Stephen H. Polmar

Adenosine deaminase deficiency with late onset of recurrent infections: Response to treatment with polyethylene glycol-modified adenosine deaminase

We report a 5-year-old girl with adenosine deaminase (ADA) deficiency who was asymptomatic during the first years of life. At 3 years of age, she developed chronic and recurrent sinopulmonary infections, and at 4 1/2 years of age she had one major infection with Streptococcus pneumoniae (bacteremia and septic arthritis of the hip). Immunologic evaluation at 5 years of age revealed persistent lymphopenia, decreased helper-suppressor T cell ratios, and low proliferative responses to mitogens. The IgG, IgM, and IgA levels were normal; the IgG2 level was low normal or below normal. The patient had specific antibodies against toxoids and viral antigens but failed to produce antibodies against Haemophilus influenzae type b and pneumococcal polysaccharides. Although no symptoms of allergy were present, she had persistent eosinophilia and elevated IgE levels. The patient had 0.6% of normal ADA activity in erythrocytes and approximately 1% of normal ADA activity in peripheral blood mononuclear cells. Beginning at 6 years of age, she was treated with weekly injections of polyethylene glycol-modified bovine ADA. This treatment was well tolerated and effectively reversed the biochemical consequence of ADA deficiency. Concomitantly, she improved clinically and her T lymphocyte numbers and blastogenic responses to mitogens in vitro became normal. The late onset of clinical symptoms and relatively benign clinical course in this patient emphasize the need to consider ADA deficiency in a broad spectrum of immunodeficient children.

Spectrum of IgG2 subclass deficiency in children with recurrent infections: prospective study

Serum immunoglobulins and IgG subclasses were measured in 30 children with recurrent infections. Seven patients had low IgG2 concentrations (less than 3SD below the geometric mean for age). Four of these seven patients had normal concentrations of IgG, IgA and IgM, and thus would have been considered immunologically normal by routine criteria. The seven children with IgG2 deficiency had more severe infections than the 23 children with normal IgG2. Five children had recurrent pneumonia or sinusitis, one had recurrent invasive Haemophilus influenzae type b infections, and one had severe pneumococcal meningitis. Their immunologic abnormalities were heterogeneous. Two children had isolated IgG2 deficiency, two had IgG2-IgG4 deficiency, one had IgG2-IgG4-IgA deficiency, one had IgG2-IgA deficiency, and one had severe IgG1-IgG2 deficiency with abnormal T cell function and thrombocytopenia. Thus IgG2 deficiency occurs frequently among children with recurrent infections, and is associated with a variety of clinical and immunologic abnormalities.

Purine nucleoside metabolism in the erythrocytes of patients with adenosine deaminase deficiency and severe combined immunodeficiency.

Deficiency of erythrocytic and lymphocytic adenosine deaminase (ADA) occurs in some patients with severe combined immunodeficiency disease (SCID). SCID with ADA deficiency is inherited as an autosomal recessive trait. ADA is markedly reduced or undetectable in affected patients (homozygotes), and approximately one-half normal levels are found in individuals heterozygous for ADA deficiency. The metabolism of purine nucleosides was studied in erythrocytes from normal individuals, four ADA-deficiency patients, and two heterozygous individuals. ADA deficiency in intake erythrocytes was confirmed by a very sensitive ammonia-liberation technique. Erythrocytic ADA activity in three heterozygous individuals (0.07,0.08, and 0.14 mumolar units/ml of packed cells) was between that of the four normal controls (0.20-0.37 mumol/ml) and the ADA-deficient patients (no activity). In vitro, adenosine was incorporated principally into IMP in the heterozygous and normal individuals but into the adenosine nucleotides in the ADa-deficient patients. Coformycin (3-beta-D-ribofuranosyl-6,7,8-trihydroimidazo[4,5-4] [1,3] diazepin-8 (R)-ol), a potent inhibitor of ADA, made possible incorporation of adenosine nucleotides in the ADA-deficient patients...

