Where Does Morphology Fit in Myelodysplastic Syndrome Diagnosis in the Era of Molecular Testing?

The recognition of cytologic dysplasia in blood and bone marrow remains the cornerstone of myelodysplastic syndromes (MDS) diagnosis because it distinguishes MDS from clonal hematopoiesis of indeterminate potential or clonal cytopenia of undetermined significance. Expert morphologists achieve high concordance in the diagnosis of MDS if appropriate clinical information is provided. Because of the low prevalence of MDS, diagnostic approaches based solely on molecular diagnosis will likely be erroneous.

Concomitant Non-Small Cell Lung Cancer and Hairy Cell Leukemia in a Patient Harboring BRAF-V600E Mutation in Both Tissues: A Case Report.

The BRAF-V600E mutation has been established as a signature alteration occurring almost universally in hairy cell leukemia. Moreover, it can be detected in a small percentage of patients with non-small cell lung cancer. We report the case of a patient with a metastatic BRAF-V600E-mutated lung adenocarcinoma suffering from concomitant hairy cell leukemia. The identification of an identical BRAF mutation in both malignancies raises physiopathological considerations and might offer unique therapeutic strategies for this group of patients.

Staphylococcal major autolysin (Atl) is involved in excretion of cytoplasmic proteins.

Many microorganisms excrete typical cytoplasmic proteins into the culture supernatant. As none of the classical secretion systems appears to be involved, this type of secretion was referred to as "nonclassical protein secretion." Here, we demonstrate that in Staphylococcus aureus the major autolysin plays a crucial role in release of cytoplasmic proteins. Comparative secretome analysis revealed that in the wild type S. aureus strain, 22 typical cytoplasmic proteins were excreted into the culture supernatant, although in the atl mutant they were significantly decreased. The presence or absence of prophages had little influence on the secretome pattern. In the atl mutant, secondary peptidoglycan hydrolases were increased in the secretome; the corresponding genes were transcriptionally up-regulated suggesting a compensatory mechanism for the atl mutation. Using glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as a cytoplasmic indicator enzyme, we showed that all clinical isolates tested excreted this protein. In the wall teichoic acid-deficient tagO mutant with its increased autolysis activity, GAPDH was excreted in even higher amounts than in the WT, confirming the importance of autolysis in excretion of cytoplasmic proteins. To answer the question of how discriminatory the excretion of cytoplasmic proteins is, we performed a two-dimensional PAGE of cytoplasmic proteins isolated from WT. Surprisingly, the most abundant proteins in the cytoplasm were not found in the secretome of the WT, suggesting that there exists a selection mechanism in the excretion of cytoplasmic proteins. As the major autolysin binds at the septum site, we assume that the proteins are preferentially released at and during septum formation.

Lenalidomide: a brief review of its therapeutic potential in myelodysplastic syndromes.

Lenalidomide is a novel thalidomide analogue with enhanced immunomodulatory and antiangiogenic action lacking most of the typical thalidomide-associated adverse events. In myelodysplastic syndromes (MDS), it has been used primarily in the IPSS low- and intermediate-1 risk setting. Several trials have demonstrated its potential to lead to both erythroid and cytogenetic responses in these disease groups. In a clinical trial of patients with a del(5q) chromosomal abnormality, lenalidomide treatment resulted in red blood cell (RBC) transfusion independence in 67% of patients. Moreover, 45% of patients achieved a complete cytogenetic remission, and 28% achieved a minor cytogenetic remission. This result was independent of karyotype complexity. Lenalidomide might also induce long-term remissions in del(5q) patients with an elevated medullary blast count. In non-del(5q) patients, 43% of patients with confirmed low- and intermediate-1 risk achieved transfusion independence or a reduction of at least 50% of pre-treatment RBC transfusion levels. Adverse events are common but manageable and include neutropenia and thrombocytopenia, pruritus, rash, diarrhea, and others. Lenalidomide will prove an essential part in the armamentarium of MDS therapeutics. Combination therapies with cytokines, demethylating agents, tyrosine kinase inhibitors, or chemotherapy are being investigated and may show additional benefit in both low- and high risk MDS.

