Patient centered guidelines for the laboratory diagnosis of Gaucher disease type 1

Gaucher disease (GD) is an autosomal recessive lysosomal storage disorder due to the deficient activity of the acid beta-glucosidase (GCase) enzyme, resulting in the progressive lysosomal accumulation of glucosylceramide (GlcCer) and its deacylated derivate, glucosylsphingosine (GlcSph). GCase is encoded by the GBA1 gene, located on chromosome 1q21 16 kb upstream from a highly homologous pseudogene. To date, more than 400 GBA1 pathogenic variants have been reported, many of them derived from recombination events between the gene and the pseudogene. In the last years, the increased access to new technologies has led to an exponential growth in the number of diagnostic laboratories offering GD testing. However, both biochemical and genetic diagnosis of GD are challenging and to date no specific evidence-based guidelines for the laboratory diagnosis of GD have been published. The objective of the guidelines presented here is to provide evidence-based recommendations for the technical implementation and interpretation of biochemical and genetic testing for the diagnosis of GD to ensure a timely and accurate diagnosis for patients with GD worldwide. The guidelines have been developed by members of the Diagnostic Working group of the International Working Group of Gaucher Disease (IWGGD), a non-profit network established to promote clinical and basic research into GD for the ultimate purpose of improving the lives of patients with this disease. One of the goals of the IWGGD is to support equitable access to diagnosis of GD and to standardize procedures to ensure an accurate diagnosis. Therefore, a guideline development group consisting of biochemists and geneticists working in the field of GD diagnosis was established and a list of topics to be discussed was selected. In these guidelines, twenty recommendations are provided based on information gathered through a systematic review of the literature and two different diagnostic algorithms are presented, considering the geographical differences in the access to diagnostic services. Besides, several gaps in the current diagnostic workflow were identified and actions to fulfill them were taken within the IWGGD. We believe that the implementation of recommendations provided in these guidelines will promote an equitable, timely and accurate diagnosis for patients with GD worldwide.

Prodromal substantia nigra sonography undermines suggested association between substrate accumulation and the risk for GBA-related Parkinson's disease

BACKGROUND AND PURPOSE

Individuals with GBA (glucocerebrosidase) mutations are at increased risk of Parkinson's disease (PD). It is still debated, however, whether this increased risk results from impaired glucocerebrosidase activity leading to substrate accumulation. Comparing the presence of prodromal PD marker in GBA mutation carriers and patients with Gaucher disease (GD) (in which substrate accumulation is extensive) can assist in clarifying this issue.

METHODS

In this cross-sectional study, we compared the hyperechogenic area of the substantia nigra, a prodromal PD marker, in large cohorts of GBA mutation carriers (n = 71) and patients with GD (n = 145). Our control populations were healthy, non-carriers (n = 49) and patients with GBA -related PD (n = 11). Substrate accumulation was assessed from dry blood spot levels of glucosylsphingosine.

RESULTS

Our findings indicate no contribution of substrate accumulation, as the area of hyperechogenicity is similarly enlarged relative to healthy controls in both GBA mutation carriers and patients with GD. Moreover, this similarity between GBA carriers and patients with GD persists when comparing only carriers of the N370S (c.1226A>G) mutation (n = 38) with untreated patients with GD who were homozygotes for the same mutation (n = 47). In addition, measurements of hyperechogenic area did not correlate with levels of glucosylsphingosine in the untreated patients with GD.

CONCLUSION

The presence of a marker of prodromal PD (substantia nigra hyperechogenicity) is independent of substrate accumulation in a population with mutated GBA . Although further longitudinal studies are needed to determine the precise predictive value of this marker for GBA -related PD, our findings raise doubts regarding the contribution of substance reduction strategies to PD prevention.

Post-thrombotic syndrome after central venous catheter removal in childhood cancer survivors: A prospective cohort study

BACKGROUND

Although the use of central venous catheters (CVCs) has greatly improved the quality of care of children with cancer, these catheters increase the risk of deep vein thrombosis (DVT) and the potential long-term complication of post-thrombotic syndrome (PTS). We aimed to study PTS post-CVC removal using physical, functional and health related quality of life (HRQoL) domains in childhood cancer and bone marrow transplantation (BMT) survivors.

