Multiple isolated extramedullary relapse of acute promyelocytic leukemia after allogeneic hematopoietic stem cell transplant: a case report and review of literature

Isolated extramedullary disease (EMD) is uncommon, especially in acute promyelocytic leukemia (APL) after allogeneic hematopoietic stem cell transplantation (HSCT). We review the literature and present a 32 year old woman with APL who developed multiple EMDs after allogeneic HSCT within the calvarium, and later found to have various isolated lesions including femur, humerus and thoraco lumbar vertebrae. She was treated with local radiotherapy (XRT) to EMD lesions, all-trans retinoic acid, arsenic trioxide and donor lymphocyte infusion at different time points in her clinical course, without success. Out of reported cases in clinical setting as ours, average onset of isolated EMD is 25 months and median survival 14 months. Effective treatment of isolated EMD after HSCT is not yet clear, but ATO in combination with local XRT, tamibarotene and second HSCT have shown good results in some reported cases, but accumulation of more cases is needed to elucidate optimal therapy in such setting.

Chimerism and tolerance without GVHD or engraftment syndrome in HLA-mismatched combined kidney and hematopoietic stem cell transplantation

The toxicity of chronic immunosuppressive agents required for organ transplant maintenance has prompted investigators to pursue approaches to induce immune tolerance. We developed an approach using a bioengineered mobilized cellular product enriched for hematopoietic stem cells (HSCs) and tolerogenic graft facilitating cells (FCs) combined with nonmyeloablative conditioning; this approach resulted in engraftment, durable chimerism, and tolerance induction in recipients with highly mismatched related and unrelated donors. Eight recipients of human leukocyte antigen (HLA)-mismatched kidney and FC/HSC transplants underwent conditioning with fludarabine, 200-centigray total body irradiation, and cyclophosphamide followed by posttransplant immunosuppression with tacrolimus and mycophenolate mofetil. Subjects ranged in age from 29 to 56 years. HLA match ranged from five of six loci with related donors to one of six loci with unrelated donors. The absolute neutrophil counts reached a nadir about 1 week after transplant, with recovery by 2 weeks. Multilineage chimerism at 1 month ranged from 6 to 100%. The conditioning was well tolerated, with outpatient management after postoperative day 2. Two subjects exhibited transient chimerism and were maintained on low-dose tacrolimus monotherapy. One subject developed viral sepsis 2 months after transplant and experienced renal artery thrombosis. Five subjects experienced durable chimerism, demonstrated immunocompetence and donor-specific tolerance by in vitro proliferative assays, and were successfully weaned off all immunosuppression 1 year after transplant. None of the recipients produced anti-donor antibody or exhibited engraftment syndrome or graft-versus-host disease. These results suggest that manipulation of a mobilized stem cell graft and nonmyeloablative conditioning represents a safe, practical, and reproducible means of inducing durable chimerism and donor-specific tolerance in solid organ transplant recipients.

Rituximab, gemcitabine, vinorelbine, and methylprednisone (R-GVM), a hematopoietic cell (HC) mobilizing and salvage regimen for malignant lymphoma (ML)

