Practical management of myelofibrosis with ruxolitinib.

Treatment for the majority of patients with myelofibrosis is primarily based on symptom control as curative allogeneic stem cell transplantation is typically offered only to younger patients, especially those with poor prognosis disease. Around 50% of patients with myelofibrosis have the JAK2(V617F) mutation, but almost all patients have aberrant activation of the JAK-STAT signalling pathway. Recent efforts have focussed on the clinical use of JAK2 inhibitors to treat myelofibrosis. In this article, we present our recommendations for the practical management of myelofibrosis with ruxolitinib, a selective inhibitor of both JAK1 and JAK2. Ruxolitinib can significantly improve the quality of life of patients with myelofibrosis. There is also increasing evidence of a positive impact on survival. Consistent with the physiological role of JAK signalling the major toxicity of ruxolitinib is cytopenia. Managing cytopenia is key to maximising the therapeutic benefit of ruxolitinib. Further research into the safety of ruxolitinib in patients with thrombocytopenia is warranted, as is its role in special subgroups of patients, such as those undergoing stem cell transplantation and those experiencing thrombosis as a major manifestation of myelofibrosis.

Prognostic utility of spontaneous erythroid colony formation and JAK2 mutational analysis for thrombotic events in essential thrombocythaemia.

BACKGROUND: Thrombotic events in essential thrombocythaemia (ET) are difficult to predict with current risk stratification based on age and prior history of thrombosis. AIMS: We aimed to assess the predictive value of the JAK2 V617F mutation (JAK2) and spontaneous erythroid colony (SEC) growth for the development of thrombotic events post diagnosis in patients with ET. METHODS: Consecutive patients with ET were retrospectively identified, and clinical and laboratory correlates were evaluated. Thrombotic events were categorized according to their occurrence at or prior to diagnosis (prior thrombosis), and any time post diagnosis of ET (subsequent thrombosis). JAK2 analysis was performed by allele-specific PCR on whole blood or bone marrow. RESULTS: A total of 62 patients was identified, median age 63 years; 67% (41/61) JAK2-positive and 47% (25/53) SEC-positive. Median follow-up was 33 months (range, 1 to 137). JAK2-positive patients showed a trend to increased prior thrombosis (27% vs 5%, P= 0.08), and a significant increase in the development of subsequent thrombosis (5-year event rate 31% vs 6%, P= 0.04), which persisted when stratified for a history of prior thrombosis (P= 0.04). Survival was not affected by JAK2 status. The SEC assay predicted an increased rate of baseline thrombosis (16% vs 0%, P= 0.04), but was not found to be predictive of any subsequent thrombotic events. CONCLUSIONS: Patients with ET who are JAK2-positive by whole blood allele-specific PCR appear to be at increased risk of thrombotic complications, which is independent of a prior history of thrombosis.

Results of a phase I/II study of ocrelizumab, a fully humanized anti-CD20 mAb, in patients with relapsed/refractory follicular lymphoma.

BACKGROUND: Ocrelizumab is a humanized anti-CD20 antibody with increased antibody-dependent cellular cytotoxicity compared with rituximab. This phase I/II study evaluated its safety and efficacy in patients with relapsed/refractory follicular lymphoma (FL) after prior rituximab therapy. DESIGN AND METHODS: Forty-seven patients were treated in three dose cohorts and received eight infusions every 3 weeks: cohort A, 200 mg/m(2) (n = 15); cohort B, 375 mg/m(2) (n = 16); cohort C, first dose 375 mg/m(2), seven subsequent doses of 750 mg/m(2) (n = 16). Patients were assessed for safety, efficacy, pharmacodynamics and pharmacokinetics. RESULTS: The median patient age was 58 years, the majority had Ann Arbor stage III/IV disease and had received a median of 2 (range 1-6) prior regimens. Ocrelizumab was well tolerated with grade 3/4 toxicity occurring in 9% of patients. The most common toxicity was infusion-related reactions (74% patients), all grade 1/2 except one grade 3 event. The objective response rate was 38% and was similar in patients with low-affinity and high-affinity variants of the Fcgamma receptor IIIa (FcgammaRIIIa). With follow-up of approximately 28 months, the median progression-free survival was 11.4 months. CONCLUSION: Ocrelizumab demonstrated activity in patients with relapsed/refractory FL following prior rituximab treatment, with safety similar to rituximab although adverse events appeared milder.

