Unique morphological spectrum of lymphomas in Nijmegen breakage syndrome (NBS) patients with high frequency of consecutive lymphoma formation.

Nijmegen breakage syndrome (NBS) is an autosomal recessive disorder characterized by microcephaly, immunodeficiency, radiation hypersensitivity, chromosomal instability and increased incidence of malignancies. In Poland 105 NBS cases showing mutations in the NBS gene (nibrin, NBN), have been diagnosed, approximately 53% of which have developed cancer, mainly (>90%) lymphoid malignancies. This study is based upon the largest reported group of NBS-associated lymphomas. The predominant lymphoma types found in these 14 NBS children were diffuse large B cell lymphoma (DLBCL) and T cell lymphoblastic lymphoma (T-LBL/ALL), all showing monoclonal Ig/TCR rearrangements. The spectrum of NBS lymphomas is completely different from sporadic paediatric lymphomas and lymphomas in other immunodeficient patients. Morphological and molecular analysis of consecutive lymphoproliferations in six NBS patients revealed two cases of true secondary lymphoma. Furthermore, 9/13 NBS patients with lymphomas analysed by split-signal FISH showed breaks in the Ig or TCR loci, several of which likely represent chromosome aberrations. The combined data would fit a model in which an NBN gene defect results in a higher frequency of DNA misrejoining during double-strand break (DSB) repair, thereby contributing to an increased likelihood of lymphoma formation in NBS patients.

PCR-based diagnosis of Helicobacter pylori infection in Polish children and adults.

Infection and associated disease caused by Helicobacter pylori are common in Poland, as in much of Eastern Europe, although the genotypes of strains have not been much studied, especially in terms of traits that might be important in disease. This study developed a sensitive and efficient polymerase chain reaction (PCR) test for the presence of H. pylori in gastric biopsy samples with ureA gene-specific primers and primers for the virulence-associated cag pathogenicity island (PAI). These tests were used with biopsy samples from 246 symptomatic children (age range 1-17 years) and 82 adults (age range 18-53 years) in Warsaw. An assessment was also made of the success of metronidazole-based therapy intended to eradicate infection. H. pylori was detected by ureA-specific PCR in 83 (76.9%) children and in 41 (87.2%) adults with histologically proven gastritis, and in 28.4% and 29.2%, respectively, of the 38 children and 7 adults with little or no evidence of gastritis. In general, H. pylori was detected more often by PCR than by culture (70.3% compared with 52.8% in children and 62.8% compared with 38.6% in adults), although in several cases a negative PCR was associated with a positive culture result. The rate of H. pylori infection increased with age from 5.4% in children up to 5 years old to 29.2% to age 10 and 65.4% to age 18. The tests detected the cagPAI in 97 (75%) and 44 (85%) of the H. pylori-infected children and adults, respectively. Some H. pylori-infected patients with a ureA+ PCR result contained the 'empty site' of the cagPAI and only four patients were infected with mixed cag+ cag- strains. PCR with cagPAI and 'empty site' of the cagPAI represents a novel tool for fast screening of mixed cag+ cag- infection. These results confirm and further illustrate that direct PCR of biopsy specimens can be useful for detection of infection and genotyping of resident strains, and that H. pylori infection is very common among children as well as adults in Poland. They also show that Polish strains vary with regard to the presence or absence of the cagPAI, and suggest that the proportion of strains that are cag+ is higher in Poland than in Western European countries, which may reflect the relatively higher risk of infection in this society.

Genotypes of Helicobacter pylori in Polish population.

Here we have studied the genetic diversity of Helicobacter pylori strains recovered from 64 individual patients, 5 family members and 13 unsuccessfully treated patients. The recovered bacteria were finger-printed by the PCR-RFLP and RAPD methods and virulence associated loci (cagPAI, vacA) were PCR studied. Unique differentiation of every independently isolated strain from not-related persons was possible by RAPD technique. In PCR-RFLP technique several profile groups (7 and 15) for particular endonuclease tested were found. Eleven patients carried strains of the same gene profile (PCR-RFLP) and the same overall genotype (RAPD) before and after therapy. In the family studies, essentially the same strain was found in different relatives in three cases, and different strains were found in the other two cases. Island of cagPAI was present in 79% of all strains tested, half and one-fifth of all strains tested presented, s1am2 and s1m1 alleles of vacA gene, respectively. Independently from identity or diversity of pre- and post-treatment strains and strains recovered from the family members we have been observed identical cagPAI/vacA genotypes. These results suggest that H. pylori infections in Poland can be mixed, although just one strain may often predominate, and that inter-family transmission may be significant even in this high risk society. The genetic feature of virulence-associated loci are similar to those seen elsewhere in Europe, although strains that carry the cagPAI and the potentially more toxigenic alleles of the vacA gene are more common. RAPD technique is proven as most differentiating, however PCR-RFLP allows for easy recognition of mixed infection with two or more different strains. Molecular typing study in case of children therapy may allow reduce rate of relapses by reduction of possible transmission from family source.

[Apoptosis and hepatic cell proliferation in autoimmune hepatitis and chronic viral hepatitis C in children: analysis of APO-1/Fas (CD95), bcl-2 and Ki67 expression]. / Apoptoza i proliferacja komórek watrobowych w autoimmunologicznym zapaleniu watroby i przewleklym wirusowym zapaleniu watroby typu C u dzieci: analiza ekspresji APO-1/Fas (CD95), bcl-2 i Ki67.

