CT radiomics compared to a clinical model for predicting checkpoint inhibitor treatment outcomes in patients with advanced melanoma

INTRODUCTION

Predicting checkpoint inhibitors treatment outcomes in melanoma is a relevant task, due to the unpredictable and potentially fatal toxicity and high costs for society. However, accurate biomarkers for treatment outcomes are lacking. Radiomics are a technique to quantitatively capture tumour characteristics on readily available computed tomography (CT) imaging. The purpose of this study was to investigate the added value of radiomics for predicting clinical benefit from checkpoint inhibitors in melanoma in a large, multicenter cohort.

METHODS

Patients who received first-line anti-PD1±anti-CTLA4 treatment for advanced cutaneous melanoma were retrospectively identified from nine participating hospitals. For every patient, up to five representative lesions were segmented on baseline CT, and radiomics features were extracted. A machine learning pipeline was trained on the radiomics features to predict clinical benefit, defined as stable disease for more than 6 months or response per RECIST 1.1 criteria. This approach was evaluated using a leave-one-centre-out cross validation and compared to a model based on previously discovered clinical predictors. Lastly, a combination model was built on the radiomics and clinical model.

RESULTS

A total of 620 patients were included, of which 59.2% experienced clinical benefit. The radiomics model achieved an area under the receiver operator characteristic curve (AUROC) of 0.607 [95% CI, 0.562-0.652], lower than that of the clinical model (AUROC=0.646 [95% CI, 0.600-0.692]). The combination model yielded no improvement over the clinical model in terms of discrimination (AUROC=0.636 [95% CI, 0.592-0.680]) or calibration. The output of the radiomics model was significantly correlated with three out of five input variables of the clinical model (p < 0.001).

DISCUSSION

The radiomics model achieved a moderate predictive value of clinical benefit, which was statistically significant. However, a radiomics approach was unable to add value to a simpler clinical model, most likely due to the overlap in predictive information learned by both models. Future research should focus on the application of deep learning, spectral CT-derived radiomics, and a multimodal approach for accurately predicting benefit to checkpoint inhibitor treatment in advanced melanoma.

Long-term survival of patients with advanced melanoma treated with BRAF-MEK inhibitors

Recent results of patients with advanced melanoma treated with first-line BRAF-MEK inhibitors in clinical trials showed 5-year survival in one-third of patients with a median overall survival (OS) of more than 2 years. This study aimed to investigate these patients' real-world survival and identify the characteristics of long-term survivors. The study population consisted of patients with advanced cutaneous melanoma with a BRAF-V600 mutated tumor who were treated with first-line BRAF-MEK inhibitors between 2013 and 2017. Long-term survival was defined as a minimum OS of 2 years from start therapy. The median progression-free survival (mPFS) and median OS (mOS) of real-world patients ( n  = 435) were respectively 8.0 (95% CI, 6.8-9.4) and 11.7 (95% CI, 10.3-13.5) months. Two-year survival was reached by 28% of the patients, 22% reached 3-year survival and 19% reached 4-year survival. Real-world patients often had brain metastases (41%), stage IV M1c disease (87%), ECOG PS ≥2 (21%), ≥3 organ sites (62%) and elevated LDH of ≥250 U/I (49%). Trial-eligible real-world patients had an mOS of 17.9 months. Patients surviving more than 2 years ( n  = 116) more often had an ECOG PS ≤1 (83%), normal LDH (60%), no brain metastases (60%), no liver metastases (63%) and <3 organ sites (60%). Long-term survival of real-world patients treated with first-line BRAF-MEK inhibitors is significantly lower than that of trial patients, which is probably explained by poorer baseline characteristics of patients treated in daily practice. Long-term survivors generally had more favorable characteristics with regard to age, LDH level and metastatic sites, compared to patients not reaching long-term survival.

Adjuvant treatment for melanoma in clinical practice - Trial versus reality

BACKGROUND

Little is known about outcomes of adjuvant-treated melanoma patients beyond the clinical trial setting. Since 2019, adjuvant-treated melanoma patients have been registered in the DMTR, a population-based registry to monitor the quality and safety of melanoma care in the Netherlands. This study aims to describe treatment patterns, relapse, and toxicity rates of adjuvant-treated melanoma patients beyond the clinical trial setting.