Diagnostic and prognostic utility of the serum free light chain assay in patients with AL amyloidosis.

BACKGROUND: Organ dysfunction in AL amyloidosis is related to the production and deposition of amyloidogenic monoclonal light chains. These pathological light chains can now be quantified using the recently developed serum free light chain assay. METHODS: We retrospectively reviewed 31 patients with AL amyloidosis to determine the frequency of abnormal free light chain assay results at diagnosis and whether changes in the serum free light chain assay predict outcome after therapy. RESULTS: An abnormal free light chain assay was found in 30 of 31 patients (97%) at the time of diagnosis. In the subset of our patients who received treatment for AL amyloidosis, a >50% reduction of the pathological free light chain following treatment was shown to predict improved overall survival. In our series of analyses, achievement of greater magnitudes of reduction of the free light chain result did not appear to provide additional prognostic information, nor did the baseline free light chain result predict outcome. CONCLUSION: Our findings support the use of the free light chain assay in the diagnostic work-up of patients with suspected AL amyloidosis, and also as a sensitive biomarker of response to therapy.

Autografting followed by rituximab for chemosensitive mantle cell lymphoma: a pilot study and literature review.

Mantle cell lymphoma (MCL) is rarely cured with either conventional-dose chemotherapy or autografting. Recent evidence suggests that anti-CD20 monoclonal antibody therapy (rituximab) in combination with chemotherapy may improve the response rate. We report a pilot study of autografting using busulfan-melphalan conditioning followed by rituximab in 9 patients (median age 52 years) with chemosensitive MCL. Rituximab was given for 4 doses of 375 mg/m(2) between 4 and 10 weeks post-transplant. Three of 5 patients autografted after induction therapy remain alive in clinical and molecular complete remission at 33-50 months post-transplant. Only 1 of 4 patients autografted after relapse remains in complete remission. Two of the 3 patients with persistent marrow molecular positivity post-autograft became negative after rituximab therapy. Molecular negativity was first observed in 2 patients only after rituximab therapy. Overall, 2 patients have relapsed and the remaining 3 died of late-onset respiratory failure, probably reflecting infection and/or aggressive conditioning in an older patient population. These preliminary results, together with a review of the literature, suggest that the combination of autografting and rituximab may lead to durable molecular remissions in patients with chemosensitive MCL. Further studies are required to clarify whether the administration of rituximab: (1) is optimal pre- or post-autograft and (2) impacts on the incidence of infection and idiopathic pneumonitis in this context.

A simplified endogenous erythroid colony assay for the investigation of polycythaemia.

The in vitro growth of erythroid colonies in the absence of erythropoietin, known as endogenous erythroid colonies (EEC) forms part of the diagnostic criteria for polycythaemia vera (PV). The availability of EEC culture in routine laboratory setting is limited as culture methods are technically demanding, difficult to standardize, expensive and laborious. In this study, we assessed the performance characteristics of a simplified method using ammonium chloride red cell lysis followed by culture on commercially available, batch-tested, methylcellulose media. Seventy-six patients were included; four were secondarily excluded on the basis of culture failure. Of the 14 patients with PV, 13 (93%) were positive for EEC on at least one occasion: 90% (nine of 10) of bone marrow and 67% (six of nine) of peripheral blood specimens were positive. All 30 patients with secondary polycythaemia (n = 12) or apparent polycythaemia (n = 18) were negative for EEC. The incidence of EEC in idiopathic erythrocytosis was 40% (eight of 28); 50% (five of 10) in those who met one of the minor criteria for PV and 17% (three of 18) in those who did not. We conclude that our EEC assay yield results comparable with that of more elaborate methods.

