytotoxicity at doses of 2.5 and 25ng/ml (37% and 42%) compared with PIFscr (18%; P<0.001), regardless of the proportion of peripheral-blood NKCD56+ cells to lymphocytes. Pre-incubation of blood from infertile patients with sPIF for 24h decreased NKCD69+ expression versus incubatino with PIFscr (P<0.05). In conclusion, sPIF inhibits NK cell cytotoxicity by reducing NKCD69 expression, suggesting a significant role in RPL patients. There is a continuous search to identify safe and effective agents to counteract recurrent pregnancy loss (RPL). Preimplantation factor (PIF) secreted by the embryo at the 2-cell stage is present throughout viable pregnancy but absent in nonviable pregnancy. Its immunomodulatory (not suppressive) effects promote embryo acceptance and maintenance by mother/host, control inflammation, facilitate uterine environment and placental embedding. Synthetic PIF (sPIF) was used to complete PIF's role as a targeted, safe treatment for immune-based RPL. Previous reports showed sPIF's significant protective systemic effect against maternal factors present in RPL serum. Herein is examined sPIF's ability to inhibit the local protective toxicity induced by natural killer (NK) immune cells in a representative number of RPL patients. When elevated in blood, NK cells are associated with RPL. Low-dose physiological sPIF was highly effective to inhibit NK cell toxicity. Side-by-side comparison showed that sPIF is equally effective at a lower dose than intravenous gamma immunoglobulin or Intralipid treatment currently used. The sPIF effect on NK cells was targeted, indicating specific action. Overall, sPIF may represent a safe, effective and nontoxic immune-based therapy against RPL.

Towards a platform PBPK model to characterize the plasma and tissue disposition of monoclonal antibodies in preclinical species and human.

The objectives of the following investigation were (1) development of a physiologically based pharmacokinetic (PBPK) model capable of characterizing the plasma and tissue pharmacokinetics (PK) of nonspecific or antigen specific monoclonal antibodies (mAbs) in wild type, FcRn knockout, tumor bearing and non tumor bearing mice and (2) evaluation of the scale up potential of the model by characterizing the mouse, rat, monkey and human plasma PK of mAbs, simultaneously. A PBPK model containing 15 tissues, a carcass and a tumor compartment was developed by modifying/augmenting previously published PBPK models. Each tissue compartment was subdivided into plasma, blood cell, endothelial, interstitial and cellular sub-compartments. Each tissue was connected through blood and lymph flow to the systemic circulation. Lymph flow was set to a value 500 times lower than plasma flow and vascular reflection coefficients for each tissue were adjusted according to their vascular pore size. In each tissue endothelial space, mAb entered via pinocytosis and the interaction of FcRn with mAb was described by on and off rates. FcRn bound mAb was recycled and unbound mAb was eliminated by a first order process (K(deg)). The PBPK model was simultaneously fit to the following datasets to estimate four system parameters: (1) plasma and tissue PK of nonspecific mAb in wild type mouse with or without simultaneous intravenous immunoglobulin (IVIG) administration, (2) plasma and tissue PK of nonspecific mAb in FcRn knockout mouse, (3) plasma and tissue PK of nonspecific mAb in tumor bearing mouse, (4) plasma and tissue PK of tumor antigen specific mAb in tumor bearing mouse, and (5) plasma PK of mAb in rat, monkey and human. The model was able to characterize all the datasets reasonably well with a common set of parameters. The estimated value of the four system parameters i.e. FcRn concentration (FcRn), rate of pinocytosis per unit endosomal space (CL(up)), K(deg) and the proportionality constant (C_LNLF) between the rate at which antibody transfers from the lymph node compartment to the blood compartment and the plasma flow of the given species, were found to be 4.98E-05 M (CV% = 11.1), 3.66E-02 l/h/l (%CV = 3.48), 42.9 1/h (%CV = 15.7) and 9.1 (CV% > 50). Thus, a platform PBPK model has been developed that can not only simultaneously characterize mAb disposition data obtained from various previously published mouse PBPK models but is also capable of characterizing mAb disposition in various preclinical species and human.

Retrospective analysis of weekly intravenous immunoglobulin prophylaxis versus intravenous immunoglobulin by IgG level monitoring in hematopoietic stem cell transplant recipients.

Patients undergoing allogeneic hematopoietic stem cell transplant (allo HCT) have a higher incidence of infections partly due to secondary hypogammaglobulinemia. We evaluated the role of IVIG in allo HCT patients who received prophylactic IVIG 200 mg/kg once weekly regardless of IgG level (Group 1, n = 115) compared with patients who received IVIG based on IgG level <400 mg/dL (Group 2, n = 114). Primary endpoints were the utilization of IVIG, incidence of veno-occlusive disease (VOD), graft-versus-host disease (GVHD), and documented infections within the first 100 days after allo HCT. Patients in both groups were similar except for a higher number of matched unrelated donor (MUD) transplants in Group 2 (62 vs. 41, P = 0.01). There were no significant differences in the incidence all grades of GVHD (55 vs. 50), VOD (2 vs. 0) or infections in the two groups except for a higher incidence of para-influenza infections in group 1 (9 vs. 0, P = 0.003) coinciding with the flu season. We recommend monthly monitoring of IgG level and replacement only if IgG level is <400 mg/dL.

