CardioneuROablation for reflex syncope: efficacy and effects on autonoMic cArdiac regulatioN. The Roman 1 study

Purpose

To assess the effects of CNA on syncope recurrences in patients with VVS

Methods

The Roman 1 study was a prospective, randomized, investigator-initiated trial comparing CNA versus optimal standard therapy in patients with asystolic VVS. Patients were included if they had documented symptomatic cardioinhibitory or mixted spontaneous VVS (at least 3 seconds of asystole), frequent and/or severe symptoms (at least one syncope or 3 presyncopal events during preceding 12 months or very severe syncope in the past, leading to injury) and positive atropine test (>30% increase in sinus rate). CNA was performed using RF ablation of the ganlionated plexi from the left and right atrium. Follow-up lasted 2 years. Primary endpoint was time to first syncope recurrence. One of secondary endpoints were changes in quality of life (QoL) assessed using dedicated questionnaire The Impact of Syncope on Quality-of-Life Questionnaire University of Calgary.

Results

48 patients (17 males, mean age 38±10, 24 – CNA group, 24 – control group) entered the study. Baseline demographic and clinical characteristics were similar in both groups. The primary end-point – syncope recurrence, occurred in 2 (8%) patients from the CNA group versus 12 (50%) controls (p=0.00037, see Kaplan-Meier curve). QoL significantly improved in the CNA group (30±10 vs 10±7 points, p=0.0001) whereas remained stable in controls (31±10 vs 30±10 points, p=0.5501).

Conclusion(s)

This is the first randomized study documenting efficacy of CNA in patients with asystolic VVS. Larger studies are needed to confirm these findings.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Centre of Postgraduate Medical Education

Optimal catheter-tissue contact value for ablation of ventricular arrythmias originating from the left ventricular papillary muscles

Funding Acknowledgements

Type of funding sources: None.

Background

Good catheter-tissue contact is mandatory to create effective ablation lesions. The minimal contact force (CF) value for successful ablation of arrhythmias originating from the left ventricle (LV) was reported at the 8-10 g level, however, optimal CF values for ablation of arrhythmias arising from papillary muscles (PM) are not known.

Purpose

To determine optimal CF value for ablation of arrhythmias from LV PM.

Methods

Twenty-four consecutive patients (mean age 57,9 ± 11,9 years, 16 males) who from May 2017 to June 2020 underwent ablation of premature ventricular complexes (PVC) originating from LV PM were included. The primary endpoints were an acute procedural success (total elimination of PVC) and long-term success (median 27 months). Ablation was performed with the use of the CARTO electro-anatomical system and intracardiac echocardiography (ICE).

Results

Acute success – complete abolition of PVC, was obtained in 23 (96%) patients. The fluoroscopy time was 3,9 ± 3,5 min and the procedure duration was 114,8 ± 38 min. The mean number of applications was 8,74 ± 6,78 and the mean application time - 518,5 ± 437,25 sec. The mean CF during successful ablations was 3,1 ± 1,5 g, with 3 ± 1,1 g and 3,18 ± 1,8 g for anterolateral and posteromedial PM, respectively (p= 0,809975). The mean CF during one unsuccessful ablation was 3 g. At control Holter ECG, the mean PVC burden in all patients was reduced from 28,36 ± 14,48 % to 2,42 ± 2 %: in the anterolateral PM group from 18 ± 8 % to 2,6 ± 2 % (p= 0,005415) and in the posteromedial PM group - from 34,8 ± 13,7 % to 1,7 ± 1,3 % (p= 0,012694). During long-term follow-up (median 27, IQR 17-34) there was one recurrence among 23 patients who had acutely successful procedures.

Conclusion

The values of CF for successful ablation of PVC originating from LV PM are lower than those for ablation in other parts of LV. The values slightly exceeding 3 g seem to be sufficient to achieve ablation success.

Bipolar catheter ablation for highly refractory cardiac arrhythmia - does the success rate depend on arrhythmia origin?

