IMMUNOGLOBULIN E IN BRONCHIOLITIS

(1)

Abbreviations DEAE : Diethylaminoethylcellulose

IgE: Immunoglobulin E

IgE

(

ND

)

: Immunoglobulin E

myeloma protein from patient ND

IgE

(

PS

)

: Immunoglobulin E

myeloma protein from patient PS

RS : Respiratory syncytial virus

SD IgE age : Standard deviation of

the IgE concentration on age

(

Received September 7; revision accepted for publication November 12, 1971.)

A.B.M. was supported in part by a grant from the Charles H. Hood Foundation.

ADDRESS FOR REPRINTS: ( S.H.P.

)

Department of Pediatrics, Case Western Reserve University School

of Medicine, Rainbow Babies’ and Children’s Hospital, Cleveland, Ohio 44106.

PEDIATRICS, Vol. 50, No. 2, August 1972

279

IMMUNOGLOBULIN

E IN BRONCHIOLITIS

Stephen H. Polmar, Ph.D., M.D., Lawrence D. Robinson, Jr., M.D.,

and Anthony B. Minnefor, M.D.

From the Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda,

Maryland, The Department of Pediatrics, Sinai Hospital, Baltimore, Maryland, and The Department of

Pediatrier, The University of Vermont College of Medicine, Burlington, Vermont

ABSTRACT. Serum immunoglobulin E (IgE ) was

measured by double antibody radioimmunoassay in

32 children with bronchiolitis and 30 age-matched

control subjects. Bronchiolitis in 15 patients

(Ver-mont group ) was associated with a respiratory

syn-cytial (RS ) virus epidemic. Bronchiolitis occurred

sporadically (nonepidemic) in 17 patients from

Baltimore. The geometric mean serum IgE

concen-tration of the sporadic bronchiolitis group (

Balti-more) was significantly higher than that of their

age- and race-matched controls ( 100 ng/ml versus

25 ng/ml, respectively, p < .025 ). No difference

was found in geometric mean IgE concentration

between the epidemic bronchiolitis group

(Ver-mont) and their age- and race-matched controls

(

47 ng/ml versus 38 ng/ml, respectively, p .1).

Thirty-five percent (6/17) of the children with

sporadic bronchiolitis had IgE levels above the

95th percentile for age as compared to

approxi-mately 6% for children with epidemic bronchiolitis

and the normal control groups. These findings lend

support to the concept of a heterogeneous etiology

for bronchiolitis. Furthermore, the data suggest

that measurement of the serum IgE concentration

may be of value in identifying those bronchiolitic

children at high risk for the subsequent

develop-ment of asthma and other respiratory allergies.

Pe-diatrics-, 49:279, 1972, ALLERGY, ASTHMA,

BRON-CHIOLITIS, IMMUNOGLOBULIN E, RESPIRATORY

SYN-CYTIAL viRuS.

B

RONCHIOLITI5, a common problem in

in-fancy, is generally considered to be a self-limited nonrecurring illness. The asso-ciation of respiratory syncytial

(

RS

)

virus

and epidemic bronchiolitis has been well

established.13 However, the studies of

Wit-tig, et al. and Eisen and Bacal’ indicate

that 25 to 32% of patients with bronchioli-tis subsequently develop asthma or other

respiratory allergies. This apparent

heteno-geneity in the etiology of bronchiolitis was

pointed out by Simon and Jordan.6 These

authors suggested that RS-positive

bron-chiolitis was an epidemic disease primarily

seen in infants under the age of 6 months

and was not of allergic origin, while RS negative bronchiolitis occurred sporadically

and was associated with an increased risk

of developing asthma.

