Acquired haemophilia A and Kaposi's sarcoma in an HIV-negative, HHV-8-positive patient: a discussion of mechanism and aetiology.

BACKGROUND: Acquired haemophilia A (AHA) is a rare bleeding disorder caused by an imbalance in the immune system leading to the production of factor VIII antibodies. In half of the cases, the underlying cause is not known. CLINICAL HISTORY: We report on a patient with AHA and Kaposi's sarcoma (KS), which is caused by the human herpes virus 8 (HHV-8). The patient presented with appendicitis and developed several severe post-operative haemorrhages. He spent 3 months in intensive care due to long and difficult infections. While recuperating on the ward, the patient developed KS in the lower extremities. He had a positive HHV-8 infection. DISCUSSION/CONCLUSION: Due to its latency and replication in the lymphoid system, HHV-8 is an ideal candidate for causing an imbalance in the immune system in susceptible patients. Our conclusion is that AHA was caused or prompted by the HHV-8 infection. Since HHV-8 viral infection is often subclinical, viral testing might be an important tool in acquired haemophilia diagnostics even when viral symptoms are absent.

Angiogenesis in relation to clinical stage, apoptosis and prognostic score in myelodysplastic syndromes.

The International Prognostic Scoring System (IPSS), based on the number of cytopenias, percentage of bone marrow blasts and cytogenetics, is an important prognostic tool for patients with myelodysplastic syndrome (MDS). In addition, factors such as high bone marrow cellularity and lactate dehydrogenase levels have been associated with an adverse outcome, spontaneously and after chemotherapy. Recently, increased bone marrow angiogenesis, measured as, e.g. microvascular density (MVD), was reported to be more intense in high-risk than in low-risk MDS. To assess the prognostic role of MVD in MDS, a cohort of 56 patients, thoroughly investigated for various clinical and morphological parameters, were followed-up for survival > or =60 months after the diagnostic analysis. As a group MDS patients had higher MVD compared to healthy controls (p<0.02). The highest median MVD value was observed in the RAEB group, but there was no overall significant difference between the FAB groups. No significant correlations were observed between MVD and peripheral blood counts, bone marrow cellularity, percentage of bone marrow blasts and CD34 positive cells, apoptotic index (TUNEL), proliferation index (MIB-1), erythroid index, FAB group and IPSS score. MVD was not correlated to overall survival. In contrast, bone marrow blast count <5%, low or normal cellularity, as well as a high erythroid index, indicated a favorable survival. Thus, our data do not support an important prognostic role of angiogenesis, reflected by microvessel density, in the myelodysplastic syndromes.

Expression of cox-2, tie-2 and glycodelin by megakaryocytes in patients with chronic myeloid leukaemia and polycythaemia vera.

When evaluating bone marrow sections for markers of neo-angiogenesis, we found that megakaryocytes stained markedly positive for cyclooxygenase-2 (Cox-2), Tie-2 and glycodelin. This apparently novel finding was further evaluated for disease-specific variations. Bone marrow sections from two patient groups, known to be characterized by clonal megakaryocytopoiesis, viz. chronic myeloid leukaemia and polycythaemia vera, stained, however, similarly to healthy marrows for these markers. The biochemical background and clinical significance of Cox-2, Tie-2 and glycodelin remains to be elucidated.