Successful extracorporeal membrane oxygenation in four children with malignant disease and severe Pneumocystis carinii pneumonia

BACKGROUND

Toxic deaths due to intensified treatment are of increasing concern in view of the generally improved prognosis for children with malignancies. Pneumocystis carinii pneumonia (PCP) during immunosuppressive treatment in children with malignancies is a severe complication with a poor prognosis if mechanical ventilation is required. Extracorporeal membrane oxygenation (ECMO) is a recognized technique that provides temporary respiratory support for patients with intractable respiratory failure.

PROCEDURE

We here report successful ECMO support in four children with PCP, secondary to chemotherapy-induced immunosuppression, in whom the respiratory situation deteriorated despite pharmacological treatment and mechanical ventilation. The duration of ECMO was 7-43 days.

RESULTS

Three children with acute lymphoblastic leukemia recovered from their PCP to continue chemotherapy and are now in complete continuous remission. Their pulmonary function normalized completely during 6-12 months after ECMO therapy. One child with a primitive neuroectodermal tumor survived the PCP and was off ECMO for 11 days before succumbing to unrelated complications.

CONCLUSIONS

We conclude that ECMO offers an important means of respiratory support in children with severe PCP that can also be adopted during treatment for malignant disease.

Involvement of caspases in neutrophil apoptosis: regulation by reactive oxygen species

Human neutrophils have a short half-life and are believed to die by apoptosis or programmed cell death both in vivo and in vitro. We found that caspases are activated in a time-dependent manner in neutrophils undergoing spontaneous apoptosis, concomitant with other characteristic features of apoptotic cell death such as morphologic changes, phosphatidylserine (PS) exposure, and DNA fragmentation. The treatment of neutrophils with agonistic anti-Fas monoclonal antibodies (MoAbs) significantly accelerated this process. However, in cells treated with the potent neutrophil activator phorbol 12-myristate 13-acetate (PMA), caspase activity was only evident after pharmacologic inhibition of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. Similarily, inhibition of the NADPH oxidase in constitutive and Fas/APO-1-triggered apoptosis resulted in increased rather than suppressed levels of caspase activity, suggesting that reactive oxygen species may prevent caspases from functioning optimally in these cells. Moreover, oxidants generated via the NADPH oxidase were essential for PS exposure during PMA-induced cell death, but not for neutrophils undergoing spontaneous apoptosis. We conclude that caspases are an important component of constitutive and Fas/APO-1-triggered neutrophil apoptosis. However, these redox sensitive enzymes are suppressed in activated neutrophils, and an alternate oxidant-dependent pathway is used to mediate PS exposure and neutrophil clearance under these conditions.

Elevated erythrocyte sedimentation rate and thrombocytosis as possible indicators of active disease in Langerhans' cell histiocytosis

Langerhans' cell histiocytosis (LCH) is a disease with an unpredictable course and unpredictable reactivations. Since active disease may cause life-long sequelae, early detection of reactivation is important. The usefulness of erythrocyte sedimentation rate (ESR) and thrombocytosis as indicators of disease activity in patients with LCH were examined. The mean values for ESR and platelet count for each quarter of a year were compiled. The means of all the ESR estimates (n = 76) during each quarter of a year with active disease was 21 mm h(-1), with intermediate disease activity 11 mm h(-1) and with resolution 7 mm h(-1). The corresponding platelet count estimates (n = 139) were 433 x 10(9) l(-1), 365 x 10(9) l(-1) and 304 x 10(9) l(-1), respectively. In conclusion, elevated ESR and platelet count may be clinically valuable indicators of disease activity in LCH.

Persistent B19 parvovirus infection in pediatric malignancies

BACKGROUND AND PROCEDURE

The frequency and clinical importance of parvovirus B19 infection were studied in children investigated or treated for various malignancies and cytopenias.