The role of immunoglobulin E

(

IgE

)

in

the mediation of immediate

hypensensitiv-mty

reactions in man has been well estab-lished.7 Elevation of IgE in the serum of

patients with allergic asthma and some

other atopic diseases has been

demon-strated by johansson8 and others.9h1 The present study was undertaken :

(

1

)

to

de-tenmine if serum IgE levels might be help-ful in identifying which children with acute

bnonchiolitis are at high risk for the

subse-quent development of asthma or other

res-piratory allergies and (2) to further eluci-date the apparent heterogeneity ill the

(2)

TABLE I

COMPARISON OF SERUM IGE CONCENTRATIONS BETWEEN

BR0NCIII0LITIs AND CONTROL GROUPS

Group B

Mean Age

(zisos)

±S. D.

Geometric

Mean

(ng/ml) p

Baltimore

Bronchiolitis 17 6.9±5.9 100

Control 16 5.3±6.0 25 <.025

Vermont

Bronchiolitis 15 6.7±3.3 47

Control 14 10.6±8.1 38 >>.1

* p values computed by Student’s t test.

MATERIALS AND METHODS

Description of Patient Population and

Methods

The study group consisted of 33 children

seen at the Department of Pediatrics, Sinai

Hospital, Baltimore, Maryland, and 29

chil-dren seen at the Department of Pediatrics, Medical Center Hospital of Vermont,

Bur-lington, Vermont. The children studied ranged in age from 2 weeks to 22 months. Eighty-eight percent of the Baltimore group was black; all children in the Ver-mont group were white. The clinical diag-nosis of bronchiolitis was made in those children presenting with an acute upper

res-piratory tract infection characterized by

some degree of respiratory distress with

dif-fuse expinatory wheezing. Chest films were

normal except for evidence of hyperaena-tion. Only children seen with their first at-tack of bronchiolitis were included in the

study.

Control groups consisted of children seen

at the same hospitals during the same time

period for either routine well-child care, elective surgery or mild upper respiratory

tract infections, who did not have bron-chiolitis or a history of atopic disease. Infor-mation concerning personal and family

his-tories of asthma, eczema, or other allergies

was obtained for all individuals included in

the study.

Patients in the Baltimore group were

studied between June 1970 and January 1971. This group consisted of 17 children

with bronchiolitis and 16 control subjects.

There was no evidence of an epidemic of bronchiolitis in the community during the

study period.

The clinical diagnosis of bronchiolitis

was made in 15 patients in the Vermont

group, while 14 served as control subjects.

This group of patients was studied in

Octo-ben and November 1970, at which time a

bronchiolitis epidemic was occurring in the

community. Respiratory syncytial

(

RS

)

vi-rus was cultured from some of the affected

*

Serum samples were obtained from bron’ chiolitic patients when seen in the

Outpa-tient Department or upon admission to the Inpatient Service. Serum samples from

pa-tients and controls were stored frozen at

-20#{176}C

prior to testing.

Radioimmunoassay of Serum

Immunoglobulin E

Anti-IgE was produced by immunization of rabbits with purified preparations of IgE

myeloma protein, PS.f Copolymens contain-ing bovine serum albumin, fetal bovine

se-rum, IgG, IgA, 1gM, PS light chains, and agammaglobulinemie plasma prepared by ethyl chioroformate insolubilization,12 were used to render the antisera specific for IgE.

Purified IgE myeloma protein, ND, kindly

provided by Doctors H. Bennich and S. G.

0. Johansson, was labeled with 1251 using

the chloramine-T method.13

Serum IgE was measured by a double antibody method employing specific rabbit

anti-IgE

(

PS

)

and 1251 labeled IgE

(

ND

)

Standard inhibition curves were obtained by the addition of known amounts of

pun-fled unlabeled IgE

(

ND

)

. A standard curve

was constructed for each assay by plotting

* C. A. Phillips, personal communication.

t

Purified IgE (PS ) was prepared from plasma,

kindly provided by Dr. 0. Ross McIntyre, by di-ethylaminoethyl (DEAE ) cellulose column

chroma-tography followed by gel filtration on Sephadex

(3)

A) 5 000)

