[Disseminated fungal infections in neonates--risk factors, treatment and course]

During 10 1/2 months in 1990/91 eight premature babies and one mature baby with an intra-abdominal disease had disseminated Candida albicans infections. The incidence in premature newborns was 9% (8/92 patients). Risk factors such as respirator therapy, the use of broad spectrum antibiotics, supplemental parenteral nutrition and central intravascular catheters were frequently seen. Four patients survived the fungal infection. These included three of five babies treated with amphotericin B 0.5 mg/kg/day. Two patients who received fluconazole 3 mg/kg/day died after three days. In one patient the diagnosis was obtained post-mortem, and one patient with possible fungemia survived without therapy. The treatment of these patients depends on optimal fungal cultures and good co-operation between paediatricians and microbiologists.

Disseminated fungal disease resistant to fluconazole treatment in a child with leukemia

During a chemotherapy induced leukopenic period fluconazole (3 mg/kg/day i.v.) was administered as empiric antifungal treatment in a 5-year-old girl with leukemia and a presumed catheter infection due to Staphylococcus epidermidis. Despite intensive treatment with antibiotics and fluconazole the patient died. In one blood culture Candida krusei was isolated post mortem, and at autopsy Aspergillus fumigatus was found in multiple organs. Both fungi showed high MIC values to fluconazole. We feel that this drug should not be used when the possibility of a systemic infection with an unidentified fungus exists.

X-linked thrombocytopenia and thrombocytopathia: attenuated Wiskott-Aldrich syndrome. Functional and morphological studies of platelets and lymphocytes

Detailed studies on the rare disorder X-linked thrombocytopenia showed that it resembles the Wiskott-Aldrich syndrome (WAS) in inheritance, clinical bleeding tendency, platelet morphology, marked thrombocytopenia and microplatelets. The calculated platelet mass was 5% of normal. Functional and biochemical studies indicated qualitatively normal aggregation and release mechanisms, whereas a moderate storage pool defect was present. The classical platelet membrane glycoproteins and lymphocyte sialophorin (CD 43) were normal. The reason for the bleeding tendency was concluded to be deficient hemostatic plug formation resulting from the low platelet mass and a moderate storage pool defect. The only clear distinction from WAS was the normal immunofunctional tests, the moderate tendency to infections and the absence of eczema. We therefore consider the trait as an attenuated form of WAS. That women are affected may indicate a particular variant.

Absence of modulation of monokine production via endogenous cyclooxygenase or 5-lipoxygenase metabolites: MK-886 (3-[1-(4-chlorobenzyl)-3-t-butyl-thio-5-isopropylindol-2-yl]-2,2- dimethylpropanoic acid), indomethacin, or arachidonate fail to alter immunoreactive interleukin-1 beta, or TNF-alpha production by human monocytes in vitro

Human peripheral blood monocytes exposed to MK-886 (3-[1-(4-chlorobenzyl)-3-t-butyl-thio-5-isopropylindol-2-yl]-2,2- dimethylpropanoic acid) at doses which abolish formation of 5-lipoxygenase metabolites showed unaltered interleukin-1 beta (IL-1 beta) or tumor necrosis factor-alpha (TNF-alpha) levels in response to phorbol ester, concanavalin A, serum-treated zymosan, or lipopolysaccharide. Indomethacin (10 microM), alone or in combination with MK-886, also failed to modulate monokine production in response to any stimulus. Exogenous arachidonate (3-30 microM) which augmented the formation of PGE2 and LTB4 in the absence of stimulation, also had no effect on monokine production. LPS-induced IL-1 and TNF production occurred despite stimulation of PGE2 synthesis. The results make a role for endogenous prostaglandins and leukotrienes in the regulation of monocyte IL-1 beta and TNF-alpha production unlikely. These data also indicate that MK-886, a novel inhibitor of 5-lipoxygenase product formation, is a potentially useful leukotriene inhibitor which does not affect monokine production.