PROCEDURE

We conducted a prospective study in a cohort of childhood cancer and BMT survivors post-CVC use. Participants were evaluated for PTS with the Modified Villalta Score (MVS) and the Manco-Johnson Instrument (MJI). HRQoL was assessed using the PedsQL™ questionnaire.

RESULTS

A total of 158 children were enrolled at a median of 41 (4-149) months from CVC removal. Signs and symptoms of PTS were present in 34% (95% confidence interval [CI] 27-43%) (MVS criteria) and 30.5% (95% CI 23.1-37.8%) (MJI criteria). Diagnosis of PTS was associated with history of CVC occlusion, history of CVC-related DVT and the use of ≥2 CVCs. The presence of signs and symptoms of PTS was a predictor for low HRQoL tested by the PedsQL™ Total Scale scores and Physical Health Summary scores.

CONCLUSIONS

PTS post-CVC removal in pediatric cancer survivors is not a rare event. The association between PTS and the history of CVC occlusion confirms earlier findings, and suggests that CVC occlusion may indicate asymptomatic DVT. PTS is also associated with lower HRQoL scores highlighting the need to study preventive measures, especially for high risk groups. Pediatr Blood Cancer 2015;62:285-290. © 2014 Wiley Periodicals, Inc.

Activity of cytochrome P450 1A2 in relation to hepatic iron accumulation in transfusion-dependent β-thalassaemia major patients

BACKGROUND

Cytochrome P450 1A2 (CYP1A2) is a cytochrome enzyme with a pivotal role in hepatic drug metabolism. Data from CYP1A2((-/-)) mouse suggest that CYP1A2 plays a role in aspects of hepatic iron toxicity. The aim of this study was to assess the activity of CYP1A2 in relation to hepatic iron load in patients with transfusion-dependent β-thalassaemia major.

METHODS

The (13) C-methacetin continuous breath test was performed on 30 consecutive patients with transfusion-dependent β-thalassaemia major. CYP1A2 activity was measured by the rate at which the (13) C substrate is metabolized and exhaled expressed as percentage dose recovery (PDR) per hour. CYP1A2 activity was correlated with clinical and laboratory parameters and hepatic iron accumulation by T2* magnetic resonance imaging (T2*MRI).

RESULTS

Cytochrome P450 1A2 activity in patients with transfusion-dependent β- thalassaemia major was positivity correlated with plasma ferritin levels. No correlation was found with age, duration and amount of red blood cell transfusion and type of iron chelation therapy. Low CYP1A2 activity was negatively associated with hepatic iron accumulation (T2*MRI ≤ 6.3 ms); adjusted odds ratio (OR; 95% CI) for hepatic iron accumulation in patients with low CYP1A2 activity was 0.047 (0.003-0.72; P = 0.021). Of the six patients with decreased activity of CYP1A2, five had no hepatic iron accumulation and one had mild hepatic iron accumulation by T2*MRI.

CONCLUSION

Activity of CYP1A2 is associated with hepatic iron accumulation in patients with transfusion-depended β-thalassaemia major. Further studies are needed to assess the exact role of CYP1A2 in iron metabolism in human.

Effect of intracranial bleeds on the neurocognitive, academic, behavioural and adaptive functioning of boys with haemophilia

