Audit of once-daily dosing gentamicin therapy in neutropenic fever.

During a 12-month study, 42 adult patients with febrile neutropenia (granulocytes < 1 x 10(9)/l) were treated with once-daily gentamicin (5 mg/kg). Serum gentamicin trough levels were measured 24 hours after the first dose, then twice weekly if < 1 mg/l. Gentamicin was halved if the trough level was 1-2 mg/l and usually stopped if > 2 mg/l. One hundred and sixty samples were assayed: 122 (76%) < 1 mg/l, 27 (17%) l-2 mg/l and 11 (7%) > 2 mg/l. All 1-2 mg/l samples and three of the > 2 mg/l samples (taken at the wrong time) reverted to <1 mg/l with dosage adjustment. The protocol proved simple and effective with a low incidence of gentamicin-associated nephrotoxicity (7%) and no sepsis-related deaths.

The value of the bone marrow plasma cell cytoplasmic light chain ratio in differentiating between multiple myeloma and monoclonal gammopathy of undetermined significance.

We compared the plasma cell light chain ratios in the bone marrows of 13 patients with multiple myeloma (MM), with those of 13 patients with monoclonal gammopathy of undetermined significance (MGUS). The mean light chain ratio in favour of the paraprotein isotype in the myeloma group was 51.83 (95% confidence limits (CL) 29.52-74.14), while in the MGUS group it was 5.30 (CL 2.07-8.52). The difference between the MGUS and MM groups was significant (p = 0.0005). Neither the bone marrow plasma cell count nor the paraprotein level were significantly correlated with the light chain ratio in either of these two groups. We found a cut-off ratio of 8 to be the most useful in differentiating between myeloma and MGUS. Only one patient with myeloma had a ratio below 8, and one MGUS patient had a ratio above this cut-off point. We conclude that determination of the bone marrow plasma cell light chain ratio is a simple and useful test in differentiating between myeloma and MGUS in difficult cases.

Changes in serum erythropoietin levels during allogeneic bone marrow transplantation.

Serial serum erythropoietin levels were measured in 10 consecutive patients undergoing allogeneic bone marrow transplantation. Observed erythropoietin levels are compared with those predicted from a large control population of anaemic patients not receiving chemotherapy. There was an initial acute rise in serum erythropoietin, peaking between days 1 and 4 after marrow transfusion, which was unrelated to changes in haemoglobin concentration. Patients maintained serum erythropoietin concentrations at around twice the predicted level for the first 2 weeks following transplantation, with a gradual fall into the expected range by wk 3. Erythropoietin levels did not change with episodes of bacterial infection or acute graft-versus-host disease. A patient with severe aplastic anaemia had initial successful engraftment with normalisation of erythropoietin levels, but showed a marked and amplified rise in erythropoietin 2 wk before falling peripheral blood counts indicated failure of the bone marrow graft.

Twin-track studies of ifosfamide and mitoxantrone (I-M) in recurrent high grade non-Hodgkin's lymphoma and Hodgkin's disease. Yorkshire Regional Lymphoma and Central Lymphoma Groups.

Fifty-seven patients, initially diagnosed as having advanced high grade non-Hodgkin's lymphoma (NHL) or Hodgkin's disease (HD) refractory to first-line treatment or in relapse, were treated with ifosfamide 6 g/m2, infused over 48 h, followed by mitoxantrone 12 mg/m2. The regimen repeated at three-weekly intervals. Of 33 patients with NHL evaluable for response, 10 (30 per cent) achieved complete remission and six partial remission, giving an overall response rate of 48 per cent. Two patients subsequently went on to bone marrow transplant (BMT)--one allogeneic and the other autologous. Of 18 patients with HD evaluable for response, seven (39 per cent) achieved complete remission and six partial remission, giving an overall response rate of 72 per cent. Two of this group also went on to BMT (both autografts). The principal toxicity was neutropenia, though central nervous system changes were observed in 10 patients. The possibility of increasing the safety of the regimen by increasing the time of infusion to 72 h is discussed. Given the need to offer alternative treatment to patients in these categories, this combination (I-M) is of value in relapsed patients, especially where options are limited because of previous multi-drug treatment. Remissions may not be prolonged but allow the effective application of additional intensive treatment including bone marrow transplantation.