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction

Despite technological progress, some arrhythmias are still refractory to standard unipolar ablation. They include arrhythmias arising from left ventricular (LV) summit, cardiac crux or epicardium. Bipolar ablation may be useful in some cases, however, data on efficacy of this approach in various arrhythmia localisatons are scarse.

Purpose

Aim of the study was to assess efficacy of bipolar catheter ablation in patients with cardiac arrhythmias refractory to standard ablation approach.

Methods

Observational, single-center study was conducted over 30-month period. Twenty-six consecutive patients (male=18, aged = 54.26 ± 16.4) who were referred for bipolar ablation were included. All patients had a history of previously failed unipolar ablation procedures. Bipolar ablations were performed using dedicated RF generator and electroanatomic mapping system.

Results

Twenty-seven procedures in 26 patients with a mean of 2.52 ± 0.83 previously failed unipolar ablations were included in the final analysis. There were 4 ablations of accessory pathways (3 postero-septal and 1 left free wall) with acute success rate of 100%, 11 procedures of ventricular arrhythmias originating from crux of the heart with acute success rate of 73% and 12 from left ventricular summit (LV summit) with acute success rate of 50%. Mid-term success rate (median follow-up of 182 days) was 100%, 63% and 50% respectively. There was one major complication (not related to RF bipolar ablation): cardiac tamponade due to aortic cusp rupture requiring urgent cardiac surgery procedure.

Conclusions

Bipolar ablation is a promising method of catheter ablation for refractory arrhythmias. The highest success rate was observed in ablation for difficult pathways, followed by ventricular arrhythmias originating from cardiac crux and LV summit.

Ultrasound-guided extra-cardiac vagal stimulation during cardioneuroablationa-a pilot feasibility study

Funding Acknowledgements

Type of funding sources: None.

OnBehalf

N/A

Background. Cardioneuroablation (CNA) is a promising method for treatment of vagally-induced vasovagal syncope or functional atrio-ventricular block. Extra-cardiac vagal stimulation (ECVS) from the internal jugular vein is used during CNA to document asystolic response prior to CNA and lack of effects of vagal stimulation on heart rate after CNA.  The recommended technique is placing the pacing catheter under fluoroscopy in the internal right and left jugular vein up to the level of the upper wisdom tooth. However, this technique has several limitations such as increased radiation exposure, unselective cranial nerves stimulation and lack of visualization of vagal nerve. Ultrasound-guided (USG) approach may be an interesting option because it allows visualization of the vagal nerve and enables selective  stimulation under visual control.

Purpose. To assess the utility of USG-guided ECVS during CNA procedures.

Methods. The study group consisted of 6 patients (4 males, mean age 35 ± 12-year-old) underwent CNA.  Firstly, electrode for ECVS was introduced under fluoroscopy into the right and left jugular veins up to the level of the upper wisdom tooth and ECVS was performed. Next, the USG-guided examinations were performed in supine position with head extension. The probe was placed in the transverse plane above the medial edge of the sternocleidomastoid muscle. The course of vagal nerve was identified and place for imaging in the close neighborhood of the jugular vein was chosen. ECVS was performed when the electrode was in good contact with the vein wall and was in the vicinity of the vagal nerve. In both approaches vagal response (asystole and atrio-ventricular block) during ECVS was assessed before and after CNA.

Results. In all patients ECVS was performed from both right and left jugular vein. Localization of vagal nerve using USG was possible in all patients and took less than one minute (see Figure). The effects of ECVS were identical using standard fluoroscopic and USG-guided approach.

Conclusions. USG-guided ECVS during CNA is easy, results are comparable with standard fluoroscopic approach and is probably associated with less fluoroscopy. Since this non-invasive method is the only one which enables vagal nerve visualization, it should become a preferred approach when using ECVS during CNA procedures. Abstract Figure. A electrode position for USG-guided ECVS

Left atrial function after successful catheter ablation for paroxysmal atrial fibrillation: cryoablation versus radiofrequency techniques

Funding Acknowledgements

Type of funding sources: None.

Purpose

It has been suggested that cryoballoon (CB) ablation for paroxysmal atrial fibrillation (PAF) may lead to more extensive left atrial (LA) injury than radiofrequency (RF) ablation, however, results are conflicting. We sought to address this issue using modern echocardiographic techniques.

