Life quality, depression, and anxiety levels in parents of children with primary immunodeficiency.

BACKGROUND: Primary immune deficiencies (PID) encompasses genetic disorders that result in recurrent infections and immune dysregulation, often increasing the risk of malignancies. The aim of this study is to determine the quality of life, depression, and anxiety in parents of children with PID. METHODS: Various validated assessment tools, including the Beck Depression Inventory (BDI), State and Trait Anxiety Inventory (STAI), the 36-item Short Form Survey (SF-36), and a demographic form, were employed to gather data from 85 parents of 64 PID patients and 85 parents of 75 healthy children. RESULTS: The findings reveal that parents of PID patients exhibited higher BDI, STAI-S, STAI-T, and fatigue subdomain of SF-36 (p = .013, p = .013, p = .027, p = .000). Both parents had lower energy levels than the normal population, but mothers experienced higher levels of anxiety and depression. PID mothers' had higher scores than fathers of PID patients with healthy children in BDI, STAI-S, and STAI-T (p = .002, p = .010, p = .001). Mothers of PID patients reported lower scores in RLEP, E/F, EWB, P, and GH compared to fathers (p = .009, p = .005, p = .034, p = .001, p = .003). Additionally, the study found that STAI-T influenced all subdimensions of HRQOL. These results highlight the substantial emotional and psychological burden placed on parents caring for children with PID. CONCLUSION: The study underscores the importance of supporting caregivers to enhance the overall well-being of both parents and children with PID. Such support can potentially alleviate depression and anxiety levels among parents, ultimately improving their quality of life and aiding in the management of children with PID.

Malignancies and Lymphoproliferations in Children With Primary Immune Deficiency-A Single-center Experience.

Primary immune deficiencies (PIDs) are rare genetic disorders characterized by impaired immune function, leading to frequent infections and immune dysregulation. Studies have shown that individuals with PID are at an increased risk of developing malignancies and lymphoproliferative disorders compared with the general population. In this single-center study, we aimed to analyze the occurrence of malignancies and lymphoproliferations in children diagnosed with PID. We retrospectively analyzed the medical records of 550 pediatric patients diagnosed with PIDs at our center. Among them, 17 (3,0%) patients were identified with malignancy and/or benign lymphoproliferation. Eight of the 17 patients (47.0%) had immune dysregulatory diseases, whereas ataxia-telangiectasia was the second most common PID associated with malignancy and/or benign lymphoproliferation (n = 5, 29.4%). Lymphoma was the predominant malignancy (n = 11, 64.7%), and Epstein-Barr virus was identified as the most common viral agent associated with malignancy and/or benign lymphoproliferation in patients with PID (n = 8, 47.0%). Our study highlights the association between PID and malignancies/lymphoproliferations, with immune dysregulation syndromes being the most common subclass associated with malignancies/lymphoproliferations. Early diagnosis, multidisciplinary management, and regular surveillance are crucial in improving patient outcomes and saving lives.

Neurologic Status of Patients with Purine Nucleoside Phosphorylase Deficiency Before and After Hematopoetic Stem Cell Transplantation.

BACKGROUND: Purine nucleoside phosphorylase (PNP) deficiency is a rare autosomal recessive combined immunodeficiency. The phenotype is profound T cell deficiency with variable B and NK cell functions and results in recurrent and persistent infections that typically begin in the first year of life. Neurologic findings occur in approximately two-thirds of patients. The mechanism of neurologic abnormalities is unclear. Hematopoietic stem cell transplantation (HSCT) is the only curative treatment for PNP deficiency. METHODS: We report here six patients from five unrelated families with PNP deficiency treated in two centers in Turkey. We evaluated the neurological status of patients and compared to post-transplantation period if available. Then, we performed PubMed, Google Scholar, and Researchgate searches using the terms "PNP" and "hematopoietic stem cell transplantation" to find all reported cases of PNP transplantation and compared to our cohort. RESULTS: Six patients were treated in two centers in Turkey. One patient died from post-transplant complications. The other four patients underwent successful HSCT with good immune reconstitution after transplantation (follow-up 21-48 months) and good neurological outcomes. The other patient with a new mutation is still waiting for a matching HLA donor. DISCUSSION: In PNP deficiency, clinical manifestations are variable, and this disease should be considered in the presence of many different clinical findings. Despite the comorbidities that occurred before transplantation, HSCT currently appears to be the only treatment option for this disease. HSCT not only cures immunologic disorders, but probably also improves or at least stabilizes the neurologic status of patients.