METHODS

Analyses were performed on adjuvant-treated melanoma patients included in the DMTR. Descriptive statistics were used to analyse patient-, and treatment characteristics. A baseline registration completeness analysis was performed, and an analysis on trial eligibility in clinical practice patients. Recurrence-free survival (RFS) at 12-months was estimated with the Kaplan-Meier method.

RESULTS

A total of 641 patients were treated with adjuvant anti-PD-1 therapy. RFS at 12-months was 70.6% (95% CI, 66.9-74.6) with a median follow-up of 12.8 months. Sex, stage of disease and Breslow thickness were associated with a higher hazard for RFS. Eighteen per cent of the anti-PD-1-treated patients developed grade ≥3 toxicity. Sixty-one per cent of patients prematurely discontinued anti-PD-1 therapy.

CONCLUSION

Adjuvant anti-PD-1 treatment of resected stage III/IV melanoma in daily practice showed slightly higher toxicity rates and more frequent premature discontinuation but similar RFS rates compared to trials.

Perceptions of involvement in advance care planning and emotional functioning in patients with advanced cancer

Purpose

Advance Care Planning (ACP) is positively associated with the quality of care, but its impact on emotional functioning is ambiguous. This study investigated the association between perceptions of ACP involvement and emotional functioning in patients with advanced cancer.

Methods

This study analyzed baseline data of 1,001 patients of the eQuiPe study, a prospective, longitudinal, multicenter, observational study on quality of care and quality of life in patients with advanced cancer in the Netherlands. Patients with metastatic solid cancer were asked to participate between November 2017 and January 2020. Patients’ perceptions of ACP involvement were measured by three self-administered statements. Emotional functioning was measured by the EORTC-QLQ-C30. A linear multivariable regression analysis was performed while taking gender, age, migrant background, education, marital status, and symptom burden into account.

Results

The majority of patients (87%) reported that they were as much involved as they wanted to be in decisions about their future medical treatment and care. Most patients felt that their relatives (81%) and physicians (75%) were familiar with their preferences for future medical treatment and care. A positive association was found between patients’ perceptions of ACP involvement and their emotional functioning (b=0.162, p<0.001, 95%CI[0.095;0.229]) while controlling for relevant confounders.

Conclusions

Perceptions of involvement in ACP are positively associated with emotional functioning in patients with advanced cancer. Future studies are needed to further investigate the effect of ACP on emotional functioning.

Trial registration number

NTR6584 Date of registration: 30 June 2017

Implications for Cancer Survivors

Patients’ emotional functioning might improve from routine discussions regarding goals of future care. Therefore, integration of ACP into palliative might be promising.

Postapproval trials versus patient registries: comparability of advanced melanoma patients with brain metastases

Postapproval trials and patient registries have their pros and cons in the generation of postapproval data. No direct comparison between clinical outcomes of these data sources currently exists for advanced melanoma patients. We aimed to investigate whether a patient registry can complement or even replace postapproval trials. Postapproval single-arm clinical trial data from the Medicines Evaluation Board and real-world data from the Dutch Melanoma Treatment Registry were used. The study population consisted of advanced melanoma patients with brain metastases treated with targeted therapies (BRAF- or BRAF-MEK inhibitors) in the first line. A Cox hazard regression model and a propensity score matching (PSM) model were used to compare the two patient populations. Compared to patients treated in postapproval trials (n = 467), real-world patients (n = 602) had significantly higher age, higher ECOG performance status, more often ≥3 organ involvement and more symptomatic brain metastases. Lactate dehydrogenase levels were similar between both groups. The unadjusted median overall survival (mOS) in postapproval clinical trial patients was 8.7 (95% CI, 8.1-10.4) months compared to 7.2 (95% CI, 6.5-7.7) months (P < 0.01) in real-world patients. With the Cox hazard regression model, survival was adjusted for prognostic factors, which led to a statistically insignificant difference in mOS for trial and real-world patients of 8.7 (95% CI, 7.9-10.4) months compared to 7.3 (95% CI, 6.3-7.9) months, respectively. The PSM model resulted in 310 matched patients with similar survival (P = 0.9). Clinical outcomes of both data sources were similar. Registries could be a complementary data source to postapproval clinical trials to establish information on clinical outcomes in specific subpopulations.

