ALBERT

Description: Author Posting. © American Meteorological Society 2006. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Climate 19 (2006): 5100–5121, doi:10.1175/JCLI3902.1.

Description: Three interrelated climate phenomena are at the center of the Climate Variability and Predictability (CLIVAR) Atlantic research: tropical Atlantic variability (TAV), the North Atlantic Oscillation (NAO), and the Atlantic meridional overturning circulation (MOC). These phenomena produce a myriad of impacts on society and the environment on seasonal, interannual, and longer time scales through variability manifest as coherent fluctuations in ocean and land temperature, rainfall, and extreme events. Improved understanding of this variability is essential for assessing the likely range of future climate fluctuations and the extent to which they may be predictable, as well as understanding the potential impact of human-induced climate change. CLIVAR is addressing these issues through prioritized and integrated plans for short-term and sustained observations, basin-scale reanalysis, and modeling and theoretical investigations of the coupled Atlantic climate system and its links to remote regions. In this paper, a brief review of the state of understanding of Atlantic climate variability and achievements to date is provided. Considerable discussion is given to future challenges related to building and sustaining observing systems, developing synthesis strategies to support understanding and attribution of observed change, understanding sources of predictability, and developing prediction systems in order to meet the scientific objectives of the CLIVAR Atlantic program.

Description: Acquired deficiency of factor X occurs in patients with systemic amyloid light-chain (AL) amyloidosis, presumably due to adsorption of factor X to amyloid fibrils. Of 368 consecutive patients with systemic AL amyloidosis evaluated at Boston Medical Center, 32 patients (8.7%) had factor X levels below 50% of normal. Eighteen of these patients (56%) had bleeding complications, which were more frequent and severe in the 12 patients below 25% of normal; 2 episodes were fatal. Ten factor X–deficient patients received high-dose melphalan chemotherapy followed by autologous stem cell transplantation. Of 7 patients alive 1 year after treatment, 4 had a complete hematologic response, and all 4 experienced improvement in their factor X levels. One of 2 additional patients with partial hematologic responses had improvement in factor X. Thus, aggressive treatment of the underlying plasma cell dyscrasia in AL amyloidosis can lead to the amelioration of amyloid-related factor X deficiency.

Description: AL amyloidosis is caused by a clonal plasma cell dyscrasia and characterized by widespread, progressive deposition of Amyloid fibrils derived from monoclonal Ig light chains, leading to multisystem organ failure and death. Aggressive treatment of AL amyloidosis with high-dose melphalan followed by autologous stem cell transplant (HDM/SCT) can induce hematologic and clinical remissions and extend survival. However, not all patients are able to tolerate HDM/SCT, particularly those with severe multisystem disease. Consequently, we investigated an alternative treatment regimen consisting of pulsed low-dose intravenous melphalan (LDM) for a series of patients considered ineligible for HDM/SCT because of severe cardiac involvement and poor performance status. LDM was administered at 17.5–25 mg/m2 every 4–6 weeks for 3–4 cycles depending upon patients’ clinical condition, renal function and performance status. Growth factor support was used with each cycle, and the dose of melphalan was reduced by 20% for white blood cell counts