RESULTS

B19 infection was thus demonstrated in six out of 53 unselected children with malignancies by bone marrow examination, using the B19, DNA-specific, polymerase chain reaction (PCR). Examinations using the PCR in serum samples were equally or less sensitive than in bone marrow samples. One of the children had a persistent B19 infection during maintenance therapy for acute lymphoblastic leukemia. She developed a prolonged and severe cytopenia, and the clinical signs included facial rash, chills, high undulating fever, and pharyngitis. She also seroconverted and became B19 IgM-antibody positive during the study period.

CONCLUSIONS

Parvovirus B19 infection was detected in 10% of the children and was either asymptomatic or was associated with severe and prolonged cytopenia. Bone marrow examinations are recommended for the detection of B19 DNA in immunosuppressed children.

Infection- and malignancy-associated hemophagocytic syndromes. Secondary hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis represents a spectrum of pathogenetically different diseases in which a T-cell induced, uncontrolled activation of phagocytosing macrophages may lead to fever, organomegaly, and pancytopenia. The underlying immunologic disturbance can either be genetically transmitted, like in FHL, or acquired, as in IAHS or MAHS. Triggering infections can be found in all these diseases and do not allow a reliable differentiation. An international treatment protocol has been developed for FHL. IAHS and MAHS also have a high fatality rate, justifying immunomodulatory treatment if the disease is progressive.

Familial hemophagocytic lymphohistiocytosis. Primary hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis represents a spectrum of pathogenetically different diseases including the rapidly fatal autosomal recessive disease of familial hemophagocytic lymphohistiocytosis (FHL). The onset is usually during the first years of life with fever, cytopenia, and hepatosplenomegaly. Neurologic symptoms may supervene. Similar symptoms may occur in the infection-(virus-)associated or malignancy-associated hemophagocytic syndromes (IAHS/MAHS). Triggering infections can be found in all these diseases and do not allow for reliable differentiation. An international treatment protocol (HLH-94) has been developed for FHL, but immunomodulatory treatment may be justified in IAHS and MAHS as well, since they also have a high fatality rate.

Autopsy findings in 27 children with haemophagocytic lymphohistiocytosis

AIMS

Primary haemophagocytic lymphohistiocytosis (HLH) is a fatal childhood disorder. The diagnosis is difficult to establish, clinically as well as histopathologically, and it is markedly underdiagnosed. Because of these difficulties, we wanted to elucidate the histopathological findings in population-based patient material.

METHODS AND RESULTS

The post-mortem findings in 27 children with primary HLH diagnosed in Sweden between 1971 and 1986 was reviewed. Twelve of these patients had an affected sibling and three additional children had parental consanguinity. Some of the children showed generalized disease, whereas in others only one or a few organs were affected. The major histological alteration was an accumulation of primarily lymphocytes, but also of histiocytes, some of which exhibited evidence of haemophagocytosis. The haemophagocytic activity may be difficult to detect if there are pronounced post-mortem changes, particularly in the spleen, and it is therefore preferable to perform the autopsy as soon as possible after death in order to minimize autolysis. Haemophagocytosis was most commonly observed in the spleen (17/24), the lymph nodes (17/23) and the bone marrow (9/23), indicating that a negative bone marrow examination does not rule out this diagnosis. Three additional patients had discrete signs of haemophagocytosis in the bone marrow. In the spleen, the lymph nodes and the bone marrow, lymphocytic depletion, pronounced in some cases, could be observed, even without prior treatment with steroids or cytostatics. In the liver, most of the patients demonstrated an infiltration of lymphocytes into the portal tracts similar to that seen in chronic persistent hepatitis (22/27), a finding which is uncommon in infancy and therefore suggestive of the diagnosis HLH. Other organs involved included the thymus, lungs intestine, pancreas, kidney, heart and striated muscle.

CONCLUSIONS

The diagnosis of HLH must be based on clinical, histological and additional laboratory findings. A negative bone marrow examination is common. Previous treatment with steroids and/or cytostatic drugs may attenuate or even eliminate the typical histological findings. Liver findings similar to those in chronic persistent hepatitis are common.