Methods

We performed transthoracic echocardiography in 90 patients (66% males, mean age 57 ± 10 years) successfully treated  with RF (51%) or CB (49%) ablation for PAF before and 6 months after the procedure. Peak longitudinal LA strain (LAS) and strain rate (LASR) during the reservoir (r), conduit (cd) and contraction (ct) phases were measured during sinus rhythm by speckle tracking. The LA diameter and volume (LAV) index - using biplane area-length method divided by the body surface area were also calculated.

Results

The LA diameter decreased (38.1 ± 4.0 vs 37.2 ± 3.8 mm, p = 0.004), the LAV index did not change (33.5 ± 11.9 vs 34.4 ± 8.9 mL/m², p = 0.272) at 6 months in the whole study group. The LASRr and LASRcd increased, whereas there were no changes in remaining LA function parameters in either ablation strategy (table). The CB subgroup did not differ in LA function parameters comparing to RF subgroup at six months after procedure (table).

Conclusion

CB and RF ablation did not differentially affect the LA function. Successful ablation for PAF resulted in improvement of  rate of deformation during reservoir and conduit LA cycle and stable contractile LA function.

LA function parameters RF N = 46 (51%) CB N = 44 (49%) 6 months RF vs CB Parameter Baseline 6 months p Baseline 6 months p p* Global LASr [%] 27.7 ± 6.35 27.9 ± 6.0 0.833 27.9 ± 7.2 27.0 ± 6.4 0.370 0.539 Global LAScd [%] -14.6 ± 4.1 -14.8 ± 4.6 0.761 -15.3 ± 5.3 -14.1 ± 3.2 0.080 0.399 Global LASct [%] -13.0 ± 4.84 -13.0 ± 3.20 1.00 -12.6 ± 3.81 -12.9 ± 4.18 0.629 0.897 Global LASRr [sˉ¹] 1.18 ± 0.22 1.27 ± 0.26 0.046 1.07 ± 0.27 1.18 ± 0.30 0.041 0.141 Global LASRcd [sˉ¹] -1.11 ± 0.33 -1.25 ± 0.35 0.013 -1.07 ± 0.31 -1.16 ± 0.30 0.044 0.214 Global LASRct [sˉ¹] -1.46 ± 0.40 -1.50 ± 0.31 0.500 -1.42 ± 0.51 -1.39 ± 0.42 0.742 0.187 *p value corrected for baseline values

P1096Cardioneuroablation changes the type of vaso-vagal response in patients with asystolic reflex syncope

Funding Acknowledgements

Centre of Postgraduate Medical Education No. 501-1-10-14-19

Background. Cardioneuroablation (CNA) - ablation of ganglionated plexi (GP) to eliminate or reduce parasympathetic overactivity, has been recently proposed as a new therapeutic method in patients with vaso-vagal syncope (VVS) due to cardioinhibitory or mixed mechanism.

Purpose. To assess the impact of CNA on the type of VV response during tilt testing (TT).

Methods. The study group consisted of the first 20 patients (7 males, mean age 38 ± 9 – year – old) enrolled in the ongoing prospective Roman study (NCT 03903744). All patients had a history of ECG documented syncope due to asystole and confirmed asystolic form of VVS at baseline TT. CNA was performed using electroanatomical system Carto 3 and radiofrequency applications delivered in the right and left atrium at the right anterior GP and right inferior GP sites. The second TT was performed three months later. Resting heart rate (HR) and heart rate variability parameter (SDDN) were also assessed.

