Allergen and protein content of latex gloves

BACKGROUND

Proteins eluting from surgical gloves and other medical rubber products elicit immediate local and systemic hypersensitivity reactions in latex-allergic subjects but detailed knowledge about the amount and allergenic potential of these proteins is scanty.

OBJECTIVE

To protect latex-allergic people and to diminish the risk of sensitization, adequate methods are needed to measure and monitor the allergen content of surgical latex gloves.

METHODS

Extracts of six surgical and one household latex glove brand were studied. Bradford and Lowry methods were used for total protein measurements. Sera from 17 latex-allergic patients were used as a source of latex IgE antibodies. Allergen content of extracts was studied in vitro by immunoblot, crossed radioimmunoelectrophoresis and immunospot methods, and in vivo by skin prick testing in 35 latex-allergic patients.

RESULTS

The total protein concentration of the glove extracts varied from 3 to 337 micrograms/g glove. The Bradford method gave lower values than the Lowry method. Immunoblotting showed allergenic rubber proteins in four of the seven glove brands. Ten proteins in two surgical and six proteins in one household glove brand bound latex IgE antibodies in a heterogeneous manner. The results from crossed radioimmunoelectrophoresis and immunospot assays were mostly in line with immunoblotting findings. Extracts from five of the seven glove brands elicited positive prick tests; in all five also the presence of allergens could be shown by in vitro tests. Prick test reactivity and total protein concentration were not directly correlated.

CONCLUSIONS

In vitro assays showed considerable variation in the total protein and allergen contents of different latex glove brands. The amount of protein eluting from the gloves did not always correlate with their allergenicity in skin prick tests indicating that total protein measurement is not a sufficient method to monitor the allergenic properties of latex gloves.

Are we really allergic to mosquito bites?

Most, if not all, people are sensitized to mosquito bites in childhood. Cutaneous symptoms include immediate wheal-and-flare reactions and delayed bite papules, which tend to be more severe at the onset of the mosquito season. Systemic reactions to mosquito bites are, however, very rare. Recent immunoblot studies have demonstrated IgE antibodies to Aedes communis mosquito saliva 22 and 36 kD proteins. This confirms that specific sensitization occurs in man and indicates that mosquito-bite whealing is a classic type I allergic reaction. The delayed mosquito-bite papules seem to be cutaneous late-phase reactions mediated by eosinophils or they could also represent type IV lymphocyte-mediated immune reactions. People living in heavily infested areas such as Lapland frequently acquire tolerance to mosquito bites, and seem to have negligible levels of IgE but high amounts of IgG4 antisaliva antibodies. Desensitization treatment is a theoretical possibility but prophylactically given cetirizine, an H1-blocking antihistamine, has been shown to be helpful for people suffering from mosquito bites.

Frequent occurrence of IgE and IgG4 antibodies against saliva of Aedes communis and Aedes aegypti mosquitoes in children

We examined the prevalence of IgE and IgG4 class antibodies to the saliva of Aedes communis and Aedes aegypti mosquitoes in the sera of three groups of exposed children using a sensitive immunoblot method. The frequencies of IgE antibodies to the major 36-kD A. communis and A. aegypti saliva antigens ranged from 82 to 90% in the 20 Finnish, 17 Kenyan, and 20 Mexican children. The corresponding IgG4 antibody frequencies were 85, 41, and 20%, respectively. The nonexposed 20 Icelandic children did not show IgE or IgG4 antisaliva antibodies. Several of the Finnish children showed also IgE and IgG4 antibodies to a 22-kD A. communis saliva antigen. The Finnish children abnormally sensitive to mosquito bites had frequently IgE and IgG4 antibodies to the 22-kD A. communis saliva antigen, suggesting that these antibodies play a role in the pathogenesis of immediate cutaneous mosquito bite reactions. In contrast to this, no increase was found in the A. aegypti antibody frequencies in the Kenyan and Mexican children with papular urticaria, suggesting that humoral immune response to A. aegypti saliva is not involved in the development of this disorder. The present results show that humoral IgE and IgG4 immune responses to Aedes mosquito saliva antigens is common in children living both in temperature and tropical zones. The IgE antibodies seem to be involved in the immediate mosquito bite whealing, and the occurrence of the IgG4 subclass antisaliva antibodies might be an indicator of intense mosquito bite exposure.

