Mutations in Pol gene of hepatitis B virus in patients with chronic hepatitis B before and after therapy with nucleoside/nucleotide analogues.

Chronic hepatitis B (CHB) is one of the most common infections worldwide. Currently approved treatments of CHB include nucleoside/nucleotide analogues (NAs). However, long-term NA therapy is associated with accumulation of resistant mutations within the hepatitis B virus (HBV) polymerase gene. The incidence of naturally occurring HBV mutations leading to primary antiviral resistance has not been fully elucidated yet. The objective of present study was to detect the frequency of mutations within the HBV polymerase gene in 263 patients naïve to nucleoside/nucleotide analogues. Prevalence of HBV Pol gene mutations secondary to NA treatment in patients without pre-existing antiviral resistance mutations was also examined. Retrospective analysis showed that HBV Pol gene mutations were present in 7 out of 263 patients prior to the treatment. Mutations observed in NA-naïve CHB patients were associated only with resistance to lamivudine and adefovir. Compensatory mutations were observed as well. In the course of antiviral treatment, HBV Pol gene mutations were identified in 65 out of the remaining 256 CHB patients (25.39%), while no mutations of any type were detected in 160 patients (62.5%). The profiles of detected mutations were comparable to those observed in other studies that focused on the analysis of clinically relevant NA-resistant mutations. In conclusion, we found out that antiviral resistance mutations may pre-exist in the overall viral population present in untreated patients, although the incidence of HBV Pol gene mutations in NA-naïve CHB patients was low and reached only up to 2.66%. However, possible circulation and transmission of NAs-resistant HBV mutants in human population should be taken into account.

PTPN22, PDCD1 and CYP27B1 polymorphisms and susceptibility to type 1 diabetes in Polish patients.

Type 1 diabetes (T1DM) is a common autoimmune disease with a complex genetic background. This study was aimed to investigate the association of PTPN22 G(-1123)C and C1858T, PDCD1 G7146A and CYP27B1 C(-1260)A polymorphisms with T1DM among Polish subjects. The PTPN22 gene encodes lymphoid tyrosine phosphatase, a potent negative regulator of T cell activation. PDCD1 gene gives rise to an inhibitory cell-surface receptor, expressed on activated lymphocytes. CYP27B1 encodes 1-alpha hydroxylase, responsible for conversion of the vitamin D(3) precursor into its active form, involved in the immune function. Polymorphic variants of these genes have previously been associated with various autoimmune disorders. The four polymorphisms were genotyped by PCR-restriction fragment assays in a case-control study comprising 215 T1DM patients and 236 healthy controls. The PTPN22 T1858 allele appeared significantly increased in T1DM compared to the control group (P=0.004), yielding an OR of 1.73 (95% CI 1.19-2.51). The difference in distribution of C1858T genotypes also demonstrated statistical significance (P=0.015). The frequencies of PTPN22 G(-1123)C alleles and genotypes did not differ between T1DM cases and controls, although the haplotype comprising both mutant PTPN22 alleles, C(-1123) and T1858, was significantly more frequent in affected individuals (P=0.003). G(-1123)C and C1858T were in linkage disequilibrium (D' = 0.98; r(2) =0.61 in T1DM and D' = 0.97; r(2) =0.41 in controls). No significant differences in the allele and genotype frequencies of PDCD1 and CYP27B1 polymorphisms were found between patients and controls. This study confirms the association of PTPN22 C1858T polymorphism with T1DM, whereas the effects of PTPN22 G(-1123)C, PDCD1 G7146A and CYP27B1 C(-1260)A seem unlikely, at least in the Polish population.

Association of the CYP27B1 C(-1260)A polymorphism with autoimmune Addison's disease.