Results. At baseline TT, nineteen patients had cardioinhibitory syncope (asystole ranging from 3 to 60 s)  (sinus node arrest – 17 patients, A-V block – 2 patients) and 1 had mixed form of VVS (asystole lasting 3 s preceded by hypotension). During three-month follow-up no syncopal episodes were noted. At the 3-month TT, 6 (30 %) patients had no syncope whereas the remaining 13 (65 %)  had syncope – twelve (60 %) due to vasodepressor mechanism and only one (5 %) due to asystole - as before CNA. One patient did not have TT because of pregnancy. Mean resting HR after CNA was significantly faster and SDNN significantly lower than before the procedure (82 ± 9 vs 69 ± 11 beats/min, p = 0.0004 and 74 ± 22 vs 143 ± 40 ms, p = 0.00003, respectively) and these changes were was similar in those who fainted during second TT and those who did not (82 ± 11 vs 81 ± 4 beats/min, p = NS and (75 ± 2 vs 77 ± 18 ms, p = NS, respectively).

Conclusions. CNA profoundly affects the type of VV reaction causing normalization of the response to tilting or changing cardiodepression to vasodepression. These effects are also depicted by changes in HR and heart rate variability. Elimination of TT-induced reflex asystole may prevent clinical recurrences of syncope during short-term follow-up. These findings encourage to conduct further studies involving CNA since this method appears to be effective and obviates the need for pacemaker implantation in young people with reflex asystolic syncope.

Germline gene polymorphisms predisposing domestic mammals to carcinogenesis

Cancer is a complex disease caused in part by predisposing germline gene polymorphisms. Knowledge of carcinogenesis in companion mammals (dog and cat) and some livestock species (pig and horse) is quite advanced. The prevalence of certain cancers varies by breed in these species, suggesting the presence of predisposing genetic variants in susceptible breeds. This review summarizes the present understanding of germline gene polymorphisms, including BRCA1, BRCA2, MC1R, KIT, NRAS and RAD51, associated with predisposition to melanoma, mammary cancer, osteosarcoma and histiocytic sarcoma in dogs, cats, pigs and horses. The predisposing variants in these species are discussed in the context of human germline gene polymorphisms associated with the same types of cancer.

The effect of platelet autoantibodies on the course of the disease and clinical response of patients with idiopathic thrombocytopenic purpura

In this study, we evaluated the response to treatment of 409 idiopathic thrombocytopenic purpura (ITP) patients who were tested for the presence of platelet-associated autoantibodies by direct-platelet immunofluorescence test (PIFT) and for the presence of plasma antibodies directed against the GPIIb/IIIa, GPIb and GPIa/IIa by monoclonal antibody immobilization of platelet antigens (MAIPA). In patients with platelet autoantibodies in comparison with patients without antibodies more frequently were observed the chronic form of disease (83.5%vs. 68.5%) and severe symptoms of haemorrhage diathesis (17.3%vs. 6.9%). Evaluation of the treatment response (to corticosteroids, immunosuppressive drugs and splenectomy) referred to patients with complete response, e.g. complete remission defined as platelet count of >100 x 10(9)/l for at least 2 years. The percentage of complete response in the whole population of ITP patients, both with and without autoantibodies regardless of the method of treatment, was similar (about 54%). However, the presence of platelet autoantibodies had effect on patients treated with corticosteroids: complete response approximately 71% (36/51) of patients with autoantibodies and in 60% (72/120) of patients without antibodies, as well as in patients treated with immunosuppressive drugs (cyclophosphamide, azathioprine, vincristin and vinblastin); complete response approximately 51% (11/21) of patients with autoantibodies and in 34.8% (6/17) of patients without autoantibodies. The presence of autoantibodies had no effect on the response of splenectomy patients.

The use of vinca alkaloids in preparation for splenectomy of corticosteroid refractory chronic immune thrombocytopenic purpura patients