Latex allergy: frequent occurrence of IgE antibodies to a cluster of 11 latex proteins in patients with spina bifida and histories of anaphylaxis

Proteins and allergens in natural rubber latex were characterized by a two-dimensional immunoblot method with serum samples from 17 patients with latex allergy of whom 10 had spina bifida and 7 were health care workers. We demonstrated in rubber tree sap approximately 240 polypeptides of which 57 bound immunoglobulin E (IgE) in patient serum samples. Forty-six of the 57 allergens were identified by patients with spina bifida, 19 of 57 allergens by health care workers, and 8 of 57 allergens by both patient groups. IgE antibodies from all 5 patients with spina bifida with histories of anaphylaxis bound three allergens with molecular weights of 27 kd and isoelectric points ranging from pH 4.6 to pH 4.8. Four of these 5 patients also identified a complex of eight other allergens with molecular weights ranging from 13 kd to 27 kd and isoelectric points from pH 4.4 to pH 5.6. This cluster of 11 allergens was identified by none of the 7 health care workers and by only 1 of 5 patients with spina bifida without demonstrable anaphylaxis. These preliminary findings indicate that patients with spina bifida in whom latex hypersensitivity has developed exhibit a strong anti-latex IgE immune response, which seems to differ markedly from the immune response of health care workers with latex allergy. The characteristic anti-latex IgE profile in patients with spina bifida and with a history of an anaphylactic reaction may be valuable in the evaluation of pathogenetic processes in latex allergy.

IgE immune response to rubber proteins in adult patients with latex allergy

In the present immunoblot study we examined IgE immune responses to natural rubber latex proteins in sera from 27 adult patients with latex allergy. We demonstrated at least 30 proteins in the rubber tree sap, of which 19 bound IgE antibodies in a heterogeneous manner in patient sera. Twenty-two of the 27 patient sera (81%) showed positive immunoblot test results. IgE antibodies in the patient sera bound most frequently to a 20 kd allergen, which was recognized by 17 of the 22 (77%) patient sera with positive immunoblot test results. These results suggest that a 20 kd rubber protein could be a major allergen in adult patients with latex allergy. Immunoblotting with a representative set of allergens as antigen would offer a sensitive, confirmatory in vitro test to demonstrate hypersensitivity to latex.

Detection of mosquito saliva-specific IgE and IgG4 antibodies by immunoblotting

IgE and IgG subclass antibodies against Aedes communis mosquito saliva were studied by immunoblotting in 12 adults with immediate and/or delayed skin reactions to mosquito bites. Four antigenic proteins, with molecular weights of 22, 30, 36, and 64 kd, were found in the mosquito saliva. Almost all subjects (11 of 12) had anti-mosquito saliva-specific IgE antibodies directed against the 36 kd protein. The IgG antibody response appeared to be restricted mostly to IgG4 (11 of 12) and IgG1 (8 of 11) subclasses against the same 36 kd antigen. Ten of the 12 subjects had both IgE and IgG4 antibodies to the 36 kd protein. No anti-mosquito antibodies were found in pooled sera of five infants never exposed to mosquito bites. These results show that most persons with immediate skin reactivity to A. communis mosquito bites have both IgE and IgG4 antibodies that recognize the 36 kd antigen present in the mosquito saliva, suggesting that anti-saliva antibodies may play a role in the pathogenesis of mosquito bite reactions.

Improved immunoturbidimetric method for rheumatoid factor testing

The performance of two immunoturbidimetric modifications for rheumatoid factor (RF) testing, which differ with respect to the means of complement inactivation (heat treatment and inactivation with polyvinyl sulphonate), were compared in serum samples from 87 patients with rheumatoid arthritis (RA) and from 403 healthy subjects. IgM-rheumatoid factor titres were also measured with an enzyme linked immunosorbent assay (ELISA). Both immunoturbidimetric tests gave positive reactions (rheumatoid factor > or = 20 IU/ml) in 74 out of the 87 (85%) RA sera. In cases with high RF concentrations the results after chemical inactivation tended to be slightly higher compared with heat inactivation. In healthy subjects rheumatoid factor was detected in 19/403 (4.7%) sera using heat inactivation and in 22/403 (5.5%) sera with chemical inactivation of complement. Interrun coefficient of variation in the chemical inactivation assay was 4.4%; with the heat inactivation method it was 8.1%. In the ELISA, a marginally better correlation was noted in the results obtained using chemical inactivation. Inactivation of complement by means of polyvinyl sulphonate offers the advantage of easier test performance and better reproducibility, and the results may reflect more accurately true rheumatoid factor concentrations.