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Background: The prognosis of pts with recurrent ML remains poor. High-dose therapy (HDT) with HC rescue can cure a proportion of such pts. HC mobilization can be adversely affected by number and duration of prior treatments, interval from diagnosis to HC collection, prior radiotherapy and marrow involvement. There remains a need for more effective and less toxic salvage regimens, capable of mobilizing HCs. Methods: The mobilizing potential of R-GVM salvage regimen with hematopoietic growth factor (HGF) support (G- and GM-CSF) was evaluated in 6 pts with relapsed (n=5) or primary refractory (n=1) ML. Pts received R-GVM salvage therapy [rituximab (375 mg/m2, day 1), gemcitabine (1 g/m2, day 1, 8), vinorelbine (30 mg/m2, day 1, 8) and methylprednisone (1 g/m2, day 1, 8)] with HGF administration and subsequent HC collection. The HGF support was started on day 9 and was continued through apheresis which started when the CD34+ cell count ≥ 20/μl (median day of R-GVM cycle: 15, range 14–19). Pts had daily apheresis with continued HGF support until at least 5 x 106 CD34+ cells/kg were collected. The hematologic and non-hematologic toxicity were tolerable in all pts; no pt required hospitalization. Results: 6 pts (age range 20–45 years) with Hodgkin (n =3) and non- Hodgkin lymphoma (n =3) were evaluated in this study. Pts had received 1–3 previous treatment regimens. The median number of R-GVM courses given before HC collection was 2.5 (range 1–5). Effective HC mobilization (≥5x106 CD34+ cells/kg) was obtained in all ps. A single apheresis resulted in satisfactory HC collection in 4 pts (range 8.2–17.7 x 106 CD34+ cells/kg); 2 pts required 3 aphereses to collect an adequate number of cells (6.7 and 7.4 x 106 CD34+ cells/kg). One pt was heavily pretreated and had failed two previous attempts of HC mobilization (one with HGF alone and one with cyclophosphamide and HGF); the other pt was HIV+ treated with HAART and had prior marrow involvement. As a salvage regimen, one pt had progressive disease, 1 had stable disease, 1 had a partial response, and 3 had a complete response before proceeding with HDT with HC rescue. Conclusions: R-GVM regimen is feasible, tolerable and effective in mobilizing HPC in patients with relapsed and refractory lymphoma.

No significant financial relationships to disclose.

Selective inhibitors of CYP24: mechanistic tools to explore vitamin D metabolism in human keratinocytes

Human keratinocytes are fully competent cells of the vitamin D (VD) hormone system. They have the capacity to generate VD, to convert it to hormonally active 1alpha,25(OH)(2)D(3) and subsequently, to metabolize the hormone by self-induced CYP24. These reactions generate a cascade of highly transient products and, eventually terminate biologic activity. To elucidate regulatory principles in the VD cascade in more detail, we made use of novel selective CYP24 inhibitors, recently synthesized by our group. Here, we describe the effects of VID400 and SDZ 89-443 on the metabolism of 20 nM (3)H-25(OH)D(3) in human keratinocytes, analyzed by sensitive HPLC methods. First, we present evidence that freshly generated 1alpha,25(OH)(2)D(3) does not down-regulate 1alpha-hydroxylation, as commonly assumed. The transient time course of 1alpha,25(OH)(2)D(3), could be explained by its fast 24-hydroxylation to polar products, undetectable by usual HPLC-analysis of organic extracts. On inhibition of CYP24, 1alpha-hydroxylation continued throughout extended periods, indicating its constitutive nature. Asking whether 1alpha,25(OH)(2)D(3) derived metabolites [1alpha,25(OH)(2)-3epi-D(3), 1alpha,24(R),25(OH)(3)D(3), 1alpha,25(OH)(2)-24oxo-D(3), 1alpha,23(S),25(OH)(3)-24-oxo-D(3) and calcitroic acid] would regulate 1alpha-hydroxylase, we pre-treated cells with 20 nM of these metabolites for 5 h and 24 h. Subsequent incubation with (3)H-25(OH)D(3) demonstrated that neither metabolite substantially impaired 1alpha-hydroxylase, while all of them transiently induced CYP24 activity. Analyzing the effects of VID400 on the kinetics of (3)H-25(OH)D(3), we showed that 1alpha-hydroxylation rather than 24-hydroxylation was rate-limiting in the C-24 oxidation pathway - again suggesting constitutive expression of 1alpha-hydroxylase. CYP24 inhibitors effectively increased the levels and lifetime of all transient 1alpha-hydroxylated metabolites, especially of 1alpha,25(OH)(2)-3epi-D(3) that became the predominant lipid soluble metabolite. Highly increased levels of 1alpha,23(S),25(OH)(3)-24-oxo-D(3), the metabolite preceding side chain cleavage, indicated involvement of CYP24 also in the terminal step of the cascade. Besides using inhibitors of CYP24 as tools to explore mechanisms in the VD cascade, they also appear to be valuable to discover the intrinsic biologic functions of distinct metabolites.