.9J

E

cc

uJ

(-)

L) uJ

qeorrerc

meon

0 4 20 24

ARTICLES

the logit of the percent specific counts

bound versus log10 nanograms of IgE added to the reaction mixture.14 These

curves were linear from 0.2 to 28 ng. IgE

concentration of unknown serum samples

was calculated from the coordinates of the

least squares regression equation of the

standard inhibition curve. The average standard deviation of duplicate

determina-tions performed on different days was 2.6%. Specificity of the assay for IgE was

checked through the study of purified IgG

and IgA myeloma proteins as well as sera

from patients with IgG, IgA and IgD my-eloma, Waldenstr#{246}m’s macroglobulmnemia,

and sex-linked recessive

agammaglobu-linemia.

Statistical Methods

Serum IgE concentrations are not

distnib-uted in a Gaussian manner.15 The logarithm

to the base 10 of IgE values is, however, normally distributed.15’16 For this reason, the geometric mean, rather than the

arith-metie mean, was used to estimate the

me-dian IgE values of the groups studied and

the log1 of the IgE concentrations was

used in all statistical tests. Statistical

analy-ses were performed by Student’s t test, Fisher’s exact test for 2 X 2 contingency

ta-bles, binomial distribution, and least squares regression analysis using standard

methods.

RESULTS

The geometric mean IgE concentrations

of the groups studied are shown in Table I.

The geometric mean IgE concentration of

the Baltimore (sporadic) bronchiolitis group, 100 ng/ml, differed significantly

from that of its control group, 25 ng/ml. In

contrast, no significant differences in IgE concentration were found between the

Ver-mont

(

epidemic) bronchiolitis and control

groups. The mean ages of the bronchiolitis and control groups did not differ signffi-cantly from one another.

The relation of IgE concentration to age

in normal children between 2 weeks and 22 months was evaluated by pooling the

two

8 2 16

AGE(In months)

Fic. 1. Relation of serum IgE concentration to age

in Baltimore (sporadic) bronchiolitis patients ( )

and controls

(#{149}

)

.Diagonal lines represent the

geo-metric mean and the 5th and 95th percentile limits.

control groups and computing a least squares regression equation.

(

IgE conc. [ng/mlIJ = antilog10 [1.2662 + .0285 (age

in months )}, SD IgE . age 0.453, r

0.453.

)

Percentile boundaries were

deter-mined from the standard deviation of the IgE concentration on age in months

(

SD

IgE . age ). The distribution of serum IgE

values relative to age for the bronchiolitis and control groups are shown in Figures 1 and 2 and Table II. Six of seventeen

chil-dren (35%) in the Baltimore

(

sporadic)

p = .00001 (binomial distribution). The

prob-ability of selecting 17 children from the normal

population of whom six have IgE levels above the

(4)

E

z

0

4 2 Li

C-,

2

0 C-,

Li IC

AGE (in months)

Fic. 2. Relation of serum IgE concentration to age

in Vermont (epidemic) bronchiolitis patients (Ls)

and controls ( ). Diagonal lines represent the

geo-metric mean and the 5th and 95th percentile limits.

bronchiolitis group have IgE values above

the 95th percentile while only 1 of 16 chil-dren

(

6.3%) in the Baltimore control group is above the 95th percentile. In contrast, the distribution of IgE values relative to age percentiles in the Vermont

(

epidemic

)

bron-chiolitis and control groups is identical. In both of these groups only 6.6%

(

1 of 14

)

of the children were above the 95th percentile.

In the Baltimore bronchiolitis group 80%

(4/5) of the children with significantly

ele-vated IgE levels had positive family histo-ries for allergy (Table III ). None had a

positive personal history of allergy.