Calcium-dependent eicosanoid metabolism by concanavalin A-stimulated human monocytes in vitro. Synergism with phorbol ester indicates separate regulation of leukotriene B4 synthesis and release

Human monocytes obtained by counter-current centrifugal elutriation released arachidonic acid when challenged in vitro with Con A, as well as with other soluble (PMA or ionomycin) or particulate stimuli (serum-treated zymosan). Cyclo-oxygenase metabolites were the principal eicosanoids detected in the supernatants of Con A-stimulated, [3H]arachidonate-labeled monocytes, 5-Lipoxygenase (5-LO) products, such as leukotriene B4 (LTB4), were conspicuously absent. Release of arachidonate and its metabolites in response to Con A was dependent on the presence of extracellular Ca2+, but not Mg2+. In contrast to serum-treated zymosan challenge, which resulted in increased inositol trisphosphate and LTB4 release, Con A-induced inositol phospholipid hydrolysis in monocytes was limited to phosphatidylinositol or phosphatidylinositol monophosphate. Despite an inability to augment LTB4 release, Con A or PMA induced a loss of 5-lipoxygenase from a cytosolic compartment that was similar to that achieved with a calcium ionophore (ionomycin), a potent stimulus for LTB4 generation. When cell-associated LTB4 was evaluated, evidence for increased LTB4 production was obtained in response to either stimulus (PMA greater than Con A). In combination, however, PMA and Con A treatment resulted in monocyte LTB4 release comparable with that observed with the calcium ionophore or STZ. LTB4 release in response to all stimuli tested was inhibited by MK-886, a drug that binds to 5-lipoxygenase-activating protein. These results indicate the following: 1) Phospholipase A2 activation and attendant arachidonic acid release induced by agents that increase intracellular Ca2+ and/or generate diacylglycerol results in increased synthesis and release of PG and increased synthesis of leukotrienes, but not necessarily leukotriene release. 2) 5-LO translocation, which may occur independently of increased intracellular Ca2+, may be necessary for LTB4 generation but is insufficient for its release. 3) 5-Lipoxygenase-activating protein activity is necessary for 5-LO activation and LTB4 release in response to all stimuli investigated here. 4) Phorbol ester, an activator of protein kinase C, may synergize with agents such as Con A (which by themselves induce a minimal intracellular Ca2+ rise), so as to result in the release of LTB4. Thus, Con A may represent a class of surface receptor-aggregating agents that initiates inflammatory changes or immunomodulation associated with liberation of PG and might predispose to release of other inflammatory mediators, such as leukotrienes, in the presence of additional signals including protein kinase activation.

Calcium-dependent eicosanoid metabolism by concanavalin A-stimulated human monocytes in vitro. Synergism with phorbol ester indicates separate regulation of leukotriene B4 synthesis and release

Human monocytes obtained by counter-current centrifugal elutriation released arachidonic acid when challenged in vitro with Con A, as well as with other soluble (PMA or ionomycin) or particulate stimuli (serum-treated zymosan). Cyclo-oxygenase metabolites were the principal eicosanoids detected in the supernatants of Con A-stimulated, [3H]arachidonate-labeled monocytes, 5-Lipoxygenase (5-LO) products, such as leukotriene B4 (LTB4), were conspicuously absent. Release of arachidonate and its metabolites in response to Con A was dependent on the presence of extracellular Ca2+, but not Mg2+. In contrast to serum-treated zymosan challenge, which resulted in increased inositol trisphosphate and LTB4 release, Con A-induced inositol phospholipid hydrolysis in monocytes was limited to phosphatidylinositol or phosphatidylinositol monophosphate. Despite an inability to augment LTB4 release, Con A or PMA induced a loss of 5-lipoxygenase from a cytosolic compartment that was similar to that achieved with a calcium ionophore (ionomycin), a potent stimulus for LTB4 generation. When cell-associated LTB4 was evaluated, evidence for increased LTB4 production was obtained in response to either stimulus (PMA greater than Con A). In combination, however, PMA and Con A treatment resulted in monocyte LTB4 release comparable with that observed with the calcium ionophore or STZ. LTB4 release in response to all stimuli tested was inhibited by MK-886, a drug that binds to 5-lipoxygenase-activating protein. These results indicate the following: 1) Phospholipase A2 activation and attendant arachidonic acid release induced by agents that increase intracellular Ca2+ and/or generate diacylglycerol results in increased synthesis and release of PG and increased synthesis of leukotrienes, but not necessarily leukotriene release. 2) 5-LO translocation, which may occur independently of increased intracellular Ca2+, may be necessary for LTB4 generation but is insufficient for its release. 3) 5-Lipoxygenase-activating protein activity is necessary for 5-LO activation and LTB4 release in response to all stimuli investigated here. 4) Phorbol ester, an activator of protein kinase C, may synergize with agents such as Con A (which by themselves induce a minimal intracellular Ca2+ rise), so as to result in the release of LTB4. Thus, Con A may represent a class of surface receptor-aggregating agents that initiates inflammatory changes or immunomodulation associated with liberation of PG and might predispose to release of other inflammatory mediators, such as leukotrienes, in the presence of additional signals including protein kinase activation.