Subnormal serum concentrations of IgG2 in children with frequent infections associated with varied patterns of immunologic dysfunction

To characterize more fully the immunologic basis for increased susceptibility to infection in patients with low serum concentrations of IgG2, we identified eight infection-prone children, 1 to 2 years of age, with serum IgG2 concentrations greater than 2 SD below the mean for age and followed their serologic and clinical courses for 1 to 3 years. Two of the eight children became clinically and immunologically normal and may have had transient IgG2 deficiency with an exaggerated developmental delay of this late-maturing subclass. The remaining six subjects had persistently subnormal or low-normal serum IgG2 levels and continued to experience frequent infections. All six of these children responded poorly to Haemophilus influenzae type b (Hib) polysaccharide, and four of six responded poorly to Streptococcus pneumoniae type 3 polysaccharide. Both IgG1 and IgG2-specific antibody responses to these vaccines were abnormal. Three of these six children also responded poorly to tetanus toxoid, an antigen that normally induces a predominant IgG1 response. Although five of these six children produced antibodies in response to Hib polysaccharide protein conjugate vaccine, three of four given Hib oligosaccharide CRM conjugate vaccine required booster doses to respond, a pattern of response characteristic of infants less than 6 months of age. Further, although serum concentrations of IgG1 were normal, peripheral blood mononuclear cells from four of six children tested produced extremely small amounts of IgG1 and IgG3 as well as IgG2. Finally, varied patterns of abnormalities of IgG, IgA, IgM, and IgG4 became apparent in five of the six children with persistently low serum IgG2 values. This study demonstrates that subnormal serum concentrations of IgG2 may be associated with varied patterns of immunologic dysfunction, some of which are evolving and may be responsible for increased susceptibility of these children to infection.

Demonstration of an adenosine receptor on human lymphocytes in vitro and its possible role in the adenosine deaminase-deficient form of severe combined immunodeficiency☆

Abstract Adenosine receptors have been described in brain, bone, and platelets. Stimulation of this receptor by adenosine results in increased adenyl cyclase activity and accumulation of cyclic AMP. We have identified an adenosine receptor on human peripheral lymphocytes. Adenosine (5–100 μ M ) increased lymphocyte cyclic AMP levels by 100% during a 5-min incubation. Adenine was without stimulatory effect. Theophylline, which did not alter cyclic AMP levels when added alone, reduced the effect of added adenosine by 33% during a 5-min incubation. Norepinephrine alone elevated cyclic AMP levels 500–900% and the effects of adenosine and norepinephrine were additive. These data fulfill the criteria for the demonstration of a specific adenosine receptor. T lymphocytes isolated from a patient with x-linked agammaglobulinemia also demonstrated the presence of the adenosine receptor linked to cyclic AMP accumulation. Persistently elevated levels of cyclic AMP inhibit both lymphocyte proliferation and antibody synthesis. Patients with adenosine deaminase deficiency and severe combined immunodeficiency have markedly impaired lymphocyte proliferation and antibody production. These patients have also been found to have an increased intracellular concentration of ATP and elevated levels of plasma adenosine. Theophylline (0.5 m M ), which decreases cyclic AMP breakdown by inhibiting phosphodiesterase, inhibited normal lymphocyte proliferation by 50%. In contrast, the same concentration of theophylline inhibited adenosine deaminase-deficient lymphocyte proliferation by 89%. These data suggest that the immunologic defects in severe combined immunodeficiency and adenosine deaminase deficiency may result in part from excessive cyclic AMP synthesis associated with overstimulation of the adenosine receptor-adenyl cyclase pathway.

Cartilage hair hypoplasia: Immunological aspects and their clinical implications☆

Cartilage hair hypoplasia (CHH) is an autosomal recessive form of short-limbed dwarfism prevalent among the Old Order Amish. Mild to moderately severe cellular immunodeficiency is associated with this disorder. Antibody synthesis is, however, normal in CHH. Individuals affected with CHH were found to have marked impairment of T-lymphocyte function due to an intrinsic defect in cell proliferation. Defective proliferation was also found in B cells and fibroblasts from CHH individuals suggesting that impaired T-cell function reflects a generalized defect in cell proliferation in this syndrome. Studies of cytotoxic mechanisms in CHH patients revealed that proliferation-dependent mechanisms (e.g., cell-mediated cytotoxicity and natural killer [NK]-like activity) were markedly impaired while proliferation-independent NK activity was normal. In spite of impairment of T-cell function, an increased incidence of malignancy was not observed in CHH patients. These observations suggest that NK activity is vital in host defense against malignancies and that marked impairment of T-cell-mediated immunity need not be associated with an increased susceptibility to malignancy if NK function is preserved.