Administration of vinca alkaloids (VA) to chronic corticosteroid refractory immune thrombocytopenia (ITP) patients results in a temporary increase of platelet count. The aim of the study was to evaluate the efficacy of vinca alkaloids in preparing adult corticosteroid refractory chronic ITP patients for splenectomy as well as to compare the costs of this method with costs of applying intravenous immunoglobulins. The study included 12 chronic ITP patients refractory to corticosteroids applied for 3-144 months. The patients were prepared for splenectomy with average 3.0 (from 1 to 4) 2-h intravenous infusions of vinca alkaloids at 7 day intervals. In eight patients, vincristin was used in a total dose of 6 mg (2 mg per infusion), in two patients, vinblastin was used in total dose of 30 mg (10 mg per infusion), and in two patients, vincristin and vinblastin infusions were administered alternatively. In nine of the 12 treated patients (75%) the platelet count increased to > or = 80 x 10(9)/l, which allowed safe splenectomy. Three patients unreactive to VA treatment were prepared for splenectomy with intravenous gammaglobulin infusions. Splenectomy was performed in 12 patients, in eight with laparoscopic method, in four with classic method. No complications during surgical intervention were observed. In none of the VA treated patients was myelosupression or liver or/and kidney dysfunction observed. Splenectomy resulted in normalization of platelet count in all patients after operation and in six of nine patients followed up for 10 months (on the average). Matching of VA costs with treatment efficacy and comparison with similar costs for intravenous immunoglobulin treatment revealed many fold lower costs of the former method.

The use of vinca alkaloids in adult patients with refractory chronic idiopathic thrombocytopenia

The aim of the study was to evaluate the application of vincristin or vinblastin in patients with chronic idiopathic thrombocytopenic purpura (ITP), resistant to corticosteroids or with partial contraindication to their application. Twenty-two patients were treated with vincristin or vinblastin in doses of 2 and 10 mg, respectively. Eight of these patients were additionally administered prednisone in an oral dose of 0.5 mg/kg body mass (bm). Two-hour intravenous infusions of drugs were made once a week, at least three times. In every patient, the platelet count was evaluated before and after the three infusions. A rise of the platelet count of at least 100 x 10(9)/l was assumed to signify improvement. Statistically significant improvement (P <0.01) was obtained in nine (41%) patients (including five (35%) patients treated with vinca alkaloids only and in four (50%) patients treated with vincristin and corticosteroids). On the average, 8 weeks after the termination of the treatment there was a 40% drop in the platelet. Patients with a shorter duration of the disease and without detectable platelet antibodies responded well to the treatment more frequently. Minor complications were observed in five patients (23%), notably in the form of paresthesia. Leukopenia was not present. Vinca alkaloids could find their application in clinical situations requiring short-term increase of the platelet count in chronically ill patients with ITP, resistant to corticosteroids or with counterindication to their application.

B cells CD19+ in patients with B-cell chronic lymphocytic leukaemia and autoimmune haemolytic anaemia

The study presents results of B and T lymphocytes population analysis in patients with chronic lymphocytic leukaemia B cells and autoimmune haemolytic anaemia (CLL-B + AIHA). We evaluated the following groups of patients: (1) with newly recognized CLL-B and co-existent AIHA (untreated), (2) after short-term treatment with corticosteroids, (3) after treatment with chemotherapy and corticosteroids. The control groups were made of patients with CLL-B without AIHA. The populations of lymphocytes and determination of cells immunophenotype were performed by means of flow cytometry. The analysed data were obtained from 25 patients. The untreated patients with CLL-B + AIHA presented significantly more numerous population of neoplastic cells CD19+ CD5+ in comparison with patients without AIHA. The patients with AIHA showed a reduced percentage of B CD19+ CD22+ cells in comparison with those without AIHA. Untreated patients with AIHA or after a short-term corticosteroid treatment showed a higher ratio of the number of CD19+ CD5+ cells to the number of T CD4+ and T CD8+ lymphocytes than CLL-B patients without AIHA. It can be presumed that the differences found may be related to the pathogenesis of the autoimmune haemolysis syndrome in patients with CLL-B.

