Combined immunodeficiency and reticuloendotheliosis with eosinophilia

A generalized erythematous scaly rash, alopecia, lympadenopathy, and hepatosplemonegaly developed in an infant girl during the first 6 weeks of life. Repeated bacterial and fungal infections, persistent diarrhea, and generalized wasting complicated the course of her illness, and death occurred at 5 1/2 months of age. Lymph node architecture was completely obliterated by histiocytes and eosinophils; no plasma cells or germinal centers were present. Both humoral and cellular immune systems were severely but not completely impaired. Familial reticuloendotheliosis with eosinophilia is, in some cases, associated with combined immune deficiency.

Dissociation between results of in vitro and in vivo antibiotic susceptibility tests for some strains of Pseudomonas aeruginosa

The relative efficacy in vivo of the polymyxin and aminoglycoside antibiotics in experimental Pseudomonas infection has apparently never been established. This study was designed to determine such efficacy in experimental infection of mice. Eleven strains of Pseudomonas aeruginosa were selected for the study, representing six of the seven recognized immunotypes. All strains were susceptible to colistin, gentamicin, and tobramycin in vitro, and all were virulent for mice. None was lethal because of preformed toxins. Infections were established in mice by intraperitoneal (i.p.) injection of 100 ID(50) of bacteria (infectious doses that would kill 50% of the mice). Graduated doses of antibiotics or saline were given subcutaneously 1 h later. Infections by three strains of P. aeruginosa were cured by low doses of all three antibiotics. Infections by two strains were relatively resistant in vivo to all three antibiotics. Infections by seven strains were relatively resistant in vivo to colistimethate. For most strains, colistimethate was less effective in vivo than gentamicin or tobramycin. To determine the influence of the size of the bacterial inoculum upon the results of chemotherapy, groups of mice were infected with serial dilutions of bacterial suspensions and treated with antibiotics. The antibiotics were more effective when a lighter bacterial inoculum was used. However, colistimethate at 30 mg/kg failed to cure some infections established with an inoculum of only 10 ID(50). To examine the possibility that death despite apparently adequate chemotherapy might be due to bacterial lysis and delayed release of toxins, numbers of viable bacteria in the peritoneal cavity of treated animals were determined by colony count. Antibiotic failure by colistimethate was associated with a steady rise in the number of i.p. bacteria. The findings support the conclusion that i.p. infections in mice with some strains of P. aeruginosa that are fully susceptible in vitro are relatively resistant to chemotherapy in vivo. The dissociation between in vitro and in vivo results was greatest for colistimethate.

Antagonistic effect of calcium in serum on the activity of tobramycin against Pseudomonas

Physiological concentrations of calcium in serum antagonize the activities of colistin, polymyxin B, and gentamicin against Pseudomonas aeruginosa. Studies were carried out to determine whether tobramycin, a new aminoglycoside antibiotic, is also antagonized by calcium. The activity of tobramycin in vitro was shown to be antagonized by human serum and by physiological concentrations of calcium. The addition of human serum in broth-dilution tests produced a fourfold rise in the minimal inhibitory concentrations of tobramycin for five strains of Pseudomonas. In disc diffusion tests, the addition of calcium to the agar significantly decreased the size of inhibition zones, and the addition of a chelating agent to the agar increased the zone sizes. In a limited comparative study, tobramycin and gentamicin were tested against both light and heavy bacterial inocula of two strains of Pseudomonas. Tobramycin appeared to be antagonized less by serum than was gentamicin at equal antibiotic concentrations.

Influence of serum and calcium on the bactericidal activity of gentamicin and carbenicillin on Pseudomonas aeruginosa

Because calcium was found to be antagonistic in vitro to the activity of colistin and polymyxin B on Pseudomonas aeruginosa, the effects of calcium and serum on gentamicin and carbenicillin were also examined. Serum was antagonistic to gentamicin in antibiotic tube dilution tests on five strains of P. aeruginosa. Serum was not antagonistic to carbenicillin in tube dilution tests. Physiologic concentrations of calcium antagonized the activity of gentamicin but not carbenicillin. The antagonism observed with gentamicin was less than that previously seen with colistin. The antagonistic effect of calcium and serum was removed by a chelating agent. Gentamicin and carbenicillin may be more active in vivo against P. aeruginosa than colistin or polymyxin B.

Immunologic responses to bacteriophage phi-X 174 in immunodeficiency diseases

Immunologic responses to bacteriophage varphiX 174 were studied in 26 patients with immunodeficiency diseases. In eight cases of infantile X-linked agammaglobulinemia, there was prolonged circulation of phage and no detectable antibody response. The remaining 18 patients cleared phage normally and produced antibodies. 10 of these patients made only IgM antibody in spite of repeated immunization; all of these have recurrent respiratory tract infections and require treatment with gamma globulin and antibiotics. Eight patients made both IgM and IgG antibody; they experience either milder or no infections, and only one requires treatment with gamma globulin. Prolonged circulation of bacteriophage varphiX 174 and the absence of a detectable antibody response appear to be distinguishing characteristics of X-linked agammaglobulinemia if severe combined immunodeficiency can be excluded.

Teratogenicity of vitamin B6 deficiency: omphalocele, skeletal and neural defects, and splenic hypoplasia

Vitamin B(6) deficiency was induced in pregnant rats with a deficient diet and with 4-deoxypyridoxine, a B(6) antagonist. Treated animals developed typical skin changes of B(6) deficiency. Fetuses were small and appeared anemic. Major fetal malformations were omphalocele, exencephaly, cleft palate, micrognathia, digital defects, and splenic hypoplasia. This teratologic system was developed as a model for human syndromes that exhibit combined immunologic and neurologic or skeletal defects.