Detection of minimal residual disease in acute lymphoblastic leukemia by in vitro amplification of rearranged T-cell receptor delta chain sequences

Human T-cell receptor (TCR) delta-chain diversity mainly originates from high junctional variability, since only a limited number of germline elements is available. This extraordinary diversity at the V.J junction, due to the use of two D delta elements and extensive incorporation of N nucleotides, constitutes a specific clonal marker for cell populations exhibiting rearranged TCR delta genes. To this end we amplified in vitro by polymerase chain reaction (PCR) the TCR delta junctional region of five acute lymphoblastic leukemias (ALL), isolated respective DNA fragments, and used them directly as clonospecific probes. The combination of PCR technology and hybridization to clonospecific probes permitted the detection of leukemia DNA at dilution of 1:100,000 in all five cases. Moreover, we were able to investigate one of the ALL patients 11 months after achieving continuous complete remission. Conventional Southern blot analysis failed to detect rearranged TCR genes at this stage. However, residual leukemic cells could readily be detected by PCR technique. We conclude that the strategy proposed here is a very sensitive tool to detect minimal residual disease in a significant proportion of human lymphoid neoplasias.     

A point mutation in the integrin beta 3 cytoplasmic domain (S752-->P) impairs bidirectional signaling through alpha IIb beta 3 (platelet glycoprotein IIb-IIIa)

Agonist-induced inside-out signaling results in an increased affinity of integrin alpha IIb beta 3 (platelet glycoprotein IIb-IIIa) for soluble ligands (fibrinogen [Fg] and PAC1). Ligand binding to integrins initiates outside-in signaling that leads to cellular responses such as cell spreading and focal adhesion formation. A point mutation in the beta 3 cytoplasmic domain (S752-->P) is associated with blocked inside- out alpha IIb beta 3 signaling in a variant Glanzmann's thrombasthenia. This mutation was introduced into beta 3 and cotransfected into Chinese hamster ovary cells with a chimeric alpha subunit consisting of the alpha IIb extracellular and transmembrane domains and the alpha 6B cytoplasmic domain. The substitution of the alpha IIb cytoplasmic domain with that of alpha 6 led to activation of alpha IIb beta 3 to bind PAC1, mimicking inside-out signaling. This effect was reversed by the S752-->P mutation, indicating a disruption of inside-out signaling by the mutation. In addition, transfectants expressing this beta 3 variant showed reduced alpha IIb beta 3-mediated cell spreading on immobilized Fg, focal adhesion, and fibrin clot retraction, suggesting an impairment in outside-in alpha IIb beta 3 signaling. Therefore, a single point mutation in the beta 3 cytoplasmic domain impaired bidirectional signaling through alpha IIb beta 3.     

Differential effect of phorbol esters and interleukin-3 on protein kinase C isoform content and kinase activity in the FDC-P1 cell line

FD/PMA is a subclone of the interleukin-3 (IL-3)-dependent, FDC-P1 cell line, which proliferates in response to either 12-O- tetradecanoylphorbol-13 acetate (PMA) or IL-3. While several endogenous substrates were phosphorylated in response to protein kinase C (PKC) activation in FDC-P1, phospholipid-dependent phosphorylation in the FD/PMA grown in PMA was not observed. Basal, phosphatidylserine- independent, and diolein-independent phosphorylation of cytosolic substrates with molecular weights of 17, 52, 57, and 105 Kd were enhanced in FD/PMA cells grown in PMA as compared with FDC-P1 cells cultured in IL-3. Phosphorylation of a 105-Kd substrate was enhanced in the particulate fraction of FD/PMA cells maintained in PMA. The 17-Kd substrate in FD/PMA cells comigrated with a substrate phosphorylated in a PKC-dependent manner in FDC-P1 cells. Phosphorylation of the 52- and 57-Kd substrates, but not of the 17-Kd substrate, was inhibited by H-7 and staurosporine. A portion of the PMA-induced cytosolic kinase activity coeluted with PKC on diethyl aminoethyl chromatography. While FD/PMA cells cultured in PMA contained negligible PKC-dependent phosphorylation of endogenous substrates or histone, alpha and epsilon PKC isoforms were detected by Western blot analysis. PKC phosphotransferase activity was observed in FD/PMA cells grown in PMA when peptides corresponding to residues 720 to 737 of PKC-epsilon or residues 4 to 14 of myelin basic protein were used as substrates. These data indicate that maintenance of FD/PMA cells in PMA stimulates proliferation and markedly alters PKC substrate specificity. Generation of at least two phospholipid-independent kinases occurs in PMA-treated cells.     