Anti-RA 33 as a marker antibody of rheumatoid arthritis in a Finnish population

To obtain information on anti-RA 33 as a marker antibody of rheumatoid arthritis (RA), a panel of Finnish sera were tested by immunoblotting with partially purified RA 33 antigen. Six of 100 specimens from patients with RA, one of 39 specimens from subjects who later developed seropositive RA, and one of 50 specimens from subjects with "false-positive" rheumatoid factor reactions were positive. The findings are compatible with the concept that anti-RA 33 is associated with RA from its onset and can even precede the disease. However, the prevalence of this antibody in Finnish RA patients is remarkably low compared to patients from continental Europe.

Antikeratin antibody and antiperinuclear factor as markers for subclinical rheumatoid disease process

OBJECTIVE

Antikeratin antibody (AKA) and antiperinuclear factor (APF) are antibodies characteristic for rheumatoid arthritis (RA). Our purpose was to obtain information on the occurrence of APF before the onset of clinical disease and on the occurrence of AKA and APF in cases with false-positive rheumatoid factor (RF) reactions.

METHODS

AKA and APF were measured with indirect immunofluorescence technique using rat esophagus and buccal mucosa cells, respectively, as antigen source.

RESULTS

Five of 30 preillness specimens from subjects who later developed seropositive RA were positive for AKA and APF, 3 sera were positive for only AKA and 3 for only APF. All the eleven sera positive for AKA or APF were RF positive. Both AKA and APF were detected in 6 of 70 sera from RF positive subjects who did not develop RA within a 10-year followup, 3 sera were positive for only AKA and 3 for only APF.

CONCLUSION

AKA and APF appear to be linked markers of an immunological process which, in RF positive subjects, predicts the development of clinical arthritis. However, disease manifestations develop in only a proportion of cases.

Immunoglobulin E reactivity to latex antigens in the sera of patients from Finland and the United States

BACKGROUND

Patients with latex sensitivity and latex antigens from the United States and Finland, two countries where allergic reactions to latex have been widely reported, were evaluated to determine the spectrum of immune responses.

METHODS

Sera from 27 patients from Finland and 18 from the United States with latex allergy and control sera from nonsensitive individuals were studied for latex-specific IgE antibodies. Four antigen preparations were used: two extracted from gloves and one each extracted from rubber tree sap from Malaysia and India. All 45 patients had skin prick test results that were positive to latex antigens, and all sera were evaluated by enzyme-linked immunosorbent assay (ELISA) with the various antigens.

RESULTS

There were considerable differences in the reactivity of patient sera with the different antigens. Only 50% of the sera from patients with latex allergy from Finland demonstrated significant levels of IgE to latex as determined by enzyme-linked immunosorbent assay. These patients showed more reactivity with rubber tree sap antigens than with glove antigens. However, 72% of the patients from the United States demonstrated antibodies to latex, and no marked differences were noted between the antigen extracts.

CONCLUSIONS

The results indicate that reagents such as rubber tree sap, which contain multiple clinically significant antigenic components, should be included in evaluation of latex allergy and that differences in patient populations may result in serologic variances.

A prospective study of 63 couples with a history of recurrent spontaneous abortion: contributing factors and outcome of subsequent pregnancies