Selective inhibition of vitamin D hydroxylases in human keratinocytes

Human keratinocytes convert 25(OH)D(3) to hormonally active 1alpha,25(OH)(2)D(3) and respond to its antiproliferative/prodifferentiating action in vitro and in vivo. Levels and activity of 1alpha,25(OH)(2)D(3) are short-lived. 1alpha,25(OH)(2)D(3) induces 24-hydroxylase (CYP24) that rapidly metabolizes the hormone, yielding a cascade of side-chain oxidized products and this eventually results in the loss of activity. Aiming at stabilizing the levels of active hormone, we have searched for potent, selective inhibitors of CYP24. Selective inhibition was crucial in order to avoid impairment of 1alpha,25(OH)(2)D(3) synthesis, catalyzed by 1alpha-hydroxylase - a related member of cytochrome P-450 (CYP) superfamily. We describe here the testing protocol, using primary human keratinocyte cultures as an appropriate source of CYP24 and 1alpha-hydroxylase, (3)H-25(OH)D(3) (at physiological concentrations) as substrate and sensitive HPLC techniques to analyze the complex metabolite profiles. Four hundred potential inhibitors were screened by this method; most of them were synthesized in our laboratory. These compounds (entitled azoles) were capable of direct binding to the heme iron and of additional interactions with other parts of the enzyme. In this paper, we present VID400 and SDZ 89-443, as first examples of powerful selective CYP24 inhibitors. As anticipated, these compounds increased the levels of 1alpha-hydroxylated products generated from (3)H-25(OH)D(3) and extended their lifetime. Importantly, blocking of 24-hydroxylation led to a switch in metabolism, namely to preferential conversion of 1alpha,25(OH)(2)D(3) to 1alpha,25(OH)(2)-3epi-D(3). As spin-off from our program, selective inhibitors of 1alpha-hydroxylase were also found (e.g. SDZ 88-357). Using (3)H-25(OH)D(3) as substrate in the absence of SDZ 88-357, CYP24 showed high preference for freshly generated 1alpha-hydroxylated metabolites over abundant 25(OH)D(3). In the presence of SDZ 88-357, we noticed a great increase in 24-hydroxylation of (3)H-25(OH)D(3). Besides their use as valuable tools in elucidating regulatory mechanisms, inhibitors of VD hydroxylases may give rise to novel therapeutic strategies, especially in defects of cell growth and differentiation.

Skin is an autonomous organ in synthesis, two-step activation and degradation of vitamin D(3): CYP27 in epidermis completes the set of essential vitamin D(3)-hydroxylases

The current understanding of the vitamin D(3) system shows skin as the unique site of vitamin D(3) production and liver is thought to be the main site of conversion to 25(OH)D(3). Skin is capable of activating 25(OH)D(3) via 1alpha-hydroxylation and the resulting 1alpha,25(OH)(2)D(3) plays a role in epidermal homeostasis in normal and diseased skin. It also rapidly up-regulates the major vitamin D(3) metabolizing enzyme 24-hydroxylase at the mRNA level, which is an established indicator for 1alpha,25(OH)(2)D(3)-presence. We investigated the capability of primary human keratinocytes to produce 25(OH)D(3) and subsequent metabolites from vitamin D(3). Thus, by orchestrating the entire system of production, activation and inactivation, skin could be independent of other organs in supply of hormonally active vitamin D(3). First, we demonstrated substantial conversion of (3)H-D(3) to (3)H-25(OH)D(3) in primary human keratinocytes. 25-Hydroxylation was slow, followed first order rate kinetics and was not saturable under our experimental conditions. Then we showed expression of 25-hydroxylase mRNA and compared it to levels of 1alpha-hydroxylase and 24-hydroxylase. Pre-incubation with vitamin D(3) resulted in dose and time dependent up-regulation of 24-hydroxylase mRNA, whereas neither 1alpha-hydroxylase nor 25-hydroxylase expression was affected. Since both, D(3) and 25(OH)D(3) are lacking intrinsic 24-hydroxylase-inducing capacity, up-regulation had to be the consequence of a two-step activation process via 25-hydroxylation and subsequent 1alpha-hydroxylation. 24-Hydroxylase-activities closely followed the corresponding mRNA levels. When 1alpha,25(OH)(2)D(3) itself or its precursor 25(OH)D(3) were used as inducing agents, 24-hydroxylase mRNA and enzyme activity followed a transient time course. In contrast, induction observed with physiological doses of D(3) remained high, even after a 20 h-time period. These differing characteristics may be explained by the slow but constant formation of 1alpha,25(OH)(2)D(3) from a large reservoir of D(3) in the target cell, providing constant supplies for induction.