Hyperreactivity to cow milk in young children with pulmonary hemosiderosis and cor pulmonale secondary to nasopharyngeal obstruction

Six black infants and young children with high titers of milk precipitins were identified by screening the sera of 160 children with idiopathic chronic lung disease. None of the six had immunoglobulin deficiency, elevation of sweat chlorides, SS hemoglobin, or recurrent aspiration. All six children had typical manifestations of milk-induced pulmonary hemosiderosis: recurrent pulmonary infiltrates (6/6), hemosiderin-laden pulmonary macrophages (5/6), intermittent wheezing (5/6), eosinophilia (4/6), anemia (4/6), iron deficiency (4/4), failure to thrive (4/6), and elevated levels of serum IgE (4/4). Three children also had chronic rhinitis and eventually developed large adenoids, hypercapnia and acidosis during sleep, and right heart failure. Elimination of cow milk from the diet, symptomatic therapy, and adenoidectomy when indicated resulted in improvement of all six patients. Pulmonary hemosiderosis and some cases of upper airway obstruction with pulmonary hypertension appear to be two stages, early and delayed, of the same immunophysiologic process. Early dietary intervention may prevent the cardiovascular complications of this process.

CIRCULATING THYMIC-HORMONE ACTIVITY IN CONGENITAL IMMUNODEFICIENCY

Circulating thymic-hormone activity was assayed by measuring Thy 1-2 antigen induction on null lymphocytes from athymic mice incubated with human plasma or serum. Plasma from 19 normal children aged under 10 had inductive activity equivalent to 10-6-16-2 ng thymopoitin/ml. Plasma from 15 infants were severe combined immuno-deficiency, 2 of whom had appreciable immunoglobulin synthesis, and from 2 infants with DiGeorge syndrome had little or no inductive activity. Successful reconstitution with thymus or bone-marrow grafts and with red-cell infusions (if adenosine-deaminase deficiency is present) was followed by a rise in circulating thymic-hormone activity.

DEPENDENCE OF A GM(B) ANTIGEN ON THE QUATERNARY STRUCTURE OF HUMAN GAMMA GLOBULIN.

The antigens associated with the Gm(b) factor of human 7S γ-globulin differ in Caucasoids and Negroids. The studies reported here show that an antigen, Gm(bw), associated with the Gm(b) of whites but not with that of Negroes, is present on the S (slow) fragment of 7S γ-globulin obtained by digestion with papain or pepsin. All other Gm antigens thus far studied have been found on the F (fast) fragment. The antigens Inv(a) and Inv(b) were detected on isolated L-chains, and Gm(a) and Gm(b) were detected on isolated H-chains, but Gm(bw) was detected on neither. Recombining the H- and L-chains restored activity for Gm(bw) comparable to that of intact γ-globulin

Lymphocyte responsiveness to Pseudomonas aeruginosa in cystic fibrosis: Relationship to status of pulmonary disease in sibling pairs

Lymphocyte proliferative responses to Pseudomonas aeruginosa and Staphylococcus aureus were evaluated in six sibling pairs with cystic fibrosis. In each pair, one sibling had advanced clinical disease, whereas the other sibling was in good clinical condition. Three in this latter group had no clinically apparent Pseudomonas bronchitis. In all cases, the average responses to Pseudomonas isolated from each sibling pair were lower in the sibling with advanced clinical disease. This difference was not observed in the responses to Staphylococcus. Normal plasma or plasma from patients with CF in good clinical condition does not restore the responses in patients with advanced clinical disease. However, plasma from patients with low or no responses to Pseudomonas inhibits the responses of responding siblings. A progressive specific lymphocyte unresponsiveness to Pseudomonas may play an important role in the increasing destructiveness of chronic pulmonary Pseudomonas infection in cystic fibrosis.