Sixty-three percent (7/11

)

of the bnonchiolitic children with normal IgE levels also had positive family histories and 27% (3/11) had positive personal histories of allergy. Analysis of the data presented in Table III fail to show a signfficant correlation be-tween family or personal history of allergy

and elevated IgE levels in the Baltimore bronchiolitis group. No correlation of IgE

level and family or personal history of

al-h lergy was observed in the Vermont

bron-.95 chiolitis group or in either control group.

Among the six patients in the Baltimore

bronchiolitis group with IgE levels greater

than the 95th percentile, one child was 1 month of age, another was 5 months, and

the remainder were 12 months or older. There were three other children with IgE

values greater than the 95th percentile : an 18-month-old Baltimore control, a

6-month-. th old Vermont brochiolitic, and a

17-month-5 old Vermont control.

To date, follow-up of patients included in these studies has been incomplete. How-ever, five of the six patients with elevated

IgE levels

(

> 95th percentile

)

in the

Balti-more

(

sporadic) bronchiolitis group have had repeated episodes of wheezing and are, at present, clinically indistinguishable from

asthmatics. No follow-up information is

available concerning the sixth patient in

this group.

DISCUSSION

Serum IgE levels were determined in

pa-tients with bronchiolitis and their age- and race-matched controls using a sensitive double antibody nadioimmunoassay. The geometric mean IgE concentration of

pa-tients with sporadic bronchiolitis was

sig-nificantly higher than that of the

age-matched control group, while no significant increase in geometric mean IgE concentra-lion was seen in the group with epidemic bronchiolitis compared to their age-matched controls. Thirty-five percent of the group with sporadic bronchiolitis had se-rum IgE levels greaten than the 95th

per-centile for age. Only 6% of the children

with epidemic bronchiolitis or in the two

control groups had IgE values above the

95th percentile. Therefore, the population of patients with sporadic bronchiolitis dif-fers from that with epidemic bronchiolitis

(and normal controls) with regard to their IgE levels. Since elevation of IgE has been

primarily associated with allergic asthma

and other atopic thsease,8l the elevated

(5)

TABLE II

DISTRIBUTION OF SERUM IGE VALUES ABOVE AND BELOW THE 95Th PERCENTILE FOR AGE IN

BRONCJIIOLITIS AND CONTROL GROUPS

Percentile

<95th >95th

Baltiniore

Bronchiolitis 1 1 6*

Control 15 1

Vermont

Bronchiolitis 14 1

Control 14 1

* P .00001 (binomial distribution).

bronchiolitis may reflect a predisposition to

the development of atopic diseases in these children. These data are in good agreement with the observations of Simon and Jordan6 that RS virus-positive bronchiolitis was an epidemic disease and not of allergic origin, while RS-negative bronchiolitis, which

oc-TABLE III

FAMILY hISTORY OR PERSONAL HISTORY OF ALLERGY VERSUS IGE LEVEL IN THE BALTIMORE

BRONCHIOLITIS PATIENTS

A. Family History

IgE percentile + - Total

>95th <95th ‘lotal

pt>.37

B. Personal History

IgE percentile + - Total

>95th

<95th

i’otal t >.29

* One individual in the Baltimore bronchiolitis group

could not he included in this analysis because accurate

personal and family history were not available.

t Correlation of family or personal history of allergy

to IgE level was evaluated using Fisher’s exact test.

p values greater titan 0.05 indicate no statistically sig-niuicant correlation.

curned sporadically, was associated with an increased risk of developing asthma.

Although a positive family history of al-lergy was more frequently

(

80%) found among sporadic bronchiolitic patients with

IgE elevation than among patients without IgE elevation (63%), no statistically signif-icant correlation of elevated IgE level and

family on personal history of allergy was found in any group. The absence of this correlation may be due to the absence of overt allergic symptoms in many children under the age of 2 years as well as the small number of patients studied.