First-line BRAF/MEK inhibitors versus anti-PD-1 monotherapy in BRAFV600-mutant advanced melanoma patients: a propensity-matched survival analysis

BACKGROUND

Anti-PD-1 antibodies and BRAF/MEK inhibitors are the two main groups of systemic therapy in the treatment of BRAF^V600-mutant advanced melanoma. Until now, data are inconclusive on which therapy to use as first-line treatment. The aim of this study was to use propensity score matching to compare first-line anti-PD-1 monotherapy vs. BRAF/MEK inhibitors in advanced BRAF^V600-mutant melanoma patients.

METHODS

We selected patients diagnosed between 2014 and 2017 with advanced melanoma and a known BRAF^V600-mutation treated with first-line BRAF/MEK inhibitors or anti-PD-1 antibodies, registered in the Dutch Melanoma Treatment Registry. Patients were matched based on their propensity scores using the nearest neighbour and the optimal matching method.

RESULTS

Between 2014 and 2017, a total of 330 and 254 advanced melanoma patients received BRAF/MEK inhibitors and anti-PD-1 monotherapy as first-line systemic therapy. In the matched cohort, patients receiving anti-PD-1 antibodies as a first-line treatment had a higher median and 2-year overall survival compared to patients treated with first-line BRAF/MEK inhibitors, 42.3 months (95% CI: 37.3-NE) vs. 19.8 months (95% CI: 16.7-24.3) and 65.4% (95% CI: 58.1-73.6) vs. 41.7% (95% CI: 34.2-51.0).

CONCLUSIONS

Our data suggest that in the matched BRAF^V600-mutant advanced melanoma patients, anti-PD-1 monotherapy is the preferred first-line treatment in patients with relatively favourable patient and tumour characteristics.

Prospective cohort study of patients with advanced cancer and their relatives on the experienced quality of care and life (eQuiPe study): a study protocol

BACKGROUND

Palliative care is becoming increasingly important because the number of patients with an incurable disease is growing and their survival is improving. Previous research tells us that early palliative care has the potential to improve quality of life (QoL) in patients with advanced cancer and their relatives. According to limited research on palliative care in the Netherlands, patients with advanced cancer and their relatives find current palliative care suboptimal. The aim of the eQuiPe study is to understand the experienced quality of care (QoC) and QoL of patients with advanced cancer and their relatives to further improve palliative care.

METHODS

A prospective longitudinal observational cohort study is conducted among patients with advanced cancer and their relatives. Patients and relatives receive a questionnaire every 3 months regarding experienced QoC and QoL during the palliative trajectory. Bereaved relatives receive a final questionnaire 3 to 6 months after the patients' death. Data from questionnaires are linked with detailed clinical data from the Netherlands Cancer Registry (NCR). By means of descriptive statistics we will examine the experienced QoC and QoL in our study population. Differences between subgroups and changes over time will be assessed while adjusting for confounding factors.

DISCUSSION

This study will be the first to prospectively and longitudinally explore experienced QoC and QoL in patients with advanced cancer and their relatives simultaneously. This study will provide us with population-based information in patients with advanced cancer and their relatives including changes over time. Results from the study will inform us on how to further improve palliative care.

TRIAL REGISTRATION

Trial NL6408 ( NTR6584 ). Registered in Netherlands Trial Register on June 30, 2017.

Reductions in body weight and insulin resistance are not associated with changes in grey matter volume or cortical thickness during the PREVIEW study

INTRODUCTION

The effect of changes in body weight or insulin resistance on grey matter volume and cortical thickness change are unclear. The present observational study assessed effects of an 8-week weight loss period (≥8% of body weight), and a subsequent 22-month weight maintenance period on grey matter volume and cortical thickness.