Lenalidomide in the context of complex karyotype or interrupted treatment: case reviews of del(5q)MDS patients with unexpected responses.

Lenalidomide has particular activity in patients with transfusion-dependent del(5q) myelodysplastic syndromes (MDS), but mechanistic information is limited regarding the relationship between erythroid and cytogenetic responses. We reviewed medical records from three distinct subgroups of del(5q) MDS patients who had unexpected effects with lenalidomide treatment: 1. two patients with complex karyotypes who achieved both cytogenetic remissions and transfusion independence; 2. two patients with 5q- syndrome who took lenalidomide for less than 12 weeks but remained transfusion independent for 15+ months still displaying del(5q) metaphases after 6 and 12 months; and 3. one patient who was a non-responder on lenalidomide during treatment but became transfusion independent for 13+ months after discontinuation. All but the latter patient in this series had reduction of affected metaphases, suggesting that erythroid responses might be mediated by result from partial or complete suppression of the malignant clone, either directly or indirectly through modulation of the bone marrow microenvironment. These clinical observations illustrate the heterogeneity of del(5q)MDS pathogenesis and the diversity of lenalidomide responses within this patient subset.

Treatment of myelodysplastic syndrome with isolated del(5q) including bands q31-q33 with a combination of all-trans-retinoic acid and tocopherol-alpha: a phase II study.

All-trans-retinoic acid (ATRA) alone or in combination with cytokines and vitamins has been shown to stimulate erythropoiesis in low-risk myelodysplastic syndromes (MDS). We performed a phase II study on 29 patients with MDS and isolated del(5q) including bands q31-q33 to determine the efficacy and safety of ATRA in combination with tocopherol-alpha. All patients had low/intermediate-1 risk MDS according to the international prognostic scoring system. They received 45 mg/m(2) ATRA on days 1 to 90, and 90 mg/m(2) on days 91 to 180. Tocopherol dosage was 600 IU three times daily. Twenty-four patients completed dose level I, and 12 patients dose level II. Eighty-six percent of patients experienced side effects. Thirty discontinued the drug treatment due to such events as skin reactions, cheilitis, conjunctivitis, joint pain, creatinine increase, or CNS symptoms. One patient (3%) achieved a major erythroid response resulting in transfusion independence throughout the study. Four patients (14%) achieved a minor erythroid response with >50% reduction of transfusion needs. None of the participants had a cytogenetic response. There was no significant improvement in quality of life among responding patients as measured by the European Organization for the Research and Treatment of Cancer (EORTC) quality of life questionnaire. Based on these results, the combination of ATRA and tocopherol-alpha is not recommended for the treatment of del(5q) MDS.

Neuronal apoptosis in the dentate gyrus in humans with subarachnoid hemorrhage and cerebral hypoxia.

Apoptosis of dentate granule cells is a typical feature of several animal models of disease. In 20 autopsy cases of subarachnoid hemorrhage (SAH) and global cerebral hypoxia caused by protracted shock or respiratory failure, we evaluated by light microscopy and in situ tailing whether this pattern of neuronal damage also occurs in humans. In subarachnoid hemorrhage, 4.0/mm2 (0-13.0/mm2) apoptotic neurons were observed in the dentate gyrus, in cerebral hypoxia 3.6/mm2 (0-19.9/mm2) (p>0.05), and in 10 aged-matched control cases dying rapidly from non-neurological diseases 0/mm2 (0-0/mm2) (median [range]) (p<0.001 versus SAH and hypoxia). Neuronal apoptosis in the dentate gyrus was most frequent, when death occurred later than 24 hours and less than 11 days after disease onset. Neuronal damage in the hippocampus was always necrotic. It was more severe in hypoxia than in SAH (median neuronal damage score 3 [range: 0-3] versus 0 [0-3], p<0.001). Apoptosis appears to be the predominant mechanism of death in dentate granule cells irrespective of the underlying disease, whereas neuronal death in the hippocampus generally is of necrotic morphology.