Carcinoid tumor of the rectum

PURPOSE: This study was designed to evaluate the clinical characteristics, surgical treatment, and outcome of carcinoid tumors of the rectum and to assess flow cytometry deoxyribonucleic acid (DNA) analysis as a potential prognostic factor for management of these tumors. METHODS: Medical records, tumor registry database, and pathology slides were retrospectively reviewed. Flow cytometry DNA analysis was performed on archived specimens. RESULTS: One hundred nine patients with rectal carcinoid tumors underwent surgery between 1962 and 1987. Follow-up was available in 86 patients for a mean period of 12 years. Of 100 patients with tumors less than 2 cm, only one with a 1.5 cm ulcerated tumor developed liver metastases. Of nine patients with a tumor more than or equal to 2 cm, three with known liver metastases underwent rectal biopsy only, and three had rectal biopsy and laparotomy with biopsy of liver metastases. Three patients underwent radical resection. Following abdominoperineal resection, one patient died with local recurrence after 5 years, and one developed hepatic recurrence after 5.5 years and died at 9 years. One patient with coloanal anastomosis developed local and hepatic metastases seven years after surgery and died at ten years. No patients developed carcinoid syndrome. DNA ploidy did not correlate with metastases at presentation or recurrence of carcinoid tumor. CONCLUSION: Radical resection of rectal carcinoids with ulceration or size greater than or equal to 2 cm is associated with a poor prognosis; however, survival may be long term, even in the presence of metastatic disease. DNA ploidy does not appear to be a useful prognostic factor for rectal carcinoid tumors.Poster presentation at the meeting of The American Society of Colon and Rectal Surgeons, Orlando, Florida, May 8 to 13, 1994.     

Detection of monoclonal plasma cells in the peripheral blood of patients with primary amyloidosis

We evaluated the blood from 150 patients with primary AL-amyloidosis for circulating monoclonal plasma cells using a sensitive slide-based immunofluorescence technique. The percentage of monoclonal blood plasma cells (BPC) that were in S-phase was determined by the bromodeoxyuridine labelling index (BLI). Monoclonal BPC were detected in 16% (24/150) of patients. The median number of monoclonal BPC was 1 × 10⁶/l and 4.6% (7/150) of patients had a high number. The BLI was zero in all but three patients. This study demonstrates that monoclonal plasma cells circulate in the peripheral blood of patients with AL-amyloidosis.     

Early harvest and late transplantation as an effective therapeutic strategy in multiple myeloma

Transplantation after high-dose chemotherapy prolongs survival in patients with multiple myeloma compared with standard therapy. It is unclear whether the optimal timing of transplantation is immediately after induction chemotherapy or whether stem cells may be cryopreserved for transplantation at subsequent progression or relapse. In this study, stem cells were collected within 6 months of diagnosis, followed by transplantation only at progression of myeloma. One hundred and eighteen patients with multiple myeloma had stem cells collected and cryopreserved. Eleven had transplants early in the disease after they demonstrated failure to respond to primary therapy. The remaining 107 were eligible for transplants when there was evidence of progressive disease. Of the 118 patients, 67 had transplants, nine died of progressive disease before transplantation, and 42 remain alive in plateau phase. The median survival of the group is 58.5 months; 67 are alive. Serum beta2-microglobulin, bone marrow labeling index (S phase), and hemoglobin level predicted overall survival (P < 0.006, P < 0.001, and P < 0.01, respectively). We conclude that early cryopreservation of blood stem cells followed by transplantation at progression is a feasible approach to therapy in patients with myeloma. The underlying biology of the disease has a greater impact on survival than the timing of transplantation. A prospective randomized trial is required to answer definitively the question of the optimal timing of blood cell transplantation.     

