Antibody response to unconjugated Haemophilus influenzae b and pneumococcal polysaccharide vaccines in children with recurrent infections

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1 Antibdy respnse t uncnjugated Haemphilus influenzae b and pneumcccal plysaccharide vaccines in children with recurrent infectins Rebecca Raby, MD, Michael Blaiss, MD, Sharn Grss, MT (ASCP), and Henry G. Herrd, MD Memphis, Tenn. Backgrund: Increasingly, antibdy testing is' being used t evaluate the status f humral immunity in patients with recurrent infectin and suspected immundeficiency. In the past, we had been impressed that immunizatin with uncnjugated Haemphilus influenzae b (uhib) vaccine prvided useful infrmatin abut the ability t prduce antibdy t plysaccharides and that the use f pneumcccal plysaccharide (PPS) vaccine frequently prduced results that were difficult t interpret. Objective: The study was carried ut t cmpare antibdy respnsiveness t vaccinatin with uhib with the respnse seen after PPS vaccinatin. Methds: Twenty children (ages, 2 t 13 years; 11 male) wh were referred t ur immunlgy clinic because f recurrent infectins were immunized with bth ultib vaccine and PPS vaccine. Nine children had previusly received cnjugated Hib vaccine. Results: All 2 children either respnded with a twfld r greater increase in antibdy titer after uhib vaccine r had preimmunizatin antibdy cncentratins f greater than 4 nangrams antibdy nitrgen per milliliter (ng Ab N/ml). All f the children respnded t PPS-3 with pstimmunizatin antibdy cncentratins greater than 4 ng Ab N/ml. Three children had an increase in titer t PPS- 7 f less than twfld, seven did nt have a twfld increase in titer t PPS-9, and 15 had an increase in titer t PPS-14 f less than twfld. Cnelusin: Uncnjugated Hib vaccine is a ptent immungen in children ver 2 years f age. Prir immunizatin with the cnjugate vaccine did nt prevent a respnse t uncnjugated vaccine. Uncnjugated Hib vaccine appears t be at least as immungenic as PPS-3 when used as an assessment vaccine fr evaluating antibdy respnsiveness. (J Allergy Clin Immunl 1996;98:451-9.) Key wrds: Uncnjugated H. influenzae b vaccine, pneumcccal plysaccharide vaccine, recurrent infectin, antibdy respnse The clinical immunlgist is ften called n t evaluate the patient with recurrent infectin and suspected immundeficiency. It is nly rarely that a well-described immundeficiency such as IgA deficiency, Wisktt-Aldrich syndrme, X-linked agammaglbulinemia, r cmmn variable hyp- Frm the Department f Pediatrics, University f Tennessee, Memphis; and The Crippled Children's Fundatin Research Center at Le Bnheur Children's Medical Center, Memphis. Received fr publicatin June 29, 1995; revised Nv. 7, 1995; accepted fr publicatin Nv. 13, Reprint requests: Henry G. Herrd, MD, Le Bnheur Children's Medical Center, 5 Nrth Dunlap, Rm. 31 West Patient Twer, Memphis, TN Cpyright 1996 by Msby-Year Bk, Inc /96 $5. + 1/1/7627 Abbreviatins used ARS: Hib: ng Ab N/ml: PPS: uhib: Antibdy respnse scre Haemphilus influenzae b Nangrams antibdy nitrgen per milliliter Pneumcccal plysaccharide Uncnjugated H. influenzae b gammaglbulinemia is diagnsed in such patients. If an immunlgic defect is present, it is generally mre subtle than that fund in these well-characterized cnditins. This bservatin has led t greater effrts t evaluate the immune system f 451