IMPLICATIONS

In retrospective studies, Wittig and asso-ciates4 and Eisen and Bacal#{176}found that 25 to 32% of patients with bronchiolitis

subse-quently developed asthma or respiratory

al-lergies. In our study, 35% (6/17) of the

patients with sporadic bronchiolitis had

IgE levels greater than the 95th percentile for age. The similarity of the frequency of IgE elevation in sporadic bronchiolitis and the risk for the subsequent development of

asthma in children with bronchiolitis4’5 may

be fortuitous. Alternatively, it suggests that

the determination of the serum IgE concen-tration may be of value in assessing a bron-chiolitic child’s risk for the subsequent de-velopment of asthma. Indeed, what appears

4 1 5 to be bronchiolitis in some patients may

7 4 1 1 really be the child’s first attack of asthma.

11 5 16* The early identification of children with

probable atopic disease is of value to both the parent and physician. The institution of

environmental control in the home may re-duce the frequency of repeated episodes of wheezing. In such high risk patients,

al-0 5 5 lergy evaluation and desensitization, if

mdi-3 8 11 cated, might also be undertaken at an early

3 13 16*

stage.

______

In order to assess the value of the serum

IgE concentration in identifying those bronchiolitic children at high risk for the

subsequent development of asthma or

res-piratory allergy, a large prospective study

with good follow-up is necessary. Such a

(6)

284

personal history of allergy, age at onset,

and viral diagnostic information on each

patient as well as epidemiological

informa-tion concerning the presence or absence of RS virus and other viral epidemics in the community during the period of study. Be-cause less than 6 months have elapsed since the completion of our study, sufficient follow-up information is not as yet available to appraise the value of the IgE determina-lion in assessing the risk of subsequent asthma in bronchiolitic infants; but the lim-ited follow-up data now available suggests that it may be a useful tool for this purpose. A larger prospective study, along the lines

outlined above, is planned.

REFERENCES

1. Chanock, R. M., Kim, H. W., Vargosko, A. J.,

Delava, A., Johnson, K. M., Cumming, C.,

and Parrott, R. H. : Respiratory syncytial

virus. I. Virus recovery and other

observa-tions during the 1960 outbreak of

bron-chiolitis, pneumonia, and minor repiratory

diseases in children. J.A.M.A., 176:647,

1961.

2. Parrott, R. H., Vargosko, A. J., Kim, H. W.,

Cumming, C., Turner, H., Huebner, R. J., and Chanock, R. M. : Respiratory syncytial

virus. II. Serologic studies over a 34-month

period of children with bronchiolitis,

pneu-monia and minor respiratory disease.

J.A.M.A., 176:653, 1961.

3. Forbes, J. A., Bennett, N. McK., and Gray, N.

1.

: Epidemic bronchiolitis caused by a

re-spiratory syncytial virus: Clinical aspects.

Med. J. Aust., 2:933, 1961.

4. Wittig, H. J., Cranford, N. J., and Closer, J.:

The relationship between bronchiolitis and

childhood asthma: A follow-up study of

100 cases of bronchiolitis in infancy. J.

Al-lergy, 30:19, 1959.

5.

Eisen, A. H., and Bacal, H. L.: Relationship of

acute bronchiolitis to bronchial asthma.

PntArmcs, 3:859, 1963.

6. Simon, G., and Jordan, W. S., Jr.: Infectious

and allergic aspects of bronchiolitis. J. Ped-iat., 70:533, 1967.

7. Ishizaka, K., and Ishizaka, T. : Identification of

?E antibodies as a carrier of reaginic

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8. Johansson, S. G. 0. : Raised levels of a new

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mt.

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Middleton, E., Jr., and Hornbrook, M. M.:

IgE levels in sera of children with asthma. Psnwrmcs, 47:848, 1971.

12. Avrameas, S., and Ternynck, T.: Biologically

active water insoluble protein polymers. I.

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Prepa-ration of iodine 131 labelled human growth

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Rapid calculation of radioimmunoassay

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(7)

1972;50;279

Pediatrics

Stephen H. Polmar, Lawrence D. Robinson, Jr. and Anthony B. Minnefor