Incidence of bacterial and fungal infections in Polish pediatric patients with acute lymphoblastic leukemia during the pandemic

The most common complications related to the treatment of childhood acute lymphoblastic leukemia (ALL) are infections. The aim of the study was to analyze the incidence and mortality rates among pediatric patients with ALL who were treated in 17 Polish pediatric hematology centers in 2020-2021 during the pandemic. Additionally, we compared these results with those of our previous study, which we conducted in the years 2012-2017. The retrospective analysis included 460 patients aged 1-18 years with newly diagnosed ALL. In our study, 361/460 (78.5%) children were reported to have microbiologically documented bacterial infections during chemotherapy. Ten patients (2.8%) died due to sepsis. Fungal infections were reported in 99 children (21.5%), of whom five (5.1%) died due to the infection. We especially observed an increase in bacterial infections during the pandemic period compared to the previous study. The directions of our actions should be to consider antibiotic prophylaxis, shorten the duration of hospitalization, and educate parents and medical staff about complications (mainly infections) during anticancer therapy. It is necessary to continue clinical studies evaluating infection prophylaxis to improve outcomes in childhood ALL patients.

Characteristics and Outcome of FLT3-ITD-Positive Pediatric Acute Myeloid Leukemia-Experience of Polish Pediatric Leukemia and Lymphoma Study Group from 2005 to 2022

BACKGROUND

The FMS-like tyrosine kinase 3 (FLT3) gene mutated in 10-15% of pediatric acute myeloid leukemia (AML) is associated with an inferior outcome. The aim of the study was to analyze the outcome and characteristics of FLT3-ITD-positive pediatric AML.

METHODS

We retrospectively analyzed the nationwide pediatric AML database from between 2005 and 2022. FLT3-ITD was found in 54/497 (10.7%) patients with available analysis. Three consecutive treatment protocols were used (AML-BFM 2004 Interim, AML-BFM 2012 Registry, AML-BFM 2019 recommendations).

RESULTS

Probabilities of 5-year overall (OS), event-free (EFS) and relapse-free survival were significantly lower in the FLT3-ITD-positive patients compared to FLT3-ITD-negative (0.54 vs. 0.71, p = 0.041; 0.36 vs. 0.59, p = 0.0004; 0.47 vs. 0.70, p = 0.0029, accordingly). An improvement in the outcome was found in the analyzed period of time, with a trend of better survival in patients treated under the AML-BFM 2012 and AML-BFM 2019 protocols compared to the AML-BFM 2004 protocol (5-year EFS 0.52 vs. 0.27, p = 0.069). There was a trend of improved outcomes in patients treated with FLT3 inhibitors (n = 9, 2-year EFS 0.67 vs. 0.33, p = 0.053) and those who received stem cell transplantation (SCT) (n = 26; 5-year EFS 0.70 vs. 0.27, p = 0.059). The co-occurrence of the WT1 mutation had a dismal impact on the prognosis (5-year EFS 0.23 vs. 0.69, p = 0.002), while the NPM1 mutation improved survival (5-year OS 1.0 vs. 0.44, p = 0.036).

CONCLUSIONS

It seems that SCT and FLT3 inhibitors have a beneficial impact on the prognosis. Additional genetic alterations, like the WT1 and NPM1 mutations, significantly influence the outcome.

Viral Infection Profile in Children Treated for Acute Lymphoblastic Leukemia—Results of Nationwide Study

