Peculiarities of Immune Response in Infants with Herpes Simplex Virus Infection Eka Uberi*, Manana Zhvania*, Nugzar Uberi*, George Kamkamidze** *Department on Specialization in Pediatrics, Pediatric Clinic of Tbilisi State Medical University **Infectious Diseases, AIDS and Clinical Immunology Research Center Address for Correspondence: Nugzar Uberi Pediatric Clinic of the Tbilisi State Medical University Tel: +(995 32) 22 47 27 Email: eubri@hotmail.com Abstract Herpes Simplex Virus (HSV) infection is one of the most frequent infections in newborns. Main goal of the study was the investigation of peculiarities of immune response to Herpes Simplex Virus infection in newborns. Parameters of humoral and cellular immunity, as well as phagocytic activity had been studied in 45 infants with primary HSV mono and mixed (associated with bacteria) infection. In these patients IgM and IgA levels were increased, while IgG level, T and B lymphocyte counts and phagocytic activity were decreased in comparison with the control group. Low IgG level, CD4 lymphocyte count and phagocytic activity correlated with the generalization of the HSV infection and were negative predictive factors for the outcome of the disease. Mixed infection differed from the HSV mono infection by higher CD8 lymphocyte count, lower phagocytic activity. Keywords: herpes simplex virus, newborns, immune response Introduction I nfections of the fetus and infant are the most important problems in contemporary perinatology. 50-60% of hospitalized normal newborns and 70% of premature newborns have one of the infectious diseases (8). Most frequently perinatal infections are caused by Cytomegalovirus, Herpes Simplex Virus, Chlamydia and Mycoplasma. Herpes Simplex Virus (HSV) infection in newborns is characterized by severe course of the disease resulting in psycho-neurological disturbances and high mortality. In most cases HSV infection is associated with other viral or bacterial infections (2-7). Severe mixed infection can substantially change immunological status and clinical course of the infection in newborn infants. That's why it is very important to investigate clinical peculiarities of HSV infection in relation to indices of immune response (9,10). The main goal of our study was the investigation of humoral and cellular immune response and 87
phagocytosis as well as comparative analysis of these indices in different clinical forms of HSV infection. Materials and Methods We have studied 250 infants selected from the newborn intensive care unit and department of newborn pathology of the Pediatric Clinic of the Tbilisi State Medical University. Screening on HSV infection was performed by detection of specific anti-hsv IgM antibodies by ELISA method. Positive ELISA results was considered to correspond to the primary HSV infection. 45 newborns 0-1 months of age with primary HSV infection were included in the study group. Among these infants 38 had generalized form, while 7 had CNS form of HSV infection. According to the bacteriologic data patients were divided into two groups: first group included 19 infants with HSV monoinfection while the second group included 26 infants with mixed infection. Associated bacterial pathogens were represented both by Gram-positive (Staph. aureus et epidermidis) and Gram-negative (E.coli, Pseudomonas aeruginosa) bacteria and fungi. For the control group 20 infants have been selected from the newborn intensive care unit. In these infants presence of any congenital infections has been excluded by clinical and laboratory investigations. In infants from the both - study and control groups' presence of Cytomegaloviral infection, Toxoplasmosis or Chlamidial infection has been excluded by appropriate laboratory investigations. Evaluation of humoral immunity was performed by detection of three main classes of serum antibodies by the gel radial immunodifussion method by Manchini. Indirect Immunofluorescence Assay determined T and B lymphocyte count. Phagocytic function was evaluated by Nitroblue tetrazolium (NBT) method. Results and Discussion In the control group the level of IgG was lower compared with normal values for this age group, which could be explained by the fact that the babies were selected from intensive care unit. In this group the levels of IgM and IgA were not significantly different from normal values. The parameters of humoral immunity were significantly different from those in control group. IgG level was substantially decreased and levels of IgA