Therapeutic modalities and clinical outcomes in a large cohort with LRBA deficiency and CTLA4 insufficiency.

BACKGROUND: LPS-responsive beige-like anchor (LRBA) deficiency (LRBA-/-) and cytotoxic T-lymphocyte-associated antigen-4 (CTLA4) insufficiency (CTLA4+/-) are mechanistically overlapped diseases presenting with recurrent infections and autoimmunity. The effectiveness of different treatment regimens remains unknown. OBJECTIVE: Our aim was to determine the comparative efficacy and long-term outcome of therapy with immunosuppressants, CTLA4-immunoglobulin (abatacept), and hematopoietic stem cell transplantation (HSCT) in a single-country multicenter cohort of 98 patients with a 5-year median follow-up. METHODS: The 98 patients (63 LRBA-/- and 35 CTLA4+/-) were followed and evaluated at baseline and every 6 months for clinical manifestations and response to the respective therapies. RESULTS: The LRBA-/- patients exhibited a more severe disease course than did the CTLA4+/- patients, requiring more immunosuppressants, abatacept, and HSCT to control their symptoms. Among the 58 patients who received abatacept as either a primary or rescue therapy, sustained complete control was achieved in 46 (79.3%) without severe side effects. In contrast, most patients who received immunosuppressants as primary therapy (n = 61) showed either partial or no disease control (72.1%), necessitating additional immunosuppressants, abatacept, or transplantation. Patients with partial or no response to abatacept (n = 12) had longer disease activity before abatacept therapy, with higher organ involvement and poorer disease outcomes than those with a complete response. HSCT was performed in 14 LRBA-/- patients; 9 patients (64.2%) showed complete remission, and 3 (21.3%) continued to receive immunosuppressants after transplantation. HSCT and abatacept therapy gave rise to similar probabilities of survival. CONCLUSIONS: Abatacept is superior to immunosuppressants in controlling disease manifestations over the long term, especially when started early, and it may provide a safe and effective therapeutic alternative to transplantation.

Comparing the levels of CTLA-4-dependent biological defects in patients with LRBA deficiency and CTLA-4 insufficiency.

BACKGROUND: Lipopolysaccharide-responsive beige-like anchor protein (LRBA) deficiency and cytotoxic T-lymphocyte protein-4 (CTLA-4) insufficiency are recently described disorders that present with susceptibility to infections, autoimmunity, and lymphoproliferation. Clinical and immunological comparisons of the diseases with long-term follow-up have not been previously reported. We sought to compare the clinical and laboratory manifestations of both diseases and investigate the role of flow cytometry in predicting the genetic defect in patients with LRBA deficiency and CTLA-4 insufficiency. METHODS: Patients were evaluated clinically with laboratory assessments for lymphocyte subsets, T follicular helper cells (TFH ), LRBA expression, and expression of CD25, FOXP3, and CTLA4 in regulatory T cells (Tregs) at baseline and 16 h post-stimulation. RESULTS: LRBA-deficient patients (n = 29) showed significantly early age of symptom onset, higher rates of pneumonia, autoimmunity, chronic diarrhea, and failure to thrive compared to CTLA-4 insufficiency (n = 12). In total, 29 patients received abatacept with favorable responses and the overall survival probability was not different between transplanted versus non-transplanted patients in LRBA deficiency. Meanwhile, higher probability of survival was observed in CTLA-4-insufficient patients (p = 0.04). The T-cell subsets showed more deviation to memory cells in CTLA-4-insufficiency, accompanied by low percentages of Treg and dysregulated cTFH cells response in both diseases. Cumulative numbers of autoimmunities positively correlated with cTFH frequencies. Baseline CTLA-4 expression was significantly diminished in LRBA deficiency and CTLA-4 insufficiency, but significant induction in CTLA-4 was observed after short-term T-cell stimulation in LRBA deficiency and controls, while this elevation was less in CTLA-4 insufficiency, allowing to differentiate this disease from LRBA deficiency with high sensitivity (87.5%) and specificity (90%). CONCLUSION: This cohort provided detailed clinical and laboratory comparisons for LRBA deficiency and CTLA-4 insufficiency. The flow cytometric approach is useful in predicting the defective gene; thus, targeted sequencing can be conducted to provide rapid diagnosis and treatment for these diseases impacting the CTLA-4 pathway.

Expanding the Clinical and Immunological Phenotypes and Natural History of MALT1 Deficiency.