Viral infections can be a serious complication of therapy in children with acute lymphoblastic leukemia (ALL). In this study, we focused on the incidence and the profile of viral infection in children with ALL treated in 17 pediatric oncology centers in Poland in the two-year periods of 2018–2019 and 2020–2021. We also compared the frequency of viral infections in 2018–2019 to that in 2020–2021. In 2020–2021, a total of 192 children with ALL had a viral infection during intensive chemotherapy. A total number of 312 episodes of viral infections were diagnosed. The most common infections detected in the samples were: COVID-19 (23%), rhinovirus (18%), and respiratory syncytial virus (14%). COVID-19 and BK virus infections were the reason for the death 1% of all patients. In 2018–2019, a total of 53 ALL patients who had a viral infection were reported and 72 viral events were observed, mainly adenovirus (48.6%), rotavirus (31.9%), and herpes zoster (8.3%). No deaths were reported during this period. The cumulative incidence of viral infections in 2018–2019 was 10.4%, while for 2020–2021, it was 36.7%. In conclusion, a high incidence of COVID-19 infection was observed among pediatric patients with ALL in Poland. The mortality rate in our material was low. The viral profile in ALL children undergoing chemotherapy can be useful for clinicians to improve prophylactic and therapeutic strategies.

Concentrations of Insulin-like Growth Factors and Insulin-like Growth Factor-Binding Proteins and Respective Gene Expressions in Children before and after Hematopoietic Stem Cell Transplantation

Insulin-like growth factors (IGF-1 and IGF-2) and insulin-like growth factor-binding proteins (IGFBP-1 to -7) are involved in the regulation of cell proliferation and differentiation and may be associated with various metabolic parameters. The aim of our study was to compare levels of IGFs and IGFBPs and the expressions of their genes in children before and after hematopoietic stem cell transplantation (HSCT) to assess their potential as markers of late metabolic complications of HSCT. We also conducted additional comparisons with healthy controls and of correlations of IGF and IGFBP levels with anthropometric and biochemical parameters. We analyzed 19 children treated with HSCT and 21 healthy controls. We found no significant differences in the levels of IGFs and IGFBPs and expressions of their genes before and after HSCT, while IGF and IGFBP levels were significantly lower in children treated with HSCT compared with controls. We conclude that our results did not reveal significant differences between the levels of IGFs and IGFBPs before and after HSCT, which would make them obvious candidates for markers of late complications of the procedure in children. However, due to the very low number of patients this conclusion must be taken with caution and may be altered by further research.

Advances in the First Line Treatment of Pediatric Acute Myeloid Leukemia in the Polish Pediatric Leukemia and Lymphoma Study Group from 1983 to 2019

Simple Summary

We retrospectively analyzed the results of the five consecutive treatment protocols for pediatric acute myeloid leukemia (AML) used in Poland from 1983 to 2019 (excluding promyelocytic, secondary, biphenotypic, and Down syndrome AML). The study included 899 children. The probability of three-year overall, event-free, and relapse-free survival increased from 0.34 ± 0.03 to 0.75 ± 0.05, 0.31 ± 0.03 to 0.67 ± 0.05, and 0.52 ± 0.03 to 0.78 ± 0.05, respectively. A systematic reduction of early deaths and deaths in remission was achieved, while the percentage of relapses decreased only in the last therapeutic period. Surprisingly good results were obtained in the group of patients with unfavorable genetic abnormalities like KMT2A-MLLT10/t(10;11)(p12;q23) and DEK-NUP214/t(6;9)(p23;q24) who were treated in the AML-BFM 2012 Registry, while an unsatisfactory outcome was found in patients with FLT3-ITD. The use of standardized therapeutic protocols with the successive consideration of genetic prognostic factors and advances in supportive care led to a significant improvement in AML treatment outcomes over the last 40 years.