Description: A detailed understanding of the genetic basis of inherited and acquired hematologic diseases has emerged during recent decades, encouraging efforts to develop genetically targeted reagents as both experimental tools and novel therapeutics. Peptide nucleic acid (PNA), a DNA mimic in which the phosphate deoxyribose backbone of DNA has been replaced by a pseudopeptide polymer, first described in 1991, has attracted particular interest as a gene-targeting reagent, since it is highly stable and binds to complementary RNA and DNA with high affinity and specificity. However, because PNA oligomers resist cellular uptake, their development as tools for modifying gene expression in whole animal studies or as potential therapeutic agents has been limited. To explore the possibility that the transmembrane "transport" domains of microbial toxin proteins might serve as vehicles for cellular delivery of PNA, we studied the ability of recombinant Anthrax "protective antigen" (PA), the non-toxic component of Anthrax toxin that mediates cell binding and delivery, to transport antisense PNA oligomers effectively into cells. For these studies, we first generated CHO-K1 cell lines (CHO-Luc654) that had been engineered by stable transfection to express a modified luciferase gene (Luc-βIVS2-654) interrupted by a mutant β-globin intron-2 with an aberrant splice site that could be blocked by antisense PNA, thereby inducing luciferase expression as an indicator of antisense activity (ref.Sazani & Kole, J Clin Invest112:481, 2003). We then synthesized PNA oligomers with poly-lysine tails and 18-mer nucleobase sequences antisense to a region of Luc-βIVS2-654 pre-mRNA flanking the aberrant IVS2-654 splice site. As anticipated from prior reports (Nucleic Acids Res29:3965, 2001), antisense PNA-(Lys)8 oligomers demonstrated detectable sequence-specific activity in inducing luciferase expression in CHO-Luc654 cells when incubated with the cells for 48–72 hrs at micromolar concentrations. However, this activity was greatly and significantly amplified when CHO-Luc654 cells were incubated with antisense PNA-(Lys)8 together with Anthrax PA (0.3–1.0 μg/mL), which had no effects on the cells by itself, such that antisense activity could be detected at PNA concentrations as low as 30 nM. Antisense PNA-(Lys)8 (300 nM), with but not without Anthrax PA (0.3 μg/mL), was also found by rtPCR to induce correctly spliced β-globin transcripts in cultured erythroid progenitor cells obtained from a patient with β-thalassemia [genotype, IVS2-654(βo/βE), kindly provided to us by Dr. Edmond Ma, Queen Mary Hospital, Univ. of Hong Kong]. These studies provide proof-of-principle evidence that the transmembrane transport function of microbial toxins (e.g. Anthrax PA) can be harnessed to deliver antisense PNA oligomers effectively into cells. Since microbial toxin proteins can be molecularly engineered to achieve cell selective binding (as exemplified by the IL2-diphtheria fusion toxin, ONTAK®), our findings support the possibility that novel therapeutic agents, based on PNA oligomer constructs and modified microbial toxin proteins, can be developed that combine both genetic targeting and cell selectivity.

Description: AL amyloidosis is caused by a clonal plasma cell dyscrasia and characterized by widespread, progressive deposition of amyloid fibrils derived from monoclonal Ig light chains, leading to multisystem organ failure and death. Aggressive treatment of AL amyloidosis with high-dose melphalan followed by autologous stem cell transplant (HDM/SCT) can induce hematologic and clinical remissions and extend survival. Several approaches have been used to define hematologic responses of plasma cell dyscrasias underlying AL amyloidosis following HDM/SCT and other forms of treatment. The definition of a hematologic complete response (CR) that we have used requires that there be no evidence of a persistent monoclonal gammopathy by immunofixation electrophoresis (IFE) of serum and urine proteins, or of persistent plasmacytosis or plasma cell clonality in a bone marrow biopsy by immunohistochemistry. Others have defined hematologic response as a ≥ 50% reduction in free light chain (FLC) measurements. Hematologic responses by both criteria correlate with survival and clinical improvement following HDM/SCT. We have carried out a retrospective analysis of HDM/SCT treatment outcomes for patients with AL amyloidosis to determine the extent to which hematologic CR, by our standard criteria, correlates with FLC response. Serum free light chain concentrations (FLC) were measured by a sensitive nephelometric immunoassay in 67 patients with AL amyloidosis before and after treatment with HDM/SCT. After treatment with HDM/SCT, 27 patients (40%) achieved a CR by standard criteria. Of these 27 patients, 63% (n=17) demonstrated normalization of FLC levels and an improvement of ≥50% in FLC occurred in 100%. Of the 40 patients who did not achieve a CR, 25% (n=10) experienced normalization of FLC levels, and an improvement of ≥50% occurred in 78% (n=31), while only 5 patients (13%) experienced no significant change in FLC. The average improvement in FLC was 94% for patients who achieved a CR by standard criteria and 72% for those who did not (p=0.0001, t-test). Thus, HDM/SCT was found to induce improvements in FLC levels of ≥50% in the vast majority of AL amyloidosis patients treated with HDM/SCT (87%, or 58/67). These data indicate that a decrease in FLC of ≥50% is a substantially less stringent indicator of hematologic response than is CR, as defined by standard criteria. Nonetheless, these measures of hematologic response are complementary, since decreases in FLC can be detected earlier following treatment than changes in IFE and marrow studies required to determine CR.