Autoimmune Addison's disease (AAD) is a complex endocrine disorder with several susceptibility loci. This study was aimed to investigate the associations of CYP27B1 C(-1260)A and PDCD1 G7146A polymorphisms with AAD in a Polish cohort, comprising 101 AAD patients and 251 healthy controls. CYP27B1 encodes 1alpha-hydroxylase, responsible for conversion of the vitamin D (3) precursor into its active form, involved in the immune function. PDCD1 gene gives rise to an inhibitory immune receptor, expressed on activated lymphocytes. Polymorphic variants of these genes had previously been associated with various autoimmune disorders. Genotyping was performed by PCR-RFLP method. The CYP27B1 C(-1260) allele appeared significantly more frequent in AAD compared to controls ( P=0.020), yielding an OR of 1.53 (95% CI 1.07-2.19). The distribution of C(-1260)A genotypes also demonstrated significant difference ( P=0.003). Stratification according to the presence of concomitant autoimmune disorders revealed an association of the C(-1260) allele with the polyendocrine cases of AAD ( P=0.031), while no significance was found for the isolated ADD compared with healthy controls ( P=0.253). Overall, the association between AAD and C(-1260)A was confirmed in a meta-analysis of 325 AAD patients and 952 controls from three different European populations. Under a fixed-effect model, C(-1260) allele and CC genotype were associated with AAD susceptibility with a pooled OR of 1.44 (95% CI 1.18-1.75) and 1.88 (95% CI 1.42-2.36), respectively. No differences were observed for the PDCD1 G7146A between affected subjects and controls (p>0.05). In conclusion, this study confirms the association of the CYP27B1 C(-1260)A polymorphism with AAD, whereas the contribution of PDCD1 G7146A seems less likely.

Transmission of HCV infection among long-term hospitalized onco-haematological patients.

Hepatitis C virus (HCV) infection is becoming a substantial problem in long-term hospitalized patients. Onco-haematological patients undergoing chemotherapy are especially prone to HCV infection. These patients are usually immunosuppressed and therefore antibodies to HCV are not produced despite the presence of HCV RNA in peripheral blood. The aim of the study was to see how often long-term hospitalized patients acquired HCV infection, and what were the possible sources and routes of virus transmission. The study involved 129 children with lymphoproliferative diseases, 36 patients with solid tumours, and 61 healthcare workers from onco-haematological wards. All were HCV RNA and anti-HCV negative at the time of first hospitalization. During a two and a half-year follow-up study among 165 onco-haematological patients, HCV RNA appeared in 87 in subsequent hospitalizations. The majority of infections were (82/87) were 1a genotype, 2 were 1b, 1 was 1a + 1b and 1 was 1a + 3a. In an attempt to establish the origin of HCV infection, healthcare workers were screened for HCV genotyping. All HCV-infected staff working on wards had the same genotype (1a). None of the staff was infected with 1b genotype. As the most prevalent genotype in Polish blood donors is 1b, HCV infection in onco-haematological patients is most likely due to horizontal transmission, probably involving genotype 1a, and potential horizontal transmission of HCV is implied by the presence of 1a genotype of HCV in saliva and urine of selected patients. Spread of hospital HCV infection among children may be facilitated by micro-injury of the skin and mucosa. Early detection of HCV RNA is important in such immunosuppressed patients, as they are not able to produce anti-HCV antibodies. This may enable the introduction of prophylactic steps to prevent the spread of HCV infection by horizontal transmission.

[Genetic determination of smell]. / Genetyczna determinacja wechu.

The recent study of olfactory receptor genes sheds new light on the significance of this receptor not only for smell recognition but also in human embryogenesis. In this work current data concerning the role of olfactory receptors in human as well as their genetic determination are presented. Olfactory receptors are encoding approximately by 1000 hOR genes. The hOR gene family is most likely the largest in human genome. Among 1000 hOR genes, 347 are functional, the rest 70% being pseudogenes are not expressed. HOR genes reside at 25 locations in human genome in multiple clusters on all human chromosomes, except 2, 4, 18, 20, 21, and Y. Each receptor recognizes single as well as multiple odorant, and each odorant binds to multiple receptors to generate specific activation patterns for each of a great number of distinct smells. There is more and more evidence showing close correlation between HLA complex and smell recognition, which influence mating behavior in animals, consequently leading to increase immune response to various pathogens. The last investigations showed hOR expression in germinal cells and in developing embryo, suggest that hOR may play functional role in cell recognition in organogenesis.