Abstract

Background: From 1983, standardized therapeutic protocols for pediatric acute myeloid leukemia (AML) based on the BFM group experience were introduced in Poland. We retrospectively analyzed the results of pediatric AML treatment in Poland from 1983 to 2019 (excluding promyelocytic, therapy-related, biphenotypic, and Down syndrome AML). Methods: The study included 899 children suffering from AML treated with the following: AML-PPPLBC 83 (1983–1993, n = 187), AML-PPGLBC 94 (1994–1997, n = 74), AML-PPGLBC 98 (1998–2004, n = 151), AML-BFM 2004 Interim (2004–2015, n = 356), and AML-BFM 2012 (2015–2019, n = 131). Results: The probability of three-year overall survival was 0.34 ± 0.03, 0.37 ± 0.05, 0.54 ± 0.04, 0.67 ± 0.03, and 0.75 ± 0.05; event-free survival was 0.31 ± 0.03, 0.34 ± 0.05, 0.44 ± 0.04, 0.53 ± 0.03, and 0.67 ± 0.05; and relapse-free survival was 0.52 ± 0.03, 0.65 ± 0.05, 0.58 ± 0.04, 0.66 ± 0.03, and 0.78 ± 0.05, respectively, in the subsequent periods. A systematic reduction of early deaths and deaths in remission was achieved, while the percentage of relapses decreased only in the last therapeutic period. Surprisingly good results were obtained in the group of patients treated with AML-BFM 2012 with unfavorable genetic abnormalities like KMT2A-MLLT10/t(10;11)(p12;q23) and DEK-NUP214/t(6;9)(p23;q24), while unsatisfactory outcomes were found in the patients with FLT3-ITD. Conclusions: The use of standardized, systematically modified therapeutic protocols, with the successive consideration of genetic prognostic factors, and advances in supportive care led to a significant improvement in AML treatment outcomes over the last 40 years.

The Expression of Genes Related to Lipid Metabolism and Metabolic Disorders in Children before and after Hematopoietic Stem Cell Transplantation-A Prospective Observational Study

Metabolic disorders in children after hematopoietic stem cell transplantation (HSCT) are poorly characterized. However, it is known that dyslipidemia and insulin resistance are particularly common in these patients. We conducted a prospective study of 27 patients treated with HSCT to assess the possibility of predicting these abnormalities. We measured gene expressions using a microarray technique to identify differences in expression of genes associated with lipid metabolism before and after HSCT. In patients treated with HSCT, total cholesterol levels were significantly higher after the procedure compared with the values before HSCT. Microarray analysis revealed statistically significant differences in expressions of three genes, DPP4, PLAG1, and SCD, after applying the Benjamini-Hochberg procedure (pBH < 0.05). In multiple logistic regression, the increase of DPP4 gene expression before HCST (as well as its change between pre- and post-HSCT status) was associated with dyslipidemia. In children treated with HSCT, the burden of lipid disorders in short-term follow-up seems to be lower than before the procedure. The expression pattern of DPP4 is linked with dyslipidemia after the transplantation.

Methylation and Expression of FTO and PLAG1 Genes in Childhood Obesity: Insight into Anthropometric Parameters and Glucose-Lipid Metabolism

The occurrence of childhood obesity is influenced by both genetic and epigenetic factors. FTO (FTO alpha-ketoglutarate dependent dioxygenase) is a gene of well-established connection with adiposity, while a protooncogene PLAG1 (PLAG1 zinc finger) has been only recently linked to this condition. We performed a cross-sectional study on a cohort of 16 obese (aged 6.6-17.7) and 10 healthy (aged 11.4-16.9) children. The aim was to evaluate the relationship between methylation and expression of the aforementioned genes and the presence of obesity as well as alterations in anthropometric measurements (including waist circumference (WC), body fat (BF_kg) and body fat percent (BF_%)), metabolic parameters (lipid profile, blood glucose and insulin levels, presence of insulin resistance) and blood pressure. Expression and methylation were measured in peripheral blood mononuclear cells using a microarray technique and a method based on restriction enzymes, respectively. Multiple regression models were constructed to adjust for the possible influence of age and sex on the investigated associations. We showed significantly increased expression of the FTO gene in obese children and in patients with documented insulin resistance. Higher FTO expression was also associated with an increase in WC, BF_kg, and BF_% as well as higher fasting concentration of free fatty acids (FFA). FTO methylation correlated positively with WC and BF_kg. Increase in PLAG1 expression was associated with higher BF%. Our results indicate that the FTO gene is likely to play an important role in the development of childhood adiposity together with coexisting impairment of glucose-lipid metabolism.