Brain insults are a risk factor for neuropsychological and academic deficits across several paediatric conditions. However, little is known about the specific effects of intracranial haemorrhage (ICH) in boys with haemophilia. The study compared neurocognitive, academic and socio-emotional/behavioural outcomes of boys with haemophilia with and without a history of ICH. Of 172 consecutive patients seen at a Pediatric Comprehensive Care Hemophila Centre, 18 had a history of ICH. Sixteen boys between the ages of 3 and 17 years were available for study and were matched to controls with haemophilia of the same age and disease severity and on the basis of maternal education. Groups were compared on neuropsychological and academic outcomes. Attention, socio-emotional function and executive skills were compared using data from parent questionnaires. Differences were found in intellectual function, visual-spatial skill, fine motor dexterity and particularly language-related skills, including vocabulary, word reading and applied math problem solving. Despite these group differences, outcomes were within the average range for most boys with ICH. No group differences were found in behavioural and socio-emotional functioning. Although ICH in haemophilia is not benign, it was not associated with significant cognitive and academic consequences for most boys. Early neuropsychological assessment may be indicated when there is a history of ICH. Investigation of age at ICH and quantitative measures of brain in relation to neurocognitive outcomes in larger groups of boys with ICH would be useful.

The changing face of hepatitis in boys with haemophilia associated with increased prevalence of obesity

Hepatitis in children with haemophilia was historically most often associated with transfusion-transmitted infections. However, with the use of recombinant clotting factor concentrates, acquisition of such infections has now become rare. We studied the profile of hepatitis in North-American children with haemophilia in the modern era of safe blood products and excess childhood obesity. A total of 173 boys (<18 years) registered in the Pediatric Comprehensive Care Haemophilia Program were included in this retrospective study. Hospital records were reviewed for baseline data, serial height and weight measurements and serial alanine aminotransferase (ALT) levels. A body mass index (BMI) ranking was available for 170 boys, of whom 25 (14.7%, 95% CI 9.7-20.9%) were obese. The rate of obesity was higher in severe haemophilic boys. Compared with the general childhood population, the rate of obesity trended towards being higher in young haemophilic boys (2-5 years), but was similar in other age groups. A persistently high ALT (≥80 U L(-1) ) was documented in 5 boys and was associated with obesity. Three boys had clinical and imaging studies compatible with non-alcoholic fatty liver disease (NAFLD). Overweight and obesity are common among haemophilic boys, especially those who are younger and with severe disease. In this large group of haemophilic boys, chronic viral hepatitis was rare and NAFLD was a more common cause of liver disease. Overweight and obese haemophilic boys should be evaluated for NAFLD and interventional programmes should be designed to reduce the potential complications associated with obesity.

Risk factors for central venous catheter thrombotic complications in children and adolescents with cancer

BACKGROUND

The use of central venous catheters (CVCs) has greatly improved the quality of care in children with cancer, yet these catheters may cause serious infectious and thrombotic complications. The aim of this prospective registry study was to assess the host and CVC-related risk factors for CVC-created thrombotic complications.

METHODS

Patients undergoing CVC insertion for chemotherapy were followed prospectively for CVC complications. At the time of enrollment, demographic, clinical, and CVC-related data, and family history of thrombosis were collected. Survival and Cox regression analyses were performed.

RESULTS

A total of 423 CVCs were inserted into 262 patients for a total of 76,540 catheter days. The incidence of CVC-related deep-vein thrombosis (DVT) was 0.13 per 1000 catheter-days (95% confidence interval [CI], 0.06-0.24). Insertion of peripherally inserted central catheters (PICCs) and insertion in an angiography suite significantly increased the risk of symptomatic CVC-related DVT. The incidence of CVC occlusion was 1.35 per 1000 catheter-days (95% CI, 1.1-1.63). Positive family history of thrombosis significantly increased the risk of CVC occlusion (hazard ratio [HR], 2.16; 95% CI, 1.2-3.8). The CVC-related risk factors were insertion of Hickman catheters, insertion in angiography suite, and proximal-tip location. Patients developing at least 1 episode of both CVC occlusion and infection had an increased risk for developing symptomatic CVC-related DVT (HR, 4.15; 95% CI, 1.2-14.4).

CONCLUSIONS

Both patient-related and CVC-related factors are associated with higher risk of symptomatic thrombotic complications. These risk factors could be used in the clinical setting and in developing future studies for CVC thromboprophylaxis.