Description: High-dose melphalan and autologous stem cell transplant (HDM/SCT) can induce complete hematologic responses (CR), defined as disappearance of the underlying monoclonal gammopathy from serum and urine by immunofixation electrophoresis, and of the clonal plasma cell dyscrasia by bone marrow immunohistochemistry, and extend survival in patients with AL amyloidosis. HDM/SCT results in a CR in 40% of patients, and leads to clinical improvements in organ function in 〉70% of those who achieve a CR. However, hematologic and clinical relapses occur in ~5% of patients who initially achieve a CR. Tandem cycles of HDM/SCT, for which sufficient PBSC collected during the initial cycle are saved for the second cycle of treatment, have been shown to achieve a higher ultimate CR rate of 〉60%. Among patients who do not achieve a CR following a single cycle of HDM/SCT, 30% nonetheless experience improvements in organ function. However, in this latter group, clinical improvements are not durable. Because there is limited experience with second PBSC collections in patients who have undergone prior myeloablative chemotherapy and because of the potential benefits of repeated cycles of HDM/SCT, we designed a study to explore the feasibility, and efficacy, of a second PBSC mobilization and collection followed by a second cycle of HDM/SCT in patients who relapse after initially responding to a first cycle of HDM/SCT. Results: Five patients, median age 52 (range 43–59), M:F 1.5:1.0, who had achieved hematologic and clinical responses after an initial cycle of HDM/SCT, were treated with a second cycle of HDM/SCT when a hematologic and/or clinical relapse occurred after a median time interval of 39 mo.(range 16–63 mo.). After G-CSF mobilization a mean of 5.2 million CD34 cells/kg was collected in a median of 3 days (range 2–4 days). The yields were not significantly different from those of the first cycle of HDM/SCT. Engraftment occurred at a median of 10 days for neutrophils, and 13 days for platelets (two days without platelet transfusion support); this engraftment timing is similar to that following initial transplants (11 and 12 days respectively). There was no treatment-related mortality, but toxicity was moderate; all patients experienced grade III/IV non-hematologic toxicities. For the 3 patients evaluable at 1 year, no hematologic CR was observed; these patients expired at 38, 37 and 15 mo. Two patients are alive at 5 and 11 mo. post transplant. Conclusion: Patients with AL amyloidosis who experience a hematologic or clinical relapse after responding to an initial course of HDM/SCT can successfully be re-mobilized, and undergo a second cycle of HDM/SCT, with prompt hematopoietic recovery. Clinical benefits of second cycles of HDM/SCT in this setting have yet to be determined. Patient data prior Rx CD34 yield #1/#2 (10E6 cells/kg) HDM #1/#2 (melphalan dose mg/m2) Days to WBC eng #1/#2 Days to PLT eng #1/#2 CR#1/CR#2 Survival (mo.) #1/#2 refer to first/second transplant 1 none 8.0/4.1 200/200 9/11 9/12 yes/no 38 2 M/P x2 8.8/7.7 200/200 11/10 12/34 no/no 37 3 VAD x3 7.9/4.6 200/140 11/10 17/13 no/no 15 4 M/P x2 5.9/6.2 200/200 9/9 12/24 no/? alive at 11 mo. 5 none 4.3/3.4 200/140 11/10 11/11 no/? alive at 5 mo.

Description: Over the past 10 years, HDM/SCT has been employed for treatment of patients with AL amyloidosis. Although peri-transplant mortality is greater than for other hematologic diseases, HDM/SCT leads to durable hematologic complete responses (CR), improvements in organ function, and extended survival in a substantial proportion of patients (Skinner et al., Ann. Int. Med. 2004). In that study, the proportion of patients eligible for HDM/SCT was lower for patients 〉65 years of age than for younger patients (34.3% vs. 68.4%), but the hematologic complete response (CR) rate and survival appeared to be no different. Here, we update these results and present a detailed analysis of outcomes in patients 〉65 vs. those 65. The median age of the 66 patients was 68, range 65–80; 73% male; 18% ? and 82% ?, while for the 283 patients 65 versus 10.3% of patients 65 received an IV dose of melphalan of 200 mg/m2 (the remainder being treated with 140 mg/m2 or less), vs. 64% of those 65 years old. Figure. Figure.

Description: Treatment of AL amyloidosis patients with high-dose melphalan chemotherapy followed by autologous peripheral blood stem cell transplantation (HDM/SCT) can produce hematologic complete responses (CRs) and improvement in organ function. To determine whether these responses are accompanied by improvement in quality of life (QOL), we employed the Medical Outcomes Study (MOS) 36-item Short Form General Health Survey (SF-36) questionnaire for 544 patients evaluated between 1994 and 2002. At baseline, the scores were significantly lower on all 8 SF-36 scales compared with age-matched population norms: the composite physical component summary (PCS) for the AL patients was 34.5 versus the population norm of 46.8, and the mental component summary (MCS) was 45.0 versus the norm of 51.5. All SF-36 scores improved at 1 year, with the MCS reaching the population norm. The PCS, though improved, was still lower than normal but was greater in the subgroup of patients who achieved a hematologic CR; the PCS normalized at 2 years in these patients. Thus, treatment of AL amyloidosis patients with HDM/SCT produces measurable and sustained improvements in quality of life, particularly in those patients who achieve hematologic CR.