Renal involvement as part of systemic lymphoma (LY) is quite frequent, however, primary extranodal renal non-Hodgkin's lymphoma (NHL) is extremely rare, and only about 65 cases have been reported in the world literature. In a retrospective study of renal manifestations in 700 patients with documented LY and chronic lymphocytic leukemia (CLL) seen at our hospital during 1986-95, 83 patients had signs of acute renal failure. Only five of these had proven renal infiltration, but none of them satisfied the criteria for primary renal LY. Glomerulonephritis (GN) has also rarely been reported in association with LY and CLL, and only 37 glomerular lesions in NHL and 42 in CLL have been documented, respectively. GN may precede, coexist, or follow the diagnosis of LY by several years. Of the 42 cases of CLL reported worldwide, 36 had nephrotic syndrome. Renal failure was seen in about one third. The most common glomerular lesion reported is membranoproliferative GN, followed by membranous GN. In our study, we found only five biopsy-proven cases with GN amongst the 700 patients seen. In this report we also briefly describe some rare interesting associated renal syndromes in CLL and NHL.

Summary. A higher than normal incidence of thromboembolic events has been observed in adult patients with bthalassaemia major (TM) and certain haemostatic anomalies found in these patients suggest the existence of a chronic hypercoagulable state. Thalassaemic red blood cells (RBC) were demonstrated to facilitate thrombin formation due to altered asymmetry of the membrane phospholipids with enhanced exposure of phosphatidylserine. Since RBC anomalies exist in thalassaemia from the ®rst months of life, we studied markers of hypercoagulability and thrombophilia in 36 adult patients (range 19±38 years) and 26 children (range 2±18 years) with b-TM. All the patients were in steady state and none had experienced clinical signs or symptoms of thrombosis. Highly elevated urinary levels of 11-dehydro-thromboxane B 2 and signi®cantly elevated plasma levels of thrombin±antithrombin III (TAT) complexes were observed to the same extent in TM children and adults. The levels of factor II were decreased while factors V, VII X and plasminogen were within the normal range. The natural coagulation inhibitors, protein C (PC) and protein S (PS) were signi®cantly decreased in all TM patients investigated, regardless of age, but the PS binding protein (C4bBP) and antithrombin III levels were normal. The frequency of other thrombophilic mutations was not increased. Thus, a chronic hypercoagulable state already exists in thalassaemia in childhood and may contribute to the cardiac and pulmonary anomalies and the thrombotic events which occur later.

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Reactive oxygen species (ROS) contribute to the pathogenesis of several hereditary disorders of red blood cells (RBCs), including thalassaemia. We report here on a modified flow cytometric method for measuring ROS in normal and thalassaemic RBCs. RBCs were incubated with 0.4 mM 2',7'-dichlorofluorescin diacetate (DCFH-DA), then washed and further incubated either with or without 2 mM H2O2. Flow cytometric analysis showed that RBC fluorescence increased with time; it increased faster and reached higher intensity (by 10-30-fold) in H2O2-stimulated RBCs as compared to unstimulated RBCs. In both cases, the antioxidant N-acetyl-l-cysteine reduced fluorescence, confirming previous reports that DCFH fluorescence is mediated by ROS. While the fluorescence of unstimulated RBCs increased with time, probably because of exposure to atmospheric oxygen, in H2O2-stimulated RBCs fluorescence decreased after 30 min. The latter effect is most likely related to H2O2 decomposition by catalase as both sodium azide, an antimetabolite that inhibits catalase and low temperature increased the fluorescence of stimulated RBCs. Washing had a similar effect, suggesting that maintenance of the oxidised DCF requires a constant supply of ROS. We next studied RBCs of beta-thalassaemic patients. The results demonstrated a significantly higher ROS generation by stimulated and unstimulated thalassaemic RBCs compared to their normal counterparts. These results suggest that flow cytometry can be useful for measuring the ROS status of RBCs in various diseases and for studying chemical agents as antioxidants.

Summary. Several clinical and laboratory findings suggest the presence of a chronic hypercoagulable state in patients with b-thalassaemia major (TM). We have previously shown that isolated TM red blood cells (RBC) strongly enhance prothrombin activation, suggesting an increased membrane exposure of procoagulant phospholipids (i.e. phosphatidylserine). In this study we quantitated the procoagulant activity of RBC in TM and thalassaemia intermedia (TI) patients. We also determined the fraction of activated platelets expressing p-selectin (CD62p) or CD63 in these subjects. Both assays were performed by dual-colour flow cytometry. A significantly (P < 0 . 01) higher fraction of FITCannexin V-labelled RBC was found in TM and TI patients, compared to the controls. A highly significant correlation (P < 0 . 001) was found in TM patients between the number of RBC-bound annexin V molecules and the fraction of CD62p (p-selectin) or CD63-positive platelets. This association between annexin V binding to TM RBC and the expression of platelet activation markers was also found in individual TM patients over time. Thus, the procoagulant surface of TM RBC may accelarate thrombin generation in vivo which, in turn, triggers platelet activation.