Monoclonal gammopathy of renal significance (MGRS) histopathologic classification, diagnostic workup, and therapeutic options.

Monoclonal gammopathy of renal significance (MGRS) includes all kidney disorders caused by a monoclonal protein (M-protein) secreted by a small plasma cell clone or other B-cell clones in patients who do not meet the diagnostic criteria for multiple myeloma or other B-cell malignancies. The underlying disorder in patients with MGRS is generally consistent with monoclonal gammopathy of undetermined significance (MGUS). MGRS-associated kidney disorders are various and the list is still expanding. The kidney disorders can manifest as glomerular diseases, tubulopathies, and vascular involvement with varying clinical presentations. Diagnosis is often challenging because of the wide spectrum of MGRS, and it is difficult to establish a pathogenic link between the presence of the M-protein or serum free light chains and kidney diseases; further complicating accurate diagnosis is the high incidence of MGUS and/or kidney disorders, independent of MGRS, in elderly patients. However, MGRS can significantly impair kidney function. Because treatment can stop and also reverse kidney disease, early recognition is of great importance. A combined haematologic and nephrologic approach is crucial to establish the causative role of the M-protein in the pathogenesis of kidney disease. Clone-directed therapy, which may include autologous stem cell transplantation in eligible patients, often results in improved outcomes. In this review, we discuss the histopathologic classification of MGRS lesions, provide a renal and haematologic diagnostic workup, discuss treatment options for MGRS, and introduce a Benelux MGRS Working Group.

Bullous lesions of the vulvar region revealing both AL amyloidosis and vulvar carcinoma.

We report a patient with a bullous disorder which revealed both AL amyloidosis and a vulvar squamous cell carcinoma. Bullous amyloidosis is the rarest clinical manifestation of the amyloidoses, and is usually accompanied by systemic amyloid deposition with multiorgan involvement. This case illustrates that a localized disorder can trigger the diagnosis of a systemic disease.

Splenectomy for the treatment of thrombotic thrombocytopenic purpura.

Plasma exchange is the treatment of choice for patients with thrombotic thrombocytopenic purpura (TTP) and results in remission in >80% of the cases. Treatment of patients who are refractory to plasma therapy or have relapsing disease is difficult. Splenectomy has been a therapeutic option in these conditions but its value remains controversial. We report on a series of 33 patients with TTP who were splenectomised because they were plasma refractory (n = 9) or for relapsed disease (n = 24). Splenectomy generated prompt and unmaintained remissions in all except five patients, in whom remission was delayed (n = 4) or who died with progressive disease (n = 1). Four postoperative complications occurred: one pulmonary embolism and three surgical complications. Median follow-up after splenectomy was 109 months (range 28-230 months). The overall postsplenectomy relapse rate was 0.09 relapses/patient-year and the 10-year relapse-free survival (RFS) was 70% (95% CI 50-83%). In the patients with relapsing TTP, relapse rate fell from 0.74 relapses/patient-year before splenectomy to 0.10 after splenectomy (P < 0.00001). Two patients died from first postsplenectomy relapse. Although these results are based on retrospective data and that the relapse rate may spontaneously decrease with time, we conclude that splenectomy, when performed during stable disease, has an acceptable safety profile and should be considered in cases of plasma refractoriness or relapsing TTP to reach durable remissions and to reduce or prevent future relapses.

[Oral fluoropyrimidines registered for the treatment of metastatic colorectal carcinoma: a possible gain]. / Orale fluoropyrimidinen geregistreerd voor de behandeling bij gemetastaseerd colorectaal carcinoom: een mogelijke aanwinst.