PURPOSE: MALT1 deficiency is a combined immune deficiency characterized by recurrent infections, eczema, chronic diarrhea, and failure to thrive. Clinical and immunological characterizations of the disease have not been previously reported in large cohorts. We sought to determine the clinical, immunological, genetic features, and the natural history of MALT-1 deficiency. METHODS: The clinical findings and treatment outcomes were evaluated in nine new MALT1-deficient patients. Peripheral lymphocyte subset analyses, cytokine secretion, and proliferation assays were performed. We also analyzed ten previously reported patients to comprehensively evaluate genotype/phenotype correlation. RESULTS: The mean age of patients and disease onset were 33 ± 17 and 1.6 ± 0.7 months, respectively. The main clinical findings of the disease were recurrent infections (100%), skin involvement (100%), failure to thrive (100%), oral lesions (67%), chronic diarrhea (56%), and autoimmunity (44%). Eosinophilia and high IgE were observed in six (67%) and two (22%) patients, respectively. The majority of patients had normal T and NK cells, while eight (89%) exhibited reduced B cells. Immunoglobulin replacement and antibiotics prophylaxis were mostly ineffective in reducing the frequency of infections and other complications. One patient received hematopoietic stem cell transplantation (HSCT) and five patients died as a complication of life-threatening infections. Analyzing this cohort with reported patients revealed overall survival in 58% (11/19), which was higher in patients who underwent HSCT (P = 0.03). CONCLUSION: This cohort provides the largest analysis for clinical and immunological features of MALT1 deficiency. HSCT should be offered as a curative therapeutic option for all patients at the early stage of life.

Primary immunodeficiencies: HSCT experiences of a single center in Turkey.

BACKGROUND: Primary immunodeficiency diseases (PID) are characterized by the occurrence of frequent infections and are caused by many genetic defects. Hematopoietic stem cell transplantation (HSCT) is the only curative treatment option for the majority of PID. As a Pediatric Hematology-Oncology-Immunology Transplantation Unit, we wanted to present our HSCT experience regarding treatment of primary immunodeficiency diseases. METHODS: 58 patients were included in the study between January 2014 and June 2019. We searched 9/10 or 10/10 matched-related donor (MRD) firstly, in the absence of fully matched-related donor. We screened matched unrelated donor (MUD) from donor banks. MRD was used in 24 (41.3%) patients, MUD in 20 (34.4%) patients, and haploidentical donors in 14 (24.1%) patients. Demographic data, HSCT characteristics, and outcome were evaluated. While 16 patients had severe combined immunodeficiency (SCID), the remaining was non-SCID. RESULTS: Of the 58 patients, 38 were male and 20 were female. Median age at transplantation was 12 months (range: 2.5-172 months). Combined immunodeficiencies consisted 67.2% of patients. Mean follow-up time was 27 months (6 months-5 years). Median neutrophil, lymphocyte, and thrombocyte engraftment days were similar in comparison of both donor type and stem cell source. The most common complication was acute GvHD in 15 (25.8%) patients. In total, five patients (31%) belonging to the SCID group and 10 patients (23.8%) belonging to the non-SCID group died. Our total mortality rate was 15 (25.8%) in all patients. CONCLUSIONS: We would like to present our HSCT experiences as a pediatric immunology transplantation center. Existing severe infections before transplantation period, BCGitis, and CMV are important issues of transplantation in Turkey. However, the follow-up time is shorter than some studies, our results regarding complications and survival are similar to previous reports.

Asthma and allergic diseases are not risk factors for hospitalization in children with coronavirus disease 2019.

BACKGROUND: Coronavirus disease 2019 (COVID-19) emerged as a pandemic toward the end of 2019, causing large numbers of people to become infected and die. OBJECTIVE: To determine whether allergic diseases are a risk factor for hospitalization in COVID-19. METHODS: We conducted a study including 107 pediatric patients after COVID-19 recovery. The International Study of Asthma and Allergies in Childhood Phase 3 questionnaires were distributed together with a detailed history of environmental factors and an allergic evaluation including skin prick tests, specific immunoglobulin E tests, and spirometry. We investigated the prevalence of allergic diseases and evaluated the factors associated with hospitalization in COVID-19. RESULTS: A total of 61 (57%) patients were hospitalized and 46 (43%) patients were followed closely in the outpatient clinic. The prevalences of allergic rhinitis, asthma, atopic dermatitis, and episodic wheezing were 10.3%, 6,5%, 4.7%, and 3.7%, respectively, within the whole study population. Although having asthma with or without allergic rhinitis, atopic dermatitis, and passive tobacco exposure were not found to be related to hospitalization because of COVID-19, having a pet at home was found to decrease the risk of hospitalization (odds ratio, 0.191; 95% confidence interval, 0.047-0.779; P = .02). Spirometry tests revealed a higher forced expiratory volume in one second to forced vital capacity ratio and a peak expiratory flow reversibility in hospitalized patients than in nonhospitalized ones (P = .02 and P = .003, respectively). CONCLUSION: Asthma and allergic diseases do not seem to be risk factors for hospitalization in children because of COVID-19, and having a pet at home can be a protective effect. Pulmonary function testing seems to be important for monitoring lung damage after COVID-19.