Retrospective multivariate analysis of hepatic veno-occlusive disease after blood or marrow transplantation: possible beneficial use of low molecular weight heparin

This retrospective cohort study of 462 consecutive adult allogeneic and autologous blood or marrow transplantation (BMT) patients compared the incidence of hepatic veno-occlusive disease (VOD) after BMT with three prophylactic regimens. Patients receiving heparin (Hep), heparin + prostaglandin E1 (Hep + PGE1) or low molecular weight heparin (LMWH) as a prophylactic VOD regimen were compared to a historical cohort receiving no VOD prophylaxis. Of 462 BMT patients, VOD was diagnosed in 22% (31 of 142) of the no prophylaxis group, 11% (11 of 104) of the Hep, 12% (13 of 110) in the Hep + PGE1 and 4% (four of 106) of the LMWH group (P = 0.0002). VOD was the primary cause of death in 20% (12 of 59). By multivariate logistic regression, independent risk factors for developing VOD were: no VOD prophylactic regimen, unrelated allogeneic BMT, Karnofsky performance score (KPS) < 80 and aspartate aminotransferase (AST) > or =50 U/l. There was no increase in the rate of death due to hemorrhagic events or VOD in any prophylaxis group compared to the control group. Prospective randomized trials of Hep vs LMWH vs placebo are warranted to assess the efficacy of heparin compounds in the prevention of VOD.

1alpha,25-Dihydroxy-3-epi-vitamin D3 a physiological metabolite of 1alpha,25-dihydroxyvitamin D3: its production and metabolism in primary human keratinocytes

Recent studies of metabolism using pharmacological substrate concentrations of 1alpha,25-dihydroxyvitamin D3 [1alpha,25(OH)(2)D3] in several tissues including primary cultures of human keratinocytes, bovine parathyroid cells and bone cells led to the identification of 1alpha,25-dihydroxy-3-epi-vitamin D3 [1alpha,25(OH)(2)-3-epi-D3] as a major natural metabolite of 1alpha,25(OH)(2)D3. In the present study, we demonstrate that human keratinocytes incubated with 25-hydroxy[26,27-(3)H] vitamin D3 produce 1alpha,25(OH)(2)-3-epi-D3 along with 1alpha,25(OH)(2)D3. The production of 1alpha,25(OH)(2)-3-epi-D3 is also identified in human keratinocytes incubated with physiological substrate concentrations of 1alpha,25(OH)(2)D3. Unlike 24-hydroxylase, the major enzyme involved in the further metabolism of 1alpha,25(OH)(2)D3 in human keratinocytes, the enzyme(s) responsible for the production of 1alpha,25(OH)(2)-3-epi-D3 is constitutive and is not inhibited by ketoconazole. It is also noted that 1alpha,25(OH)(2)-3-epi-D3 is further metabolised in human keratinocytes into several as yet unidentified metabolites, the production of which is inhibited to a great extent by SDZ 89-443, an inhibitor of 24-hydroxylase. This finding indicates that the 24-hydroxylase like in the case of 1alpha,25(OH)(2)D3, also plays a major role in the metabolism of 1alpha,25(OH)(2)-3-epi-D3. The results obtained from the metabolism studies performed in parallel among 25OHD3, 1alpha,25(OH)(2)D3 and 1alpha,25(OH)(2)-3-epi-D3 indicate that 1alpha,25(OH)(2)-3-epi-D3 and its metabolites exhibit higher metabolic stability. In summary, we demonstrate for the first time that 1alpha,25(OH)(2)-3-epi-D3 is a physiological metabolite of 1alpha,25(OH)(2)D3 in human keratinocytes. Also, 1alpha,25(OH)(2)-3-epi-D(3) is further metabolised in human keratinocytes mainly through the activity of 24-hydroxylase. Furthermore, our finding of the relative metabolic stability of 1alpha,25(OH)(2)-3-epi-D3 and especially its metabolites when compared to 1alpha,25(OH)(2)D3 and its metabolites provides an important explanation for its previously observed potent inhibitory effect on keratinocyte growth in spite of its low affinity to vitamin D receptor.