To evaluate the possible causes of recurrent spontaneous abortion (RSA) and to elucidate the prognosis for subsequent pregnancies 63 RSA patients were studied. Parental karyotyping revealed chromosomal aberrations in six of the 63 couples (4.8%). The rate of increased concentrations of antibodies against cardiolipin was comparable in the patients (10.0%) and in 30 parous controls (6.7%), as was also the occurrence of other autoantibodies (43.3 and 36.7%, respectively). Hysteroscopy revealed uterine cavity abnormalities in 11 of the 55 patients studied (20.0%). Altogether, for 35 RSA women (55.4%) investigations resulted in entirely normal findings; abnormal findings were more frequently encountered in primary aborters (56.8%) than in secondary aborters (26.9%, P < 0.05). During the follow-up period of 24.1 +/- 15.4 months, 48 patients became pregnant a total of 65 times, and the cumulative live birth rate was 62.5%. A living fetus was seen in ultrasound examination in 46 pregnancies (70.7%), whereas a blighted ovum was diagnosed in nine pregnancies (13.8%). An additional nine pregnancies aborted so suddenly that no ultrasound examination was performed, and one ectopic pregnancy was treated laparoscopically. Of the initially viable pregnancies, 13 (28.3%) ended in miscarriage and two were terminated due to fetal anomalies. Normal findings in the investigations were associated with a smaller risk for abortion (40.0%) than were abnormal findings (65.5%, P < 0.05). Of the 30 babies, six (20.0%, with babies from one twin pregnancy excluded) were growth-retarded, 9.7% were born before 37 weeks of gestation, and 22.8% of the mothers had impaired glucose tolerance during pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)

Pregnancy in lupus nephropathy

The purpose of this study was to obtain information about the fetal and maternal outcome of pregnancy in patients with pre-existing lupus nephritis and to evaluate risk factors for poor fetal outcome. Twenty-six pregnancies in 16 patients were retrospectively analyzed. Induced abortions were performed in two patients and one patient had a spontaneous abortion. Of the 23 completed pregnancies, all clinically established on inactive lupus nephritis with normal renal function, seven (30%) were complicated by pre-eclampsia. Two of the three patients with severe pre-eclampsia had increased levels of antiphospholipid antibodies (aPL). Of the 23 newborns, seven (30%) were premature (< 37 weeks) and seven (30%) had neonatal complications. Six of the seven pregnancies associated with neonatal complications were hypertensive. There was one early neonatal death. Four newborns (16%) were severely growth retarded (< -2 SD). The presence of hypertension before pregnancy tended to correlate with low relative birth weight in the newborns (p = 0.079). Flares of systemic lupus erythematosus (SLE) during pregnancy and six months post partum occurred in two (9%) of the 23 completed pregnancies. Renal function was not affected irreversibly in any patient. Thus, the outlook for pregnancy in patients with stable lupus nephritis at conception is good. However, the risk of obstetric complications is greater and fetal morbidity, especially in hypertensive pregnancies, is common.

Crossreaction between antibodies to oxidised low-density lipoprotein and to cardiolipin in systemic lupus erythematosus

Serum lipoproteins contain phospholipids and modified low-density lipoprotein (LDL) may thus act as a target for antiphospholipid antibodies. Raised concentrations of IgG antibodies against oxidised LDL were found in 47 of 61 (80%) patients with systemic lupus erythematosus (SLE). 46% of patients also had raised concentrations of IgG anticardiolipin antibodies. Binding of anticardiolipin antibodies to solid-phase cardiolipin was inhibited by oxidised LDL but not by native LDL in 16 of 21 sera from SLE patients. These observations suggest crossreactivity between antiphospholipid antibodies, which are closely associated with thrombosis in SLE, and antibodies to oxidised LDL, thus providing a possible link between thrombotic and atherosclerotic complications in SLE.

Fetal outcome in lupus pregnancy: a retrospective case-control study of 242 pregnancies in 112 patients

Fetal outcome in systemic lupus erythematosus (SLE) was retrospectively analysed in 242 pregnancies in 112 unselected patients, and the outcome was compared with that of 417 pregnancies in 192 control women matched for age, parity and socio-economic status. Relative risk for fetal loss after the diagnosis of SLE was 2.5 (95% confidence interval (CI), 1.4-4.5), for prematurity 5.8 (3.2-10.5) and for intra-uterine growth retardation (IUGR) 8.6 (3.0-24.3). Fetal outcome of pregnancy in patients with pre-existing stable lupus nephritis was no worse than in other SLE pregnancies. Relations of three lupus anticoagulant (LA) assays and tree anticardiolipin (aCL) enzyme-linked immunosorbent assays to fetal outcome were studied. Patients positive by any LA assay had a previous fetal loss more often than patients negative by all LA assays (odds ratio 3.4; 95% CI, 1.3-9.0; P = 0.01). Of the 41 patients whose antiphospholipid antibody (aPL) tests were all negative, five (12%) had a history of fetal loss (16% in controls). As a group, aCL was more sensitive for fetal loss than LA (64% vs 50%), but LA was more specific (77% vs 52%). Combinations of one aCL assay with one LA assay had a 41-73% sensitivity and a 64-73% specificity for a history of fetal loss. aPL did not correlate to prematurity or fetal growth retardation. In conclusion, fetal loss in SLE is 2.5 times more prevalent than in the normal population. The presence of LA indicates a high risk for fetal loss, and the absence of aPL is an indication of a favorable pregnancy outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

