Critical evaluation of ASO RQ-PCR for minimal residual disease evaluation in multiple myeloma. A comparative analysis with flow cytometry.

We have analyzed the applicability, sensitivity and prognostic value of allele-specific oligonucleotide real-time quantitative PCR (ASO RQ-PCR) as a method for minimal residual disease (MRD) assessment in patients with multiple myeloma (MM), comparing the results with those of multiparameter flow cytometry (MFC). A total of 170 patients enrolled in three consecutive Spanish trials achieving at least partial response after treatment were included. Lack of clonality detection (n=31), unsuccessful sequencing (n=17) and suboptimal ASO performance (n=51) limited the applicability of PCR to 42% of cases. MRD was finally investigated in 103 patients (including 32 previously studied) with persistent disease identified by PCR and MFC in 54% and 46% of cases, respectively. A significant correlation in MRD quantitation by both the techniques was noted (r=0.881, P<0.001), being reflective of treatment intensity. Patients with <10(-4) residual tumor cells showed longer progression-free survival (PFS) compared with the rest (not reached (NR) vs 31 months, P=0.002), with similar results observed with MFC. Among complete responders (n=62), PCR discriminated two risk groups with different PFS (49 vs 26 months, P=0.001) and overall survival (NR vs 60 months, P=0.008). Thus, although less applicable than MFC, ASO RQ-PCR is a powerful technique to assess treatment efficacy and risk stratification in MM.

A multiparameter flow cytometry immunophenotypic algorithm for the identification of newly diagnosed symptomatic myeloma with an MGUS-like signature and long-term disease control.

Achieving complete remission (CR) in multiple myeloma (MM) translates into extended survival, but two subgroups of patients fall outside this paradigm: cases with unsustained CR, and patients that do not achieve CR but return into a monoclonal gammopathy of undetermined significance (MGUS)-like status with long-term survival. Here, we describe a novel automated flow cytometric classification focused on the analysis of the plasma-cell compartment to identify among newly diagnosed symptomatic MM patients (N=698) cases with a baseline MGUS-like profile, by comparing them to MGUS (N=497) patients and validating the classification model in 114 smoldering MM patients. Overall, 59 symptomatic MM patients (8%) showed an MGUS-like profile. Despite achieving similar CR rates after high-dose therapy/autologous stem cell transplantation vs other MM patients, MGUS-like cases had unprecedented longer time-to-progression (TTP) and overall survival (OS; ~60% at 10 years; P<0.001). Importantly, MGUS-like MM patients failing to achieve CR showed similar TTP (P=0.81) and OS (P=0.24) vs cases attaining CR. This automated classification also identified MGUS patients with shorter TTP (P=0.001, hazard ratio: 5.53) and ultra-high-risk smoldering MM (median TTP, 15 months). In summary, we have developed a biomarker that identifies a subset of symptomatic MM patients with an occult MGUS-like signature and an excellent outcome, independently of the depth of response.

Clinical significance of CD81 expression by clonal plasma cells in high-risk smoldering and symptomatic multiple myeloma patients.

The presence of CD19 in myelomatous plasma cells (MM-PCs) correlates with adverse prognosis in multiple myeloma (MM). Although CD19 expression is upregulated by CD81, this marker has been poorly investigated and its prognostic value in MM remains unknown. We have analyzed CD81 expression by multiparameter flow cytometry in MM-PCs from 230 MM patients at diagnosis included in the Grupo Español de Mieloma (GEM)05>65 years trial as well as 56 high-risk smoldering MM (SMM). CD81 expression was detected in 45% (103/230) MM patients, and the detection of CD81(+) MM-PC was an independent prognostic factor for progression-free (hazard ratio=1.9; P=0.003) and overall survival (hazard ratio=2.0; P=0.02); this adverse impact was validated in an additional series of 325 transplant-candidate MM patients included in the GEM05 <65 years trial. Moreover, CD81(+) SMM (n=34/56, 57%) patients had a shorter time to progression to MM (P=0.02). Overall, our results show that CD81 may have a relevant role in MM pathogenesis and represent a novel adverse prognostic marker in myeloma.

[Basophilic blast crisis in chronic myeloid leukemia]. / Crisis blástica basófila de leucemia mieloide crónica.

Acute basophilic leukaemia is usually characterized by a very rapid clinical course, hyperhistaminemia, resistance to antineoplastic therapy and early death due to complications related to disease. This entity is a rare condition, accounting for less than two percent of all haematopoietic malignancies. Most of the case reports are basophilic blast crisis in patients with a previous lympho or myeloproliferative disorder. A 62-year-old woman who was diagnosed as Philadelphia positive chronic myelogenous leukaemia after four years of evolution developed a basophilic blast crisis, whose characteristics are reported. Accompanying this transformation there was also a cytogenetic change. Despite chemotherapy the patient died of disease progression.