Down-regulation of lymphokine synthesis by intravenous gammaglobulin is dependent upon accessory cells

We have investigated one mechanism by which pooled human IgG preparations for intravenous use (i.v.Ig) selectively down-regulates lymphokine synthesis. Effects of i.v.Ig on cytokine production were quantified at a cellular level by using an immunocytochemical staining technique. Pure T-lymphocyte preparations (from the peripheral blood of healthy adults) were separated by the use of magnetic beads and were then used in parallel experiments with unfractionated mononuclear cells (MNC). Cell activation was induced either by a combination of the protein kinase C activator, phorbol 12-myristate 13-acetate (PMA), and the calcium ionophore, ionomycin, or by direct ligation of the T-cell receptor, using immobilized anti-CD3 monoclonal antibody (MoAb). Cells were cultured in the presence or absence of i.v.Ig and subsequently harvested and stained for the following cytokines: interleukin-2 (IL-2), interferon-gamma (IFN-gamma), tumour necrosis factor-beta (TNF-beta) and granulocyte-macrophage colony-stimulating factor (GM-CSF). Assessment of the frequencies of positively stained cells was performed by manual microscopy and by computerized image analysis. Activation by PMA/ionomycin or by immobilized anti-CD3 MoAb induced substantial lymphokine production in both MNC and in purified T cells. Addition of i.v.Ig led to a diminished synthesis of all of the T-cell products studied in unfractionated MNC preparations, whereas production was maintained or occasionally increased in the purified T-cell preparations. These findings indicate that the immunomodulatory effect by i.v.Ig on T-cell activation and lymphokine production was dependent on accessory cells.

Transient red cell aplasia in siblings: a common environmental or a common hereditary factor?

During the years 1987-89, transient erythroblastopenia of childhood was diagnosed in 52 previously healthy Swedish children aged less than 4 y. Among these children there were four pairs of siblings, including one pair of identical female twins. This is a much higher familial occurrence than expected. The probability of finding 4 pairs of siblings with this disease in 50 families was estimated to be considerably less than 10-6. In the retrospectively analysed material, no environmental factor was implicated and no association with human leucocyte antigen could be proven. The twins demonstrated the disease simultaneously. Their anaemia was transient and did not recur, but showed certain features usually seen in congenital hypoplastic anaemia. The other pairs of siblings fulfilled the criteria for transient erythroblastopenia of childhood and several years elapsed between the development of the disease in siblings. Two of the fathers were reported to have had transient anaemia during their childhood. Our findings indicate that transient erythroblastopenia of childhood may involve hereditary factors, eventually demonstrating an autosomal dominant inheritance.

Contemporary classification of histiocytic disorders. The WHO Committee On Histiocytic/Reticulum Cell Proliferations. Reclassification Working Group of the Histiocyte Society

Pathologists and pediatric hematologist/ oncologists of the World Health Organization's Committee on Histiocytic/Reticulum Cell Proliferations and the Reclassification Working Group of the Histiocyte Society present a classification of the histiocytic disorders that primarily affect children. Nosology, based on the lineage of lesional cells and biological behavior, is related to the ontogeny of histiocytes (macrophages and dendritic cells of the immune system). Dendritic cell-related disorders of varied biological behavior are dominated by Langerhans cell histiocytosis, but separate secondary proliferations of dendritic cells must be differentiated. Juvenile xanthogranuloma represents a disorder of dermal dendrocytes, another dendritic cell of skin. The hemophagocytic syndromes are the most common of the macrophage-related disorders of varied biological behavior. Guidelines for distinguishing the exceedingly rare malignant diseases of histiocytes from large cell lymphomas through the use of a battery of special studies are provided.