Evaluation of children with a suspected bleeding disorder applying the Impact-R [Cone and Plate(let) Analyzer]

BACKGROUND

A convenient screening test for children with bleeding symptoms before more labor-intensive diagnostic steps are taken would be of value. The Impact-R was designed in an attempt to analyse platelet function under near physiological conditions. Results are presented as surface coverage (SC, %) and average size (AS, microm(2)).

OBJECTIVE

In this cross-sectional retrospective study, we assessed the use of the Impact-R in the evaluation of children with a suspected bleeding disorder (BD).

METHODS

The hospital charts of 110 children referred to the coagulation laboratory were reviewed for personal and family bleeding history (BH) as well as results of the laboratory evaluation.

RESULTS

A laboratory 'diagnosable' BD (LBD) was found in 23 children (21%, 95% CI 14-30%). A diagnosis of LBD was associated with the severity of bleeding but not with family BH. By receiver-operating characteristic (ROC) curve analysis, the SC was superior to the AS for diagnosis of a LBD. The Impact-R was abnormal in 43/97 children (44.3%, 95% CI 34-55%). The predictive values of a normal and abnormal Impact-R were 96% (95% CI 92-97%) and 42% (95% CI 28-56%), respectively. When considering the personal and family BH, the post-test probability for LBD after a normal Impact-R was reduced from 20% to 3.5% (95% CI 2.5-7%).

CONCLUSIONS

A normal Impact-R test is highly effective in excluding LBDs. Yet, in case of an abnormal Impact-R test, further testing is needed. An algorithm that includes the personal and family BH and the results of a screening test may improve the diagnostic process. Prospective studies are now needed to confirm these findings.

Antiphospholipid syndrome and recurrent thrombosis in children

OBJECTIVE

Few studies have addressed antiphospholipid syndrome (APS) among children. Our aims were to analyze the clinical and laboratory manifestations in a pediatric APS cohort and to assess the influence of inherited thrombophilia factors on the outcome of children with APS.

METHODS

This was a multicenter study of children with APS who had no previous systemic autoimmune disease. We retrospectively reviewed their clinical and laboratory data, including hereditary thrombophilic deficits and outcomes.

RESULTS

The cohort comprised 28 patients (17 females, mean +/- SD age at onset 10.6 +/- 6.1 years). The most common initial manifestations of APS were venous thrombosis, stroke, and thrombocytopenia. Lupus anticoagulant was detected in 96% of those tested. After a mean +/- SD followup of 5.7 +/- 4.8 years, 16 children (57.1%) had central nervous system disease, 9 exhibited hematologic involvement, and 5 (all females) had systemic lupus erythematosus (SLE). None had renal, heart, or new skin disease. Seven of 24 patients exhibiting vascular thrombotic events had recurrences. Infants with perinatal stroke had monophasic disease, and other manifestations of APS did not develop later. Hereditary thrombophilia was more common in children who experienced a single episode of APS (8 [53.3%] of 15 patients) than in those who experienced recurrences (2 [28.6%] of 7 patients). However, only 2 patients in the latter group (28.6%) received anticoagulants after the first manifestation, compared with 12 (70.6%) of the 17 patients without recurrences.

CONCLUSION

APS in children has unique features. SLE may develop in a significant percentage of girls presenting with APS. Hereditary thrombophilia did not predict recurrent thrombosis, whereas the preventive impact of anticoagulant treatment following the first thrombotic event was noteworthy.

Natural history of arterial and venous thrombosis in children treated with low molecular weight heparin: a longitudinal study by ultrasound

