Peter Biberfeld

Failing Transcervical Thymectomy in Myasthenia Gravis: An Evaluation of Transsternal Re-exploration

Twenty cases of failing transcervical thymectomy are reported. They were selected for transsternal re-exploration from a series of 95 patients who had previously undergone transcervical thymectomy because of myasthenia gravis (MG). A specific method for pre-operative detection of remnants of the non-tumorous thymic gland is lacking, but the applied clinical selection criteria were so far reliable: generalized, disabling, fluctuating MG despite cholinesterase inhibitor and/or immunosuppressive treatment, and no or inconsistent improvement after transcervical thymectomy. At transsternal re-exploration the commonest findings were intact lower thymic lobes with persistent venous drainage into the brachiocephalic vein. Presence of thymic tissue was histologically confirmed in all the excised specimens (weight range 10-60, mean 23 g), and the examination showed thymic hyperplasia in 18 cases, fatty involution of the gland in two, and a lympho-epithelial thymoma in one case. The re-operation was followed by objectively registrable improvement in all but one of the 20 patients during observation periods of 8-75 (mean 21) months. There was statistically significant reduction in disability scores (means 8.2-4.9) and in need for anticholinesterase medication (to 67% of pretreatment dose). Immunosuppression became unnecessary in 6 of 11 patients and could be reduced in 4 patients. The incidence of failure in transcervical thymectomy was alarmingly high (27%), and more re-operations are anticipated. Since the transcervical approach involves a high risk of incomplete thymectomy, its use should be abandoned. However, in most of the patients with re-operation, subsequent progress has been sufficiently promising for advocacy of sternotomy whenever the clinical criteria of failure are fulfilled.

Epstein-Barr virus (EBV) DNA in saliva and EBV serology of HIV-1-infected persons with and without hairy leukoplakia.

Secretion of Epstein-Barr virus (EBV) in saliva, as well as serum antibody titres against various EBV antigens, were analyzed in respect of (1) 15 HIV-1-infected patients with oral hairy leukoplakia proven to contain EBV by in situ hybridization, (2) 45 HIV-1 infected patients without hairy leukoplakia, (3) 10 HIV-1 infected patients treated with acyclovir or foscarnet and (4) 21 healthy controls. The numbers of CD4+ cells in the peripheral blood were also recorded. The HIV-1 infected patients were at various stages of HIV-1-associated disease. Excretion of EBV DNA in the saliva was determined by means of the polymerase chain reaction (PCR) while the amount of EBV DNA in positive samples was estimated by repeated titrations. The frequency of shedding of EBV DNA increased from 33% in healthy controls to 78% in asymptomatic HIV-1 infected persons, but did not increase significantly with progression of HIV-1-associated disease. The titres of EBV DNA in saliva correlated inversely and significantly with the number of CD4+ cells in the peripheral blood. All patients with hairy leukoplakia shed by EBV DNA in their saliva but the titres were not significantly higher than those of other HIV-1 infected persons. The serum titres of antibodies against EBV nuclear antigen 1 (EBNA-1) correlated positively and significantly with the CD4+ cell count in the peripheral blood. EBNA-1 IgG antibody in the serum was also significantly lower in symptomatic than in asymptomatic HIV-1 infected persons. There were, however, no significant differences in serum antibodies to various EBV antigens between patients with and without hairy leukoplakia.

Tanzanian malignant lymphomas: WHO classification, presentation, ploidy, proliferation and HIV/EBV association.

BackgroundIn Tanzania, the International Working Formulation [WF] rather than the WHO Classification is still being used in diagnosing malignant lymphomas (ML) and the biological characterization including the HIV/EBV association is sketchy, thus restraining comparison, prognostication and application of established therapeutic protocols.MethodsArchival, diagnostic ML biopsies (N = 336), available sera (N = 35) screened by ELISA for HIV antibodies and corresponding clinical/histological reports at Muhimbili National Hospital (MNH) in Tanzania between 1996 and 2006 were retrieved and evaluated. A fraction (N = 174) were analyzed by histopathology and immunohistochemistry (IHC). Selected biopsies were characterized by flow-cytometry (FC) for DNA ploidy (N = 60) and some by in-situ hybridization (ISH) for EBV-encoded RNA (EBER, N = 37).ResultsA third (38.8%, 109/281) of the ML patients with available clinical information had extranodal disease presentation. A total of 158 out of 174 biopsies selected for immunophenotyping were confirmed to be ML which were mostly (84. 8%, 134/158) non-Hodgkin lymphoma (NHL). Most (83.6%, 112/134) of NHL were B-cell lymphomas (BCL) (CD20+), of which 50.9%, (57/112) were diffuse large B-cell (DLBCL). Out of the 158 confirmed MLs, 22 (13.9%) were T-cell [CD3+] lymphomas (TCL) and 24 (15.2%) were Hodgkin lymphomas (HL) [CD30+]. Furthermore, out of the 60 FC analyzed ML cases, 27 (M:F ratio 2:1) were DLBCL, a slight majority (55.6%, 15/27) with activated B-cell like (ABC) and 45% (12/27) with germinal center B-cell like (GCB) immunophenotype. Overall, 40% (24/60) ML were aneuploid mostly (63.0%, 17/27) the DLBCL and TCL (54.5%, 6/11). DNA index (DI) of FC-analyzed ML ranged from 1.103-2.407 (median = 1.51) and most (75.0%) aneuploid cases showed high (>40%) cell proliferation by Ki-67 reactivity. The majority (51.4%, 19/37) of EBER ISH analyzed lymphoma biopsies were positive. Of the serologically tested MLs, 40.0% (14/35) were HIV positive, mostly with high (≥40.0%) Ki-67 reactivity.ConclusionsAccording to the 2001 WHO Classification, most subtypes are represented in Tanzanian ML. Extranodal presentation was common among MNH lymphoma patients who also showed high aneuploidy, tumor proliferation (KI-67) and EBER positivity. DLBCL was frequent and phenotype heterogeneity appeared similar to observations in Western countries suggesting applicability of established intervention approaches. HIV was apparently associated with high ML cell proliferation but extended studies are needed to clarify this.