Diamond-Blackfan anaemia: genetic homogeneity for a gene on chromosome 19q13 restricted to 1.8 Mb

Diamond-Blackfan anaemia (DBA; MIM#205900) is a rare disorder manifested as a pure red-cell aplasia in the neonatal period or in infancy. The clinical hallmark of DBA is a selective decrease in erythroid precursors and anaemia. Other lineages are usually normal and the peripheral white blood cell count is normal. In approximately one-third of cases, the disease is associated with a wide variety of congenital anomalies and malformations. Most cases are sporadic, but 10-20% of them follow a recessive or a dominant inheritance pattern. A female with DBA and a chromosomal translocation involving chromosome 19q was recently identified. We undertook a linkage analysis with chromosome 19 markers in multiplex DBA families of Swedish, French, Dutch, Arabic and Italian origin. Significant linkage to chromosome 19q13 was established for dominant and recessive inherited DBA with a peak lod score at D19S197 (Zmax = 7.08, theta = 0.00). Within this region, a submicroscopic de novo deletion of 3.3 Mb was identified in a patient with DBA. The deletion coincides with the translocation break-point and, together with key recombinations, restricts the DBA gene to a 1.8-Mb region. The results suggest that, despite its clinical heterogeneity, DBA is genetically homogeneous for a gene in 19q13.

Contemporary classification of histiocytic disorders. The WHO Committee On Histiocytic/Reticulum Cell Proliferations. Reclassification Working Group of the Histiocyte Society

Pathologists and pediatric hematologist/ oncologists of the World Health Organization's Committee on Histiocytic/Reticulum Cell Proliferations and the Reclassification Working Group of the Histiocyte Society present a classification of the histiocytic disorders that primarily affect children. Nosology, based on the lineage of lesional cells and biological behavior, is related to the ontogeny of histiocytes (macrophages and dendritic cells of the immune system). Dendritic cell-related disorders of varied biological behavior are dominated by Langerhans cell histiocytosis, but separate secondary proliferations of dendritic cells must be differentiated. Juvenile xanthogranuloma represents a disorder of dermal dendrocytes, another dendritic cell of skin. The hemophagocytic syndromes are the most common of the macrophage-related disorders of varied biological behavior. Guidelines for distinguishing the exceedingly rare malignant diseases of histiocytes from large cell lymphomas through the use of a battery of special studies are provided.

Neuropathologic findings and neurologic symptoms in twenty-three children with hemophagocytic lymphohistiocytosis

BACKGROUND

Primary hemophagocytic lymphohistiocytosis (HLH) is an autosomal recessive disorder with very high mortality rates, mainly affecting infants and young children, which is characterized by fever, hepatosplenomegaly, and cytopenias. Of great clinical importance are the neurologic symptoms, which are common and may even dominate the clinical picture and precede the systemic presentation. These symptoms are extremely variable, ranging from irritability, bulging fontanelle, and neck stiffness, to convulsions, cranial nerve palsies, ataxia, hemiplegia/tetraplegia, and unconsciousness.

METHODS

To elucidate this neurologic involvement further, we reviewed the neuropathologic postmortem findings from 23 children and their neurologic symptoms.

RESULTS

Macroscopically, edema was present in many cases, and in some with advanced disease, softening and destruction of the tissue were conspicuous. The microscopic picture was exceedingly variable, ranging from almost normal to very advanced changes. In the mildest form of HLH, only the meninges were involved with infiltration of lymphocytes and macrophages (stage I), whereas more advanced cases in addition also showed perivascular infiltrates (stage II). In even more advanced disease there was also a diffuse infiltration in the tissue (stage III), as well as a multifocal necrosis. A prominent astrogliosis was present in such cases. Hemophagocytosis was seen in most patients, most commonly in the leptomeninges.

CONCLUSIONS

HLH affecting the central nervous system imitates several neurologic disorders and may be misdiagnosed. A staging system for the neuropathologic findings is presented. In children with obscure central nervous systems symptoms and a progressive encephalopathy, the diagnosis of HLH may be considered, in particular because treatments are available.