Stimulatory effect of counterflow centrifugal elutriation in large-scale separation of peripheral blood monocytes can be reversed by storing the cells at 37 degrees C

Transfusion of peripheral blood monocytes may be of benefit as adjuvant treatment of leukopenic patients with serious infections. To study the feasibility of this approach, a large-scale monocyte separation procedure employing leukapheresis, density gradient centrifugation, and counterflow centrifugal elutriation was established. By processing 5 to 6 liters of normal donor blood, it was possible to obtain a mean of 1.1 x 10(9) (range: 0.5-1.7 x 10(9) cells) of mononuclear cells, of which 89% (range: 82-94%) were monocytes by Wright's stain morphology. When the elutriation was performed in XVIVO-10, a commercially available, serum-free medium developed for adoptive immunotherapy, spontaneous secretion of superoxide by the monocytes was significantly higher than for monocytes elutriated in Hanks' balanced salt solution without calcium and magnesium or non-elutriated peripheral blood mononuclear cells. This stimulated state of the monocytes was observed both immediately after elutriation and after overnight storage at 4 degrees C, and it was not affected by the type of storage vessel used. Overnight storage of the monocytes at 37 degrees C resulted in a reversal of the stimulated state of the cells. Monocytes elutriated in XVIVO-10 and kept overnight at 4 degrees C released high amounts of arachidonic acid. A subsequent decrease in this release was seen after additional storage at 37 degrees C for 18 hours. These observations demonstrate that separation and storage variables have important effects on the state of stimulation of monocytes. Further investigations of such variables may suggest improved procedures for preparation and storage of these cells, as well as possible ways to stimulate monocytes prior to transfusion.

[Rotavirus in stools from hospitalized children]

Electron microscopy, ELISA for rotavirus and virus cultivation in cell cultures were used to study the occurrence of rotavirus in 451 fecal samples collected from hospitalized children. Rotavirus was found in samples from 24 of 27 patients admitted with acute diarrhoea. All specimens from randomly selected patients without diarrhoea were negative. Two patients developed nosocomial rotavirus infection. ELISA was positive, but electron microscopy was negative in two specimens obtained from asymptomatic newborns. In this investigation rotavirus was the dominating agent isolated in infectious gastroenteritis. We found no rotavirus excretors without diarrhoea.

Alterations in the terminal complement pathway in leukopenic children with malignant diseases during episodes with evidence of infection

A prospective study comprising 23 children under treatment with cytostatic drugs for malignant diseases was undertaken to search for complement abnormalities during episodes with evidence of infection. Eleven patients developed 17 episodes with fever (temperature greater than or equal to 38 degrees C) (n = 13) and/or increased concentration greater than or equal to 10 mg/l) of C-reactive protein (CRP) (n = 16). Complement factor C9 increased significantly (greater than or equal to 150%) in 12/13 of the events with fever, in 16/16 with increased CRP, and in 1 additional event with normal temperature and CRP concentration. The terminal complement complex (TCC) increased excessively (37.2 units/ml) parallel to a fall in C9 and S-protein in a single patient with a lethal septic shock, and was slightly increased (2.9 units/ml) in a 2nd case who was efficiently treated. These were also the only 2 cases with verified bacterial infections. We conclude that C9 is a valuable supplement to CRP for detection of events with probable infection and that TCC is increased only in severe infection and may be of prognostic importance.

Flavobacterium meningosepticum infections in a neonatal intensive care unit

An outbreak of nosocomial infections by Flavobacterium meningosepticum in a neonatal intensive care unit is described. During a period of eleven weeks two patients presented with septicaemia and meningitis. In addition, nine patients were found to be colonized and three of these neonates developed septicaemia. The infected patients were treated with clindamycin and piperacillin. All the patients survived, but the neonates with meningitis developed hydrocephalus. An extensive bacteriological screening of the staff was negative, but in the ward environment, F. meningosepticum was found around sinks, on rubber stoppers for milk bottles and on "cleaned" teats. Several infection control measures were instituted. Established routines were revised, with particular emphasis on the handling of objects containing or in regular contact with water.