Ultrasound imaging as the basis of a clinical diagnosis of systemic bartonellosis in a patient after bone marrow transplantation. A case report

Infections in immunocompromised patients after hematopoietic stem cell transplantation can have a severe and atypical course. Some opportunistic pathogens are difficult to detect in microbiological tests, and that is why treatment success depends on an accurate clinical diagnosis. This article presents a case of a 7-year-old girl with severe aplastic anemia treated with bone marrow transplantation with post-transplantation period complicated by persistent, hectic fever, with peak episodes of 39–40°C, lasting several weeks. Repeated microbiological tests failed to reveal the etiological agent, and empirical anti-infective treatment was ineffective. In the fourth week of fever, imaging showed multiple foci resembling abscesses in the patient's internal organs and, subsequently, in soft tissues. The characteristics of these changes and data concerning environmental exposure led to the clinical diagnosis of cat scratch disease (bartonellosis) with multi-organ involvement and enabled the targeted treatment to be implemented. Fever subsided and organ lesions regressed. In this case, repeated ultrasound imaging was the basic diagnostic tool that helped arrive at a correct diagnosis and implement effective treatment of this life-threatening complication after hematopoietic stem cell transplantation.

Status of immunity for vaccine--preventable diseases in children after hematopoietic stem cells transplantation

INTRODUCTION

patients treated with hematopoietic stem cell transplantation (HSCT) lose immune memory accumulated through a lifetime. They are at increased risk of developing infections with microorganisms such as Haemophilus influenza, Streptococcus pneumoniae and others for which vaccines are available. Therefore, all patients after HSCT should be routinely revaccinated. Systemic reimmunization after HSCT is a relatively neglected area especially in countries which have not national recommendations and there is lack of systemic regulations in health care system.

OBJECTIVE

the rate of immunization before transplantation and the persistence of vaccine-specific antibodies after HSCT was assessed.

STUDY DESIGN

a group of38 children after stem cell transplantation (19 autologous, 19 allogeneic) was studied.

RESULTS

only a few patients completed standard vaccination protocol before HSCT. At the median time of 29 (range: 6-67) months after autologous and 13 (range: 8-33) months after allogeneic HSCT, when the revaccination was commenced, the majority of children had concentration of antibody lower than the minimum protective thresholds. That was 82% for tetanus, 71% for Hib and varicella, 46% for HBV and 38% for diphtheria.

CONCLUSIONS

all HSCT recipients should be routinely revaccinated to stimulate the immunity to the vaccine-preventable diseases.

Allogeneic haematopoietic stem cell transplantation as therapy for chronic granulomatous disease--single centre experience

Chronic granulomatous disease (CGD) is phagocytic cell metabolic disorder resulting in recurrent infections and granuloma formation. This paper reports the favourable outcome of allogeneic transplantation in six high-risk CGD patients. The following donors were used: HLA-matched, related (two) and unrelated (three), and HLA-mismatched, unrelated (one). One patient was transplanted twice using the same sibling donor because of graft rejection at 6 months after reduced-intensity conditioning transplant (fludarabine and melphalan). Myeloablative conditioning regimen consisted of busulphan and cyclophosphamide. Stem cell source was unmanipulated bone marrow containing: 5.2 (2.6-6.5) × 10(8) nucleated cells, 3.8 (2.0-8.0) × 10(6) CD34+ cells and 45 (27-64) × 10(6) CD3+ cells per kilogramme. Graft-versus-host disease prophylaxis consisted of cyclosporine A and, for unrelated donors, short course of methotrexate and anti-T-lymphocyte globulin. Mean neutrophile and platelet engraftments were observed at day 22 (20-23) and day 20 (16-29), respectively. Pre-existing infections and inflammatory granulomas resolved. With the follow-up of 4-35 months (mean, 20 months), all patients are alive and well with full donor chimerism and normalized superoxide production.