IgE reactivity to 14-kD and 27-kD natural rubber proteins in latex-allergic children with spina bifida and other congenital anomalies

We examined by immunoblotting sera from 39 latex-allergic patients, 19 from USA and 20 from Finland, including 15 children with spina bifida and 5 children with other congenital anomalies, for IgE antibodies to natural rubber latex (latex) antigens. IgE antibodies in 10 of the 12 (83%) US spina bifida patients and in 2 of the 3 Finnish spina bifida patients recognized a previously undescribed 27-kD antigen which, together with a 14- and a 20-kD peptide, appeared to be a major latex allergen. Two patients with other congenital anomalies, one from the US and one from Finland, also demonstrated anti-27-kD bands. IgE antibodies to the 27-kD antigen were not detected in other latex-allergic patients from the US or Finland although most of them showed IgE binding to 14- and/or 20-kD latex antigens. All 21 controls, including 3 spina bifida patients with no evidence of latex allergy, gave negative immunoblot results. This observation suggests that patients with spina bifida or other congenital anomalies who have been subject to multiple operations and other invasive therapeutic procedures may have been exposed to different antigenic source materials than other latex-allergic patients.

Intravenous immunoglobulin treatment of pregnant patients with recurrent pregnancy losses associated with antiphospholipid antibodies

The effects of high dose iv-immunoglobulin on antiphospholipid antibody levels and on pregnancy outcome was studied in one patient with secondary (SLE) and two patients with primary antiphospholipid syndrome during their four pregnancies. These three women had had two pulmonary embolies related to pregnancy and estrogen containing pills, 13 miscarriages and only one liveborn after pre-eclamptic pregnancy. During the four pregnancies the patients also received 75 mg of aspirin per day. Progressive depression of IgG-anticardiolipin antibody titer was observed after repetitive high dose iv-immunoglobulin (1 g/kg body-weight) infusions. The effects on lupus anticoagulant were variable. Three pregnancies ended in a delivery of healthy child after 36-38 weeks of gestation and one preterm child (34 weeks), with slight respiratory distress syndrome, was born. Our results support the idea that the addition of iv-immunoglobulin to aspirin prophylaxis is worth considering when the patient has a severe antiphospholipid syndrome and/or is refractory to usual treatments.

Treatment of mosquito bites with cetirizine

Eighteen adult subjects sensitive to mosquito bites participated in a double-blind, placebo-controlled study with 10 mg cetirizine. The drug was given prophylactically and the subjects were then exposed to bites of Aedes communis mosquitoes in the field. Bite lesions were measured and pruritus was scored with a visual analogue scale at 15 min, 60 min, 12 hr and 24 hr. Cetirizine significantly decreased immediate wealing and pruritus and, interestingly, also had a clear effect on the delayed 12 hr and 24 hr bite papules and pruritus. The diameter of a 15 min mosquito-bite weal was 10.1 +/- 10.4 mm (mean +/- s.d.) with the placebo and 5.9 +/- 5.9 mm with cetirizine treatment (P < 0.05). The 15 min pruritus scores were 36.0 +/- 25.2 and 11.2 +/- 13.2 (P < 0.001), respectively. The diameter of the 24 hr mosquito-bite lesion was 12.6 +/- 21.9 mm with the placebo and 7.4 +/- 16.1 mm with cetirizine treatment (P < 0.01). The 24 hr pruritus scores were 18.9 +/- 25.5 and 6.6 +/- 14.8 (P < 0.01), respectively. These results indicate that, in mosquito-sensitive subjects, prophylactically administered cetirizine is an effective drug against both immediate and delayed mosquito-bite symptoms.

