First-line Anti-GD2 Therapy Combined With Consolidation Chemotherapy in 3 Patients With Newly Diagnosed Metastatic Ewing Sarcoma or Ewing-like Sarcoma.

Despite multimodal therapy, the prognosis of patients with metastatic Ewing sarcoma (ES) remains poor, with new treatments urgently needed. The disialoganglioside GD2, a well-established tumor-associated antigen, is expressed in 40% to 90% of ES cells, making it a suitable therapeutic target. Here we report 3 cases with newly diagnosed, metastatic, GD2-positive ES or Ewing-like sarcoma treated with the anti-GD2 antibody dinutuximab beta in addition to standard chemotherapeutic regimens. Treatment was well-tolerated, and all patients achieved complete remission, without evidence of relapse. First-line anti-GD2 immunotherapy in patients with metastatic, GD2-positive ES or Ewing-like sarcoma represents a promising therapeutic option that warrants further clinical evaluation.

Congenital Cytomegalovirus Infection - Lessons from a Clinical Case.

BACKGROUND: Cytomegalovirus (CMV) is a worldwide spread herpes virus that establishes a latent infection after the primary infection. It becomes a major problem in immunocompromised patients and in cases of primary or reactivated infection during pregnancy. CMV is the most common congenital infection and is the leading infectious cause of sensoneural deafness and cerebral mental retardation. AIM: Тo raise the attention to the discordance in our knowledge of cCMV infection and the implementation of the knowledge in prac-tice. MATERIALS AND METHODS: CMV-DNA was extracted from saliva and plasma samples according to the protocol of DNA-Sorb-A, Sacace, Biotechnologies, Italy. Polymerase chain reaction (PCR) was performed using a commercial kit based on the Taq-man principle: Quantitative RT-PCR for CMV-DNA detection (Sacace, Biotechnologies, Italy). The linear range of the CMV Real-TM Quant PCR test is 500-10000000 copies/ml, and the reported sensitivity is 400 copies/ml. RESULTS: The infant was born with clinical manifestations involving development of hepatosplenomegaly, chorioretinitis, anemia, mi-crocephaly and simultaneous dilatation of the brain ventricles. CMV infection was confirmed using modern PCR studies. CONCLUSIONS: This case highlights the need for specific virological/PCR tests to be performed for all children with the least suspected congenital infection, especially when there is an option of a specific treatment.

Detection of EBV DNA in Non-Hodgkin Lymphoma Patients in Bulgaria.

Epstein-Barr virus is the first human oncogenic virus associated with a broad range of different malignant diseases but its role in non-Hodgkin lymphomas (NHL) development still needs to be fully understood. High expression levels of EBV major genes are found in NHL tumor cells and free viral DNA circulates in the plasma of such individuals. In the current study we detected EBV DNA levels in plasma samples from NHL patients in order to validate its significance as a laboratory marker for disease monitoring. We investigated a cohort of 52 patients diagnosed with NHL in The University Hospital "St. Marina" Varna, Bulgaria. Viral DNA was extracted from single plasma samples using Kit Ribo Virus (Sacace Biotechnologies S.r.l., Como, Italy) and amplified with EBV Real-TM Quant (Sacace Biotechnologies S.r.l., Como, Italy). Plasma samples of the same patients were tested for presence of EBV VCA IgM/IgG antibodies with indirect ELISA tests (Euroimmun, Luebeck, Germany). We found 15.4% (95% CI 6.9-28.1%, n = 8) of the samples from NHL patients to be positive in quantitative PCR (range 674-221,333 copies/ml). The diffuse large B cell lymphomas and peripheral T cell lymphomas were most often associated (although not statistically significant, p = 0.167) with detectable plasma EBV DNA levels. To our knowledge, this is the first study about the role of EBV in NHL development in Bulgaria. The results we have obtained should stimulate new, larger investigations to apply the quantitative PCR technique in the routine laboratory EBV diagnosis.

Evaluation of Anti-HBs Antibody Immune Response against Hepatitis B virus in Vaccinated People in a North-eastern Bulgaria Region.

INTRODUCTION: Hepatitis B virus (HBV) is one of the most significant human pathogens responsible for a huge number of acute and chronic liver infectious diseases worldwide. AIM: To find the duration of post-vaccination immune response in individuals allocated to five age groups from 6 months to 20 years. MATERIALS AND METHODS: All tested subjects were born between 1999 and 2018 and therefore covered by the compulsory vaccination program against hepatitis B. For the serological marker anti-HBs Ab we investigated 449 serum samples taken from ambulatory people and patients of St Marina University Hospital in Varna. RESULTS: A positive antibody response (anti-HBs Ab > 10 mIU/ml) was reported in 79.7% (n = 51) of the group of subjects up to one year old, in 70.0% (n = 196) of the subjects in the age range 1 year/1 month to 15 years, and in 39.3% (n = 33) of the subjects 15 years/1 month to 20 years old. Female sex had a better post-vaccination response than male sex with statistically significant relationship between sex and anti-HBs Ab titer (χ2 = 24.76, p <0.01). CONCLUSIONS: Regardless of the mass immunization against HBV in Bulgaria, the relative share of chronic HBV infections does not show a downward trend. Therefore, it is very important to study the duration of the post-vaccination immune response by demonstrating the anti-HBs antibodies and to apply a booster dose from the vaccine if needed.

Treatment of Childhood Acute Myeloid Leukemia in Bulgaria.

BACKGROUND: During the last four decades the prognosis of childhood acute myeloid leukemia (AML) has been substantially improved due to an increase in complete remission (CR) rates, event-free survival (EFS) and reduced early mortality. The relapsed AML still remains a therapeutic challenge. AIM: To report the AML treatment results of the Bulgarian pediatric oncohematological centers. MATERIALS AND METHODS: Retrospective analysis of the treatment results of children and adolescents (age from 0 to 20 years) with primary AML. Unified AML BFM- backbone type treatment protocol is used. RESULTS: This study included 97 newly diagnosed patients (44 girls and 53 boys) with AML in Bulgaria between 2003 and 2016. The median age at diagnosis was 10.2 years. The most frequent FAB-morphologic subtype was M2 followed by M4. First complete remission (CR1) was achieved in 83 patients (85.6%). The 13-year EFS was 49%, while the overall survival (OS) was 54.6%. Twenty seven (27.8%) patients relapsed, with only 5 of them being still alive towards the end of the study period. CONCLUSION: The EFS and OS for the children with AML in Bulgaria are comparable with those reported by other European groups. The prognosis of relapsed AML remains still unfavorable for the past 13 years.