[Mobilization and collection of hematopoietic stem cells in children with different neoplastic diseases for autotransplantation to support high dose chemotherapy (single centre experience)]

Currently, granulocyte colony stimulating factor (G-CSF) alone or in combination with myelosuppresive chemotherapy remain the standards of CD34+ cells mobilization allows the safe and successful collection of adequate peripheral blood stem cells (PBSC) for autologous transplantation. However, in up to 30% of patients mobilization of PBSC is ineffective. This report presents our experience in mobilization and collection of peripheral blood stem cells in 82 children with different proliferative disease. In mobilization G-CSF was administered alone in steady state (56 patients, pts) or in combination with myelosuppresive chemotherapy (26 pts). The CD34+ cell count at least 10 cells/ml was required to start apheresis procedure, which was repeated, if needed, during following 1-4 days until collection of at least 2 (optimally 3) x106 CD34+ cells/kg b.w. of recipient was obtained. Three pts in each group (3/ 56 and 3/26) failed the first course of mobilization. The median number of CD34+ cells mobilized was 4.8 (0.5-15) x106/kg b.w. The minimal and optimal number of CD34+ cells for transplantation was achieved in 85% and 61% of patients in the G-CSF + chemotherapy group and in 84% and 54% in the G-CSF group, respectively. The efficacy of presented mobilization arms in our group was similar. However, the incidence of infection and total hospitalization time during mobilization were higher in chemotherapy + G-CSF group.

[Can brain-machine interface improve quality of life of patients with chronic motor dysfunction?]

In departments of neurology, neurosurgery and hospice care there is a group of patients with compete motor function impairment having normal central nervous system function. Victims of spinal cord injury, cerebral palsy, cerebral stroke, loss of extremities, neuromuscular diseases, between others belong to them. Since two decades an intensive studies of use of brain waves to steer peripheral equipments has been performed. Brain Computer Interface and Brain-Machine Interface will allow in the near future for even partial restore of skills in permanently disabled patients. Recently new sets composed of games steered by brain waves have been introduced to the market. Exercises with such equipment will help to control an ability to concentrate and precise steer of the peripheral electronic equipments. The next phase will be use of the new skills to steer the wheelchairs and other computer programs with the brain signals to control own healthy organs or artificial machines.

[Evaluation of colonization by multidrug-resistant organisms and infections' frequency in chronically and incurably ill children under care of the Cracow children's Hospice of Father J. Tischner]

Infections are one of the most important clinical problem and most frequent cause of interventions among chronically ill children under hospice care. Frequent and long-lasting hospitalizations before admission to the hospice cause patients' colonization with nosocomial pathogens. These pathogens usually cause returning infections, difficult to cure in home care. The aim of the study was evaluation of colonization by multidrug-resistant organisms and infections' frequency in chronically and incurably ill children under care of the Cracow Children's Hospice of Father J. Tischner. We analyzed infections in patients of the Hospice in 2008-2009. Frequency of infections, their localization, pathogens and necessity of hospitalization were evaluated. On the basis of microbiological examination we distinguished infections caused by multidrug resistant pathogens. Ninety microbiological examination were made in 24 children. Urine, stool, pharyngeal and nasal swap and others were examined. Nosocomial pathogens including Gram-negative rods with ESBL phenotype, Gram-positive Enterococci with HLAR phenotype and Staphylococci with MRCNS and MRSA phenotype were isolated in 36 (40%) examinations, in 17 (71%) patients. Frequency of infections was higher in patients colonized by nosocomial pathogens in comparison with patients without colonization, but difference was not statistically important. There are many factors that increase risk of infections and make them difficult to treat, like: immobilization, impaired swallowing and coughing reflexes, thorax deformation, neurogenic bladder, tracheostomy. Multi-drug resistant pathogens are additional risk factor that can lead to the necessity of hospitalization. In chronically and incurably ill patients time of hospitalization should be minimized to reduce the risk of colonization with multi-drug resistant pathogens.

[Safety and efficacy of vaccination in children after stem cell transplantation. Part 1]

The aim of the study was the evaluation of safety and efficacy of vaccination in children after stem cell transplantation.