Intravenous immunoglobulins in systemic lupus erythematosus: from the bench to the bedside.

This article is an update on the clinical and research data available on systemic lupus erythematosus (SLE) and intravenous immunoglobulin (IVIg) therapy that includes some studies performed under the umbrella of the European Working Party on SLE. Various mechanisms of IVIg may play a role, some synergistically, in the modulation of SLE. Recently it has been suggested that IVIg also suppresses the expansion of autoreactive B lymphocytes through signalling of the FcgRIIB, idiotype-mediated inhibition of B cell receptors and neutralisation of cytokines such as the B cell survival factors (B cell activation factor (BAFF and APRIL). In case reports and in open trials, high-dose IVIg (2 g/kg over a 5-day period) has consistently been shown to be a beneficial and safe adjunct therapeutic agent for over 20 manifestations in patients with SLE. It can be given as a first choice of therapy in some cases, for example, in neurological involvement and in those patients who refuse certain immunosuppressive agents such as cyclophosphamide, or in patients who have concomitant infections. Furthermore, IVIg may have a steroid-sparing effect although this characteristic needs further investigation. Specific IVIg (an anti-idiotype to anti-DNA, phosphorylcholine and antiphospholipids) has been shown to be effective in experimental murine models. Hence, extractable IVIg that is directed to the specific pathogenic immunoglobulins will enable the more specific therapy for patients with lupus.

Intravenous immunoglobulin up-regulates the expression of the inhibitory FcgammaIIB receptor on B cells.

Intravenous immunoglobulin (IVIg) preparations are known to modulate autoimmune/inflammatory diseases through several F(ab')(2)- and Fc-dependent mechanisms. In this study, we show that the in vitro and the in vivo exposure of B lymphocytes from lupus-prone and from healthy mice to IVIg results in an increased expression of their surface inhibitory FcgammaIIB receptors. Further, this exposure enhanced the ability of a chimeric antibody, cross-linking FcgammaRIIB and immunoglobulin receptors on DNA-specific B lymphocytes, to suppress IgG anti-DNA antibody production. F(ab')(2) fragments of IVIg had a similar activity as the intact preparation, whereas Fc fragments had no effect. This study describes a novel approach with clinical relevance for modulating B lymphocyte activity.

Interaction of curcumin with intravenous immunoglobulin: a fluorescence quenching and Fourier transformation infrared spectroscopy study.

The interaction of curcumin with intravenous immunoglobulin (IVIG) mainly composed of immune gamma globulin (IgG) was studied in vitro by spectroscopic methods including fluorescence spectroscopy and Fourier transformation infrared (FTIR) spectroscopy. Docking was used to calculate the interaction mode between curcumin and IVIG. The binding parameters for the reaction were calculated according to the Sips equation, which suggested that the binding of IVIG to curcumin was characterized by two binding sites with the average affinity constant K(o) at 1.170 x 10(4) M(-1) (296 K), and it was a non-specific and weak drug-protein interaction. The secondary structure compositions of free IVIG and its curcumin complexes were calculated by the FTIR difference spectra, self-deconvolution, second derivative resolution enhancement and the curve-fitting procedures of amide I band. The observed spectral changes indicate a partial unfolding of the protein structure, but the typical beta structural conformation of IVIG is still retained. The average binding distance between curcumin and the chromophore of IVIG (5.57 nm) was obtained using the theory of Förster energy transfer. IVIG can serve as transport protein (carrier) for curcumin.

Intravenous immunoglobulins reverse acute vaso-occlusive crises in sickle cell mice through rapid inhibition of neutrophil adhesion.

Previous studies using intravital microscopy in a sickle cell disease (SCD) mouse model suggest that adherent white blood cells (WBCs) play a key role in vaso-occlusion by capturing circulating red blood cells (RBCs) in venules. Commercial intravenous immunoglobulin (IVIG) given before the inflammatory stimuli increased microcirculatory blood flow and survival. To mimic the clinical situation in which SCD patients seek medical attention after the onset of symptoms, we developed an in vivo model in which the therapeutic intervention (eg, IVIG) was administered after in the inflammatory challenge. In this setting, IVIG rapidly (<10 minutes) reduced adherent leukocyte numbers and dramatically inhibited interactions between RBCs and WBCs, resulting in improved microcirculatory blood flow and survival of sickle cell "Berkeley" mice. Longer survival correlated positively with blood flow (P=.001) and negatively with the number of adherent leukocytes (P=.001) and RBC-WBC interactions (P=.002). Using multichannel digital fluorescence videomicroscopy, we found that IVIG affected specifically the recruitment of neutrophils. Moreover, further analyses of leukocyte behavior revealed that IVIG significantly increased rolling velocities, indicating that it alters adhesion pathways involved in slow rolling. These data suggest that the potential therapeutic benefits of IVIG in SCD crises should be evaluated in a clinical trial.