Monitoring dendritic cells in clinical practice using a new whole blood single-platform TruCOUNT assay.

Dendritic cells (DC) from distinct DC subsets are essential contributors to normal human immune responses. Despite this, reliable assays that enable DC to be counted precisely have been slow to evolve. We have now developed a new single-platform flow cytometric assay based on TruCOUNT beads and the whole blood "Lyse/No-Wash" protocol that allows precise counting of the CD14(-) blood DC subsets: CD11c(+)CD16(-) DC, CD11c(+)CD16(+) DC, CD123(hi) DC, CD1c(+) DC and BDCA-3(+) DC. This assay requires 50 microl of whole blood; does not rely on a hematology blood analyser for the absolute DC counts; allows DC counting in EDTA samples 24 h after collection; and is suitable for cord blood and peripheral blood. The data is highly reproducible with intra-assay and inter-assay coefficients of variation less than 3% and 11%, respectively. This assay does not produce the DC-T lymphocyte conjugates that result in DC counting abnormalities in conventional gradient-density separation procedures. Using the TruCOUNT assay, we established that absolute blood DC counts reduce with age in healthy individuals. In preliminary studies, we found a significantly lower absolute blood CD11c(+)CD16(+) DC count in stage III/IV versus stage I/II breast carcinoma patients and a lower absolute blood CD123(hi) DC count in multiple myeloma patients, compared to age-matched controls. These data indicate that scientific progress in DC counting technology will lead to the global standardization of DC counting and allow clinically meaningful data to be obtained.

Molecular remission without blood product support using all-trans retinoic acid (ATRA) induction and combined arsenic trioxide/ATRA consolidation in a Jehovah's Witness with de novo acute promyelocytic leukaemia.

Arsenic trioxide has recently been used in the treatment of both relapsed and de novo acute promyelocytic leukaemia (APML). Molecular remissions have been attained using arsenic trioxide with minimal associated haematological toxicity, making protocols utilizing this drug an attractive option for Jehovah's Witnesses with APML. A 62-year-old female Jehovah's Witness with de novo APML was treated with all-trans retinoic acid induction followed by combined arsenic trioxide/ATRA consolidation, and achieved molecular remission with minimal haematological toxicity and no blood product support.

Endoscopic diagnosis of pyriform fossa lymphoma.

Many endoscopists do not inspect the gastrointestinal tract superior to the cricopharyngeus, despite the fact that gastrointestinal symptoms (dysphagia, odynophagia and chest pain) can be produced by glottic and supraglottic lesions. A case of incoordinate swallowing secondary to a right-sided pyriform fossa lymphoma diagnosed at gastroscopy is presented.

Cytogenetic and clinical correlates in AML patients with abnormalities of chromosome 16.

Abnormalities of chromosome 16 in AML include del(16q), inv(16) and t(16;16). These three groups have been categorized together and have been associated with high complete remission (CR) and survival rates following Ara-C-based chemotherapy. We have reviewed the 63 AML or MDS patients with an abnormality of chromosome 16 treated at MD Anderson Cancer Center (MDACC) over the past 18 years. Marked differences in survival and remission duration (RD) were noted between the inv(16) or t(16;16) patients and those with del(16q), whose outcome was no better than other M4 AML or MDS patients treated during the same period. Other differences characterizing del(16q) included a lack of CNS relapses, lower incidences of eosinophilia and M4 FAB subtype. Half the inv(16) patients had additional karyotypic abnormalities. The overall survival and remission duration for those patients were no different from those for patients with inv(16) alone, although the probability of remaining in first CR at 2 years was higher in the inv(16) alone group. There was no difference in overall survival for the 45 patients who received HDAC vs those who did not. The incidence of CNS relapse was, however, markedly reduced for the HDAC patients. Eosinophilia did not correlate with improved survival. We conclude that del(16q) confers a different prognosis from inv(16) and t(16;16) and for the purposes of prognostication or treatment recommendations should no longer be categorized with them. Additional karyotypic changes however, which accompany inv(16) in 50% of cases do not influence the overall outcome compared to patients with inv(16) alone.