and IgM was higher than in patients from control group. I children with mixed infections the deviation of parameters of humoral immunity from the normal values was more apparent then in babies with only herpes virus infection. However, the difference between parameters of humoral immunity among study and control groups was not statistically significant. In patients with CNS involvement the level of IgG was significantly higher than in those with generalized mixed infection and was within normal ranges. The level of IgM in both generalized form and infection with CNS involvement was high compared to parameters in control group. IgM level was somewhat higher in second subgroup, but this difference was not statistically significant. However, the level of IgA was significantly higher in patients with CNS involvement compared to patients with generalized infection. The comparison of parameters of humoral immunity between two subgroups of study group was also performed. In first subgroup we included deceased patients and in second group - survived. The level of IgG was substantially decreased in group of deceased patients compared to those of survived and control groups. There was no significant difference between IgM levels. IgA was relatively low in group of deceased patients. The levels of IgA and IgM are increased in patients with herpes virus infection, which could be explained by acute infection. The level of IgA was highest in patients with CNS involvement and the low level of this immonoglobulin had negative prognostic value. Total number of T lymphocytes was significantly lower both in cases of mono and mixed HSV infection compared to the control group. The same trend was observed for CD4 lymphocytes. No significant difference by these parameters was documented between the groups with mono and mixed infections. CD8 lymphocyte counts were significantly lower in the study group in comparison with the control group. In the subgroup of infants with HSV mono infection CD8 count was lower than in the subgroup with mixed infection. B lymphocyte count was decreased in the both subgroups in comparison with the control group. In the group of infants with generalized HSV infection all indices of cellular immunity were lower than in the control group, CD4 lymphocytes in this group were lower in comparison with the infants with isolated CNS involvement. In the latter group only CD8 fraction of lymphocytes was decreased. This indicates that disregulation between different arms of immune system facilitates generalization of HSV infection. In deceased infants T lymphocyte counts (mainly CD4 fraction) were significantly lower than in survived children. No significant difference has been documented between these groups by CD8 or B lymphocyte counts. Phagocytic activity was significantly lower in the group of infants with mixed infection in comparison with infants with HSV mono infection or infants of the control group. This parameter was decreased in the group of infants 88
with generalized HSV infection in contrast to the children with CNS form where this index did not deviate from the normal values. Phagocytic activity was lower in the group of deceased children than in survived children. Conclusion IgG level was decreased in children with Herpes Simplex Virus infection, which can be due to low level of these immunoglobulins in mothers and/or its inefficient transplacental transmission. The decrease of IgG was more prominent in patients with generalized infection and it represented as a negative prognostic value. In HSV infected infants T and B lymphocyte counts are decreased. Lower CD4 lymphocyte count correlates with generalization of HSV infection and serves as a negative predictive factor for the disease outcome. Low phagocytic activity was associated with generalization of HSV infection and was the negative predictive factor for the disease outcome. Mixed infection differed from the HSV mono infection by higher CD8 lymphocyte count, lower phagocytic activity. TYPE IF IG GENERALIZED INFECTION (N=38) Mono infection (n=12) IgG (mg/dl) 516.6 ± 158.3 IgM (mg/dl) 32.8 ± 14.8 IgA (mg/dl) 13.5 ± 3.8 Mixed infection (n=33) 422.3 ± 116.7 41.5 ± 12.9 21.5 ± 4.8 CNS FORM (N=7) GROUP (N=20) 789.6 ± 111.9 825.6 ± 210.4 1121 (636-1606) 42.8 ± 10.7 35.5 ± 6.7 21.3 ± 15.2 13 (6.3 25) 5.1 ± 2.8 2.3 (0-3.6) * p<0.05 ** p<0.01 (compared to the control group) Tab.1 Humoral immunity in different groups of infants with HSV infection. DECEASED TYPE IF IG INFANTS (N=21) I IgG (mg/dl) 335.2 ± 123.5 Ι ΙΙ Ι ΙΙΙ SURVIVED INFANTS (N=24) II 689.5 ± 157.9 ΙΙ ΙΙΙ GROUP (N=20) III 825.6 ± 210.4 1121 (636-1606) IgM (mg/dl) 38.2 ± 11.5 40.4 ± 21.3 21.3 ± 15.2 13 (6.3 25) IgA (mg/dl) 8.2 ± 3.1 5.1 ± 2.8 2.3 (0-3.6) Ι ΙΙ * p<0.05 ** p<0.01 ***p<0.001 29.5 ± 7.8 Ι ΙΙΙ Tab.2 Humoral immunity in deceased and survived infants. 89