METHODS

A total of 24 participants (12f/12 m; age 52.8 ± 10.6 years) with overweight/obesity and pre-diabetes were recruited. T1-weighted magnetic resonance imaging was used to determine grey matter volume and cortical thickness at baseline, after the weight loss period and after a medium to high dietary protein weight maintenance period.

RESULTS

At baseline, global grey matter volume was inversely associated with HOMA-IR, adjusted for sex and age (r = -0.42; p = .049). During the weight loss period participants decreased their BMI (32.1 ± 3.3 to 28.1 ± 2.8 kg/m², p < .01), body-fat (41.6 ± 6.4 to 35.0 ± 8.0%, p < .01) and insulin resistance (HOMA-IR: 4.0 ± 2.0 to 1.8 ± 0.9, p < .01). During the 22-month weight maintenance period, these parameters gradually increased again (BMI: 29.3 ± 3.8 kg/m²; body-fat: 37.8 ± 9.3%; HOMA-IR: 2.9 ± 1.4, p < .01). Global grey matter volume and cortical thickness did not change significantly during the weight loss or weight maintenance period. Changes in body weight, body-fat percentage or insulin sensitivity were not associated with changes in global grey matter volume.

CONCLUSION

In conclusion, we confirmed that global grey brain matter volume was inversely associated with insulin resistance at baseline, yet an intervention yielding a decrease in insulin resistance did not lead to changes in global grey brain matter volume or cortical thickness.

TRIAL REGISTRATION

The trial is registered with ClinicalTrials.gov, NCT01777893.

Long-term effectiveness and cost-effectiveness of high versus low-to-moderate intensity resistance and endurance exercise interventions among cancer survivors

PURPOSE

This study aimed to evaluate the long-term effectiveness and cost-effectiveness of high intensity (HI) versus low-to-moderate intensity (LMI) exercise on physical fitness, fatigue, and health-related quality of life (HRQoL) in cancer survivors.

METHODS

Two hundred seventy-seven cancer survivors participated in the Resistance and Endurance exercise After ChemoTherapy (REACT) study and were randomized to 12 weeks of HI (n = 139) or LMI exercise (n = 138) that had similar exercise types, durations, and frequencies, but different intensities. Measurements were performed at baseline (4-6 weeks after primary treatment), and 12 (i.e., short term) and 64 (i.e., longer term) weeks later. Outcomes included cardiorespiratory fitness, muscle strength, self-reported fatigue, HRQoL, quality-adjusted life years (QALYs) and societal costs. Linear mixed models were conducted to study (a) differences in effects between HI and LMI exercise at longer term, (b) within-group changes from short term to longer term, and (c) the cost-effectiveness from a societal perspective.

RESULTS

At longer term, intervention effects on role (β = 5.9, 95% CI = 0.5; 11.3) and social functioning (β = 5.7, 95%CI = 1.7; 9.6) were larger for HI compared to those for LMI exercise. No significant between-group differences were found for physical fitness and fatigue. Intervention-induced improvements in cardiorespiratory fitness and HRQoL were maintained between weeks 12 and 64, but not for fatigue. From a societal perspective, the probability that HI was cost-effective compared to LMI exercise was 0.91 at 20,000€/QALY and 0.95 at 52,000€/QALY gained, mostly due to significant lower healthcare costs in HI exrcise.

CONCLUSIONS

At longer term, we found larger intervention effects on role and social functioning for HI than for LMI exercise. Furthermore, HI exercise was cost-effective with regard to QALYs compared to LMI exercise.

TRIAL REGISTRATION

This study is registered at the Netherlands Trial Register [NTR2153 [ http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2153 ]] on the 5th of January 2010.

IMPLICATIONS FOR CANCER SURVIVORS

Exercise is recommended to be part of standard cancer care, and HI may be preferred over LMI exercise.