Prevalence and treatment of chronic idiopathic thrombocytopenic purpura of childhood in Sweden

The frequency and treatment of children with chronic idiopathic thrombocytopenic purpura in Sweden were characterized using a national enquiry based on a questionnaire. Seventy-five children diagnosed as having chronic idiopathic thrombocytopenic purpura on 1 September 1993 were identified. The prevalence in children between 0.5 and 15.5 years of age was calculated to be 4.6/100,000. The median age at the time of diagnosis was 5 years and the male/female ratio was 1:1.2. Almost half of the patients (43%) were not treated at all during the disease. Steroids (43%) and intravenous immunoglobulin (25%) were most commonly used. Only two children were splenectomized.

Transient hypertriglyceridemia of infancy

A premature boy who had suffered from IRDS, bronchopulmonary dysplasia and retinopathy of prematurity developed massive hypertriglyceridemia (48.1 mmol/L) together with moderate hypercholesterolemia (12.6 mmol/L) at 5 months of age. Lipoprotein electrophoresis revealed a marked elevation of the level of the very low density lipoprotein fraction. There was a moderate decrease in the activity of a lipolytic enzyme, lipoprotein lipase (LPL). The child had neither liver or renal disorder nor any inflammatory disease. The hyperlipidemia disappeared spontaneously at the age of 3 years. The cause of the decreased LPL activity could not be established. A partial genetic deficiency in lipoprotein lipase appears the most likely explanation, since no signs of secondary lowering of LPL activity could be found.

Elevated circulating levels of interleukin-1 receptor antagonist but not IL-1 agonists in hemophagocytic lymphohistiocytosis

The familial form of hemophagocytic lymphohistiocytosis (HLH) is an inherited disease with disturbed immunomodulation and characterized by fever, hepatosplenomegaly, cytopenia, hypertriglyceridemia, and coagulopathy, i.e., findings which are similar to many of the reported biological effects of the inflammatory cytokines. Due to the previously shown hypercytokinemia in active HLH with elevated levels of interleukin (IL)-6, tumor necrosis factor-alpha, and interferon-gamma, it has been suggested that cytokine dysregulation may be of pathophysiological importance. Here we have assayed the serum levels of the members of the IL-1 ligand family, the two agonists IL-1 alpha and IL-1 beta and the antagonist IL-1 receptor antagonist (IL-1ra), in nine children with HLH and cerebrospinal fluid (CSF) specimens from four children. Serum IL-1ra was elevated in all patients with active disease to a degree which correlated well with disease activity. Furthermore, the levels decreased day by day during treatment of a patient who suffered a relapse. Moreover, high levels of IL-1ra were also detected in CSF during active disease. However, IL-1 beta levels were all within normal limits and circulating IL-1 alpha levels were normal in all but two patients.

Intralesional steroids in Langerhans cell histiocytosis of bone

Langerhans cell histiocytosis may involve single or multiple organ systems. Bone involvement is the most common feature. We have examined retrospectively the effects of 20 intralesional injections of steroids into bone in seven patients seen at our department from 1988 to 1993. Most of these injections (75%) relieved the symptoms, and no side-effects were observed. However, injections into the jaw were seldom effective. Our results suggest that the dose of the steroids administered is of importance.

Hemophagocytic lymphohistiocytosis. Report of 122 children from the International Registry. FHL Study Group of the Histiocyte Society