Hemoglobin F in primary myelofibrosis and in myelodysplasia

Our study investigated two groups of adult patients with established diagnoses of primary myelofibrosis (21 patients) and myelodysplastic syndromes (MDS) (21 patients). The objective was to assess fetal hemoglobin (HbF) concentration and to investigate correlations with organomegaly and extramedullary hematopoiesis and with the level of anemia and blood transfusion requirement. In all patients, the diagnosis was confirmed by histopathological examination. Patients with myelofibrosis were investigated by ferrokinetics using 59Fe. The percentage of marrow sideroblasts was assessed in patients with refractory anemia with ringed sideroblasts. Increased values of HbF were found to occur both in patients with myelofibrosis and with MDS, although a higher incidence and higher concentrations were evident in patients with myelofibrosis. Statistically significant increases in HbF concentration were found when there was accompanying organomegaly, as compared to patients without this feature. The average HbF concentration in both groups of patients under study was twice as high in cases with as in those without marrow fibrosis. The difference was statistically significant. Increased HbF levels appear to correlate with extramedullary hematopoiesis. HbF concentration did not correlate with the level of anemia or with requirement for blood transfusion.

Family with Li-Fraumeni syndrome and no evidence of a germline mutation of the p53 gene or chromosomal aberrations

Li-Fraumeni syndrome is a rare autosomal, dominant trait of diverse types of cancers in children and young adults, with a predominance of soft tissue sarcomas, osteosarcomas, brain tumours, adrenocortical and breast carcinomas, as well as leukaemias. We present a family with an unusual cancer history fulfilling the criteria of Li-Fraumeni syndrome. Mutational analysis of the p53 gene in constitutional DNA of several affected members of the family did not show any germline p53 defect. Cytogenetic studies did not reveal any structural aberrations.

High frequency of recurrent mutations in BRCA1 and BRCA2 genes in Polish families with breast and ovarian cancer

Germ-line mutations in BRCA1 and BRCA2 genes result in a significantly increased risk of breast and ovarian cancer. Other genes involved in an increased predisposition to breast cancer include the TP53 gene, mutated in Li-Fraumeni syndrome. To estimate the frequency of germ-line mutations in these three genes in Upper Silesia, we have analyzed 47 breast/ovarian cancer families from that region. We found five different disease predisposing mutations in 17 (36%) families. Twelve families (25.5%) carried known BRCA1 mutations (5382insC and C61G), four families (8.5%) carried novel BRCA2 mutations (9631delC and 6886delGAAAA), and one family (2%) harbored novel mutation 1095del8 in the TP53 gene, which is the largest germline deletion in coding sequence of this gene identified thus far. The 5382insC mutation in BRCA1 was found in 11 families and the 9631delC mutation in BRCA2 occurred in three families. These two mutations taken together contribute to 82% of all mutations found in this study, and 30% of the families investigated harbor one of these mutations. The very high frequency of common mutations observed in these families can only be compared to that reported for Ashkenazi Jewish, Icelandic, and Russian high-risk families. This frequency, however, may not be representative for the entire Polish population. The observed distribution of mutations will favor routine pre-screening of predisposed families using a simple and cost-effective test.

[Chronic eosinophilic leukemia]

In this research one case of chronic myelogenous eosinophilic leukemia (pbe) transformed into myeloblastic crisis in male patient aged 24, efficiently treated chemotherapy with following performing allogenic bone marrow transplantation was represented. The patients was admitted to the Department of Hematology with the cause of increased leucocytosis (up to 19.9 x 10(9)/l), eosinophilia (up to 15.3 x 10(9)/l), enlarged percentage of eosinophillic granulocytes in bone marrow, splenomegaly, anaemia and thrombocytopenia. Cytogenetic tests did not reveal any chromosomal disturbances, and PCR test did not detect bcr/abl rearanzation. After 7 monthly period of chronic phase of disease there was appeared symptoms of blastic acceleration myelogenous disease i.e. enlargement of splenomegaly, intensification of anaemia and thrombocytopenia, very fast increasing leucocytosis in short time together with presence of myeloblasts in blood and bone marrow smear tests. Blastic acceleration pbe with eosinophils dominant in bone marrow was confirmed by flow cytometry. Induction chemotherapy according to schedule HAR (Hydroxyurea--H, Arabinoside Cytosine--A, Doxorubicin--R), consolidation and irradiation of spleen allowed to receive complete remission. The patients was undergone allogenic bone marrow transplantation (allo-BMT) from related donor (younger brother). The follow-up with the period 18 months after allo-BMT has not revealed the relapse of disease.