The magnitude of neurotoxicity in patients with multiple myeloma and the impact of dose modifications: results from the population-based PROFILES registry

The aim of this analysis is to assess (1) self-reported chemotherapy-induced peripheral neuropathy (CIPN) symptoms; (2) its association with sociodemographic and clinical characteristics; and (3) treatment dose modifications and its influence on the magnitude of neurotoxicity in a population-based cohort of patients with multiple myeloma (MM). MM patients (n = 156), diagnosed between 2000 and 2014, filled out the EORTC QLQ-CIPN20 (65% response). Data on treatment, outcomes, and dose modifications were extracted from the medical files. Fifty-three percent of patients reported at least one and on average three neuropathy symptoms that bothered them the most during the past week, with tingling toes/feet as most reported. In multivariate analysis, thalidomide, especially higher cumulative dose, was associated with neuropathy (β = 0.26, CI 95% 0.27-15.34, p = 0.04) and CIPN was not associated with age, sex, time since last course of therapy, number of prior therapies, osteoarthritis, or diabetes. Dose modifications were often applied (65%). Although not statistically significant, a trend towards higher sensory (22 vs. 15 vs. 12, p = 0.22) and motor neuropathy scores (21 vs. 15 vs. 11, p = 0.36) was observed among patients receiving dose modification because of CIPN (31%) compared to those receiving a dose modification for another reason or no dose modification, without altering treatment response. CIPN is a common dose limiting side effect in patients with MM. Severity of CIPN was mainly affected by treatment with thalidomide. In spite of dose modifications, patients still reported somewhat higher neuropathy scores without altered response rates. Early dose modification based on a more reliable tool for CIPN measurements may prove value.

The effect of training during treatment with chemotherapy on muscle strength and endurance capacity: A systematic review

Background Treatment of cancer with chemotherapy decreases endurance capacity and muscle strength. Training during chemotherapy might prevent this. There are no clear guidelines concerning which type of training and which training dose are effective. This review aims to gain insight into the different training modalities during chemotherapy and the effects of such training to improve endurance capacity and muscle strength in order to obtain the knowledge to compose a future training program which trains cancer patients in the most effective way. Material and methods A systematic search of PubMed was carried out. In total, 809 studies of randomized controlled trials studying the effects of training during chemotherapy on endurance capacity and muscle strength were considered. Only 14 studies met all the inclusion criteria. The studies were assessed on methodological quality by using Cochrane criteria for randomized controlled trials. Results The quality of the studies was generally poor and the study populations varied considerably as the training programs were very heterogeneous. Variables of endurance capacity reported beneficial effects in 10 groups (59%). Increases due to training ranged from 8% to 31%. Endurance capacity decreased in nine of 13 control groups (69%), which ranged from 1% to 32%. Muscle strength improved significantly in 17 of 18 intervention groups (94%), ranging from 2% to 38%. Muscle strength also improved in 11 of 14 control groups (79%), but this increase was only minimal, ranging from 1.3% to 6.5%. Conclusions This review indicates that training during chemotherapy may help in preventing the decrease in muscle strength and endurance capacity. It is important to know which training intensity and duration is the most effective in training cancer patients, to provide a training program suitable for every cancer patient. Training should be based on good research and should be implemented into international guidelines and daily practice. More research is needed.

Fatigue mediates the relationship between physical fitness and quality of life in cancer survivors

OBJECTIVES

This study aims to investigate whether fatigue mediates the association between physical fitness and quality of life.

DESIGN

Uncontrolled pre-post intervention design.

METHODS

Pre- and post-intervention measurements were conducted in 119 patients who completed chemotherapy treatment for various types of cancer. The intervention was an 18-week exercise programme consisting of high-intensity resistance and interval training. We assessed physical fitness - peak oxygen uptake and peak power output - self-reported fatigue (Multidimensional Fatigue Inventory - subscales general fatigue, physical fatigue, reduced activity, reduced motivation, and mental fatigue-, and fatigue symptom scale of EORTC QLQ-C30) and quality of life (EORTC QLQ-C30, subscale global quality of life). Linear regression analyses were conducted on the residual change scores of the variables. The mediated effect of fatigue on the association between physical fitness and quality of life was examined using the products of coefficient method. Bootstrapping was used to calculate the confidence intervals.