Antinuclear antibodies heralding the onset of systemic lupus erythematosus

On the basis of record linkage with the Social Security Institution's population register, 16 specimens from healthy subjects who subsequently developed systemic lupus erythematosus or mixed connective tissue disease could be traced from stored sera collected in connection with nationwide maternity welfare program in Finland. The sera were tested for antinuclear antibodies (ANA) using an immunofluorescence technique. Ten of the 16 specimens were positive. Eight of 11 cases were positive when the interval from taking the blood specimen to the onset of the first symptoms of disease was 2 years or less and 2 of 5 cases were positive when the interval was over 3 years. Eighteen of 21 sera with established disease and 5 of 85 control sera from the same serum collection were positive. Thus, ANA as detected by a sensitive technique frequently precede the onset of disease indicating that they are not a secondary manifestation of inflammation or tissue destruction.

Characterization of latex antigens and allergens in surgical gloves and natural rubber by immunoelectrophoretic methods

Allergy to natural rubber (latex) products is increasingly frequent among both medical personnel and lay subjects. Although individual antigens and allergens in latex products have not been fully characterized, they are believed to derive from the sap of the rubber tree. Rabbit IgG and human IgE antibodies against rubber proteins were used to characterize antigens and allergens in surgical latex gloves and natural rubber by crossed immunoelectrophoresis and its modifications. The results from crossed-line immunoelectrophoresis demonstrated that the surgical latex gloves had at least 10 antigens in common with natural rubber sap and ammoniated latex. In crossed radioimmunoelectrophoresis, at least six of the 10 protein antigens in the surgical glove extract and natural rubber were allergens since they bound IgE antibodies from the latex-allergic patients' sera. The surgical glove extract also demonstrated one allergen not found in natural rubber, suggesting that rubber proteins may be altered during glove manufacture.

Antiphospholipid antibodies and thrombosis in systemic lupus erythematosus: comparison of three lupus anticoagulant assays and anticardiolipin ELISA in 188 patients

The presence of antiphospholipid antibodies (aPL) in 188 unselected patients with systemic lupus erythematosus was studied using the recalcification time, kaolin clotting time (KCT), dilute Russell's viper venom time (dRVVT) and anticardiolipin ELISA (aCL) to identify patients with a high or low risk of thrombosis among patients with aPL. aPL were detected by at least one method in 104 (55%) of the patients. Despite heterogeneity, lupus anticoagulant (LA) methods correlated reasonably well with each other (r = 0.736-0.968), but poorly with aCL (r = 0.241-0.549). Positivity in LA assays and immunoglobulin G (IgG)-aCL were associated with patients who experienced thrombosis (P less than 0.001 for all assays). Patients with both LA and aCL had experienced thrombosis more often than those having only one (odds = 6.3, P less than 0.001). When patients with aPL were ranked by relative strength of the finding and divided into tertiles, a history of thrombosis was associated with membership in the strongest tertile of at least one assay (odds = 4.2, P = 0.002). LA and aCL had similar sensitivities for thrombosis (61% and 63%, respectively), but LA was more specific than aCL (79% vs 53%). The best combination of two assays was KCT with dRVVT (61% sensitivity, 87% specificity). Maximal sensitivity (71%) for thrombosis could be achieved by adding IgG-aCL to these two assays, but specificity was lower (73%). In conclusion, a high thrombotic risk among patients with aPL was indicated by the simultaneous presence of both LA and aCL, strongly positive aPL, and, among aCL, IgG-class antibodies.

Immunopathology of rheumatoid arthritis. Antikeratin antibodies precede the clinical disease

OBJECTIVE

We sought to determine whether circulating antikeratin antibodies (AKA) precede the onset of rheumatoid arthritis (RA).

METHODS

By matching the registers of 2 previous population studies with the registry of patients receiving antirheumatic drugs several years later, pre-illness serum specimens could be obtained from 39 individuals who subsequently developed RA. AKA were assayed with the standard indirect immunofluorescence technique.

RESULTS

Ten of 39 serum specimens from individuals who subsequently developed seropositive RA, and 1 of 15 sera from individuals who developed seronegative RA, were positive for IgG-class AKA by immunofluorescence assay. The AKA-positive sera were also positive for rheumatoid factors.

CONCLUSION

The findings focus attention on the role of pre-illness immunologic events in the pathogenesis of RA.