2 452 Raby et al. J ALLERGY CLIN immunol AUGUST 1996 TABLE I. Patient characteristics Age Gender Number evaluated 11 male: 9 female Principal recurrent infectin Sinusitis 18/2 (9%) Otitis media 9/2 (45%) Pneumnia 3/2 (15%) Mastiditis 2/2 (1%) Bacteremia 2/2 (1%) Ttal patients 17/2 (85%) underging surgery Sinus and/r ear surgery >-3+ Prcedures 14/2 (7%) <-1 t 2 Prcedures 3/2 (15%) Range Mean 2-13yr 88m patients with recurrent infectin wh d nt have an bvius immundeficiency syndrme. One apprach t evaluating these patients is the study f specific antibdy respnsiveness. There have been multiple reprts f patients with an immundeficiency characterized principally by an impaired antibdy respnse t plysaccharide antigen. 1-8 Pneumcceal plysaccharide (PPS) vaccine is ften used t evaluate antibdy respnsiveness in individuals with recurrent infectin and suspected immundeficiency. Hwever, the respnse t PPS vaccine is ften cnfusing because the patient may nt respnd t the varius sertypes f the vaccine in a unifrm fashin. 9, 1 Immunizatin with uncnjugated Haemphilus influenzae b (uhib) can als prvide useful infrmatin abut the ability t prduce antibdy t plysaccharide antigen. 5,6,u-14 In this study we cmpared the respnses t bth uhib and PPS vaccines in 2 children with a histry f recurrent infectin and suspected immundeficiency. METHODS Patient ppulatin This study was cnducted ver an 8-mnth perid frm July 1992 t March 1993 and invlved 2 patients, ages 2 t 13 years, 11 f whm were bys. These patients were referred t the Immunlgy Clinic at LeBnheur Children's Medical Center because f recurrent infectin and suspected immundeficiency (Table I). Fr the purpse f this study, recurrent infectin was defined as at least fur episdes f sinusitis and/r titis media in the previus 6 t 12 mnths, with cncern n the part f the primary care prvider great enugh t warrant a referral t ur immunlgy clinic. TABLE II. Antibdy Value respnse scres Definitin Hib ->5 ng Ab N/ml r PPS >-2 ng Ab N/ml befre immunizatin >Twfld increase with pst titer >-4 ng Ab N/ml; r <twfld increase, but pre value >4 ng Ab N/ml >Twfld increase but pst value <4 ng Ab N/ml, r <twfld increase with pre value <-4 ng Ab N/ml and pst value ->4 ng Ab N/ml <Twfld increase and pst value <4 ng Ab N/ml pst, Pstvaccinatin; pre, prevaccinatin. Surgery t crrect anatmic cnditins that might cntribute t recurrent upper airway infectin had been perfrmed in 17 children (Table I). Surgical prcedures included sinus windw surgery, endscpic sinus surgery, tnsillectmy and adenidectmy, placement f pressure equalizatin tubes, plypectmy, and septplasty. Sixteen f the patients had undergne allergy testing. Nine patients (45%) had previusly received cnjugated Hib vaccine. Three patients (15%) had received uhib vaccine nly. Tw patients (1%) were unsure whether they had received any type f Hib vaccine in the past, and six patients (3%) had nt received any type f Hib vaccine. Immunlgic studies Each f the patients in the study had, as a baseline evaluatin, prevaccinatin 14. influenzae b and pneumcccal antibdy cncentratins determined. Hib capsular plysaccharide plyribsylribitl phsphate antigen was used t measure Hib-specific IgG antibdy by indirect enzyme immunassay at Specialty Labratries Inc. (Santa Mnica, Calif.). An antibdy cncentratin f greater than 1 nangrams antibdy nitrgen per milliliter (ng Ab N/ml) is cnsidered prtective by that labratry. Pneumcccal antibdy levels were als measured by an indirect enzyme immunassay (Specialty Labratries, Inc.). Plysaccharide antigens f the Streptcccus pneumniae sertypes cmmnly classified in the Danish system as 3, 7F, 9N, and 