Variations in serum hemoglobin, albumin, and electrolytes in patients receiving intravenous immunoglobulin therapy: a real clinical threat?

BACKGROUND AND OBJECTIVE: Intravenous immunoglobulin (IVIg) is a solution of globulins containing antibodies derived from pooled human plasma of donors and used in the treatment of a number of immune deficiencies and autoimmune diseases. However, several investigators have reported biochemical alterations with use of IVIg. The objective of this study was to evaluate the effects of IVIg therapy on selected biochemical and hematologic parameters in patients with autoimmune mucocutaneous blistering diseases (AMBDs). METHODS: In this preliminary clinical study, ten patients with AMBDs (seven with pemphigus vulgaris and three with mucous membrane pemphigoid) received 133 cycles of IVIg for a total of 399 infusions. We evaluated the effects of IVIg therapy on serum hemoglobin (Hb), albumin, and electrolyte levels, including sodium (Na+), potassium (K+), chloride (Cl-) and calcium (Ca2+). Values of these parameters were measured 24 hours before, during, and 24 hours and 4 weeks after the 3-day infusion period. RESULTS: The observed variations in serum electrolyte levels were physiologically and clinically negligible. Furthermore, 24 hours after the last infusion, mean electrolyte values had spontaneously returned to normal levels without the need for additional supplementation: Na+ 137.59+/-1.42 mmol/L (p=0.6091 vs baseline); K+ 3.97+/-0.5 mmol/L (p=0.2689); Cl- 103.4+/-2.69 mmol/L (p=0.0388); and Ca2+ 9.07+/-0.44 mg/dL (p=0.5332). Conversely, significant variations in mean Hb and albumin levels were observed. When measured 24 hours after the last infusion, mild/moderate decreases in Hb (11.62+/-2.12 g/dL; p=0.009 vs baseline) and/or albumin (mean 3.14+/-0.24 g/dL; p=0.0016 vs baseline) were evident. Such changes may, albeit very rarely, be of sufficient clinical significance in individual patients as to necessitate additional treatment. CONCLUSION: In patients receiving intravenous IVIg for AMBDs, electrolyte values should be monitored but do not represent a real clinical threat. Hemoglobin and albumin values may be altered sufficiently to require additional treatment but this is a very rare occurrence. These findings confirm and extend previous reports of the safety of IVIg therapy.

Uso de inmunoglobulina intravenosa en el tratamiento de necrólisis epidérmica tóxica y síndrome de Stevens-Johnson / Use of intravenous immunoglobulin in toxic epidermal necrolysis and Stevens-Johnson syndrome

La necrólisis epidérmica tóxica (NET) y el síndrome de Stevens-Johnson (SSJ) se describen como variantes de una misma enfermedad con diferente severidad y constituyen las reacciones cutáneas más frecuentes en niños con una considerable morbilidad. Varias comunicaciones apoyan el uso de la inmunoglobulina intravenosa (IGIV) para el tratamiento de tales entidades. Nosotros presentamos el caso de 2 pacientes, uno con NET y uno con SSJ en quienes se utilizó inmunoglobulina con resultados exitosos. Además hacemos una revisión de la evolución de 13 pacientes con NET y SSJ en los últimos 10 años en el Hospital Infantil de México en quienes se utilizó tratamiento convencional

Toxic epidermal necrolysis and Stevens-Johnson syndrome are described as variants of the same disease with distinct severity and constitute the most frequent cutaneous reactions in children, causing considerable morbidity. Several reports support the use of intravenous immunoglobulin therapy in these entities. We report the cases of two patients, one with toxic epidermal necrolysis and the other with Stevens-Johnson syndrome, in whom immunoglobulin treatment was successfully used. We also reviewed the outcomes of 13 patients with toxic epidermal necrolysis and Stevens-Johnson syndrome in the previous 10 years in the Hospital Infantil de Mexico, in whom conventional treatment was used

In vivo platelet redistribution and acute transient thrombocytopenia after eptifibatide injection in baboons.