Identification and functional characterization of monocytes in rheumatoid synovial fluid

Mononuclear cell suspension from synovial fluids of 13 patients with rheumatoid arthritis and 5 patients with juvenile rheumatoid arthritis contained on average of 1.5 and 1.3% cytotoxic plaque-forming cells, respectively, when tested against a monolayer of antibody-sensitized sheep erythrocytes. The plaque-forming ability was completely abolished after removal of cells which had phagocytosed carbonyl iron. The highest proportion of plaque-forming cells was found in the cell suspensions that contained the highest percentage of peroxidase-positive mononuclear cells. The plaque-forming activity was almost completely inhibited by human IgG. Cell suspensions from patients treated with corticosteroids contained the highest proportions of plaque-forming cells and peroxidase-positive mononuclear cells compared with patients not receiving such treatment. Our findings indicate that the plaque-forming leukocytes in rheumatoid synovial fluid are monocytes.

Plaque-forming, antibody-dependent, cytotoxic cells with monocytic properties are present in rheumatoid synovial tissue

Mononuclear cells eluted from synovial tissues from 16 patients with rheumatoid arthritis (RA) and 4 patients with juvenile rheumatoid arthritis (JRA) mediate cytotoxicity in vitro against a monolayer of sheep erythrocytes sensitized with IgG. Cell fractionation experiments suggested that most of the plaque-forming cells were non-lymphocytic and had adherence and phagocytic properties.

Lymphocytes from synovial tissue of a boy with X-linked hypogammaglobulinemia and chronic polyarthritis

Lymphocytes were eluted from synovial tissue of a boy with X-linked hypogammaglobulinemia and chronic polyarthritis. The cell suspension contained 53% lymphocytes and 28% peroxidase-positive, macrophagelike cells, No B lymphocytes, 83% T lymphocytes, and 10% Fc-receptor-bearing lymphocytes were detected. Lymphocyte transformation was induced by polyclonal mitogens (phytohemagglutinin and pokeweed mitogen) whereas no response to antigens (purified protein derivative and Candida albicans antigen) was obtained. The eluted cells displayed antibody-dependent cytotoxicity.

In vitro mitogen stimulation of synovial fluid lymphocytes from rheumatoid arthritis and juvenile rheumatoid arthritis patients: dissociation between the response to antigens and polyclonal mitogens

The in vitro responses to mitogens of synovial fluid lymphocytes obtained from eight patients with rheumatoid arthritis (RA) and eight patients with juvenile rheumatoid arthritis (JRA) were studied. The results were compared to the transformation of the patient's peripheral blood lymphocytes stimulated with the same mitogens. Both RA and JRA synovial fluid lymphocytes showed a low transformation to the polyclonal mitogens PHA and PWM with a low ratio PHA-response/PWM-response. The stimulatory effect of purified protein derivative of tuberculin (PPD) was high, whereas a Candida albicans antigen preparation gave a more variable stimulation of the synovial fluid lymphocytes. In some patients the complete mitogen transformation profile of lymphocytes obtained from synovial fluid, synovial tissue and peripheral blood was studied. The results of the synovial fluid and tissue lymphocytes were similar.

Membrane characteristics of adherent cells dissociated from rheumatoid synovial tissue

Synovial tissues from rheumatoid-arthritis patients were dissociated by enzymes and the resulting cells incubated overnight in tissue-culture flasks. The adherent cell population was resuspended with EDTA-trypsin, and morphological examination showed 68--80% non-lymphoid cells, most of which had the appearance of synovial lining cells. The proportion of these cells increased during subsequent culture. Between 40 and 60% of the cells exhibited marked phagocytosis, and less than 14% of the non-lymphoid cells could form EA rosettes. Further culture diminished this Fc-receptor-bearing cell population. Indirect immunofluorescence studies with rabbit anti-human collagen sera revealed membrane staining for 30--60% of the cells; this proportion usually increased to greater than 90% after 6--14 days in culture. Omitting any changes of culture medium resulted in a marked decrease in the proportion of cells staining with anti-collagen sera, whereas the viability and phagocytic ability of the cells did not significantly alter. Subsequent cell passage was followed by an increase in the proportion of cells demonstrating membrane-associated collagen, and this effect was more pronounced when a high concentration (50%) of serum supplement was used. No clear definition could be made as to whether the membrane-associated collagen represents synthesis or phagocytosis of collagen by the cells. Faint membrane staining was also observed with non-immune rabbit serum for 4--20% of the cells after the initial overnight incubation, and this usually dropped to less than 5% during prolonged culture. Rabbit antisera to human albumin, F(ab')2 fragment of IgG or alpha2-macroglobulin also gave similar results, whereas the F(ab')2 fragment of rabbit IgG antibody to human alpha2-macroglobulin was completely negative. More than 99% of the cells commonly exhibited membrane-associated beta2-microglobulin.