14 are used in this indirect enzyme immunassay. A prtective antibdy titer is cnsidered t be greater than 2 ng Ab N/ml. Nineteen unvaccinated nrmal cntrl subjects (age range, 2 t 17 years; mean age, 92 mnths) had serum btained fr determinatin f PPS titers. Other serlgic studies perfrmed in mst but nt all patients included determinatin f quantitative serum immunglbulins, ishemagglutinins, and tetanus antibdy titers. Eleven patients had serum IgE quantitated, and an equal number had IgG subclass determinatins. Serum immunglbulin (IgG, IgM, IgA) cncentra-

3 J ALLERGY CLIN IMMUNOL Raby et al. 453 VOLUME 98, NUMBER 2 TABLE i11. Initial immune evaluatins Number evaluated Range Mean Immunglbulins 19/2 IgG mg/dl 919 mg/dl IgA IgM IgE 11/ IgG subclasses 11/2 IgG mg/dl 594 mg/dl IgG IgG IgG Befre PPS vaccinatin 2/2 Sertype ng Ab/ml 956 ng Ab/ml Sertype Sertype Sertype Befre Hib vaccinatin 2/ tins were determined by means f nephelmetry (Behring, Marburg, Germany). Nrmal values were established by calculating an age-apprpriate gemetric mean fr a grup f nrmal children frm the middle suthern regin f the United States. I~vels f serum immunglbulin were cnsidered t be lw if they were mre than 2 standard deviatins belw this mean. IgE levels were calculated by using a radiimmunassay. Serum IgG subclass istypes were measured by Specialty Labratries with an immunradimetric assay. The ageadjusted nrmal ranges fr this test were established by calculating a gemetric mean frm serum samples frm mre than 1 children referred by 1 physicians frm different regins f the United States. Values fr ur patients were cnsidered lw if they were greater than 2 standard deviatins belw the gemetric mean fr age. Ishemagglutinin titers were measured in the LeBnheur Children's Medical Center hspital labratry. Fr children between 24 and 36 mnths f age, titers greater than 1:2 dilutins are cnsidered nrmal. Fr children ver the age f 36 mnths, titers greater than 1:4 dilutins are cnsidered nrmal. Tetanus txid antibdy titers were determined by passive hemagglutinatin in ur labratry. A titer f 1:81 r greater is cnsidered nrmal in a fully immunized child. All f the patients evaluated were vaccinated with the uhib vaccine and with the PPS vaccine during the same clinic visit. Pstvaccinatin antibdy respnses were btained 3 t 6 weeks after immunizatin. Althugh antibdy titers f greater than 1 ng Ab N/ml against H. influenzae b capsular plysaccharide and 2 ng Ab N/ml against a PPS capsular antigen are cnsidered prtective, in mst nrmal subjects antibdy titers in excess f these "prtective" antibdy cncentratins will develp after immunizatin with the respective agents. 6, 7 Patients were cnsidered pr respnders r nnre- spnders if pstvaccinatin values were 4 ng Ab N/ml r less. Vaccine Uncnjugated Hib vaccine was secured frm the Natinal Institutes f Allergy and Infectius Diseases, Natinal Institutes f Health, H. influenzae b, Reference Labratry at the University f Rchester, Rchester, New Yrk. This vaccine is n lnger cmmercially available because it has been replaced by vaccines cnsisting f H. influenzae b plysaccharide cnjugated t a carrier prtein. It is available fr research use under Investigative New Drug 493 n file with the Fd and Drug Administratin. A cmmercially available PPS vaccine (Pneumvax) was used. Scring f results We established a scring system fr reprting the antibdy respnses (antibdy respnse scre [ARS]) t the uhib and PPS vaccines (Table II). This scring system was based n a scale f (pr t n respnse) t 3 (high prtective levels befre vaccinatin) and was used t help simplify data analysis. RESULTS Quantitative immunglbulins, IgG subclass determinatins, and nnplysaccharide antibdy studies Nineteen children (95%) had quantitative immunglbulins evaluated (Table III). Five f these had a lw age-adjusted IgG value. Seven f 19 had an abnrmal age-adjusted IgA value, but n abslute IgA deficiency was fund. Eleven children had IgG subclasses evaluated. Three f these had a lw IgG 3 value fr age, and anther three