Low molecular weight heparin (LMWH) is efficacious in preventing recurrent thromboembolic events (TEs) in children. The efficacy of LMWH in resolving thrombus in children is, however, unknown and may differ from what has been observed in adults due to known differences in the hemostatic system. We reviewed the ultrasound (US) scanning reports of children treated with LMWH in order to determine the rate and predictors of thrombus resolution. Of 245 children consecutively treated for a non-cerebral TE with enoxaparin (Lovenox, Aventis Pharma Inc., QC, Canada) for at least 5 consecutive days, 190 (78%) had serial ultrasound available for analysis. The mean follow-up time was 7 months (median 3 months, range 3 days to 6.6 years). The rate of complete thrombus resolution was 101/190 (53%, 95% confidence interval 46.2-60.2%). On univariate analysis, arterial and non-occlusive thrombus had an increased rate of resolution when compared with venous and occlusive thrombus. Age at time of TE (neonates vs. non-neonates), location of TE, initial treatment (unfractionated heparin vs. LMWH) and dose of enoxaparin were not related to outcome. On multivariate analysis, type of vessel (vein vs. artery) and occlusion (occlusive vs. non-occlusive thrombus) independently predicted outcome. In children, the rate of complete thrombus resolution is similar to the rate in adults. The clinical significance of residual abnormal vessels, specifically to the occurrence of post-thrombotic syndrome and for the diagnosis of recurrence, needs to be explored in prospective studies.

Prothrombotic conditions in an unselected cohort of children with venous thromboembolic disease

Venous thromboembolic events (VTEs) in children are usually associated with underlying clinical conditions. The added contribution of prothrombotic conditions to the occurrence of VTEs in children is not clear. This study reports the prevalence of prothrombotic conditions in 171 consecutive children with VTE followed in the Hospital for Sick Children Thrombosis Outpatient Clinic. The median age of the children at the time of VTE was 2.3 months (range 1 day to 16.5 years). An underlying medical condition and a central venous line (CVL) were present in 156 (91%) and 132 (77%) of 171 children, respectively. A positive family history was present in 8% of children. The prevalence of factor V Leiden was 4.7%, prothrombin G20210A polymorphism was 2.3%, protein S deficiency was 1.2%, protein C deficiency was 0.6% and increased plasma lipoprotein (a) concentration (>30 mg dL-1) was 7.5% (tested in 107 children). The overall frequency of inherited prothrombotic coagulation proteins was 13% (95% confidence interval 7 to 19%) and the frequency was not significantly different between neonates and older children with VTE. Inherited prothrombotic coagulation proteins were not associated with gender, CVL-related VTE, a positive family history of thrombosis or spontaneous VTE in neonates. Increased frequency of inherited prothrombotic coagulation proteins was, however, found in older children with spontaneous VTE (60%) compared with older children with VTEs secondary to an underlying medical condition (10%) (P = 0.02). In conclusion, this study indicates that inherited prothrombotic coagulation proteins do not contribute significantly to the pathogenesis of VTEs in neonates and children, in whom the most significant etiological factors are the presence of a CVL and/or other medical conditions.

Thromboembolic diseases of childhood

Over the last decade, pediatric thrombophilia programs have emerged around the world as a new discipline in pediatric hematology. These programs specialize in the diagnosis, prevention and treatment of children with thromboembolic events (TEs) in both the venous and arterial systems. The need for separate pediatric programs has been discussed previously. (J Pediatr Hematol Oncol 1997; 19: 7-22.) The following article will update previous reviews (Hematol Oncol Clin North Am 1998; 12: 1283-1312; Thromb Haemost 1997; 78: 715-725) and will concentrate on three aspects: (1) The risk factors for acquiring TEs; (2) The confirmatory diagnostic tests used in children with TEs; and (3) The different antithrombotic agents used for prevention and treatment. The current knowledge in respect to the above points is only the "tip of the iceberg". Well-designed prospective trials are required to establish the contribution of congenital prothrombotic disorders, appropriate diagnostic strategies, and optimal therapy for children with TEs.

The clinical course of bronchiolitis associated with acute otitis media

BACKGROUND

Acute otitis media (AOM) is the most common bacterial co-infection of viral bronchiolitis.

AIMS

To evaluate the influence of AOM on the clinical course of bronchiolitis.

SUBJECTS

150 children younger than 24 months old, diagnosed with bronchiolitis, hospitalised between December 1997 and May 1999.

