Intravenous immunoglobulin in neonatal group B streptococcal disease. Pharmacokinetic and safety studies in monkeys and humans

Numerous studies have suggested that opsonic antibody is important in neonatal immunity to group B streptococci. Immunoglobulin G is primarily transferred from the mother to the fetus across the placenta in the last few weeks of pregnancy. Premature babies may, therefore, not acquire sufficient opsonic antibody to protect them from infection with group B streptococci. Although maternal immunization may provide adequate maternal opsonic antibody, premature infants with antibody deficiency may remain susceptible to infection. Intravenous immunoglobulin administered to term pregnant rhesus monkeys did not provide reliable levels of serum opsonic activity to group B streptococci in their offspring. Pharmacokinetic and safety studies were also performed in human neonates. Significant elevations in group B streptococcal-specific IgG did occur in human neonates given 500 mg/kg intravenous immunoglobulin and the infusions appeared safe and well tolerated. The availability of intravenous immunoglobulin with functional activity against group B streptococci may provide a rapid and effective method of delivering opsonic antibody to neonates.

Zoster immunoglobulin in varicella prophylaxis. A study among high-risk patients

The efficacy of zoster immunoglobulin (ZIG) in preventing varicella was studied among patients in a high-risk group. 173 non-immune patients were observed after exposure to varicella-zoster (VZ) virus and subsequent administration of ZIG. For 138 patients (80%) no sign of varicella was recorded, 16 patients (9%) had a subclinical infection and 19 patients (11%) developed varicella. 12/19 patients with varicella contracted a very mild disease (less than 20 pocks, negligible fever), 5 got mild or normal disease and 2 children, both with acute lymphatic leukemia, developed more pronounced symptoms. Three patients protected by 0.15 ml ZIG/kg body weight after heavy exposure to VZ virus, were not protected at a second exposure 2 weeks later. In an enlarged study group of high-risk patients where 52 patients receiving ZIG developed varicella, the mean incubation period for 42 patients was 21 days. Leukemic patients were found to have a higher frequency of clinical varicella, more pronounced symptoms and a slightly longer incubation period than other high-risk patients. VZ specific antibody titers were compared for various immunoglobulin preparations and found to be 30 times higher in zoster immunoglobulins than in normal immunoglobulins.

Administration of live varicella vaccine to children wtih leukaemia

Live varicella vaccine was given to twenty-three children with lymphoreticular malignancies, twelve whose chemotherapy was complete and eleven who were still receiving therapy. Seroconversion was observed in all twenty-three children, only one of whom lost his vaccine-induced antibody. Eight of the children experienced thirteen exposures to varicella, including four continuing exposures in their households. Varicella, manifested by the appearance of seven vesicular lesions, developed in only one. In all but two of the children an invitro blastogenic response to varicella/zoster-virus (VZV) antigen developed; both children had a biphasic rash after immunisation. A sibling of one of these children seroconverted without clinical evidence of varicella, presumably because of infection with vaccine virus. None of the other household contacts had significant rises in VZV antibody. VZV was not isolated from the blood, throat, or urine samples of the twenty-three vaccinees tested.

Prophylaxis of varicella in high-risk children: dose-response effect of zoster immune globulin

Immunodeficient patients who were presumed to be susceptible received zoster immune globulin prophylaxis after exposure to varicella. The highest clinical attack rate (35.9%) was seen in household contacts; the lowest attack rate (0%) was observed in children exposed at school. Among household contacts, 48 of 100 patients who received high titer ZIG (reciprocal complement fixation titer greater than or equal to 2,560) developed fourfold rises in serum CF antibody between pre- and 48-hour post-treatment specimens, compared to only one of 34 patients treated with lower titer ZIG lots (P less than 0.001). Patients who developed fourfold antibody rises were significantly less likely to contract clinical varicella (P less than 0.01). Patients who received high titer ZIG also had significantly lower risks of death (P = 0.025) and complications (P = 0.006). Among ZIG-treated patients who contracted clinical varicella, 80% developed mild disease (less than 100 pox), and the median incubation period was prolonged. Immunodeficient children exposed to varicella benefit from ZIG prophylaxis and higher titer ZIG is of greatest benefit.

Varicella in children with renal transplants

Nineteen of 160 children developed varicella between eight days and 6.4 years following renal transplantation. Eight had severe varicella characterized by prolonged fever and new vesicle formation with rash involving mucous membranes. The severe group had an increased incidence of thrombocytopenia and markedly elevated liver enzyme values. Two patients of this group had bladder paralysis and another died. In three children post-transplant varicella represented a second attack of the disease. Children maintained on azathioprine therapy for three days or more after onset tended to have severe varicella. No graft loss occurred consequent to stopping azathioprine. Children with transplants at risk should have zoster immune plasma or globulin upon exposure, and azathioprine therapy should be stopped at onset of varicella. Corticosteroid therapy should be continued in order to avoid stress-induced Addisonian crisis.

Efficacy of zoster immunoglobulin in prophylaxis of varicella in high-risk patients

During a period of 2 1/2 years 190 children have been prophylactically treated with zoster immunoglobulin in norway. Information on 130 (68%) of these children was obtained. This group included patients suffering from leukemia, lymphoma, and other malignant disorders, and patients with autoimmune diseases, with impaired immune mechanisms or with for other reasons increased frequency of infections, as well as premature and weak newborns, and infants born to mothers who developed varicella during the last 4 days before delivery. Of the patients who received zoster immunoglobulin within 3 days after exposure, 2.9% developed weak symptoms of varicella. When zoster immunoglobulin was administered 4-5 days after exposure, 37.5% contracted varicella, and when given more than 5 days after exposure, 50% developed the disease. The 9 neonates with possible intrauterine exposure are not included in these figures.