4 454 Raby et al. J ALLERGY CLIN IMMUNOL AUGUST ' 2 35 ' < 3 25 " ' O PRE PPS 3 PRE PPS7 6 9" 8" 5 " 7 4" 6 ~.< 3 " O t PRE PPS 9 PRE PPS ~- 8 FIG. 1, Prevaccinatin respnses t PPS sertypes 3, 7, 9, and 14 in 19 nrmal subjects. Sme pints represent mre than ne patient, Hrizntal mark represents median. had a lw IgG2 value fr age. Fifteen children had tetanus titers evaluated. All had nrmal values. Nineteen children had ishemagglutinins studied. Only ne f these had an abnrmal value (bld type O with an anti-b titer f 1:1; anti-a titer was nrmal at 1:32). Of the 16 children wh underwent allergy testing, seven had psitive respnses t at least ne f the antigens studied. Respnse t plysaccharides Nrmal subjects. Antibdy cncentratins t the fur sertypes in nrmal subjects are shwn in Fig. 1. Patients: PPS ser(ype 3. Nine children (45%) had prevaccinatin antibdy cncentratins greater than 4 ng Ab N/ml (Fig. 2, A). Five f these had cncentratins greater than 2 ng Ab N/ml. Of the 11 children with a prevaccinatin cncentratin less than 4 ng Ab N/ml, all had an increase f twfld r greater t PPS-3 after vaccinatin, and pstvaccinatin titers were greater than 4 ng Ab N/ml. The mean ARS was 2.2 fr sertype 3 (Table IV). PPS Sertype 7. Only ne f the children had a prtective cncentratin f antibdy t sertype 7 befre vaccinatin (Fig. 2, B). Prevaccinatin an-

5 J ALLERGY CLIN IMMUNOL Raby et al. 455 VOLUME 98, NUMBER 2 5- _ \ 25, 2 J~ T, i O A Pre 3 Pst 3 B Pre 7 Pst 7 FIG. 2. A, Prevaccinatin and pstvaccinatin respnses t PPS-3. Twenty patients are represented. Sme lines represent mre than ne patient. B, Prevaccinatin and pstvaccinatin respnses t PPS-7. Twenty patients are represented. Sme lines represent mre than ne patient. TABLE IV. Individual patient respnse scres Patient N. PPS-3 PPS-7 PPS-9 PPS-14 Hib Average 2.2 _ _ p Value.716" <.1 <.1 <.1 -- *When cmpared with Hib.

6 456 Raby et al. J ALLERGY CLIN IMMUNOL AUGUST "~ 1 J~ "~ 1 J~ ,..,,, Y i Pst 9 A Pre 9 B i Pre 14 Pst 14 I FIG. 3. A, Prevaccinatin and pstvaccinatin respnses t PPS-9. Twenty patients are represented. Sme lines represent mre than ne patient. B, Prevaccinatin and pstvaccinatin respnses t PPS-14. Twenty patients are represented. Sme lines represent mre than ne patient. tibdy cncentratins ranged frm 1 t 25 ng Ab N/ml. Nine children (45%) had an increase f twfld r greater t sertype 7 after vaccinatin, and pstvaccinatin values were greater than 4 ng Ab N/ml (ARS f 2). Eight children (4%) had an increase f greater than twfld after vaccinatin, but pstvaccinatin values remained less than 4 ng Ab N/ml (range, 6 t 33; ARS f 1). Three children (15%) had an increase f less than twfld and pstvaccinatin levels less than 4 ng Ab N/ml (ARS f ). The mean ARS was 1.3 fr sertype 7 (Table IV). PPS Sertype 9. One child (5%) had an antibdy cncentratin f greater than 4 ng Ab N/ml befre vaccinatin and did nt exhibit an increase with vaccinatin (ARS f 2) (Fig. 3, A). Eight children (4%) had an increase f