A rare case of syndromic severe congenital neutropenia: JAGN1 mutation.

BACKGROUND: Neutrophils are essential innate cells to fight bacterial and fungal pathogens. Jagunal homolog 1 (JAGN1) mutations were recently defined as rare genetic defects causing severe congenital neutropenia. JAGN1 participates in the secretory pathway and is required for granulocyte colony-stimulating factor receptormediated signalling. This gene is required for normal ultrastructure and granulation of endoplasmic reticulum of myeloid progenitor cells. Its defect is related to increased predisposition to apoptosis. In the literature, a few cases have been reported with congenital anomalies such as cardiac and renal anomalies. CASE: Here we report a patient in which JAGN1 deficiency was found after several years. Apart from syndromic facial appearance we were unable to detect any other systemic malformations. CONCLUSION: The causes of multisystemic features of mutations in JAGN1 gene remain unknown. JAGN1 mutations must be considered in patients with severe congenital neutropenia especially with facial dismorphism even in the absence of systemic manifestations.

Abatacept as a Long-Term Targeted Therapy for LRBA Deficiency.

BACKGROUND: LPS-responsive beige-like anchor (LRBA) deficiency presents with susceptibility to infections, autoimmunity, and lymphoproliferation. The long-term efficacy of cytotoxic T-lymphocyte-associated antigen 4-immunoglobulin (abatacept) as targeted therapy for its immune dysregulatory features remains to be established. OBJECTIVE: To determine the clinical and immunologic features of LRBA deficiency and long-term efficacy of abatacept treatment in controlling the different disease manifestations. METHODS: Twenty-two LRBA-deficient patients were recruited from different immunology centers and followed prospectively. Eighteen patients on abatacept were evaluated every 3 months for long-term clinical and immunologic responses. LRBA expression, lymphocyte subpopulations, and circulating T follicular helper cells were determined by flow cytometry. RESULTS: The mean age of the patients was 13.4 ± 7.9 years, and the follow-up period was 3.4 ± 2.3 years. Recurrent infections (n = 19 [86.4%]), immune dysregulation (n = 18 [81.8%]), and lymphoproliferation (n = 16 [72.7%]) were common clinical features. The long-term benefits of abatacept in 16 patients were demonstrated by complete control of lymphoproliferation and chronic diarrhea followed by immune dysregulation, most notably autoimmune cytopenias. Weekly or every other week administration of abatacept gave better disease control compared with every 4 weeks. There were no serious side effects related to the abatacept therapy. Circulating T follicular helper cell frequencies were found to be a reliable biomarker of disease activity, which decreased on abatacept therapy in most subjects. However, high circulating T follicular helper cell frequencies persisted in 2 patients who had a more severe disease phenotype that was relatively resistant to abatacept therapy. CONCLUSIONS: Long-term abatacept therapy is effective in most patients with LRBA deficiency.

Cyclic manner of neutropenia in a patient with HAX-1 mutation.

Introduction: Severe congenital neutropenia (SCN) includes a group of genetic disorders which cause to arrest of neutrophil maturation. SCN can be associated with heterogenous group of genetic defects in ELANE, GFI1, HAX1, G6PC3, JAGN1, VPS45 or activating mutations in the Wiskott-Aldrich syndrome (WAS) gene. Aim: Here we report a patient who has a HAX1 mutation presented with cyclic manner. Case Report: A 6 year old female patients was admitted with recurrent apthous stomatitis. We followed the patient as cyclic neutropenia according to complete blood count results 2 times for 6 weeks. After persistant neutropenia developed during a severe varicella infection, we analysed HAX1 mutation, the result was interesting and incompatible with reported cyclic neutropenia patients. Conclusion: We suggest that HAX1 deficiency should be thought in patients who have normal neutrophil counts in the between of infections.