Development of a marrow transplant regimen for acute leukemia using targeted hematopoietic irradiation delivered by 131I-labeled anti-CD45 antibody, combined with cyclophosphamide and total body irradiation

In an attempt to decrease the relapse rate after bone marrow transplantation (BMT) for advanced acute leukemia, we initiated studies using 131I-labeled anti-CD45 antibody (BC8) to deliver radiation specifically to hematopoietic tissues, followed by a standard transplant preparative regimen. Biodistribution studies were performed in 23 patients using 0.5 mg/kg trace 131I-labeled BC8 antibody. The BC8 antibody was cleared rapidly from plasma with an initial disappearance half-time of 1.5 +/- 0.2 hours, presumably reflecting rapid antigen- specific binding. The mean radiation absorbed doses (cGy/mCi131I administered) were as follows: marrow, 7.1 +/- 0.8; spleen, 10.8 +/- 1.4; liver, 2.7 +/- 0.2; lungs, 2.1 +/- 0.1; kidneys, 0.7 +/- 0.1; and total body, 0.4 +/- 0.03. Patients with acute myelogenous leukemia (AML) in relapse had a higher marrow dose (11.4 cGy/mCi) than those in remission (5.2 cGy/mCi; P = .001) because of higher uptake and longer retention of radionuclide in marrow. Twenty patients were treated with a dose of 131I estimated to deliver 3.5 Gy (level 1) to 7 Gy (level 3) to liver, with marrow doses of 4 to 30 Gy and spleen doses of 7 to 60 Gy, followed by 120 mg/kg cyclophosphamide (CY) and 12 Gy total body irradiation (TBI). Nine of 13 patients with AML or refractory anemia with excess blasts (RAEB) and two of seven with acute lymphocytic leukemia (ALL) are alive disease-free at 8 to 41 months (median, 17 months) after BMT. Toxicity has not been measurably greater than that of CY/TBI alone, and the maximum tolerated dose has not been reached. This study demonstrates that with the use of 131I-BC8 substantially greater doses of radiation can be delivered to hematopoietic tissues as compared with liver, lung, or kidney, which may improve the efficacy of marrow transplantation.     

How safe is diathermy in patients with cochlear implants?

INTRODUCTION

Cochlear implants are surgically inserted electrical devices that enable severely or profoundly deaf individuals to interpret sounds from their environment and communicate more effectively. As a result of their electrical nature, they are susceptible to electromagnetic interference and can be damaged by excessive electrical energy. Surgical diathermy is one source of such potentially damaging energy. The British Cochlear Implant Group guidelines advise that monopolar diathermy should not be used in the head and neck region in patients with cochlear implants and that bipolar diathermy should not be used within 2cm of the implant (http://www.bcig.org.uk/site/public/current/safety.htm).

METHODS

A questionnaire was provided to 36 surgeons working in different specialties in the head and neck region, inquiring as to their knowledge of the safety considerations when using diathermy in cochlear implant patients. Thirty-five surgeons provided responses.

RESULTS

Overall, 77% of the respondents were unaware of the existence of published guidelines. Even when given an option to seek advice, 11% erroneously felt it was safe to use monopolar diathermy above the clavicles with a cochlear implant in situ and 49% felt that there was no restriction on the use of bipolar diathermy.

CONCLUSIONS

There is a significant deficit in the knowledge of safe operating practice in the rapidly expanding population of patients with cochlear implants which threatens patient safety. Through this publication we aim to increase awareness of these guidelines among members of the surgical community and this paper is intended to act as a point of reference to link through to the published safety guidelines.     

A phase I trial of immunostimulatory CpG 7909 oligodeoxynucleotide and 90yttrium ibritumomab tiuxetan radioimmunotherapy for relapsed B‐cell non‐Hodgkin lymphoma

Radioimmunotherapy (RIT) for relapsed indolent non‐Hodgkin lymphoma produces overall response rates (ORR) of 80% with mostly partial remissions. Synthetic CpG oligonucleotides change the phenotype of malignant B‐cells, are immunostimulatory, and can produce responses when injected intratumorally and combined with conventional radiation. In this phase I trial, we tested systemic administration of both CpG and RIT. Eligible patients had biopsy‐proven previously treated CD20+ B‐cell NHL and met criteria for RIT. Patients received rituximab 250 mg/m² days 1,8, and 15; ¹¹¹In‐ibritumomab tiuxetan days 1, 8; CpG 7909 days 6, 13, 20, 27; and 0.4 mCi/kg of ⁹⁰Y‐ibritumomab tiuxetan day 15. The doses of CpG 7909 tested were 0.08, 0.16, 0.32 (six patients each) and 0.48 mg/kg (12 patients) IV over 2 hr without dose limiting toxicity. The ORR was 93% (28/30) with 63% (19/30) complete remission (CR); median progression free survival of 42.7 months (95% CI 18‐NR); and median duration of response (DR) of 35 months (4.6–76+). Correlative studies demonstrated a decrease in IL10 and TNFα, and an increase in IL1β, in response to therapy. CpG 7909 at a dose of 0.48 mg/kg is safe with standard RIT and produces a high CR rate and long DR; these results warrant confirmation. Am. J. Hematol. 88:589–593, 2013. © 2013 Wiley Periodicals, Inc.     