Characteristic surface morphology of human and murine myeloma cells: a scanning and transmission electron microscopic study.

Summary. Cells from cultured human and murine myeloma cell lines and circulating leukacmic plasma cells from four patients with generalized myeloma were studied by transmission and scanning electron microscopy and time‐lapse cinematography. Both circulating and cultured cells exhibited consistent surface architectures and varying numbers of prominent blebs of different sizes were seen, in addition to microvilli. The presence of surface blebs appears to be a characteristic feature for secreting and non‐secreting myeloma cells.

Human herpesvirus-8 (HHV-8) sero-detection and HIV association in Kaposi's sarcoma (KS), non-KS tumors and non-neoplastic conditions

BackgroundThe association of the human herpesvirus-8/Kaposis sarcoma (KS)-associated herpesvirus (HHV-8/KSHV) serology with various malignancies in Tanzania is not currently well established while previous studies were based on either PCR or immunofluorescence assays [IFA] but not with a sensitive enzyme-linked immunosorbent assay (ELISA). Selected archival diagnostic biopsies (n = 184) and sera from indigenous patients with KS (n = 120), non-KS tumors (n = 24) and non-neoplastic lesions (n = 40) at Muhimbili National Hospital (MNH), Tanzania, were evaluated by diagnostic histopathology, immunohistology [anti-HHV-8 latency-associated nuclear antigen (LANA)] and serology for HIV (ELISA) and HHV-8 (IFA and ELISA).ResultsAbout 66.3% (n = 122) cases including AIDS-associated Kaposis sarcoma (AKS) (n = 93), reactive conditions (n = 28) and only one non-KS tumour were HIV positive. Endemic KS (EKS) patients were mostly males (96.3%, 26/27) who were less (69.9%, 65/93) predominant in AIDS-associated (AKS). A high (89%) percentage of patients with anti-HHV-8 antibodies was found in the cohort including the HIV positive (92%) cases, males (81.2%), KS patients (93%), non-KS tumors (92%), and reactive conditions (75%). All HHV-8 seronegative KS cases were nodular stage whereas both sera and corresponding biopsies from early stage KS were HHV-8+. Assay sensitivity, positive predictive value (PPV) and specificity were 98.6%, 93.5% and 16.7% for IFA and 93.5%, 98.6% and 50.0% for ELISA respectively.ConclusionHHV-8 seroprevalence at MNH appears high as expected among AKS cases and males but also in non-KS patients. ELISA showed a combination of high HHV-8 sensitivity as well as higher PPV and specificity than IFA which however, showed higher sensitivity. The apparent stage-dependent, inverted serum HHV-8 immunoreactivity supports a notion of viral immune-segregation during KS development. Routine HHV-8 screening should be considered particularly in patients at risk of KS and for selection of blood/organ donations.

The natural attachment of thymocytes and activated T lymphocytes to normal and malignant cells: An interspecies study

Abstract When mixed in vitro , thymocytes and allogeneic activated T cells attach to homologous normal and malignant cells. This was previously demonstrated also by in vivo immune activated T lymphocytes. The phenomenon designated as natural attachment (NA) was found to be expressed by low charged T cells, and seems to play an important part in the cellular immune response. Using xenogeneic reactants we found that the NA phenomenon is not entirely species restricted. Apart from the homologous interaction, there was cross reactivity between related species, as between man and other primates or between rodents like the rat and mouse. In some combinations interactions were found between non-related species also. The phylogenetic aspects emerging from these interactions are discussed.

Preventing HHV-8 transmission and Kaposi’s sarcoma (KS) risk prediction and prognostication in resource-poor countries

(p<0.001, highly statistically significant, Chi 2 Test) and as expected the majority (68.3%, 112/164) were KS. HHV-8 serology tests by IFA and ELISA were mostly (92.4%, 73/79) concordant. Sensitivity, positive predictive value (PPV), and specificity were 98.6%, 93.5%, and 16.7% for IFA and 93.5%, 98.6%, and 50.0% for ELISA, respectively. All patients with early-stage KS were HHV8 seropositive but two late-stage cases were seronegative despite LANA expression in their corresponding biopsies.

DNA ploidy, cell proliferation, and HIV/EBV association in Tanzanian malignant lymphomas

Background Malignant lymphomas (ML) are increasingly important causes of morbidity and mortality in sub-Saharan Africa including Tanzania, possibly due to HIV and AIDS. However, the biological characterization ML including their HIV and Epstein-Barr virus (EBV) association as well as DLBCL subtypes in Tanzania is still sketchy. This prevents diagnostic/prognostic comparison as well as application of established therapeutic protocols.