The effects of asbestos on macrophages

Adsorption of bovine serum albumin onto synthetic Fe-doped geomimetic chrysotile

Synthetic stoichiometric and Fe-doped geomimetic chrysotile nanocrystals represent a reference standard to investigate the health hazard associated with mineral asbestos fibres. Experimental evidence suggests that the generation of reactive oxygen species and other radicals, catalysed by iron ions at the fibre surface, plays an important role in asbestos-induced cytotoxicity and genotoxicity. In this study, structural modification of bovine serum albumin (BSA) adsorbed onto synthetic chrysotile doped with different amounts of Fe has been investigated by Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA) and analytical pyrolysis coupled with gas chromatography-mass spectrometry. FT-IR data evidenced a marked increase in disordered structures like random coil and β-turn of BSA-nanocrystal adduct with 0.52 wt% of Fe doped. The TGA profile of the BSA revealed that its interaction with the synthetic chrysotile surface was strongly affected by the substitution of Fe into the chrysotile structure. The 2,5-diketopiperazine yields, formed upon thermal degradation of the polypeptide chain (pyrolysis-gas chromatography), changed when the BSA was adsorbed on the nanofibres. In general, results suggested that minute amount (less than 1 wt%) of Fe doping in chrysotile affected the protein-nanofibre interactions, supporting the role that this element may play in asbestos toxicity. The catalytic role of iron and the consequent unfolding of protein due to the structural surface modification of nanofibres were also evaluated.

Cryptococcus pneumonia presenting in an immunocompetent host with pulmonary asbestosis: a case report

INTRODUCTION

Cryptococcal infections pose a diagnostic challenge in an immunocompetent host. Asbestos exposure has been associated with pulmonary aspergillosis. This case highlights an interesting presentation of cryptococcal lung inflammation with underlying asbestosis.

CASE PRESENTATION

A 63-year-old Mediterranean Caucasian woman presented with progressive dry cough of nine months duration. A computed tomography (CT) scan of her chest revealed multiple foci in the right infra-hilar region, which were seen as hot lung masses on a positron emission tomography (PET) scan. These multiple foci appeared metastatic in nature throughout both lung fields with early mediastinal invasion. A computed tomography (CT)-guided core biopsy was obtained from a dominant right lower lobe lung mass. Histology showed chronic granulomatous inflammation with numerous budding yeast forms that were GMS-, PAS-, and mucin-positive, consistent with cryptococcosis together with asbestos bodies (ferruginous). She was managed with fluconazole (400mg (6mg/kg) per day orally) daily. At her six-month follow up, she had marked improvement in her general condition along with a diminution of the lower lobe lung mass.

CONCLUSION

We report a clinical and radiological improvement in a patient treated for cryptococcal pneumonia. Asbestos exposure was likely to have been an important pathophysiological precursor to infection by environmental fungi.

Synthetic chrysotile nanocrystals as a reference standard to investigate surface-induced serum albumin structural modifications

Geoinspired synthetic chrysotile, which represents an ideal asbestos reference standard, has been utilized to investigate homomolecular exchange of bovine serum albumin (BSA), the major plasma protein, between the adsorbed and dissolved state at the interface between asbestos fibers and biological medium. FTIR spectroscopy has been used to quantify BSA structural modifications due to surface adhesion on chrysotile fibers as a function of the surface coating extent. Circular dichroism spectroscopy has been used to investigate the adsorption/desorption equilibrium through analysis of the BSA structural perturbations after protein desorption from chrysotile surface. Data results show clearly that in the solid state BSA modifications are driven by surface interaction with the substrate, following a bimodal adsorption evidenced by two different binding constants. On the other hand, BSA desorbed in solution is able to rearrange, in the lack of substrate, although keeping irreversible modifications with respect to the native species. The lack of regaining its native structure certainly affects albumin interaction with biological environment. The present investigation on the stoichiometric synthetic geoinspired chrysotile nanocrystals is the first approach toward a deeper attempt to use standard synthetic chrysotile reference samples in mimicking the behavior of asbestos fibers and allows to better understand their interaction with a biological environment.