Up until now the standard treatment for metastasized colorectal carcinoma has been fluorouracil (5-FU) in combination with folonic acid in low doses administered intravenously, even after the recent registration of a number of new intravenously administered cytostatics, such as irinotecan and oxaliplatin. Meanwhile there are oral alternatives for 5-FU: capecitabine and the combination of tegafur and uracil with folonic acid. In four randomised studies it was shown that these drugs were globally just as effective as the combination of 5-FU with folonic acid (in accordance with the 'Mayo Clinic' scheme). There was no survival advantage for the oral drugs compared to 5-FU with folonic acid. Compared to 5-FU and folonic acid the use of capecitabine or tegafur-uracil-folonic acid was associated with less toxic effects; however, there were differences in the side effects profile between the oral drugs and 5-FU (more hand-foot syndrome for capecitabine and less (symptomatic) leucopenia for tegafur-uracil-folonic acid). An examination of the serious side effects (grade 3 and 4) revealed that the total incidence was generally comparable. These data, together with the ease of oral administration, form the basis for the registration of capecitabine and tegafur-uracil-folonic acid. The definitive place of these drugs in the treatment of metastasized colorectal carcinoma is not yet clear.

Autologous peripheral blood stem cell transplantation in patients with relapsed lymphoma results in accelerated haematopoietic reconstitution, improved quality of life and cost reduction compared with bone marrow transplantation: the Hovon 22 study.

The present study analysed whether autologous peripheral blood stem cell transplantation (PSCT) improves engraftment, quality of life and cost-effectiveness when compared with autologous bone marrow transplantation (ABMT). Relapsing progressive lymphoma patients (n = 204; non-Hodgkin's lymphoma n = 166; Hodgkin's disease n = 38) were, after induction treatment with the DHAP-VIM (cisplatin, cytarabine, dexamethasone, etoposide, ifosfamide, methotrexate) regimen, randomly (2:1) assigned to the harvest of granulocyte-macrophage colony-stimulating factor-mobilized stem cells after the second DHAP course or autologous bone marrow cells before the second DHAP course. These stem cells were reinfused following high-dose myeloblative chemotherapy. After induction, 118 patients obtained a partial or complete response and were eligible for randomization. In the PSCT arm (n = 76) significantly faster engraftment of neutrophils [> or = 0.1 and > or = 0.5 x 10(9)/l: 10.7 d (7-36, median, range), 15 (9-45) versus 13 (8-25) and 26 (14-80), P < 0.01] and thrombocytes [> or = 20 x 10(9)/l: 13 d (7-51) versus 18 (11-65), P < 0.01] were observed. In addition, significantly fewer transfusions of red blood cells [6 (0-23) versus 8 (2-24), P < 0.01] and platelets [4 (0-60) versus 8 (2-55), P = 0.01] were required in the PSCT arm. These findings were associated with a significant reduction in the median days of intravenous antibiotics in patients with fever [8.5 (0-30) versus 14 (0-34), P = 0.04] and hospital stay [27 (8-51) versus 34 (24-78), P < 0.05]. Quality of life demonstrated a significant difference in favour of the PSCT arm. Total transplantation costs were significantly lower in the PSCT arm [$13,954 ($4913- 29,532) versus $17 668 ($10,170-44,083) P < 0.05], as a result of the reduced hospital stay and lower antibiotic costs. In summary, these results indicate that PSCT is superior to ABMT with regard to engraftment, supportive care, quality of life and cost.

Vincristine, doxorubicin and dexamethasone (VAD) administered as rapid intravenous infusion for first-line treatment in untreated multiple myeloma.

We examined the feasibility of achieving a rapid response in patients with previously untreated multiple myeloma by administering vincristine 0.4 mg and doxorubicin 9 mg/m2 as a rapid intravenous infusion for 4 d together with intermittent high-dose dexamethasone 40 mg (VAD) for remission induction treatment in patients who were scheduled to receive high-dose therapy. 139 patients (86 male, 53 female; median age 53 years, range 32-65 years; Durie & Salmon stage IIA: 42, IIB: one, IIIA: 89, IIIB: seven) were included in a prospective multicentre study in which VAD was administered as remission induction treatment and was followed by intensified treatment. The response was evaluated according to the criteria of the Eastern Cooperative Oncology Group (ECOG). The results of treatment were evaluable in 134 patients. Five patients died before evaluation. 86 patients (62%) achieved a partial response (PR) and seven patients (5%) achieved a complete response (CR), which equates to a response rate of 67%. The main side-effect was mild neurotoxicity, which was observed in 18% of the patients. Fever or infections were reported in 27% of the patients. VAD administered as an outpatient regimen, based on rapid intravenous infusion, is an effective induction regimen for untreated myeloma with a 67% response rate and acceptable toxicity.

