Blaženka Grahovac

Severe neonatal neutropenia due to anti-human leucocyte antigen B49 alloimmunization only:a case report

Summary.  Alloimmune neonatal neutropenia (ANN) is a rare but potentially life‐threatening disorder of neonates. Demonstration of alloantibodies against granulocyte‐specific antigens shared by neonatal and paternal granulocytes in the maternal serum is essential in the diagnosis of ANN. In contrast to granulocyte‐specific alloantibodies, the significance of human leucocyte antigen (HLA) class I antibodies for ANN is still a matter of debate. We report on a case of severe isolated and prolonged neutropenia due to anti‐HLA B49 alloimmunization only. Immediately after birth, severe, isolated neutropenia was observed and lasted for up to 2 months. Results of serologic testing showed only anti‐HLA B49 antibodies in the maternal and neonates sera. HLA typing showed HLA class I (B49) incompatibility between the mother and the child. Granulocyte‐specific antibodies were not detected. Adsorption of the maternal serum with HLA B49‐bearing platelets removed serum reactivity with paternal neutrophils. Our results support the idea that certain HLA class I antibodies can induce ANN.

Hypervariable Region 1 of Hepatitis C Virus Genome and Response to Interferon Therapy

Abstract The relationship between the complexity of the hypervariable region 1 (HVR1) quasispecies of hepatitis C virus (HCV) and responsiveness to interferon-α (IFN) therapy was studied in patients with chronic hepatitis C. Twelve HCV-RNA-positive patients were treated daily with high dose IFN and ribavirin for 4 weeks, and then with IFN 3 MIU (Million International Units) TIW (three times per week) and ribavirin for 6 months. The HVR1 quasispecies complexity was analyzed by nested polymerase chain reaction-mediated single-strand conformation polymorphism (SSCP). The baseline HCV-RNA levels in the study group ranged from 106 to 107 copies/ml. All patients exhibited HCV genotype 1 b. Initial SSCP analysis revealed four (33.3%) patients with a low complexity pattern (SSCP bands ≤4) and eight (66.6%) patients with high complexity pattern (SSCP bands >4). After 4 weeks of IFN therapy, one patient became HCV negative, and among those remaining positive, the HCV-RNA levels decreased by 2 to 3 logs and the number of SSCP decreased by 2 to 3 bands per sample. After 6 months of IFN therapy, five (41.7%) patients became HCV-RNA-negative. Seven (58.3%) patients did not respond to IFN therapy with sustained viral load from 103 to 105 copies/ml, and high complexity SSCP patterns. Our data support the HVR quasispecies complexity to be an independent predictive factor for IFN responsiveness in patients infected with HCV.

T2001 Quasispecies Changes Detected in Hypervariable Region 1 of Hepatitis C Genome With High-Resolution DNA Melting Analysis in Treated and Untreated Chronic Hepatitis C Patients

HCV exists in an individual as pool of closely related but genetically distinct variants. Development of resistant variants can be the reason of treatment failure. Aim of this study was to determine the changes in HCV quasispecies in region susceptible for mutations. Quasispecies were detected by new method, highresolution DNA melting analysis, in hypervariable region-1 at two points: 1. forty untreated patients: at baseline and after 6 months ; 2. sixty-nine treated patients: at baseline and at the end of treatment. Second sample was collected for all untreated and for 24 treated patients (45 had ETVR). For each sample result was shown as melting curve with 4 parameters: Tm (melting temperature), H (high), W (wide) and A (area). The most common genotype was 1 in both groups (57.5% in untreated and 83.3% in treated). Obtained baseline Tm was statistically significantly correlated with genotype obtained with commercial kits (p = 0.05). No significance was found for other baseline parameters. No statistical significances have been found in Tm, H, W and A for untreated and treated patients between paired samples but medians have changed in both groups (table 1 and 2).Trend of changes differed between groups, in untreated patients W and H raised while in treated declined. Without treatment, quasispecies become more heterogeneous while therapy makes them more homogeneous, towards resistant variants. Since no significant changes have been found in Tm it might be concluded that all observed changesdeveloped between same genotype at baseline.

Viral kinetic study of induction dosing with interferon alpha and ribavirin in the treatment of chronic hepatitis C

Viral kinetic study of induction dosing with interferon alpha and ribavirin in the treatment of chronic hepatitis C