Interaction of Bovine Serum Albumin with Chrysotile: Spectroscopic and Morphological Studies

The biodurability of chrysotile fibers, which is related to their cytotoxicity and mutagenic responses, is strongly affected by the surface chemical adsorption of biological molecules. Natural chrysotile is a heterogeneous material in both structure and composition. The availability of synthetic stoichiometric chrysotile of constant structure and uniform morphology has allowed us to investigate its interaction with bovine serum albumin (BSA). By using transmission electron microscopy (TEM) and atomic force microscopy (AFM), we have obtained the first morphological evidence of albumin adsorption onto chrysotile nanocrystals. FTIR spectroscopy was used to quantify modifications of BSA secondary structure that were induced by the surface interaction. The protein transition to beta-turns allows a stronger interaction between the protein hydrophilic side-chains and the charged asbestos surface, which is consistent with hydrogen bonds involving the superficial OH groups. Synthetic stoichiometric chrysotile nanocrystals were shown to be an ideal reference standard with which to study the interaction of asbestos fibers with biological systems, in order to elucidate the chemical mechanisms of asbestos toxicity.

Respiratory toxicity of multi-wall carbon nanotubes

Carbon nanotubes focus the attention of many scientists because of their huge potential of industrial applications, but there is a paucity of information on the toxicological properties of this material. The aim of this experimental study was to characterize the biological reactivity of purified multi-wall carbon nanotubes in the rat lung and in vitro. Multi-wall carbon nanotubes (CNT) or ground CNT were administered intratracheally (0.5, 2 or 5 mg) to Sprague-Dawley rats and we estimated lung persistence, inflammation and fibrosis biochemically and histologically. CNT and ground CNT were still present in the lung after 60 days (80% and 40% of the lowest dose) and both induced inflammatory and fibrotic reactions. At 2 months, pulmonary lesions induced by CNT were characterized by the formation of collagen-rich granulomas protruding in the bronchial lumen, in association with alveolitis in the surrounding tissues. These lesions were caused by the accumulation of large CNT agglomerates in the airways. Ground CNT were better dispersed in the lung parenchyma and also induced inflammatory and fibrotic responses. Both CNT and ground CNT stimulated the production of TNF-alpha in the lung of treated animals. In vitro, ground CNT induced the overproduction of TNF-alpha by macrophages. These results suggest that carbon nanotubes are potentially toxic to humans and that strict industrial hygiene measures should to be taken to limit exposure during their manipulation.

Comparison of the pulmonary responses to chrysotile and amosite asbestos administered intratracheally. I) Early phase of cellular reactions

To clarify whether serpentine and amphibole asbestos have different effects on the lung, UICC chrysotile and amosite asbestos were injected intratracheally into hamster lung, and the lungs were examined at 30 min, 1, 4, 8, and 24 h, and 2 and 4 days after asbestos application by light and scanning electron microscopy. A leukocyte and macrophage reaction appeared at 4 h and increased up to 2 days, and the cell reaction was stronger and more prolonged after application of chrysotile than after application of amosite asbestos. Furthermore, chrysotile induced more prominent cell (leukocytes or/and macrophages) necrosis and alveolar wall thickening. These findings indicate that chrysotile asbestos induces more stronger cell reactions in the alveolar wall, and is more noxious than amosite.

Lymphocyte-macrophage alveolitis in nonsmoking individuals occupationally exposed to asbestos

A disordered immunologic activity has been observed in humans and animal models of asbestosis and silicosis. To characterize the lung immunologic response following long-term occupational exposure to asbestos, bronchoalveolar lavage (BAL) was performed on 28 nonsmoking individuals. Increased BAL lymphocytes were observed in one third. Lung lymphocytes were predominantly of the CD4+ helper-inducer subtype with increased CD4+/CD8+ ratio and increased surface expression of DR antigen consistent with the activation phenotype. Histologic evaluation of lung tissue from two individuals with lymphocytic-macrophage alveolitis and asbestos exposure revealed an infiltration of alveolar walls with chronic inflammatory mononuclear cells (lymphocytes). Interferon gamma was spontaneously released by BAL cells from 19 (76 percent) of 25 of the individuals with asbestos exposure and only one of ten normal controls. The release of interferon gamma by BAL cells could be further stimulated with concanavalin A and suppressed by cyclosporine. Although asbestosis is characterized by a predominant alveolar macrophage alveolitis, there is a subgroup with lymphocytic alveolitis and activated lymphocytes participating in the inflammatory response, especially in those without respiratory impairment early in the course of the disease process.