PATIENTS AND METHODS

21 patients, 1.4-22 (average 7.8) years old, 13 boys and 8 girls after autologous (11-52%) and allogeneic (10-48%) transplantation were included in the vaccination protocol. Indications for transplantation were: neoplastic disease--16, immunodeficiencies--3 and aplastic anaemia 2 cases. Time between transplantation and beginning of vaccination protocol was 0.8-4 (average 1.5) years. Vaccination protocol was constructed on the basis of the European Group for Blood and Marrow Transplantation indications. We have evaluated: (1) quality of recipient immune reconstitution and protection against common pathogens (2) immunogenicity of revaccination schedule; (3) safety of the vaccination programme.

RESULTS

With the exception of one patient presenting with repeated fever, lymph node enlargement, muscle and joint pain, no important side effects were observed. Meningococcial meningitis developed in one patient who refused vaccination. The mean concentrations of antibodies in the plasma before and after vaccination were as follows: anti-diphteria (54; 2285), anti-tetanus (136; 3149) and anti-hepatitis B virus (anti-HBs: 24; 474) IU/ml.

CONCLUSIONS

(1) Vaccination in patients after transplantation is efficient and well tolerated. (2) Significant increase of antibody level was detected. (3) Any delay in beginning the vaccination can result in life threatening complications.

[An economic consideration of the lower respiratory tract infection treatment in children with severe neurodegradative diseases under the hospice care]

Congenital and acquired neurodegradative diseases are always the reason for prolonged stay in hospital, at the beginning of the establishment of diagnosis and treatment and afterwards for stabilizing all functional adaptation to an existence with the severe disability. Also infections of the lower respiratory tract accompanying the later course of the disease are usually directed to hospital treatment. The aim of the study was to delineate the role of hospice care of patients staying at home, in economical approach to the medical care of severly and incurably ill children. The study group consisted of 29 children with neurodegradative diseases, aged 6 months to 18 years, admitted to the home care of Priest Józef Tischner Cracovian Children' Hospice. The costs of yearly treatment (based on 2008 data) of the infections of the lower airways in the studied group, performed at home under the hospice care and in hospital, were compared. The actual expenses of home treatment were counted. Considering the hospital therapy costs, the simulation was performed following median expenses of a 10-day-treatment of a 20 kg-in-weight child with uncomplicated lower respiratory tract infection in pediatric department with the use of the first line therapy antibiotic. Three parameters were taken to calculations: the medical care costs, the expenses of laboratory tests and X-ray pictures and the costs of antibiotics. In studied children 61 cases of lower respiratory tract infections were diagnosed in 2008 (the median incidence was 2,1 per year; ranged 0-7), of which 48 cases were treated at home. The median time of antibiotics administration in home treatment was 13 days. In 31% of infections more than one antibiotic was used. In 19% of cases in home therapy parenteral medicine was necessary. The median summarized cost of treat- ment at home was calculated as 2657 zl. The need for hospital care in our group concerned 13 incidences. The median estimated cost of treatment of the lower airways infection in hospital for one child equaled 4942 zl. The expenses of home treatment of the lower airways infections under the hospice care were twice lower than the costs of the therapy in hospital. Apart from the obvious psychological and social benefits, also economic aspect contributes to the promotion of the hospice care of staying-at-home patient in the improvement of medical care for children with severe neurodegradative diseases.

[Hemophagocytic syndrome: diagnostic problems]

Hemophagocytic syndrome (HS) is a rare but life-threatening disease caused by inappropriate activation of T-lymphocytes and histiocytes, hipercytokinemia and hemophagocytosis. The most common symptoms are fever, hepatosplenomegaly, unspecific neurological abnormalities, pancytopenia, coagulopathy, hiperferritinemia and lipid abnormalities. HS is classified into two forms: primary, inherited (Familial Hamophagocytic Lymphohistiocytosis--FHL) and secondary (associated with infection, malignancy, autoimmune disease). In spite of the fact that diagnostic guidelines are available it often remains unrecognised. Prognosis of HS depends on the form of disease and in case of secondary HS on the underlying disease. Development of the treatment protocols (HLH-94, HLH-2004) which combine immunochemiotherapy with hematopoietic stem cell transplantation has strongly improved prognosis in HS especially in the primary form. Three-year overall survival for children with HS is now over 50%. Early diagnosis and appropriate therapy is crucial for effectiveness of the treatment. Popularisation of the knowledge about the syndrome, diagnostic guidelines and treatment protocols can contribute to more frequent appropriate recognition of HS and to improvement of the treatment results.

