Allergy to penicillin

Relationships between skin test, specific IgE and levels of cytokines in patients with penicillin allergy

The aim of this study was to investigate the relationships between skin test, specific immunoglobulin (Ig) E and cytokines in penicillin allergy. We collected the sera of 259 patients with historical positive skin test to penicillins, with immediate positive skin test and with a negative skin test results. The positive rate of specific IgE antibodies in 259 patients was 62.2% (161) by using radioallergosorbent test (RAST). Of the eight kinds of antigenic determinants, the positive rates of specific IgE to major and minor determinants were 43.63% (113) and 52.51% (136), respectively (p < 0.05). In 122 patients with immediate positive skin test, when the degrees of skin test were +, 2+, 3+ and 4+, the positive rates of specific IgE were 45.7, 57.1, 85.2 and 100%, respectively. The levels of interleukin (IL)-4, IL-13 and interferon (IFN)-gamma in the sera of patients with positive skin test were significantly increased with the degree of positive skin test (p < 0.05). The combined use of major and minor determinants in RAST offers the better test for the detection of penicillin-specific IgE antibodies. IL-4, IL-13 and IFN-gamma play important roles in penicillin allergy.

Toward an in vitro test for the diagnosis of allergy to penicillins. Synthesis, characterization, and use of beta-lactam and beta-lactam metabolite poly-L-lysines which recognize human IgE antibodies

Conjugates of poly-L-lysine (PLL) containing a penicillin or a penicilloyl residue were prepared and characterized by 1H NMR and by size-exclusion (SE) HPLC. These conjugates were used in a radio allergo sorbent tests (RAST) test for the determination of allergy toward beta-lactams. The chemiometric evaluation of the data indicates that allergy to amoxycillin is different from allergy to the other beta-lactams tested. Furthermore, careful chemical characterization of the conjugates appears to be crucial to obtain meaningful information from the RAST data.

Patients' knowledge about their drug allergies

OBJECTIVE

To investigate the nature and accuracy of information carried by patients about their drug allergies.

SUBJECTS

2500 new adult patients.

SETTING

Accident and emergency department of a tertiary referral centre.

METHODS

Patients were questioned about drug allergies. Where they claimed allergies, general practitioners were contacted for corroboration.

RESULTS

242 patients (9.7%) claimed 276 allergies; 32 different drugs were implicated. Penicillin was implicated most often (151 patients); 38 patients could not remember what they were allergic to; 21 described severe reactions, but four could not remember the drugs involved. Only seven patients carried evidence of their allergies. General practitioners were contacted about 240 of the drug allergies; only 114 were confirmed as described.

CONCLUSIONS

Many patients who believe themselves to have drug allergies are poorly informed about them. Emergency prescribing for these patients may risk anaphylaxis. The future acceptance of "Smart cards"would reduce this risk. In the meantime, patients with drug allergies should be strongly encouraged to carry evidence of their allergies.

Two-dimensional electrophoresis of human serum proteins modified by ampicillin during therapeutic treatment

Two-dimensional electrophoretograms of serum proteins from ampicillin-treated patients were analyzed-by immunoblotting with an antiserum specific for penicilloyl groups. As expected, human serum albumin (HSA) was the main ampicilloylated serum component. Transferrin main form II was found to be the second most important component as regards immunoblotting intensity. Immunoreactive spots were present on the acidic side of the transferrin isoelectric series, suggesting a modification mechanism similar to that observed in HSA, i.e., acylation of basic amino acid residues. Several additional ampicilloylated spots were detected but could not be assigned. Their electrophoretic parameters were determined using internal standards. This is the first description of serum proteins other than HSA being modified by ampicillin in the course of routine therapeutic treatment.

Antepartum screening and non-selective intrapartum chemoprophylaxis for group B streptococcus

The efficacy of antibiotic chemoprophylaxis in labour for all maternal carriers of Group B streptococcus with respect to the neonatal mortality and morbidity was analyzed. The intervention consisted of a policy of maternal screening for Group B streptococcus at 28 weeks' gestation by a low vaginal swab, cultured on to nonselective media. If positive, all carriers were treated with intrapartum ampicillin regardless of other obstetric risk factors. The main outcome measures were studied prospectively for 16 months before and for 32 months after instituting the intervention. These included the incidence of early-onset Group B streptococcal infection as defined by either a blood culture or a symptomatic neonate with a positive urinary streptococcal antigen test, the mortality and the morbidity. Intrapartum ampicillin significantly reduced the incidence of early-onset Group B streptococcal disease, from 2.0 to 0.37 per 1,000 livebirths for neonates with a positive blood culture (p < 0.03), and from 4.9 to 1.5 per 1,000 livebirths for symptomatic infants with a positive urinary antigen test (p < 0.004) and the attributable morbidity, namely, neonates who were: admitted to a level 2 or 3 unit (p < 0.004); treated with antibiotics (p < 0.004); preterm (p < 0.04); ventilated (p < 0.01). Seventy five per cent of the maternal population was overall actually screened and the carriage rate was 12%. No serious adverse reactions to ampicillin were observed. Significant reduction in early-onset neonatal Group B streptococcal disease has occurred concurrent with antepartum screening and nonselective intrapartum chemoprophylaxis.