Rheumatoid factor plaque-forming cells in rheumatoid synovial tissue

Cells producing rheumatoid factor (RF) were readily detected in vitro by means of a haemolytic plaque assay system employing sheep erythrocytes (SRBC) sensitized with reduced and alkylated rabbit IgG anti-SRBC antibody as target cells. Rheumatoid factor-producing, plaque-forming cells (RF-PFC) were observed in all of the synovial tissue cell preparations from seropositive rheumatoid arthritis patients studied. The numbers of RF-PFC varied considerably without any direct correlation with serum titres of RF antibody activity. However, high numbers of RF-PFC were never found in patients with low rheumatoid factor titres whereas, high and low numbers of RF-PFC were found among the patients with high RF titres. Synovial tissue cell preparations from a group of seronegative patients, with only one exception, failed to exhibit RF-PFC.

Lymphocytes eluted from synovial tissue of juvenile rheumatoid arthritis patients

Synovial tissues from 11 patients with juvenile rheumatoid arthritis were investigated. The elution of lymphocytes was performed according to a procedure previously described for synovial tissue of adult rheumatoid arthritis patients (1). The T lymphocytes were pre dominant (mean: 71%) in all cell suspensions studied, whereas the average proportion of B lymphocytes was 4%. In addition, Fc-receptor-bearing lymphocytes were demonstrable (mean: 8%). Transformation of the lymphocytes was induced by the unspecific mitrogens phytohemagglutinin, pokeweed mitogen, and concanavallin A, whereas antigens such as ppd and candida albicans antigen were usually ineffective.

Antigen and unspecific mitogen stimulation of lymphocytes eluted from rheumatoid inflammatory tissue

Lymphocytes were eluted from synovial tissues of 17 patients with classical rheumatoid arthritis, using a procedure previously reported. Stimulation was obtained with the unspecific mitogens phytohemagglutinin (PHA), pokeweed mitogen (PWM), and concanavalin A (Con A) as well as with purified protein derivative of tuberculin (PPD) and mitoycin-C-treated allogeneic lymphocytes, whereas candida antigen usually gave a low response. The pattern of reactivity to unspecific mitogens was similar to that obtained with lymphocytes from peripheral blood of rheumatoid arthritis patients. Two different PPD preparations usually gave transformation of the same magnitude as seen with PHA. This was in contrast to the reactivity of the peripheral blood lymphocytes. It could be demonstrated that the elution procedure initiated some degree of lymphocyte transformation, mainly potentiating the responses to PHA and Con A.

Elution and characterization of lymphocytes from rheumatoid inflammatory tissue

Lymphocytes were eluted from the synovial tissue of 19 patients with classical rheumatoid arthritis. The tissue was minced and dissociated by treatment with crude collagenase and DNase. The cell suspension obtained was filtered and incubated in plastic culture flasks overnight at 37 degrees C. The cells that did not adhere to the plastic surface were harvested and the lymphocytes further purified by the Ficoll-Isopaque gradient centrifugation technique. The lymphocyte yield varied from 0.64 to 32 times 10(6) cells. Differential counts showed on the average 85% lymphocytes, 12% mocrophage-like cells, and variable proportions of polymorphonuclear granulocytes, unclassified cells, and dead cells. An average of 77% of the cells were viable as assessed by the trypan blue exclusion test. This cell suspension was investigated for lymphocyte populations. T lymphocytes were predominant in all experiments (mean, 73.6%). The mean percentage of B lymphocytes was 9.7%, whereas the proportion of Fc-receptor-bearing lymphocytes was on the average 6.0%.