Hepatocyte damage in autoimmune hepatitis (AIH) and chronic viral hepatitis C (CVH) is attributed to an immune response. We analysed liver biopsy specimens from 4 children with AIH type I, 3 children with AIH type II and 2 children with CVH, using ApopDetek in situ hybridisation method and Mabs anti CD95, Ki67, bcl-2 by means of APAAP technique. The histological appearance of apoptotic bodies in both conditions was similar. The proliferation activity of the hepatocytes was elevated in cases of CVH and less extensive in AIH. Immunohistochemical analysis suggested that the liver damage in AIH and CVH could be mediated by CD95 system as a mechanism of T-cell mediated cytotoxicity.

Expression of antigens homologous to human retrovirus molecules in normal and severely atrophic thymus.

An immunopathologic study of normal and severely atrophic thymuses (STA) was undertaken in order to evaluate the expression of human retrovirus (envelope and core) molecules in thymic epithelial cells (TEC) in HIV negative children. Both normal and STE thymuses disclosed p19, p24, p39, p45 and p55 viral core proteins as well as gp46, gp63 glicoprotein of envelope origin. No evidence of gp160, gp120 and gp41 molecules were observed in TEC which suggested endogenous lack of receptor molecules for HIV. The results are discussed in the context of possible thymus oriented autoimmune reaction in HIV and non-HIV bearing patients and in consequence, severe injury of TEC forming microenvironment.

Secretory component, alpha 1-antitrypsin and lysozyme in IgA deficient children. An immunohistochemical evaluation of intestinal mucosa.

Nine children with IgA deficiency were studied in order to evaluate by the immunoperoxidase technique the behaviour of secretory component (SC), alpha 1-antitrypsin (alpha 1-AT), lysozyme and esterase in biopsies of intestinal mucosa. In none of the studied patients was SC found to be lacking, suggesting that the epithelial transport mechanism of IgA across enterocytes was relatively normal. The distribution of SC activity in immunodeficient children differed however from that seen in control intestinal mucosa in its non-uniform distribution on the villus, abnormal retention in the Golgi region of enterocytes or exclusive activity confined to the proliferating compartment of the villus. The staining of alpha 1-AT in enterocytes was clearly obvious in all studied cases with no alteration in zonal distribution when compared with normal human mucosa. The lysozyme staining pattern was seen exclusively in Paneth cells. The non-specific esterase positive enterocytes observed in control mucosa failed to stain in biopsies from IgA deficient children. The results of this study of SC, alpha 1-AT, lysozyme and esterase may indicate that IgA deficiency is not related to a defect in enterocyte transport of immunoglobulins and confirms previously reported findings indicating the lymphoid B-cell compartment to be altered.

Cytoplasmic immunoglobulins in giant lymph node hyperplasia (Castleman's tumour).

The immunohistologic features were studied in 6 cases of giant lymph node hyperplasia (GLNH) and the cytoplasmic immunoglobulin (CIg) characteristics were compared with those of follicular lymphoma and non-specific follicular lymph node hyperplasia. By use of the peroxidase - antiperoxidase (PAP) technique it was shown that GLNH comprised a mosaic, polyclonal population of CIG-producing cells, the CIg pattern being comparable with that observed in follicular lymphadenitis. In contrast, follicular lymphomas disclosed a definite monoclonal pattern, the cytoplasmic Ig containing only one light chain of kappa type. This led to the conclusion that GLNH is not a neoplastic change, but has the characteristics of a reactive process within the B-cell compartment.

Light and immunoelectronmicroscopic study of Hodgkin's disease: evidence of immunoglobulin synthesis by tumor cells.

The direct immunoperoxidase technique with peroxidase-conjugated F(ab')2 fragments was used at the light and electron microscopic levels to identify intracytoplasmic immunoglobulin (CIg) components in malignant cells of Hodgkin's disease. In each of the 27 cases studied, Hodgkin and Reed-Sternberg cells contained either IgG or IgM, with both light chains often present simultaneously. The number of IgG-positive malignant cells was inversely related to changes in the lymphoid compartment, as defined by the Rye grading system. The evolution from lymphocytic predominance to lymphocytic depletion was paralleled by a decrease of IgM-positive cells and by a substantial increase (to exclusiveness) of IgG-containing cells. These immunoelectronmicroscopic studies disclosed definite morphologic evidence of CIg synthesis by Hodgkin, Reed-Sternberg and lacunar cells. The immunoglobulin components were also synthesized by lymphoid B cells at different levels of modulation. Immunoglobulin synthesis by malignant cells was localized in perinuclear zone, on free cytoplasmic ribosomes and profiles of rough endoplasmic reticulum. The results of this joint light and electron microscopic study support the view that Hodgkin, Reed-Sternberg and lacunar cells belong to the B-cell compartment within Hodgkin's disease.

Angiographic evaluation of conjoined twins.

Two sets of conjoined twins were studied by angiocardiography and cerebral angiography. Conjoined heart was demonstrated in the thoracopagus twins and surgical separation was impossible. Cerebral angiography disclosed the separate circulations in craniopagus twins and surgical separation was performed.