Molecular characterization of 16p deletions associated with inversion 16 defines the critical fusion for leukemogenesis.

The inversion of chromosome 16 [inv(16)] in acute myeloid leukemia (AML) is associated with a p-arm deletion in a subset of patients. The inversion results in two fusion genes: 5'-CBFB/MYH11-3' on 16p and 5'-MYH11/CBFB-3' on 16q. We have studied cells from 42 patients with inv(16) (38 patients) or t(16;16) (four patients) to define the frequency and characteristics of the deletion further. Using fluorescence in situ hybridization (FISH) with probes from cosmids, cosmid contigs, and yeast artificial chromosomes (YACs), we found that six patients with inv(16) had a deletion of between 150 and 350 kb centromeric to the p-arm inversion breakpoint cluster region (p-ibc). This region was shown to contain the 5' portion of the myosin heavy chain (MYH11) gene. YACs containing the p-ibc, which had been useful as FISH probes in the diagnosis of inv(16), detected the inversion in deletion as well as nondeletion patient cells. Thus, the deleted region identified in patients is entirely contained within the human genomic content of the YACs. Southern blot experiments using probes flanking the p-ibc indicated that the deletion removes segments within 10 kb centromeric of the p-ibc. Reverse transcription-polymerase chain reaction (RT-PCR) using primers from the 5' region of CBFB and the 3' region of MYH11 (distal to the p-ibc) produced the 5'-CBFB/MYH11-3' chimeric transcript in inv(16)/del patients. These data confirm that the 5'-CBFB/MYH11-3' chimeric transcript, rather than the reciprocal 5'-MYH11/CBFB-3', is the critical product for chromosome 16-related leukemogenesis.

Detection of fusion transcripts generated by the inversion 16 chromosome in acute myelogenous leukemia.

Pericentric inversion of chromosome 16 [inv(16)(p13q22)] and the related t(16;16)(p13;q22) are seen in a subset of acute myelogenous leukemia (AML) phenotypically and prognostically differing from other cases. We have recently shown that inv(16) results in fusion of CBFB/PEBP2B, a gene encoded at 16q22 to MYH11, a smooth muscle myosin heavy chain gene encoded at 16p13. Chimeric transcripts consisting of upstream CBFB fused to downstream MYH11 coding sequences result from this fusion. In this study we have examined a series of 37 of these cases using reverse transcriptase-polymerase chain reaction (RT-PCR) to detect expression of a hybrid CBFB/MYH11 transcript. Chimeric cDNAs were detected in all but 1 of 37 leukemias with typical inv(16) or t(16;16). Such chimeric products were not seen in a case with inv(16)(p13q24) (ie, a variant q arm breakpoint) or any of 10 cases of AML without these chromosomal changes. Four different chimeric transcripts were found, representing differing fusion points within MYH11 spliced to position 495 of CBFB. Primer sets are described for efficient amplification of these different cDNA forms. Amplification of cDNA showed that all but 17 codons of the CBFB coding sequence are included in the abnormal transcripts. RT-PCR was shown to be highly sensitive and potentially useful for detection of leukemic cells during morphologic remission.

Smooth muscle myosin heavy chain locus (MYH11) maps to 16p13.13-p13.12 and establishes a new region of conserved synteny between human 16p and mouse 16.

The human smooth muscle myosin heavy chain locus (MYH11) was mapped by fluorescence in situ hybridization to the middle of the p arm of chromosome 16 using a genomic cosmid clone containing coding sequences of the gene as probe. Probe from coding sequence, when applied to Southern blots of a panel of hybrids containing different portions of human chromosome 16, localized the gene to 16p13.13-13.12. Coding sequence PCR primers, when used on the DNA from a CHO-mouse hybrid clone mapping panel informative for mouse chromosomes, showed that the gene was located on mouse chromosome 16. These results correct a recent assignment of MYH11 from 16q12.2 to the region of the 16p-arm inversion breakpoint seen in acute myelomonocytic leukemia (AMML) M4Eo and demonstrate that the conflicting data do not result from the presence of additional MYH genes on the q arm of the chromosome. Also, a new region of conserved synteny between human 16p and mouse 16 is established.