Tissue plasminogen activator (tPA) as therapy for hepatotoxicity following bone marrow transplantation

The treatment of established veno-occlusive disease (VOD) of the liver with tissue plasminogen activator (tPA) has been disappointing. In attempts to improve upon these results we identified a subgroup of patients with consistently elevated bilirubin levels who did not meet conventional criteria for VOD (Susp VOD) but who had a significant risk of later developing clinical VOD. In January 1994 we began to treat patients who developed Susp VOD with tPA rather than waiting until they developed clinical VOD. We now report on the results of the first 37 patients who ultimately developed clinical VOD and received tPA therapy prior to Susp VOD, or at the time they had established VOD. Significant bleeding complications occurred in 13 (35%) patients but resolved with discontinuation of therapy in all but one. We found that patients treated early in the course of hepatotoxicity prior to the development of overt VOD had a significantly higher response rate and 100 day survival than patients treated at the time of established VOD. Given the poor results seen in treating late VOD, we suggest that early treatment with tPA may improve the outcome in patients who develop signs of hepatotoxicity following marrow transplantation.

Quality assurance in day surgery: do we do enough for the parents to prevent stress?

In order to identify and analyse the factors associated with stress for the parents during day surgery, we performed a survey analysis of 568 parents whose children underwent surgery consecutively during an 18-month period. Of 368 parents who returned the questionnaire, (follow up rate=65%), 16% experienced the stress associated with day surgery as moderate to severe. The following factors had a significant positive association with the amount of stress: feeling of insufficient preparation (odds ratio; 95% confidence interval) 3. 34 (1.36-8.26; P=0.002), insecurity in nursing care at home 3.36 (1. 43-11.01; P=0.01), problems at home such as fever, vomiting, sleep disorders and others 3.15 (1.72-5.8; P=0.0007), problems with postoperative pain at home 2.43 (1.38-4.3); P=0.008), speaking a foreign language 2.28 (1.08-4.78); P < 0.0001) and no previous surgery 1.31 (0.76-2.27); P=0.03). Analysing these factors showed that often not the problems per se, but rather the insecurity in dealing with them contributed to the experienced stress. Conclusion In order to improve the quality of health care, more pronounced attention has to be given to the parents needs and expectations.

A phase I study of recombinant human soluble interleukin-1 receptor (rhu IL-1R) in patients with relapsed and refractory acute myeloid leukemia

PURPOSE

The recombinant human interleukin-1 receptor (rhu IL-1R) is a soluble truncated form of the type 1 full-length membrane-bound receptor that binds IL-1 with identical affinity to that of the membrane form. As such, it may have clinical potential by sequestering IL-1, thereby preventing it from binding to its membrane-bound receptor and eliciting a biological effect. As IL-1 has been shown to regulate leukemic cell proliferation in an autocrine fashion, a phase I trial of rhu IL-1R was conducted in patients with relapsed and refractory acute myeloid leukemia (AML).