Novel Mutation in CECR1 Leads to Deficiency of ADA2 with Associated Neutropenia.

PURPOSE: Adenosine deaminase 2 (ADA2) have been reported to cause vasculitic diseases and immunodeficiency recently. Patients present with stroke episodes and rashes mimicking polyarteritis nodosa (PAN). We report a patient who has been followed up with severe neutropenia and found an unexpectedly revealed novel mutation in CECR1 affecting ADA2. METHODS: We reviewed medical records and clinical history of the patient. No mutations in other known neutropenia genes such as ELA, G6PC3, HAX1, AP3B1, LAMTOR2, VPS13B, VPS45, GFI1, JAGN1, or WAS could be detected. Sanger sequencing was used to confirm the genetic variants in the patient and relatives. RESULTS: Genetic analysis by exome sequencing revealed a novel mutation in the gene CECR1 (c.G962A; p.G321E) which segregated perfectly in the relatives. CONCLUSION: This is the first DADA2 patient presenting with severe neutropenia. We suggest that in patients with unexplained cytopenias combined with immunodeficiency, fevers of unknown origin and high inflammation markers, DADA2 should be considered.

Regression of Cardiac Rhabdomyomas in a Neonate after Everolimus Treatment.

Cardiac rhabdomyoma often shows spontaneous regression and usually requires only close follow-up. However, patients with symptomatic inoperable rhabdomyomas may be candidates for everolimus treatment. Our patient had multiple inoperable cardiac rhabdomyomas causing serious left ventricle outflow-tract obstruction that showed a dramatic reduction in the size after everolimus therapy, a mammalian target of rapamycin (mTOR) inhibitor. After discontinuation of therapy, an increase in the diameter of masses occurred and everolimus was restarted. After 6 months of treatment, rhabdomyomas decreased in size and therapy was stopped. In conclusion, everolimus could be a possible novel therapy for neonates with clinically significant rhabdomyomas.

Paediatric Tuberculosis at a Referral Hospital in Istanbul: Analysis of 250 Cases.

Background. Tuberculosis (TB) still remains a growing public health problem globally. TB in children is often diagnosed clinically. Methods. We conducted a retrospective chart review of children with TB from November 2004 through December 2010 to determine the appropriateness of using contact history and diagnostic testing. Results. A total of 250 children with TB were identified. One hundred and sixty-two children had only pulmonary disease while 39 had features of both extrapulmonary and pulmonary TB. Mean age was 7.8 years. Thirty-six patients had known contacts. The index case/cases were first-degree relatives in 75%. Sixteen patients who were symptomless were yielded by contact investigation of newly identified TB cases. Tuberculin skin test positivity was 53.3%. Acid-fast bacilli smear positivity was 13.1%, and culture positivity was 18.7%. Twenty-six patients had histopathology of nonrespiratory specimens (lymph nodes and other tissues) showing granulomatous inflammation and caseous necrosis consistent with TB. Conclusions. Presence of contact history directed us to search for TB in children with nonspecific symptoms even if physical examinations were normal. Some children who were close contacts to TB cases were identified to have TB before development of symptoms.

HAX-1 deficiency: Characteristics of five cases including an asymptomatic patient.

BACKGROUND: Mutations in the HAX-1 gene cause an autosomal recessive form of severe congenital neutropenia (SCN), which particularly manifests with recurrent skin, lung and deep tissue infections from the first few months of life. OBJECTIVE: We retrospectively evaluated the clinical and laboratory findings of the patients diagnosed with SCN carrying HAX1 gene mutations. METHODS: A total of five patients with SCN, carrying a HAX1 gene mutation, were evaluated in terms of clinical and laboratory findings. Mutation analysis of the candidate genes (HAX1, ELANE and CSF3R) was performed. RESULTS: All of the patients lived in Turkey; four of them were of Kurdish origin and one was Turkish. Of the five patients, three were girls and two were boys, and the mean age of the patients was 8.8 years old (range 4-15 years). The mean age of diagnosis was 25.8 months (range 2 months-5 years). The infections diagnosed included recurrent gingivitis, stomatitis, and skin and soft tissue abscesses. Developmental retardation and epilepsy were present in only one patient, whereas speech retardation was present in two. All of our patients had a HAX1 mutation, and are still alive and none of them has shown malignant transformation yet. CONCLUSION: Complete blood count should be performed and absolute neutrophil count should be evaluated in patients with recurrent severe infections. In the event that neutropenia is detected, they should be investigated in terms of SCN and mutation analysis should be performed.