BACKGROUND: The occurrence of thrombocytopenia has been reported during clinical eptifibatide (Integrilin) therapy, but the exact mechanism is not yet established to explain the varied duration and severity of thrombocytopenia associated with glycoprotein (GP) IIb/IIIa inhibitors. We assessed the redistribution of platelets in juvenile baboons during acute transient thrombocytopenia that was observed after eptifibatide injection. METHODS: Eptifibatide was administered intravenously to eight baboons by infusion at 20 microg/kg/min or a bolus injection of 10 mg. Platelet distribution was measured with a gamma scintillation camera using 111In-labeled autologous platelets. Platelet function and GP IIb/IIIa receptor inhibition were evaluated using the Plateletworks system. The effects of pretreatment with abciximab (0.4 mg/kg) or human immunoglobulin concentrate (0.75 g/kg) were also investigated. RESULTS: Eptifibatide, administered as an infusion or a bolus, caused transient thrombocytopenia with uptake of platelets predominantly by the liver. The recovery of platelet aggregation was associated with the re-entry of platelets from the liver into the systemic circulation. Pretreatment with either abciximab (0.4 mg/kg) or human intravenous immunoglobulin (IVIG, 0.75 g/kg) attenuated eptifibatide-induced thrombocytopenia and the hepatic uptake of radiolabeled platelets. CONCLUSION: Acute thrombocytopenia after eptifibatide injection was caused by the transient redistribution of platelets to the liver. Attenuation of the decrease in platelet count and hepatic sequestration by abciximab and IVIG suggests that thrombocytopenia may have been caused by ligand-induced binding site antigen induction and recognition by the reticuloendothelial system.

F(ab)'2-mediated neutralization of C3a and C5a anaphylatoxins: a novel effector function of immunoglobulins.

High-dose intravenous immunoglobulin (IVIG) prevents immune damage by scavenging complement fragments C3b and C4b. We tested the hypothesis that exogenous immunoglobulin molecules also bind anaphylatoxins C3a and C5a, thereby neutralizing their pro-inflammatory effects. Single-cell calcium measurements in HMC-1 human mast cells showed that a rise in intracellular calcium caused by C3a and C5a was inhibited in a concentration-dependent manner by IVIG, F(ab)2-IVIG and irrelevant human monoclonal antibody. C3a- and C5a-induced thromboxane (TXB2) generation and histamine release from HMC-1 cells and whole-blood basophils were also suppressed by exogenous immunoglobulins. In a mouse model of asthma, immunoglobulin treatment reduced cellular migration to the lung. Lethal C5a-mediated circulatory collapse in pigs was prevented by pretreatment with F(ab)2-IVIG. Molecular modeling, surface plasmon resonance (SPR) and western blot analyses suggested a physical association between anaphylatoxins and the constant region of F(ab)2. This binding could interfere with the role of C3a and C5a in inflammation.

Evaluation by high-resolution ultrasonography of endothelial function in brachial artery after Kawasaki disease and the effects of intravenous administration of vitamin C.

Previous studies in patients with a history of Kawasaki disease (KD) have focused on the endothelial function of the coronary arteries and that of the systemic arteries is not fully understood. Furthermore, the effect of vitamin C on systemic vascular endothelial function after KD has not yet been elucidated. In the present study, 39 patients (age, 7.1 +/- 2.7 years) at 1-10 years after acute KD were compared with 17 matched healthy subjects (7.0 +/- 3.1 years). High-resolution ultrasonography was used to analyze brachial artery responses to reactive hyperemia (with increased flow causing endothelium-dependent dilation) and sublingual nitroglycerin (causing endothelium-independent dilation) after KD, and to investigate whether the acute administration of vitamin C can restore systemic endothelial dysfunction. The percent change in diameter of the brachial artery induced by reactive hyperemia in the patients with a history of KD (6.2 +/- 3.9%) was significantly less than that in the control group (14.1 +/- 6.8%, p < 0.0001). No significant difference could be found in the percent change in diameter induced by sublingual nitroglycerin between the controls (33.2 +/- 13.7%) and the patients (30.6 +/- 9.2%, p = 0.49). There was no significant difference in percent change in diameter of the brachial artery induced by reactive hyperemia between the patients who received gamma globulin (6.0 +/- 4.0) and those who did not (7.9 +/- 3.3, p = 0.33). Intravenous infusion of vitamin C significantly increased the percent change in diameter of the brachial artery induced by reactive hyperemia in 19 patients with history of KD (6.6 +/- 3.5% to 13.0 +/- 5.5%, p < 0.0001). After placebo administration in 20 patients with history of KD there was no significant increase in the percent change in the diameter of the brachial artery induced by reactive hyperemia (6.5 +/- 4.5% to 7.3 +/- 4.9%, p = 0.20). The decreased percent change in the diameter of the brachial artery induced by reactive hyperemia in patients with a history of KD compared with the healthy children indicates that systemic endothelial dysfunction exists after KD. Although it is not influenced by early treatment with high-dose gamma globulin in the acute stage of KD, systemic vascular endothelial function can be restored by acute intravenous administration of vitamin C.