[Cytogenetic alterations found by chromosome analysis and fish technique in two patients with variant chronic lymphocytic leukemia]. / Alteraciones citogenéticas encontradas por análisis cromosómico y técnica FISH en dos pacientes con variantes de leucemia linfática cronica.

Chromosomal studies in CLL have yielded poorer results than in other blood diseases because of the low mitotic index of the B cells. The FISH technique is a very useful tool for trisomy 12 detection in interphase nuclei in CLL, although this method cannot be a substitutive for conventional cytogenetics. The FISH technique was applied in two cases of CLL by means of satellite DNA probing specific for chromosome 12 according to the Oncor S 1370-CF kit protocol. Trisomy 12 was detected, along with other chromosomal abnormalities secondary to this trisomy. Both patients had lymphocyte counts lower than 5.0 x 10(9)/L and their peripheral blood immunophenotype showed 58% lymphocytes with lambda sIg of medium density, co-expressing CD5 and unable to form rosettes with mouse red-cells. Patient no. 1 was 46,XY/47,XY + 12/47,XY + 12,5q-, and patient no. 2 was 46,XX/47,XX + 12,14q-. The presence of secondary anomalies could explain the special clinico-haematological picture, characterised by low lymphocytosis and presence of irregular nuclei in mature lymphocytes, along with the lack of CD23 expression and rosette formation with mouse red-cells. FISH technique combined with chromosome analysis may prove a useful means for diagnosing and recognising variants or specific entities within low-grade lymphoproliferative syndromes.

Six new cases of prolymphocytic leukemia with heterogeneous prognosis. Clinical and immunologic features, light microscopy, and ultrastructural findings.

The clinical features and diagnostic evaluation of six patients affected by prolymphocytic leukemia (PLL), are described. Some of the cases deviate from a relatively uniform and aggressive clinical course of the disease entity. An actuarial survival analysis of 60 cases gathered from the literature and the authors' experience indicate that the cases showing the most prolongated evolution may reach 30% of the total. The different aggressiveness in the clinical course of these patients does not depend on the efficiency of the therapies applied. The percentage of prolymphocytes (PL) in peripheral blood throughout the clinical course was variable and not depending on the treatments used. This fact, in conjunction with (1) the presence of cellular types deviated from the typical PL and detected both at optical and ultrastructural levels and (2) the existence of cases of PL with minimal splenomegaly and leukocyte counts of less than 50 X 10(9)/liter, could lead to an underdiagnosis of PLL and hinder the actual cognition of the natural medical history of the disease.

Testicular malacoplakia.

We report the twentieth case in the world literature of testicular malacoplakia. This lesion occurs mainly in middle-aged men, appearing clinically as epididymo-orchitis or enlargement of the testicle with fibrous consistency and some soft areas. Malacoplakia is now considered a nonspecific inflammatory granulomatous lesion subsequent to an infection by gram-negative bacteria. In our case Escherichia coli was cultured in the urine and testicular tissue. The ultrastructural study shows the histiocytic nature of the cellular infiltrate as well as the morphology of Michaelis-Gutmann bodies. Bacilliform structures were not found. The cellular and humoral immunological studies did not show alterations.

[Familial and hereditary mesangial glomerulonephritis with IgA deposits (author's transl)]. / Glomerulonefritis mesangial con depósitos de IgA, familiar y hereditaria.

Idiopathic mesangial glomerulonephritis with IgA deposits was observed in two relatives, father and son, in a family of 5 members. In the father the disease started at age 43 with relapsing macroscopic hematuria, proteinuria, renal failure and hypertension, with a progressive course in the ensuing four years. The affected son, the oldest of three brothers, developed relapsing macroscopic hematuria at age 16; two years later renal function was normal and there was no hypertension, but microhematuria persisted without proteinuria. The mother and the other two brothers had no clinical or biological signs of renal disease. Serum immunoglobulins (IgG, IgA, and IgM) and complement (C3, C4, C3 proactivator) were normal in the patients and their relatives. Histocompatibility typing demonstrated the presence of HLA-Bw35 in the father and the two unaffected sons, being negative in the mother and the affected son. The analysis of HLA-Bw35 in 23 patients with IgA mesangial glomerulonephritis gave positive results in 30% of them, while the control group had a positivity of 15% (p non significant with the X2 test). The present observations suggest that IgA mesangial glomerulonephritis is a potentially familial and hereditary renal disease. HLA-Bw35 antigen appears not to be a genetic marker of the disease in our geographical area.