METHODS

Body temperature, respiratory rate, oxygen saturation, and the need for oxygen supplementation were recorded on admission and daily throughout hospitalisation. Complete blood count, erythrocyte sedimentation rate, and assay for respiratory syncytial virus were performed on admission. All children were examined daily for the appearance of AOM. The clinical course of children with bronchiolitis and AOM was compared to those without AOM.

RESULTS

AOM was diagnosed in 79/150 (53%) children with bronchiolitis. Most were diagnosed within the first two days of hospitalisation. No significant difference was found in the clinical and laboratory findings on admission and on daily follow up between children with and without AOM.

CONCLUSIONS

This 2.5 year prospective study showed no difference in the course of bronchiolitis, whether an ear infection was present or not.

Serum transferrin receptor in children and adolescents with inflammatory bowel disease

Iron studies are difficult to interpret in patients with chronic inflammatory states such as inflammatory bowel disease (IBD). Serum transferrin receptor (TfR) has been reported to be a reliable tool for the diagnosis of iron deficiency in adults. Our aim was to evaluate the role of serum TfR in diagnosing iron deficiency in children and adolescents with IBD. A total of 63 consecutive patients with IBD, aged 9 to 22 years (median 15 years), were tested for serum haemoglobin level, mean corpuscular volume (MCV), and serum iron, transferrin, ferritin and serum TfR levels. Those found to be anaemic were compared with seven age-matched subjects with iron deficiency anaemia (IDA) and 24 age-matched children without signs of anaemia or inflammation. Of the 63 patients with IBD, 26 had anaemia. Based on ferritin levels and MCV indices, anaemia was classified as IDA in 11 patients and as anaemia of chronic disease (ACD) in 15 patients. Mean serum TfR level in normal controls was 3.5 mg/l (range 1.2-8.2 mg/l). Mean (+/-SD) serum TfR levels were significantly lower in the IBD patients with ACD (5.3 +/- 2.3 mg/l) than in the IBD patients with IDA (8.2 +/- 3.1 mg/l) (P < 0.05). Serum TfR levels above 5 mg/l identified 10/11 IBD patients with IDA. The calculated TfR/ferritin ratio was 84 (range 17-367) for controls and 133 (range 6.4-1840) for IBD patients. A cut-off level of 350 (91% sensitivity, 100% specificity, 100% positive predictive value, 98% negative predictive value) was established for the diagnosis of IDA in IBD.

CONCLUSION

The results suggest that serum transferrin receptor is a useful parameter for the diagnosis of iron deficiency in inflammatory bowel disease, in particular, the transferrin receptor/ferritin ratio with a cut-off level > or = 350.

Hepatitis A associated with other focal infections

BACKGROUND

Concomitant bacterial and viral infection is a well-known phenomenon, however only very rarely has a bacterial infection been reported during hepatitis A virus infection.

OBJECTIVE

To evaluate retrospectively the clinical records of children hospitalized with HAV infection for a concomitant infection proved or presumed to be bacterial.

METHOD

A retrospective study was conducted on all the children hospitalized with hepatitis A infection from 1988-96 in our center. The records were evaluated for a concomitant infection.

RESULTS

Of 40 children hospitalized with HAV infection, 13 were found to have a concomitant infection: these included 6 with pneumonia, 4 with pyelonephritis and 1 case each of purulent otitis media, osteomyelitis and staphylococcal bacteremia.

CONCLUSION

In areas where hepatitis A is endemic, a simultaneous infection with hepatitis A and other common bacterial infection during childhood may co-exist. A permissive role for HAV infection is suggested.

Recurrent acute disseminated encephalomyelitis associated with acute cytomegalovirus and Epstein-Barr virus infection

We describe a 5 6/12-year-old girl with recurrent episodes of acute disseminated encephalomyelitis following an acute cytomegalovirus infection and associated reactivated Epstein-Barr virus. Complete clinical recovery was obtained with intravenous immunoglobulin.