[The assessment of efficacy of hepatitis B prophylaxis in children with acute lymphoblastic leukemia]

The aim of the study was to evaluate the efficacy of hepatitis B prophylaxis in children with acute lymphoblastic leukemia (ALL) and to try to determine the optimal procedure of protection against the infection. The retrospective analysis included 229 patients with ALL divided into three groups depending on the type of anti-HBV prophylaxis. The group 1 (1990-91, 38 patients) received only sporadically passive prophylaxis, in the group 2 (1992-94, 55 patients) passive prophylaxis was regular, and the patients of the group 3 (1995-2001, 138 children) received complete active and passive prophylaxis. Among vaccinated children three subgroups were additionally distinguished: subgroup a--vaccination was completed before the disease, subgroup b--the cycle of vaccination began before and continued during the therapy, subgroup c--the whole cycle of vaccination was performed during the ALL treatment. The efficacy of the prophylaxis was evaluated taking into account the incidence of hepatitis B and the level of anti-HBs antibodies in vaccinated children. Additionally the incidence of hepatitis C was assessed to evaluate the role of unspecific prophylaxis. The incidence of hepatitis B in the group 1, 2, and 3 was: 57.9%, 23.6%, and 0.76%, respectively, and the incidence of hepatitis C: 44.7%, 36.4%, and 5.9%, respectively. The percent of the failure of active prophylaxis in the subgroup a, b, and c was: 29%, 53%, and 93%, respectively. In spite of the reduction of exposure to the infection (unspecific prophylaxis), the role of specific prophylaxis is essential. The program of passive and active prophylaxis used by us is efficient in preventing hepatitis B in children with ALL. However, during the intensive chemotherapy only passive prophylaxis should be used with postponement of the vaccination because of very low response to the vaccination applied in this phase of treatment. Regular control of anti-HBs antibodies' level is essential in all patients with leukemia even in those with initially high level of antibodies.

A search for association between hereditary hemochromatosis HFE gene mutations and type 2 diabetes mellitus in a Polish population

BACKGROUND

Hereditary hemochromatosis (HH) is characterized by excess iron deposition. Two mutations in the HFE gene are associated with HH. Heterozygous carriers of HFE mutations are at higher risk of developing type 2 diabetes mellitus (T2DM). The aims of our project were to identify the frequency of C282Y and H63D mutations in a population from the Małopolska region of south-eastern Poland, and to search for an association of HFE mutations with T2DM.

MATERIAL/METHODS

We included 391 individuals in this study: 222 T2DM patients and 169 controls. Genotypes were determined by electrophoresis of the DNA digestion products from SnaBI and DpnII, respectively. Differences in distributions between the groups were then analyzed by the chi-squared test.

RESULTS

The frequency of wild/C282Y alleles was 98.2%/1.8% in T2DM patients and 96.7%/3.2% in controls (p=0.19). The frequency of wild/H63D alleles was 85.6%/14.4% and 88.8%/11.2% (p= 0.19), respectively. The distribution of genotypes was not statistically different. However, in stratified analyses based on age of T2DM onset and gender, we observed a higher prevalence of wild/H63D and H63D/H63D genotypes among T2DM patients diagnosed at > 49 years of age, the mean age for the entire group (p=0.018), and among male T2DM individuals (p=0.005) than in controls.

CONCLUSIONS

The frequency of HH-associated mutations in this population from south-eastern Poland is similar to other Caucasians. We found no evidence for the association of the C282Y mutation with T2DM. The results do suggest, however, that the H63D mutation may play a role in the pathogenesis of late onset T2DM and in males in this Polish population.