METHODS

The study group comprised 11 patients who were sequentially treated on one of three dose levels, receiving a single intravenous (i.v.) bolus dose on day 1 followed by 13 days of daily subcutaneous (s.c.) injections with the option of an additional 14 days of treatment if a response of stable disease or better was achieved. Dose level 1 i.v. bolus 500 microg/m2, s.c. dose 250 microg/m2 per day (five patients); dose level 2 i.v. bolus 1000 microg/m2, s.c. dose 500 microg/m2 per day (three patients); dose level 3 i.v. bolus 2000 microg/m2, s.c. dose 1000 microg/m2 per day (three patients). Owing to limited drug availability, the study was designed to only examine these three dose levels.

RESULTS

rhu IL-IR was well tolerated. There was no grade 3 or 4 non-hematological toxicity related to the study drug and the maximum tolerated dose was not reached. No IL-1R-blocking antibodies developed during the course of the study. Serum levels of IL-1beta, IL-6 and TNF were undetectable before, during and after rhu IL-IR administration. The terminal half-life after i.v. dosing was at least 7-12 h, and after s.c. dosing 2-4 days. Serum levels of rhu IL-1R up to 360- and 25-fold those of pretreatment levels were achieved after i.v. and s.c. dosing respectively. No patient had a complete, partial or minor response to treatment; four had stable disease and seven had progressive disease.

CONCLUSIONS

rhu IL-1R therapy was safe but did not have any apparent antileukemic effect at the doses administered.

Acute myelomonocytic leukemia presenting as a primary cutaneous lymphoma of true histiocytes

Malignant histiocytic and monocytic infiltrates of the skin are seen in true histiocytic lymphomas, in malignant histiocytosis, and in monocytic leukemias. Occasionally such cutaneous lesions constitute the presenting manifestation of the underlying malignancy. We report here a patient whose first manifestation of acute myelomonocytic leukemia was a malignant histiocytic infiltrate in the skin. Cytochemical and electron microscopic data confirmed the histiocytic nature of the skin tumor, and cytochemical data documented the myelomonocytic nature of the subsequent leukemia. Purely histiocytic skin tumors do not often presage myelomonocytic leukemias, although they have developed into monocytic leukemias, and monocytic leukemias have been transformed into myelomonocytic leukemias.

Veno-occlusive disease of the liver after allogeneic bone marrow transplantation: possible association with graft-versus-host disease

Acute veno-occlusive disease of the liver developed in seven of 29 patients undergoing bone marrow transplantation for treatment of leukemia, aplastic anemia, or disseminated carcinomatosis. All seven died despite successful marrow engraftment. Hepatic failure was the principal cause of death in four and contributory in three. The veno-occlusive disease did not relate to the nature of the pretransplant immunosuppressive regimen, since it occurred in patients receiving irradiation alone, chemotherapy alone, or both. Twenty-two of the patients were autopsied. Among these, the lesion was found in seven of 11 in whom a graft-versus-host reaction developed but in none of the 11 without such a reaction who had received similar pretransplant immunosuppression (P less than 0.025). Hence, acute veno-occlusive disease of the liver appears to be a complication of allogeneic bone marrow transplantation related to the development of a graft-versus-host reaction.

Combined modality treatment of American Burkitt's lymphoma

Fifteen American patients with Burkitt's lymphoma were treated in a clinical trial employing chemotherapy, radiotherapy, and immunotherapy. Two patients died during induction, and 13 achieved complete responses. Eight patients relapsed at a median of 11 weeks from initial treatment, and seven of these have died. The remaining patient has enjoyed a prolonged third remission following intensive chemotherapy and bone marrow autograft. Five patients remain in their first remission in excess of 1 year. The major therapeutic goal in the management of Burkitt's lymphoma is the prevention of relapse; the identification of risk factors and various strategies to achieve this goal are discussed.