Hemophagocytic lymphohistiocytosis (HLH) is a rare, often fatal, disease of early infancy. The diagnosis of HLH is frequently delayed or made at autopsy because no genetic or biologic marker has been identified. To improve the classification and treatment of HLH, the Histiocyte Society has established an 'International Registry for HLH'. Data collected included family history, clinical and laboratory features at the onset of illness, and treatment outcome. Stringent diagnostic criteria (ie fever, splenomegaly, cytopenia, hypertriglyceridemia, and/or hypofibrinogenemia, and hemophagocytosis without evidence of malignancy) were used for patient selection. One hundred and twenty-two patients (61 males, 61 females) were enrolled from 17 centers in 11 countries. The rate of parental consanguinity was 24%. A positive family history was reported in 49% of cases including two pairs of affected male twins. The median age at disease onset was 2.9 months, with no difference between familial and sporadic cases. Age at onset was similar in affected sibs from 10 of 14 families, but in four up to 3-year differences were observed. Hemophagocytosis was present at diagnosis in 75%. An associated infection (usually by common viral pathogens) was reported in 50 of the 122 (41%) cases, of which 25 had familial disease. Natural killer activity was impaired in 36 of 37 patients studied. Chromosome analysis was normal in all tested patients. A decreased frequency of HLA-B7 and B8 alleles and increased frequency of HLA-B21 and DQ3 were observed. The estimated 5-year survival (SE) was 21% (18.7) for all patients. It was 66% (37.8) for patients who received allogeneic bone marrow transplant and 10.1% (9.6) for patients treated with chemotherapy alone (P=0.0001). None of the previously proposed prognostic indicators (age, associated infection, cerebrospinal fluid pleocytosis, family history) correlated with treatment outcome.

Bone marrow transplantation in two children with congenital amegakaryocytic thrombocytopenia

Two thrombocytopenic infants with essentially normal initial bone marrow morphology were believed to have idiopathic thrombocytopenic purpura. However, they failed to respond to steroids and intravenous immunoglobulins and had a normal platelet recovery after transfusions. The diagnosis was revised to congenital amegakaryocytic thrombocytopenia after bone marrow biopsies, which revealed a marked paucity of megakaryocytes. Repeated biopsies disclosed gradually decreasing numbers of megakaryocytes and increasing marrow hypoplasia. At the ages of 42 and 22 months the children underwent allogeneic bone marrow transplants, one of them with an unrelated marrow donor. Both patients are well with good engraftment of donor marrow and normal peripheral blood counts, 31 and 12 months after BMT, respectively.

Allogeneic bone marrow transplantation for hemophagocytic lymphohistiocytosis in Sweden

Six children (aged 9 months to 10 and 5/12 years) with hemophagocytic lymphohistiocytosis (HLH) have undergone allogeneic BMT in Sweden. In two of the children unrelated donors were used. Parents were available as donors in two of the cases and siblings in the other two. Conditioning before BMT consisted of etoposide, busulfan and cyclophosphamide with the addition of ATG in two cases and OKT 3 in one case. For post-transplant immunosuppression, i.v. methotrexate and cyclosporin A (CsA) were used in five cases, and in one child CsA was combined with methylprednisolone. Of the six children, four are alive and well 2 and 3/12 to 3 and 1/12 years after BMT. One child, who had an unrelated donor with one DR-antigen mismatch, died 30 days after BMT of fulminant grade IV GVHD. Another patients, seropositive for CMV, received marrow from an unrelated HLA-A, -B, -DR and -DP identical donor. After an initially uneventful course, CMV was isolated from her leukocytes. Seven months after BMT she developed a progressive obstructive chronic bronchiolitis and succumbed to respiratory insufficiency 14 months after the transplant. This study supports the view that BMT is the treatment of choice in HLH, particularly if an HLA-identical related donor is available.

Kala-azar in a one-year-old Swedish child. Diagnostic difficulties because of active hemophagocytosis

A one-year-old Swedish boy developed kala-azar six months after a holiday in Spain. Upon visiting the hospital after one week of illness he demonstrated clinical and laboratory findings of fever, splenomegaly and cytopenia. A fine-needle aspiration biopsy of the spleen revealed hemophagocytosis and he had increased serum levels of the cytokines tumor necrosis factor-alpha and interferon-gamma. Initially, a diagnosis of hemophagocytic lymphohistiocytosis was made. Re-evaluation of the spleen smears and of the bone marrow aspiration revealed Leishmania parasites and subsequent therapy with sodium stibogluconate was successful. This patient illustrates the interesting similarities between these two disorders involving the mononuclear phagocyte system as well as the problems involved in differential diagnosis. This case also reminds us of the possibility of contracting visceral leishmaniasis in Mediterranean countries.