Predicting the risk of jaundice in full-term healthy newborns: a prospective population-based study

OBJECTIVE

The need to recognize infants that are at high risk for developing significant jaundice is apparent in the era of routine early discharge. The aim of the present study was to prospectively determine the ability to predict severe hyperbilirubinemia in term healthy newborns (defined as total serum bilirubin of > 10.0 mg/dl at day 2, > 14.0 mg/dl at day 3, and > 17.0 mg/dl at days 4 and 5 of life).

DESIGN

Prospective study of 1177 healthy term newborns.

SETTING

Two university-affiliated community hospitals in Jerusalem.

RESULTS

Using a multiple logistic regression analysis, neonatal jaundice was best predicted (p < 0.0001) by day 1 serum bilirubin (adjusted odds ratio of 3.1 [per mg/dl] [95% confidence limits of 2.4 to 4.1]) and by a change in serum bilirubin from the first to the second day of life (2.4 [per mg/dl] [1.9 to 3.0]). Maternal blood type 0 (2.9 [1.5 to 5.8]), age (1.1 [per year] [1.0 to 1.2]), schooling (0.8 [per year] [0.7 to 0.9]), and full breastfeeding (0.4 [0.2 to 0.9]) were also associated with jaundice (p < 0.005). Other factors considered in the regression model but not found to be significantly related to jaundice included maternal ethnic origin, smoking, hypertension, diabetes mellitus, intranatal administration of oxytocin, meperidine, anesthesia, premature rupture of the membranes, parity, newborn sex, birth weight, gestational age, presentation. Apgar scores, blood type, hematocrit, cephalohematoma, and history of jaundice in other siblings. A model for predicting neonatal jaundice based on the above factors had a sensitivity of 81.8%, a specificity of 82.9%, a false positive rate of 80.2%, and a false negative rate of 1.1%.

CONCLUSION

Individual risk assessment on discharge in association with day 1 total serum bilirubin is of value in identifying infants at greater risk for neonatal jaundice.

Immunological evaluation of patients with hematological malignancies receiving ambulatory cytokine-mediated immunotherapy with recombinant human interferon-alpha 2a and interleukin-2

Immunological parameters were evaluated in patients treated with cytokine-mediated immunotherapy (CMI) consisting of low doses of recombinant human interferon alpha 2a (rIFN alpha) and recombinant human interleukin-2 (rIL-2) administered either concomitantly or sequentially by subcutaneous self-injections in an outpatient setting. Twenty-six patients with hematological malignancies and 2 metastatic melanoma patients in a progressive stage were enrolled in this clinical trial. Of the 26 patients, 24 were at a stage of minimal residual disease, including 14 patients who had received autologous bone marrow transplantation (ABMT) 2-5 months previously, 7 chronic myelogenous leukemia (CML) and 3 acute myeloid leukemia (AML) patients. Two patients (1 CML and 1 mult. myeloma) were treated at a stage of progressive disease. Non-MHC-restricted cytotoxicity directed against natural-killer(NK)-resistant (Daudi) and NK-sensitive (K562) target cells was assessed before, during and after CMI, either in fresh peripheral blood samples (spontaneous activity) or after in vitro rIL-2 activation (induced activity). Spontaneous killing activity was low prior to treatment, but increased upon termination of treatment in 10/15 evaluated cycels. rIL-2-activated cytotoxicity in vitro was markedly elevated in 8/12 and 6/8 patients after one and two cycles, respectively, of sequential treatment, as well as in 3/8 CML and 5/6 patients after one and two cycles, respectively, of concomitant treatment. Activation of the T cell mitogenic response was demonstrated in 6/9 patients after concomitant CMI, while no such effect was observed throughout a sequential treatment in lymphoma and leukemia patients after ABMT. Although a direct correlation between immune stimulation and the in vivo antitumor response cannot yet be determined, our clinical observations support a beneficial therapeutic effect in a substantial number of patients. These results indicated that the ambulatory CMI protocol of rIL-2 and rIFN alpha could stimulate the host defense immune system and may be helpful in mediating the in vivo antitumor response in patients with minimal residual disease.