Activity of 2-chlorodeoxyadenosine (Cladribine) in 2-hour intravenous infusion in 94 previously treated patients with low grade non-Hodgkin's lymphoma

The purpose of our study was to determine the efficacy of 2-chlorodeoxyadenosine (2-CdA) administered in 2-hour intravenous infusions in previously treated patients with low grade non-Hodgkin's lymphoma (LGNHL). We treated 94 LGNHL patients with 2-CdA at a dosage of 0.12 mg/kg/24h in 2-hour intravenous infusion for 5 consecutive days. The treatment consisted of from 1 to 7 courses (median 3), repeated usually at monthly intervals. All patients were refractory to or relapsed after standard chemotherapy. Of these 94 patients 78 (83%) had clinical stage IV of the disease. Complete response (CR) was obtained in 12 (12.8%) and partial response (PR) in 36 (38.3%) giving an overall response rate of 51.1%. In 12 (12.8%) grade 4 thrombocytopenia with haemorrhagic diathesis was noted, grade 4 neutropenia was observed in 12 (12.8%) and infections complicated the course of treatment in 38 (40.4%) patients. 2-CdA treatment was the cause of death of 3 patients. The results of our study show that 2-CdA given in 2-hour infusions is an effective agent in advanced, heavily pretreated patients with LGNHL.

Degradation of glycophorin A of human erythrocytes in patients with myelo- or lymphoproliferative disorders: possible role of neutrophil proteases

We have previously reported that glycophorin A (GPA) of human erythrocytes (carrying blood group M and N determinants) was totally digested by incubation of erythrocytes with human neutrophil elastase (HNE) and cathepsin G (CathG). The membrane-bound GPA fragments fractionated by SDS-PAGE gave characteristic patterns of bands detected by immunoblotting with the monoclonal antibody PEP80. Erythrocytes were incubated with HNE and CathG at low enzyme concentrations, similar to those found in vivo. Characteristic electrophoretic patterns of bands derived from a partial GPA digestion were observed and these patterns were different for both enzymes and different from those obtained after total GPA digestion. GPA was also partially digested by incubation of erythrocytes with granulocytes in the presence of Ca2+ and calcium ionophore and electrophoretic pattern of digestion products was similar to that obtained with low doses of HNE. No GPA digestion products were detected after treatment of erythrocytes with plasmin and kallikrein. Untreated erythrocytes of 21 patients with various myelo- or lymphoproliferative disorders were tested by SDS-PAGE of RBC membranes and immunoblotting with the anti-GPA PEP80 antibody. GPA degradation products, resembling those formed by a mild CathG treatment of control RBC, were detected in nine patients. GPA fragmentation was in some cases accompanied by a reduced expression of blood group MN determinants. No distinct relation was observed between the occurrence of GPA degradation in erythrocytes and increases in plasma concentrations of HNE-alpha1-proteinase inhibitor (alpha1-PI) complex considered to be an indication of a release of neutrophil proteinases in vivo. However, the results suggested that a partial GPA degradation in haematological proliferative disorders may occur due to limited proteolysis by neutrophil proteinases, most likely by CathG.

Intermittent 2-hour intravenous infusions of 2-chlorodeoxyadenosine in the treatment of 110 patients with refractory or previously untreated B-cell chronic lymphocytic leukemia

The purpose of our study was to determine the effectiveness of 2-CdA in 2-hour intravenous infusions in the treatment of B-CLL. One hundred and ten patients with B-CLL received 1 to 10 courses of 2-CdA (median 2.5) at a dosage of 0.12 mg/kg daily for 5 consecutive days. Eighteen of them were untreated and 92 relapsed or became refractory to previous therapeutic modalities. Complete remission (CR) was achieved in 8 (7.3%) and partial remission (PR) in 35 patients (31.8%) giving an overall response rate of 39.1%. In 3 patients, cross-resistance to fludarabine was noticed. Toxic effects of 2-CdA were more frequently observed in previously treated patients. Hemorrhagic complications due to drug-induced thrombocytopenia were noticed in 25 (22.7%) and severe infections including sepsis in 14 (12.7%) patients.