The low cycling status of mobilized peripheral blood CD34+ cells is not restricted to the more primitive subfraction.

Mobilized peripheral blood progenitor cells (PBPC) have been shown to differ qualitatively from bone marrow (BM) progenitors. The released progenitor cells are predominantly in G0/G1 and show a relatively high percentage of rhodamine dull cells. Within the BM these last two features are characteristic of the more primitive progenitors. Although the mobilized PB cells can give rise to long-term repopulation and thus contain stem cells, the frequency of stem cells is not much higher if long-term initiating cell (LTC-IC) assays are used. To determine whether quiescent stem cells are selectively released or the low-cycle status of PB progenitors is related to the release from the BM microenvironment, the cell cycle status and rhodamine content in the PB and BM during mobilization were studied and compared with steady-state BM. More differentiated and more primitive progenitors were separated based on differentiation markers and cloned in single cell assay. In mobilized PB 54% of the CD34+ cells (n=5) were rhodamine dull compared to 22% in steady-state BM (P=0.014) [n=6]. The percentage of CD34+ cells in the S/G2M phases of the cell cycle was 2.1% in the mobilized PB (n=11), and 18% in steady-state BM (n=11) [P=0.002]. During mobilization the fraction of cells in the S/G2M phase of the cell cycle was 16% in BM (n=7), similar to steady-state BM (P=0.34). The released progenitors represented a selection of BM progenitors, with significantly more primitive progenitors (CD34+/13+/33dim) and less lymphoid precursors (CD34+/19+). Within the more differentiated CD34+113+/33bright, myelomonocytic precursors, both in PB as well as in BM, the percentage S/G2M was relatively higher than in the CD34+/13+/33dim subfraction: in normal BM: median 18% vs 8% (P=0.006) [n=8]; in mobilized PB 3% vs 2% (P=0.03) [n=10]; and in BM during mobilization 24% vs 7% (P=0.01) [n=6]. The cycle status of mobilized PB progenitors was low both in the primitive and more differentiated subfractions. During the mobilization period the BM progenitors are cycling as in steady-state BM. The low-cycle status of the mobilized PB progenitors may be related to the loss of contact with the micro-environment.

The role of the different CD34 epitopes in detection and positive selection of CD34+ bone marrow and peripheral blood stem cells.

Positive selection of CD34+ cells is an attractive approach to reduce tumour cell contamination in bone marrow (BM) and peripheral blood progenitor cell (PBPC) autografts in malignancies not expressing CD34. All current selection methods use monoclonal antibodies (MoAbs) specific for the class I or class II CD34 epitopes, while for detection most investigators use class III MoAbs. Since the distribution of the different CD34 epitopes on haematopoietic progenitors differs, we studied their significance in CD34+ selection procedures. Testing MoAbs against class I, II and III CD34 epitopes on normal BM we observed that +/- 23% of class III positive cells was class I negative. A higher expression of the class III epitope compared with classes I or II was observed on the KG1 cell line, whereas no differences in binding capability were found. The class III epitope anti-CD34, 561, was compared with the class I epitope anti-CD34, BI-3C5, both coupled to M450 Dynabeads. The yield of CD34+ cells obtained with the 561 beads was 1.7% of the mononuclear cells versus 0.95% using the class I epitope, a 1.95-fold increase (1.3-2.7), whereas the purity was similar (96% in both cases). The absolute number of CD34+ cells was therefore twofold higher after 561 selection, including cells with a more mature phenotype. In single cell assay comparable numbers of highly proliferative progenitors but higher numbers of differentiated colonies per phenotypic subfraction were measured. In conclusion, M450 beads coated with the 561 anti-class III CD34 epitope are more efficient in isolating CD34+ cells from bone marrow, probably due to a broader distribution of the class III epitope.