Significance of molecular identification of hepatitis C virus RNA in diagnosis of cryptogenic hepatitis in children.

Viral etiology of hepatitis is routinely proved by standard immunological tests detecting specific antibodies. However, identification of specific antibodies cannot always be conclusive. Since specific hepatitis C virus (HCV) antibodies may appear after some months of the infection, identification of HCV RNA and/or hepatitis G virus (HGV) RNA should clarify the etiology of hepatitis. The aim of this study was to diagnose etiologically unknown hepatitis by a reverse transcription-polymerase chain reaction (RT-PCR) testing of the presence of HCV RNA and HGV RNA. The study involved 33 children with histologically proved hepatitis. The presence of HCV and any signs of autoimmune disease were not observed at the beginning of the follow-up study. During 2.5 years of the follow-up HCV-RNA was found in the blood and liver biopsies in 17 patients. Eight of them became HCV antibodies-positive during the follow-up. None of them eliminated the virus from the blood during the follow-up. In two other patients HCV-RNA was found only in the liver. HGV infection in all cryptogenic patients was excluded by PCR testing. Identification of HCV RNA RT-PCR allowed to diagnose 19 out of 33 (57.6%) patients with cryptogenic hepatitis. The etiology of the hepatitis in remaining 12 patients has to be established.

Hepatitis G virus co-infection may affect the elimination of hepatitis C virus RNA from the peripheral blood of hemodialysis patients.

Hemodialysis patients are at risk for hepatitis C virus (HCV) and hepatitis G virus (HGV) infection. The aim of this study was to investigate the possible influence of HGV co-infection on HCV RNA elimination from the peripheral blood of hemodialysis patients. The study involved 144 persons, all with HCV antibodies and HCV RNA. Among 144 patients 24 (16.7%) were positive for HGV RNA. After 2.5 years of observation 80 patients (55.6%) were still HCV RNA-positive. In the latter group 18 patients were co-infected with HGV and 62 were HGV RNA-negative. During 2.5 years of the follow-up study 64 patients eliminated HCV RNA from the serum. In this group only 6 patients were HGV co-infected. None of the HGV-positive patients eliminated HGV RNA from the serum. The higher incidence of HGV co-infection in the group of patients who remained HCV RNA-positive (18/80, 22.5%), in comparison to the group of HCV antibodies-positive patients who lost HCV in the blood (6/64, 9.4%, P < 0.0001) suggests, that the co-infection with HGV may delay the spontaneous elimination of HCV RNA from the blood.

[Intermediate doses of cytosine arabinoside in the treatment of acute non-lymphoblastic leukaemia in children]. / Sredniowysokie dawki arabinozydu cytozyny w leczeniu dzieci z ostra bialaczka nielimfoblastyczna.

Between 1995-1997, at 7 centres of the Polish Paediatric Leukaemia/Lymphoma Study Group (PPLLSG) treatment was started in 102 children with acute non-lymphoblastic leukaemia. Sixty-two children treated according to the new protocol adjusted for risk factors were evaluated. Thirty-one patients belonged to standard risk and 23 to high risk group. Eight children were not evaluated due to early death. Out of 62 children, 44 (70,9%) achieved remission; in standard and high risk groups the rates of remission were 87,5% and 73%, respectively. Four-year event-free survival (EFS), relapse-free survival (RFS) and overall survival (OS) probability in all patients were: 40,2%, 42% and 59% respectively, in standard risk group: 49,5%, 52,5%, 59,1%; in high risk group: 42%, 43,4% and 57,8%. In comparison with the previous period (1983-1994) EFS increased from 30% to 42%, which was statistically insignificant.