greater than twfld after vaccinatin with pstvaccinatin values greater than 4 ng Ab N/ml (ARS f 2). Five children (25%) had an increase f greater than twfld after vaccinatin, but pstvaccinatin levels were less than 4 ng Ab N/ml (range, 8 t 33; ARS f 1). Six children (3%) had an increase f less than twfld and pst-vaccinatin levels less than 4 ng Ab N/ml (ARS f ). The mean ARS fr sertype 9 was 1.2. (Table IV). PPS Sertype 14. Tw children (2%) had prevaccinatin levels greater than 4 ng Ab N/ml (ARS f 3) (Fig. 3, B). One f these als had a greater than twfld respnse t vaccinatin. Eighteen children (9%) had prevaccinatin values f less than 4 ng Ab N/ml. Three children (15%) had a greater than twfld respnse with pstvaccinatin values greater than 4 ng Ab N/ml (ARS f 2). Tw children (1%) had pstvaccinatin levels greater than 4 ng Ab N/ml but an increase f less than twfld (ARS f 1). One child (5%) had a greater than twfld respnse but a pstvaccinatin level f less than 4 ng Ab N/ml (ARS f 1). Twelve children (6%) had a less than twfld respnse and nnprtective pstvaccinatin values (ARS f ). The mean ARS fr sertype 14 was.6 (Table IV). Respnse t uhib Fur children (2%) had prevaccinatin levels greater than 5 ng Ab N/ml (ARS f 3) (Fig. 4). Thirteen children (65 %) had prevaccinatin values

7 J ALLERGY CLIN IMMUNOL Raby et al. 457 VOLUME 98, NUMBER 2 s-. ~ / ~/, 35 I l/ / / 15.. looo 5. I~ O " I I Pre H flu Pst H flu FIG. 4, Prevaccinatin and pstvaccinatin respnses t uhib. Twenty patients are represented. Sme lines represent mre than ne patient. between 4 and 5 ng Ab N/ml (ARS f 2). Of these 13 children, eight shwed an increase f greater than twfld with vaccinatin, tw shwed an increase that was less than twfld, and three shwed n increase at all. Three children had prevaccinatin antibdy levels less than 4 ng Ab N/ml, and all f these shwed an increase f greater than twfld after vaccinatin and pstvaccinatin values greater than 4 ng Ab N/ml (ARS f 2). The average ARS fr Hib was 2.2 (Table IV). Of the six children wh had nt received any type f Hib vaccine, ne had a preimmunizatin level greater than 5 ng Ab N/ml. Fur f the six had an increase f greater than twfld with pstimmunizatin values greater than 4 ng Ab N/ml. One f these children had n increase in antibdy cncentratin after immunizatin but did have a preimmunizatin value greater than 4 ng Ab N/ml. Tw f the nine children wh had received cnjugated Hib in the past, had preimmunizatin levels greater than 5 ng Ab N/ml. Three f the nine had an increase f greater than twfld with pstimmunizatin levels greater than 4 ng Ab N/ml, and fur f nine had n increase but a prevaccinatin value greater than 4 ng Ab N/ml. Of the three patients wh had received uncnjugated Hib in the past, ne had a prevaccinatin antibdy cncentratin greater than 5 ng Ab N/ml, and tw had an increase f greater than twfld with pstimmunizatin values greater than 4 ng Ab N/ml. Tw nrmal unvaccinated children, ages 12 and 17 years, had Hib titers determined. These values were 318 ng Ab N/ml and greater than 5 ng Ab N/ml, respectively. Patient management All patients were treated with prphylactic antibitics. Each shwed a decrease in the frequency f infectin. Tw f the patients were ultimately treated with intravenus immunglbulin. Bth respnded well, with decreased frequency f infectin. DISCUSSION Of the 2 children with recurrent infectins whm we evaluated, all were cnsidered t have