Coexistence of early onset sarcoidosis and partial interferon-γ receptor 1 deficiency.

Pediatric sarcoidosis comprises a spectrum of childhood granulomatous inflammatory conditions. Pathological hallmark of the disease is granuloma formation that is seen in the affected tissues and almost any organ or system can be involved. There are two forms of pediatric sarcoidosis. One is seen in older children and the clinical picture is very similar to that of adult sarcoidosis and the other one is seen in early childhood. Sarcoidosis in early childhood can be divided as Blau syndrome (familial form) and early onset sarcoidosis (sporadic form). In both of the diseases there is a defect in the NOD2/CARD15 gene. The typical triad of early onset sarcoidosis is polyarthritis, dermatitis and uveitis. Interferon-γ receptor 1 deficiency is caused by defects in the IFNγR1 gene and non-tuberculosis mycobacterial pathogens are the leading causes of infections that start in early childhood. Herein we report a patient who presented with the symptoms of early onset sarcoidosis and also had partial interferon-γ receptor 1 deficiency that presented with BCG-osis. In addition to anti-mycobacterial treatment, methotrexate and prednisolone were used in therapy.

The effect of montelukast on wheal reactions in skin prick tests: a double-blind-placebo-controlled randomized trial.

OBJECTIVE: It is well-known that number of drugs may interfere with wheal reactions in skin prick test. However, the effect of long-term use of montelukast, a cystenil leukotriene receptor antagonist, on skin prick test hasn't been full elucidated. The aim of present study was to demonstrate the effect of montelukast on skin prick tests (SPT). METHODS: This is a single-center, randomized, double-blinded, placebo-controlled study including two treatment periods with a wash-out interval. The subjects received montelukast (5 mg per day), fexofenadine HCl (60 mg per day) and placebo (lactose) with a double-blinded manner during 7- and 21-days treatment periods with a 14 days wash-out period. Dermatophagoides farinae (D. farinae) was used as the skin test material, while histamine as positive control and normal saline as negative control. Overall, 7 skin prick tests were performed at following time points: before treatment periods, on the last days of both treatment periods, 24 h after completion of treatment periods, and on the last day of 14-days interval. RESULTS: Sixty house dust mite (HDM) allergic children (23 girls and 37 boys) with allergic rhinitis and/or asthma completed the study. Mean age was 8.3 ± 2.0 years. In the fexofenadine group, a significant suppression was observed in post-treatment values when compared to baseline values in SPT with D. farinae (p = 0.019). In the montelukast group, no significant suppression was observed in SPT with D. farinae at all time points when compared to baseline. CONCLUSIONS: Our results showed that montelukast had no effect on measurements of SPT. Thus, we concluded that there is no need to discontinue the treatment in order to perform SPT in patients receiving montelukast, even in those on montelukast treatment for at least 21 days.

Children Hospitalized for Varicella: Complications and Cost Burden.

OBJECTIVE: To evaluate the direct medical cost of hospital admissions for patients with varicella (i.e., chickenpox) to assess the cost burden of varicella from a health care perspective for ultimate use in health economics studies in Turkey. METHODS: Records of children hospitalized with varicella at the Bakirkoy Maternity and Children's Hospital between November of 2006 and June of 2011 were reviewed. Reasons for hospitalization, types of varicella-associated complications, and direct medical cost of hospitalization were noted. Patients with underlying risk factors were excluded. Data obtained from one hospital were used to estimate the national cost of the disease. RESULTS: During the 4.5-year study period, 234 patients were hospitalized with varicella. Of these cases, 48 (20%) children previously ill with underlying cancers or chronic diseases were excluded from the study. Ultimately, 186 previously healthy children (age range: 14 days to 159 months, median age: 14 months) were included. The main reasons for hospitalization were complications related to varicella (79%), the most frequent of which was skin and soft tissue infections, followed by neurological complications and pneumonia. The median cost of hospitalization per patient was US $283, 50% of which was attributed to medication costs. The annual cost for varicella hospitalizations in Turkey was estimated at US $396,200. CONCLUSIONS: A significant number of healthy children are hospitalized for varicella and associated complications. Descriptions of these complications and their related costs provide important data for cost-effectiveness studies for decisions about the inclusion of the varicella vaccine in a childhood vaccination program.