CD34 selections from myeloma peripheral blood cell autografts contain residual tumour cells due to impurity, not to CD34+ myeloma cells.

Malignant cells in haemopoietic autografts can contribute to post-transplant relapse. Engraftment of myeloma patients with CD34+ peripheral blood progenitors selected from total autografts reduces the number of tumour cells infused by 2.7-4.5 logs. Residual tumour cells detected in CD34+ selected cells may be due to selection impurity or the existence of malignant CD34+ progenitors. In three patients we evaluated the CD34 purity and tumour load of total autografts, CD34+ progenitors selected with immunomagnetic beads and highly purified CD34+ progenitors obtained in two rounds of selection (combining magnetic with flow cytometry activated cell sorting) to determine the cause of residual tumour cells in CD34 selections. Using allele-specific oligonucleotides (ASO) complementary to the unique Ig heavy chain sequence (CDRIII region) of the malignant clone, semi-quantitative ASO-PCR was capable of detecting one malignant cell in 10(4)-10(5) normal white blood cells. Selection of CD34+ cells from bone marrow (BM) with approximately 20% malignant plasma cells resulted in a 1.4 log reduction of tumour burden. Using two-colour flow-cytometry we observed CD34-, BB4+ malignant plasma cells contaminating this CD34 selection. Prior to sorting, peripheral blood cell autografts (PBCA) contained approximately 0.1% malignant cells. Selection of > 99% pure CD34+ cells using immunomagnetic beads (Dynal) resulted in an approximate 2 log reduction of malignant cells, but residual tumour cells were still detectable. ASO-PCR detected no malignant cells in > 99.9% pure CD34+ peripheral blood progenitors obtained with two rounds of selection (combining magnetic with flow cytometry activated cell sorting). We conclude that CD34+ malignant cells are not detectable in myeloma PBCA and that residual tumour cells in CD34 selections are due to contaminating CD34-negative cells.

Peripheral blood cell harvests yield primitive multilineage progenitor cells in the CD34+/33- fraction.

The presence of primitive hematopoietic progenitor cells or stem cells in peripheral blood (PBSC's) harvests was investigated in a single cell culturing assay and compared with the results obtained in aspirates of normal bone marrow. Based on the presence of CD33, rather differentiated progenitor cells (CD34+/33+) were distinguished from more primitive cells (CD34+/33-). The growth potential of CD34+/33+ and CD34+/33- cells have been studied. Single cell sorting was performed from peripheral blood harvests, obtained from three patients with multiple myeloma during hematopoietic recovery after treatment with high dose cyclophosphamide and rhu-GM-CSF. To test the effect of "stem cell recruiting factors" the cells were sorted in 96-well plates, prefilled with liquid medium both in the presence of IL-3 + G-CSF+GM-CSF+Epo and the same growth factors supplemented with SCF+IL-6. Addition of SCF and IL-6 to the culturing medium enhanced the plating efficiency of CD34+/33- cells considerably more than that of CD34+/33+ cells. This was observed in harvests of peripheral blood as well as in aspirates of normal bone marrow. The differences between CD34+/33+ and CD34+/33- were even more pronounced when only the large colonies (> 500 cells/well) were taken into consideration. Assuming that IL-6 and SCF are "stem cell recruiting factors," the CD34+/33- fraction contains more clonogenic cells than the CD34+/33+ fraction. In all three patients the first CD34+ cells appearing in the peripheral blood (PB) after cytoreductive treatment were predominantly CD34+/33- (> 80%). At later stages when the leukocyte counts had reached higher values the CD34+/33+ cells predominated.(ABSTRACT TRUNCATED AT 250 WORDS)