TYPE IF LYMPHOCY TE CD3 T CD4 T CD8 T CD19 B GENERALIZED INFECTION (N=38) I Mono infection (n=12) I 1.1 ± 0.8 Ι ΙΙΙ Ι ΙV 1.0 ± 0.5 Ι ΙΙ Ι ΙΙΙ I-IV ** 0.1 ± 0.1 Ι ΙΙ Ι ΙΙΙ I-IV *** 0.2 ± 0.1 Ι ΙV * Mixed infection (n=33) II 1.6 ± 0.4 ΙΙ ΙV 0.9 ± 0.2 ΙΙ ΙV 0.6 ± 0.2 ΙΙ ΙV 0.3 ± 0.1 ΙΙ ΙV * CNS FORM (N=7) III GROUP (N=20) IV 2.5 ± 0.4 3.6 ± 0.8 0.6 5.0 1.9 ± 0.3 2.1 ± 1.1 0.4 3.5 0.6 ± 0.3 ΙΙΙ IV * 1.4 ± 0.9 0.2 1.9 0.4 ± 0.1 0.8 ± 0.2 0.04 1.1 * p<0.05 ** p<0.01 ***p<0.001 Tab.3 Cellular immunity in different groups of infants with HSV infection. TYPE OF LYMPHOCYTE S DECEASED INFANTS (N=21) I CD3 T 0.6 ± 0.3 Ι ΙΙ Ι ΙΙΙ CD4 T 0.4 ± 0.1 Ι ΙΙ Ι ΙΙΙ CD8 T 0.3 ± 0.1 Ι ΙΙΙ CD19 B 0.3 ± 0.1 Ι ΙΙΙ SURVIVED INFANTS (N=24) II 1.9 ± 0.6 II-III * 1.3 ± 0.4 ΙΙ ΙΙΙ 0.5 ± 0.2 II-III * 0.1 ± 0.1 ΙΙ ΙΙΙ GROUP (N=20) III 3.6 ± 0.8 0.6 5.0 2.1 ± 1.1 0.4 3.5 1.4 ± 0.9 0.2 1.9 0.8 ± 0.2 0.04 1.1 *p<0.05 **p<0.01 Tab.4 Cellular immunity in deceased and survived infants. 90
INDEX GENERALIZED INFECTION (N=38) I Mono infection (n=12) I Mixed infection (n=33) II Phagocytic % 47.8 ± 12.5 26.3 ± 10.5 CNS FORM (N=7) III GROUP (N=20) IV VALUES FOR 48.8 ± 11.7 53.2 ± 11.2 40-80 p<0.05 Tab.5 Phagocytic activity in different groups of infants with HSV infection. DECEASED INDEX INFANTS (N=21) I Phagocytic % 31.2 ± 12.5 SURVIVED INFANTS (N=24) II GROUP (N=20) III 49.2 ± 11.8 53.2 ± 11.2 40 80 p<0.05 Tab.6 Phagocytic activity in deceased and survived infants. References 1. Aleksandrovski K, Kudashov N.I., Vanko L.V., Clinical and immunological peculiarities of herpes virus infection in newborns. Rus vest perinat pediatr. 1999; 5:19-22. (Russian) 2. Centsova T.B., Khan E.P., Coyunova O.U. The syndrome of infection in newborns, microbiologic peculiarities. Pediatrics 1996; 5:12-17. (Russian) 3. Chekuzaeva N.B., Perinatal CNS involvement in children according to clinical form of CMV infection, manifestations during pregnancy. Vesti perinat akush gin 1997; 5:139-142. (Russian) 4. Cinzerling A.B., Shabolov N.P. Intrauterine infections. Arc Pat 1992; 1:24-30. 5. Evsukova I.I., Chamydial infection in newborns. Pediatrics. 1997; 3:77-80. (Russian) 6. Fomicheva E.N., Zarubina E.N., Minaev V.I et al. The role of ureamycoplasmic and chlamydial infections in obstetrics. Akush gin 1997; 2:55-57. (Russian) 7. Koptyaeva I.B., Milovidova N.I., Dobrotvorceva V.G. The role of some viruses in the pathology of fetus. Voprosi Virusologii. 1995; 2:50-53. (Russian) 8. Lavrova D.B., Samcigina G.A., Mikhailov A.V., Etiology and indices of high risk for intrauterine infection. Pediatrics. 1997; 3:94-99. (Russian) 91
9. Plachter B., Jahn G. Cytomegalovirus diagnostics standard procedures and perspectives. Biotest Bulletin 1990; 4: 107-118. 10. Zubkov V.V., Kudashov N.I. The experience of using cefobid in newborns with generalized viral and bacterial infections. Abstract book. IV National Russian Congress "Human and drug". 1997; 222. (Russian) Особенности имунного ответа у новорожденных с герпесвирусной инфекцией Ека Убери*, Манана Жвания*, Нугзар Убери*, Георгий Камкамидзе** *Педиатрическая Клиника Тбилисского Государственного Медицинского Университета **Центр Инфекционной Патологии, СПИДа и Клинической Иммунологии Р Е З Ю М Е Инфекция випусом простого герпеса является одной из самых распространенных инфекций раннего возраста. Целью наших исследованиий являлось изучение особенностей иммунного ответа у новорожденных с моно и смешанным формами инфекции вирусом простого герпеса. Показатели гуморального и клеточного иммунитетa, а также фагоцитарная активность были исследованы у 45 новорожденных с герпесвирусной инфекциeй. У инфицированных детей уровень IgM and IgA был выше, а показатели IgG, T и B лимфоцитов и фагоцитарной активности были ниже по сравнению с контрольной группой. Низкий уровень CD4 лимфоцитов и слабая фагоцитарная активность коррелировала с генерализацией инфекционного процесса и являлись неблагоприятными прогностическими маркерами для исхода заболевания. Смешанная инфекция отличалась от моно инфекции более высоким уровнем CD8 лимфоцитов и более низкой фагоцитарной активностью. Ключевые слова: вирус обыкновенного герпеса, новорожденные, имунный ответ 92