8 458 Raby et al. J ALLERGY CLIN IMMUNOL AUGUST 1996 excellent antibdy respnses t PPS-3 and uhib. In each case, antibdy levels were already sufficiently high t be prtective, r they respnded with a twfld r greater increase t prtective levels. As has been bserved in the past, respnse t the ther PPS sertypes was smewhat ambiguus, s, 9 The respnse t plysaccharides in human beings is nrmally nt cnsistently seen until at least 2 years f age Recgnitin f this stimulated the develpment f the cnjugated frm f the Hib vaccine.n, 12, Hwever, after the age f 2 years, immunlgically nrmal patients shuld respnd vigrusly t plysaccharide antigen. The pneumcecal vaccine is ften used t evaluate the plysaccharide respnse. The significance f finding a gd respnse t sme but nt all PPSs is unclear. One reprt has indicated that lwer than expected respnses t six r mre f 13 sertypes is mre likely t be assciated with a histry f recurrent infectin. 2 Sme sertypes, such as PPS sertypes 3 and 7, are mre immungenic than sertypes 9 and , 22 It is intriguing t speculate that the respnse t these less immungenic sertypes might be useful as a mre sensitive indicatr f the respnsiveness t PPS vaccinatin. Hwever, we are unaware f any data t supprt this speculatin. Our data clearly demnstrate the ptent immungenic effect f PPS sertype 3. We had hypthesized that the respnse t uhib might represent a mre sensitive means f examining plysaccharide respnsiveness. The results f this study indicate that nthing is t be gained by adding uhib t an existing panel f vaccinatins used t evaluate the immune respnse in children with recurrent infectins, if such a panel already includes PPS antigens. The relatively high prprtin (2%) f children with recurrent infectin that we previusly reprted t be unrespnsive t uhib can best be explained by nting that the majrity f the pr respnders in that study were arund 2 years f age. 6 This study demnstrates that children lder than 2 years f age respnd t uhib as well as they d t PPS sertype 3. Thus a pr respnse t either uhib r PPS-3 shuld alert the physician t a ptential severe antibdy deficiency. REFERENCES 1. Blecher TE, Sthill JF, Vyce MA, Walker WHC. Antibdy deficiency syndrme: a case with nrmal immunglbulin levels. Clin Exp Immunl 1968;3: Davis SD. Antibdy deficiency diseases. In: Stiehm ER, Fulginiti VA, editrs. Immunlgic disrders in infants and children. Philadelphia: WB Saunders, 1973: Rthbach C, Nagel J, Rabin B, Fireman P. Antibdy deficiency with nrmal immunglbulins. J Pediatr 1979; 94:2: Ambrsin DM, Siber GR, Chilmnczyk BA, Jernberg JB, Finberg RW. An immundeficiency characterized by impaired antibdy respnses t plysaccharides. 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9 J ALLERGY CLIN IMMUNOL Raby et at. 459 VOLUME 98, NUMBER Madre D, Jhnsn C, Phipps D, et al. Haemphilus influenzae type b plysaccharide CRM 197 cnjugate vaccine: safety and immunlgic respnses in 1-6 mnth ld infants. Pediatrics 199;85: Andersn P, Pichicher M, Insel R. Immunizatin f 2-mnth-ld infants with prtein-cupled ligsaccharides derived frm the capsule f Haemphilus influenzae type b. J Pediatrics 1985;17: Silk H J, Zra J, Gldstein J, Schiffman G. Respnse t pneumcccal immunizatin in children with and withut recurrent infectins [Abstract]. J Allergy Clin Immunl 1994;93: Duglas RM, Patn JC, Duncan SJ, Hansman DJ. Antibdy respnse t pneumcccal vaccinatin in children yunger than five years f age. J Infect Dis 1983;148: Lawrence EM, Edwards KM, Schiffman G, Thmpsn JM, Vaughn WK, Wright PF. Pneumcccal vaccine in nrmal children. Am J Dis Child 1983;137:846-5.