Discordant neutrophil alkaline phosphatase activity and cytogenetic response in chronic myeloid leukemia treated with alpha-interferon.

Decreased neutrophil alkaline phosphatase (NAP) synthesis is a classical feature of Philadelphia (Ph) positive chronic phase chronic myeloid leukemia (CML). Whether this aberration is an integral leukemic property of the cell or results from mediation by other factors is unclear. During alpha-interferon (alpha-IFN) based therapy the relationship between Ph chromosome suppression and NAP synthesis was examined. Four categories of response were observed in 19 patients studied sequentially. Significantly, persistent low NAP activity was observed in one patient in complete cytogenetic remission, while a second group of 7 patients demonstrated normal NAP activity in spite of persistence of the Ph chromosome in 100% of metaphases. In the absence of various clinical influences that can modulate NAP activity in chronic phase CML, the results reinforce the observation that the BCR/ABL fusion gene product is not a key factor influencing NAP activity in CML.

Identification of yeast artificial chromosomes containing the inversion 16 p-arm breakpoint associated with acute myelomonocytic leukemia.

We report the cloning of the chromosome 16 p-arm breakpoint involved in inversion 16(p13;q22) associated with subtype of acute myelomonocytic leukemia (AMML) M4Eo. Inter-Alu polymerase chain reaction (PCR) products from a series of interspecific somatic cell hybrids that contain only small portions of the human chromosome 16 p-arm were generated for use as fluorescent in-situ hybridization (FISH) probes. When applied to patient cells, rapid and unambiguous identification of the inversion resulted. Using FISH analysis, cosmid clones associated with the hybrids were identified that bracketed the p-arm breakpoint. A repeat-free fragment of one of these cosmids (35B11) when used as probe on Southern blots from pulsed-field gels identified rearranged macrorestriction fragments in patient DNA. Yeast artificial chromosomes (YACs) were isolated using sequences derived from cosmids flanking 35B11 in a cosmid contig. Of 4 YACs so identified, 3 were shown by FISH to cross the inversion-16 p-arm breakpoint. Therefore, the breakpoint has been molecularly cloned, and identified as being within these 3 YACs. These clones will facilitate the unraveling of the genetic events associated with inversion-16 and are available tools with immediate clinical application.

Fusion between transcription factor CBF beta/PEBP2 beta and a myosin heavy chain in acute myeloid leukemia.

The pericentric inversion of chromosome 16 [inv(16)(p13q22)] is a characteristic karyotypic abnormality associated with acute myeloid leukemia, most commonly of the M4Eo subtype. The 16p and 16q breakpoints were pinpointed by yeast artificial chromosome and cosmid cloning, and the two genes involved in this inversion were identified. On 16q the inversion occurred near the end of the coding region for CBF beta, also known as PEBP2 beta, a subunit of a heterodimeric transcription factor regulating genes expressed in T cells; on 16p a smooth muscle myosin heavy chain (SMMHC) gene (MYH11) was interrupted. In six of six inv(16) patient samples tested, an in-frame fusion messenger RNA was demonstrated that connected the first 165 amino acids of CBF beta with the tail region of SMMHC. The repeated coiled coil of SMMHC may result in dimerization of the CBF beta fusion protein, which in turn would lead to alterations in transcriptional regulation and contribute to leukemic transformation.

Noninfectious osteitis: part of the SAPHO syndrome.

SAPHO, a rare syndrome, is a recently suggested acronym for synovitis, acne, pustulosis, hyperostosis and osteitis. It encompasses many features which have been described in different but overlapping conditions. Not all of the syndrome components need to be present for inclusion in SAPHO to be justified, especially the dermatologic components. Two cases are described as examples. Clinicians should be aware of this rare disorder if positive early diagnoses are to be made in patients presenting with skeletal pain.