RESULTS

We found significant associations between changes in physical fitness and global quality of life, between physical fitness and fatigue, and between fatigue and global quality of life. General fatigue mediated the positive association between peak power output and global quality of life, accounting for 82% of the total association. Physical fatigue, reduced activity, reduced motivation, and fatigue symptom were also mediators of this association. The mediation effects accounted for 91%, 76%, 38% and 71% of the total association, respectively. Reduced activity and reduced motivation mediated the association between peak oxygen uptake and global quality of life. Multiple mediation analyses showed that physical aspects of fatigue were stronger mediators than mental aspects.

CONCLUSIONS

General fatigue and physical aspects of fatigue mediate the relationship between physical fitness and quality of life in cancer survivors. We found no mediating effect of mental fatigue.

High-intensity strength training improves quality of life in cancer survivors

INTRODUCTION

Cancer rehabilitation programs mainly involve endurance training, and little attention is paid to strength training. Cancer survivors are generally advised to train at much lower workloads than the standard guidelines for strength training suggest. The purpose of this study is to evaluate the effectiveness of an 18-week high-intensity strength training program in cancer survivors.

METHODS

Fifty-seven patients (age 24 to 73 years) who had received chemotherapy for lymphomas, breast, gynecologic, testicular, or colorectal cancer completed the program. Outcome measures were changes in muscular strength (one-repetition maximum), cardiopulmonary function (VO2 max), maximal short exercise capacity (MSEC), body composition and health-related quality of life (HRQOL) between baseline and follow-up.

DISCUSSION

The high-intensity strength training was well tolerated by all patients. Significant improvements in muscle strength were found, with effect sizes varying from 1.32 to 2.68. VO2 max increased significantly by 10% in men and by 13% in women. Different functional scales of HRQOL improved (p < 0.01), with effect sizes varying from 0.47 to 0.82. Muscle strength correlated significantly with physical functioning before and after the training program.

CONCLUSION

We conclude that a supervised, high-intensity strength training program seems to be an effective means to improve muscle strength, cardiopulmonary function, and HRQOL and should be incorporated in cancer rehabilitation programs. Further randomized trials are needed to confirm the results.

Treatment and survival of patients with thyroid lymphoma: a population-based study with clinical and pathologic reviews

PURPOSE

The purpose of this study was to determine the incidence, clinical and histologic features, and patterns of outcome of thyroid lymphomas.

PATIENTS AND METHODS

A retrospective population-based survey of 38 patients with thyroid lymphoma was taken. Median age was 69 years (range, 33-87 years), with a 1:4 female predominance. Fifty percent of cases had a history of autoimmune thyroiditis, and coexistent thyroiditis was found in 67% of cases in which preexistent thyroid tissue was present. The most common subtype was diffuse large B-cell lymphoma (DLBCL; 63%) followed by extranodal marginal zone lymphoma (ENMZL; 29%). Ten of the patients with DLBCL showed a concomitant low-grade mucosa-associated lymphatic tissue component, and 4 cases of aggressive ENMZL were diagnosed. At diagnosis, 22 patients (58%) had localized disease, and 41% had low-risk international prognostic index scores.

RESULTS

Therapy was diverse and included all possible treatment modalities, none of which showed superiority. A complete clinical response was exhibited in 64% of patients, 14% exhibited a partial response, and 22% developed progressive disease. At a median follow-up of 43 months (range, 0-240 months), 15 patients had relapsed or developed progressive disease. Two-year overall survival rate was 59% for all patients, 68% for patients with localized disease, and 47% for patients with disseminated lymphoma.

CONCLUSION

Many thyroid lymphomas have clinical and histologic features characteristic of ENMZL and belong to this specific clinicopathologic entity.

