Roger H. Kobayashi

Treatment of Adenosine Deaminase Deficiency with Polyethylene Glycol–Modified Adenosine Deaminase

We treated two children who had adenosine deaminase deficiency and severe combined immunodeficiency disease by injecting bovine adenosine deaminase modified by conjugation with polyethylene glycol. The modified enzyme was rapidly absorbed after intramuscular injection and had a half-life in plasma of 48 to 72 hours. Weekly doses of approximately 15 U per kilogram of body weight maintained plasma adenosine deaminase activity at two to three times the level of erythrocyte adenosine deaminase activity in normal subjects. The principal biochemical consequences of adenosine deaminase deficiency were almost completely reversed. In erythrocytes, adenosine nucleotides increased and deoxyadenosine nucleotides decreased to less than 0.5 percent of total adenine nucleotides. The activity of S-adenosylhomocysteine hydrolase, which is inactivated by deoxyadenosine, increased to normal in red cells and nucleated marrow cells. Neither toxic effects nor hypersensitivity reactions were observed. In vitro tests of the cellular immune function of each patient showed marked improvement, along with an increase in circulating T lymphocytes. Clinical improvement was indicated by absence of infection and resumption of weight gain. We conclude that from the standpoints of efficacy, convenience, and safety, polyethylene glycol-modified adenosine deaminase is preferable to red-cell transfusion as a treatment for adenosine deaminase deficiency. Patients with other inherited metabolic diseases in which accumulated metabolites equilibrate with plasma could benefit from treatment with the appropriate polyethylene glycol-modified enzyme.

Parvovirus B19-Induced Anemia as the Presenting Manifestation of X-Linked Hyper-IgM Syndrome

Parvovirus B19 (B19) can cause chronic anemia due to persistent infection in immunocompromised hosts who cannot produce neutralizing antibody necessary for clearing B19. Three patients with X-linked hyper-IgM syndrome (XHIM), who were all asymptomatic until they developed B19-induced chronic anemia at the ages of 8, 14, and 17 years, respectively, were found to have mutations of the CD40L gene, including a missense mutation (T254M), a nonsense mutation resulting in a new initiation codon and loss of the intracellular domain (R11X), and a splice site mutation (nt 309+2t-->a). Antibody responses to the T cell-dependent antigen, bacteriophage phiX174, were impaired, but neutralizing antibody titers were higher than in XHIM patients with classic phenotype. All 3 patients responded to intravenous immune globulin (IVIG) treatment. Certain mutations of the CD40L gene result in a mild XHIM phenotype that may become apparent following B19 infection in patients not on IVIG therapy and therefore not protected from B19 infection.

Slow subcutaneous human intravenous immunoglobulin in the treatment of antibody immunodeficiency: use of an old method with a new product.

Human intravenous immunoglobulin (IVIG) is a valuable therapeutic agent for antibody immunodeficiency and certain immunoregulatory disorders. However, for some patients, intravenous administration is not feasible because of poor venous access, severe side effects, or rapid IgG catabolism. This report demonstrates that the slow subcutaneous infusion of IVIG is a suitable alternative in these patients. Berger et al.1 first reported the use of 16.5% intramuscular immunoglobulin given by slow subcutaneous infusions for antibody replacement in immunodeficiency. Gardulf and associates2, 3 have used the subcutaneous route in immunodeficient adults in Scandinavia for many years, and they report that it is less expensive, better tolerated, and preferable to intravenous infusions by most patients. Abrahamsen et al.4 report a similar experience in eight children with primary immunodeficiency. Because mercury-free 16.5% intramuscular immunoglobulin is not available in this country, we used preservative-free 10% IVIG in eight antibody-deficient patients, all of whom tolerated subcutaneous infusions well, including three patients with prior severe adverse reactions to IVIG infusions.

In vitro analysis of humoral immunity in antibody deficiency with normal immunoglobulins

Abstract The nature of the humoral immune defects in two unrelated patients with normal serum immunoglobulin and specific antibody deficiency was investigated. Five days after a booster immunization with soluble tetanus toxoid, peripheral blood lymphocyte B cells were assayed for the normal appearance of PWM and T-cell-independent antigen-specific IgG anti-tetanus lymphoblastoid B cells and suppressor T cells for these B cells. Patient 2 was totally unable to generate these B cells while patient 1 generated 10% of the normal tetanus specific B-cell activity. PBL samples were analyzed 21 days after immunization for PWM-dependent B-lymphocyte synthesis of total and anti-tetanus IgG and IgM and total and antigen-specific T-helper and -suppressor lymphocyte activity. Patient 1s B lymphocytes could generate normal amounts of both total and anti-tetanus IgG and IgM. However, his T lymphocytes completely suppressed IgG and anti-tetanus IgG production. Patient 2 also had excess radiation-sensitive T-suppressor cells for total and anti-tetanus IgG and IgM. However, this patients B cells demonstrated an antigen-specific defect in culture in that they produced total IgG normally but were unable to produce specific anti-tetanus IgG. Thus, even with this small patient sample, the heterogeneity of immune defects established in other humoral deficiency diseases appears to exist in the syndrome of antibody deficiency with normal serum immunoglobulin.