Evidence for Cytogenetic and Fluorescence In Situ Hybridization Risk Stratification of Newly Diagnosed Multiple Myeloma in the Era of Novel Therapies

Overall survival (OS) has improved with increasing use of novel agents in multiple myeloma (MM). However, the disease course remains highly variable, and the heterogeneity largely reflects different genetic abnormalities. We studied the impact of the Mayo risk-stratification model of MM on patient outcome in the era of novel therapies, evaluating each individual component of the model—fluorescence in situ hybridization (FISH), conventional cytogenetics (CG), and the plasma cell labeling index—that segregates patients into high- and standard-risk categories. This report consists of 290 patients with newly diagnosed MM, predominantly treated with novel agents, who were risk-stratified at diagnosis and were followed up for OS. Of these patients, 81% had received primarily thalidomide (n=50), lenalidomide (n=199), or bortezomib (n=79) as frontline or salvage therapies. Our retrospective analysis validates the currently proposed Mayo risk-stratification model (median OS, 37 months vs not reached for high- and standard-risk patients, respectively; P=.003). Although the FISH or CG test identifies a high-risk cohort with hazard ratios of 2.1 (P=.006) and 2.5 (P=.006), respectively, the plasma cell labeling index cutoff of 3% fails to independently prognosticate patient risk (hazard ratio, 1.4; P=.41). In those stratified as standard-risk by one of the 2 tests (FISH or CG), the other test appears to be of additional prognostic significance. This study validates the high-risk features defined by FISH and CG in the Mayo risk-stratification model for patients with MM predominantly treated with novel therapies based on immunomodulatory agents.CG = cytogenetics; CI = confidence interval; FISH = fluorescence in situ hybridization; HR = hazard ratio; IgH = immunoglobulin heavy chain; MM = multiple myeloma; mSMART = Mayo Stratification of Myeloma and Risk-Adapted Therapy; NR = not reached; PCLI = plasma cell labeling index; SCT = stem cell transplantationMultiple myeloma (MM) is a clonal plasma cell disorder that has witnessed considerable therapeutic advances in recent times. This progress can be attributed to improved antimyeloma therapy along with a better understanding of the tumor biology and heterogeneity.^1,2 Although a wide variation in overall survival (OS) of patients has been observed in studies analyzing the natural history of MM,³ only now are we beginning to associate the disparity in clinical outcomes with specific genetic abnormalities. Such chromosomal abnormalities are almost universally prevalent in the neoplastic plasma cells, typically occurring early in the disease process and dictating its course.⁴ Both cytogenetics (CG) and interphase fluorescence in situ hybridization (FISH) assays have played pivotal roles in the risk stratification of patients with newly diagnosed MM. Although still useful, conventional prognostic factors (β₂-microglobulin, lactate dehydrogenase, serum albumin, C-reactive protein, etc)⁵ appear to be somewhat less discerning of the outcome compared with the genetic aberrations that drive the tumor biology.^6-10The Mayo Stratification of Myeloma and Risk-Adapted Therapy (mSMART) criteria use a combination of metaphase CG, FISH, and plasma cell labeling index (PCLI; a measure of the percentage of plasma cells in the S phase of the cell cycle)¹¹ results to derive 2 composite risk categories (high-risk vs standard-risk) for prognostication of patients with newly diagnosed MM.¹² Although the initial prognostication criteria were based on the evidence predominantly garnered from patients treated with conventional chemotherapy and/or stem cell transplantation (SCT), the recommendations are periodically revised as new data emerge. Less than a decade ago, melphalan-prednisone or combination chemotherapies along with SCT were the mainstays of treatment of MM. The introduction of newer therapies, immunomodulatory drugs (thalidomide and lenalidomide), and the first-in-class proteasome inhibitor bortezomib ushered in a period of remarkable progress as the profound impact of such novel agents became evident early in the disease course.^1,13 Therefore, the Mayo prognostic model needed a formal assessment in the current era of expanded use of novel therapies. The objectives of our study were to evaluate the significance of the Mayo risk-stratification criteria since the integration of novel agents in the management of MM and to assess the independent prognostic value of each of the components (CG, FISH, and PCLI) in the model.