The risk of nodal metastases in breast cancer patients with clinically negative lymph nodes: a population-based analysis

A population-based study was performed to assess the likelihood of axillary lymph node metastases in patients with clinically negative lymph nodes, according to patient age, tumor size and site, estrogen receptor status, histologic type and mode of detection. Data were obtained from the population-based Eindhoven Cancer Registry. During the period 1984-1997, 7680 patients with invasive breast cancer were documented, 6663 of whom underwent axillary dissection. Of the 5125 patients who were known to have clinically negative lymph nodes and underwent axillary dissection, 1748 (34%) had positive lymph nodes at pathological examination. After multivariate analysis, histologic type, tumor size, tumor site and the number of lymph nodes in the axillary specimen remained as independent predictors of the risk of nodal involvement (P < 0.001). Lower risks were found for patients with medullary or tubular carcinoma, smaller tumors, a tumor in the medial part of the breast and patients with less than 16 nodes examined. This study gives reliable estimates of the risk of finding positive lymph nodes in patients with a clinically negative axilla. Such information is useful when considering the need for axillary dissection and to predict the risk of a false-negative result when performing sentinel lymph node biopsy.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) counteracts the inhibiting effect of monocytes on natural killer (NK) cells

GM-CSF is known to accelerate haematopoietic recovery following allogeneic bone marrow transplantation (BMT). In addition, it may restore and enhance both granulocyte and monocyte functions. Stimulation of monocyte functions may induce a direct or an indirect anti-leukaemic activity due to an increase of cellular cytotoxicity and production of cytokines which may result in a reduction of the relapse rate after BMT. NK cells may play a crucial role in this activity. Therefore we studied the influence of monocytes on NK activity in combination with GM-CSF. Lymphocytes and monocytes were isolated from buffy coats of healthy individuals by counterflow centrifugation elutriation (CCE). NK activity was exerted by CD3-CD56+ cell populations and could be enhanced by IL-2 incubation overnight. Incubation of CD3-CD56+ cells with GM-CSF in the presence or absence of IL-2 hardly influenced NK activity of the lymphocyte population. Low amounts of monocytes enhanced NK activity. NK activity in lymphocyte population in the presence of equivalent numbers of monocytes with or without IL-2 was strongly decreased irrespective of the effector:target ratio (ETR). This appeared not to result from sterical hindrance effects of the present number of cells. However, addition of GM-CSF abrogated the inhibition of NK activity by monocytes in the presence of IL-2. In monocyte fractions neither IL-2 nor GM-CSF yielded NK activity. Our findings indicate that GM-CSF can affect NK activity by counteracting the suppressing effects of monocytes, and hence may improve the outcome after BMT.

Familial cerebrovascular accidents due to concomitant hyperhomocysteinemia and protein C deficiency type 1

BACKGROUND AND PURPOSE

Hyperhomocysteinemia and protein C deficiency are risk factors for thromboembolism. Hyperhomocysteinemia has been reported to inhibit the expression of thrombomodulin and to inactivate both thrombomodulin and protein C irreversibly, leading to decreased protein C activity.

CASE DESCRIPTIONS

In a 16-year-old girl, who developed a sinus sagittalis thrombosis, and in her father, who experienced a transient ischemic attack, both hyperhomocysteinemia and protein C deficiency type 1 were present. Protein C deficiency alone was found in one of the two sisters, who was without any clinical vascular history.

CONCLUSIONS

In this family with independently inherited hyperhomocysteinemia and protein C deficiency, clinical cerebrovascular disease occurred only in those members with a combination of both risk factors, suggesting a synergistic interaction between these thrombogenic risk factors.

Immune response to hepatitis B vaccine in drug addicts

Drug addicts are at high risk of hepatitis B infection and are therefore candidates for vaccination against hepatitis B. Since drug addicts may have an impaired immune response, and low compliance for therapy extending over several months, we evaluated a vaccination scheme according to the instruction of the manufacturer (HB- Vax 20 micrograms at zero, one and six months) in drug addicts using daily methadone (Group M), in drug addicts in residential detoxification programmes (Group D), and in treatment centre staff who were seronegative for hepatitis Bs (Group S). All 23 controls and 20 of 21 of Group D completed the vaccination programme, in contrast to 14 of 24 in Group M. Anti-HBs developed in 91 per cent of Group S and in all addicts tested at six months. Anti-HBs titres at seven months were higher than 100 RIA units in 55 per cent of Group S, in 94 per cent of Group D and in 44 per cent of Group M. We conclude that HB- Vax induces production of anti-HBs equally well in drug addicts and in controls: a shorter-duration vaccination schedule might be more appropriate for 'non-captive' drug addicts living outside therapeutic communities.