Pharmacokinetics of a novel human intravenous immunoglobulin 10% in patients with primary immunodeficiency diseases: Analysis of a phase III, multicentre, prospective, open-label study

&NA; Intravenous immunoglobulin (IVIG) therapy is commonly used to treat patients with primary antibody deficiency. This prospective, open‐label, non‐randomised, multicentre, phase III trial investigated the pharmacokinetics of a new 10% liquid IVIG product (panzyga®; Octapharma) in 51 patients aged 2–75years with common variable immunodeficiency (n=43) or X‐linked agammaglobulinaemia (n=8). Patients were treated with IVIG 10% every 3 (n=21) or 4weeks (n=30) at a dose of 200–800mg/kg for 12months. Total immunoglobulin G (IgG) and subclass concentrations approximately doubled from pre‐ to 15min post‐infusion. The maximum concentration of total IgG (mean±SD) was 21.82±5.83g/L in patients treated 3‐weekly and 17.42±3.34g/L in patients treated 4‐weekly. Median trough IgG concentrations were nearly constant over the course of the study, remaining between 11.0 and 12.2g/L for patients on the 3‐week schedule and between 8.10 and 8.65g/L for patients on the 4‐week schedule. The median terminal half‐life of total IgG was 36.1 (range 18.5–65.9) days, with generally similar values for the IgG subclasses (26.7–38.0days). Median half‐lives for specific antibodies ranged between 21.3 and 51.2days for anti‐cytomegalovirus, anti‐Haemophilus influenzae, anti‐measles, anti‐tetanus toxoid, anti‐varicella zoster virus antibodies, and anti‐Streptococcus pneumoniae subtype antibodies. Overall, IVIG 10% demonstrated pharmacokinetic properties similar to those of other commercial IVIG 10% preparations and 3‐ or 4‐weekly administration achieved sufficient concentrations of IgG, IgG subclasses, and specific antibodies, exceeding the recommended level needed to effectively prevent serious bacterial infections. Graphical abstract: Symbol. No Caption available.

Dried Blood Spots, an Affordable Tool to Collect, Ship, and Sequence gDNA from Patients with an X-Linked Agammaglobulinemia Phenotype Residing in a Developing Country

Background New sequencing techniques have revolutionized the identification of the molecular basis of primary immunodeficiency disorders (PID) not only by establishing a gene-based diagnosis but also by facilitating defect-specific treatment strategies, improving quality of life and survival, and allowing factual genetic counseling. Because these techniques are generally not available for physicians and their patients residing in developing countries, collaboration with overseas laboratories has been explored as a possible, albeit cumbersome, strategy. To reduce the cost of time and temperature-sensitive shipping, we selected Guthrie cards, developed for newborn screening, to collect dried blood spots (DBS), as a source of DNA that can be shipped by regular mail at minimal cost. Method Blood was collected and blotted onto the filter paper of Guthrie cards by completely filling three circles. We enrolled 20 male patients with presumptive X-linked agammaglobulinemia (XLA) cared for at the Vietnam National Children’s Hospital, their mothers, and several sisters for carrier analysis. DBS were stored at room temperature until ready to be shipped together, using an appropriately sized envelope, to a CLIA-certified laboratory in the US for sequencing. The protocol for Sanger sequencing was modified to account for the reduced quantity of gDNA extracted from DBS. Result High-quality gDNA could be extracted from every specimen. Bruton tyrosine kinase (BTK) mutations were identified in 17 of 20 patients studied, confirming the diagnosis of XLA in 85% of the study cohort. Type and location of the mutations were similar to those reported in previous reviews. The mean age when XLA was suspected clinically was 4.6 years, similar to that reported by Western countries. Two of 15 mothers, each with an affected boy, had a normal BTK sequence, suggesting gonadal mosaicism. Conclusion DBS collected on Guthrie cards can be shipped inexpensively by airmail across continents, providing sufficient high-quality gDNA for Sanger sequencing overseas. By using this method of collecting gDNA, we were able to confirm the diagnosis of XLA in 17 of 20 Vietnamese patients with the clinical diagnosis of agammaglobulinemia.

Cost-effectiveness of using an extensively hydrolyzed casein formula containing Lactobacillus rhamnosus GG in managing infants with cow’s milk allergy in the US

Abstract Objective: To estimate the cost-effectiveness of using an extensively hydrolyzed casein formula containing the probiotic Lactobacillus rhamnosus GG (eHCF + LGG; Nutramigen LGG) compared with an eHCF alone and an amino acid formula (AAF) in treating cow’s milk allergy (CMA) in the US, from the perspective of third-party insurers and from parents. Methods: A decision model was used to estimate the probability of cow’s milk allergic infants developing tolerance to cow’s milk by 18 months. The model also estimated the cost to insurers and parents (US dollars at 2016 prices) of managing infants over 18 months after starting one of the formulae, as well as the relative cost-effectiveness of each of the formulae. Results: The probability of developing tolerance to cow’s milk was higher among infants who were fed eHCF + LGG compared with those fed an eHCF alone or an AAF. Infants who are initially fed with eHCF + LGG are expected to utilize fewer healthcare resources than those fed with one of the other formulae. Hence, the estimated total healthcare cost incurred by third-party insurers and parents of initially feeding infants with eHCF + LGG was less than that of feeding infants with an eHCF alone or an AAF. Conclusion: Initial management of newly-diagnosed cows milk allergic infants with eHCF + LGG was found to afford a cost-effective strategy to both third-party insurers and parents when compared to an eHCF alone or an AAF.