Modification of asbestos bioactivity for the alveolar macrophage by selective protein adsorption

The bioactivity of an inhaled particulate is likely to be influenced significantly by the adsorption of proteins and lipids from the fluid lining the respiratory tract. We have shown previously in vitro that the presence of immunoglobulin G, a protein constituent of the lining fluid, significantly and specifically enhances the response of the guinea pig alveolar macrophage to chrysotile, but not crocidolite, asbestos. In order to understand the differential response of the guinea pig alveolar macrophage to chrysotile and crocidolite, as well as to obtain a better understanding of the factors that determine the adsorption of proteins onto asbestos, we have quantitated the adsorption of model proteins, including IgG, onto asbestos. The apparent surface density to which a given protein adsorbed was found to be influenced significantly by the surface charge of the asbestos, by the net protein charge, i.e., its isoelectric point (pI), and most dramatically, by the presence of other proteins. Thus, for example, even when guinea pig IgG (gpIgG; pI approximately 8.5) and bovine serum albumin (BSA; pI = 4.8) were present together at a high molar ratio of BSA to gpIgG, gpIgG was selectively adsorbed on negatively charged crocidolite asbestos. An analogous result was found for the adsorption of gpIgG and cytochrome c (CYT; pI = 10) on positively charged chrysotile asbestos, i.e., even at high molar ratios of CYT to gpIgG, gpIgG was selectively adsorbed. This latter result provides an explanation for the differential bioactivities of chrysotile and crocidolite asbestos previously noted in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)

Kinetics of the bronchoalveolar leucocyte response in rats during exposure to equal airborne mass concentrations of quartz, chrysotile asbestos, or titanium dioxide

The kinetics of the bronchoalveolar response was assessed in rats exposed, at equal airborne mass concentration (10 mg/m3), to titanium dioxide--a non-pathogenic dust--and the two pathogenic mineral dusts quartz and chrysotile asbestos. Rats were killed at intervals over a 75 day exposure period and groups of rats exposed for 32 and 75 days after recovery for two months. Bronchoalveolar lavage was carried out and the lavage fluid characterised for cellular content, macrophage activation, and concentrations of free total protein, lactate dehydrogenase, and N-acetyl-beta-D-glucosaminidase. Inhalation exposure to the two pathogenic dusts resulted in an increased number of leucocytes, macrophage activation, and increased levels of free enzymes and total protein. The pattern and magnitude of the responses to quartz and chrysotile differed. Chrysotile caused less inflammation than quartz, and the main cellular response peaked around the middle of the period of dust exposure whereas the highest levels of enzymes occurred towards the end. The difference in timing suggests that macrophages were not available for lavage towards the end of the exposure, owing to their playing a part possibly in deposition of granulation tissue. Quartz caused a greater cellular and enzyme response than chrysotile, particularly towards the end of the dust exposure phase. There was a noticeable progression of inflammation in the quartz exposed groups left to recover for two months, but not in the chrysotile recovery groups.

Sequence of bronchoalveolar lavage and histopathologic findings in rat lungs early in inhalation asbestos exposure

To assess the early cellular inflammatory response of the lungs, 7 rats per group were exposed nose-only to 13 mg/m3 of chrysotile asbestos, 7 h/day for 2, 4, or 6 wk. Lung histopathology and bronchoalveolar lavage (BAL) were analyzed. In exposed animals, dose-related bronchiolitis and fibrosis were found that were not seen in control rats (p less than 0.001). In exposed rats, total BAL cells were increased six-to sevenfold over matched controls, and more cells were retrieved with longer exposure (p less than 0.001). In the BAL, counts of macrophages, lymphocytes, and polymorphonuclear cells (PMNs) were each elevated in the exposed rats (each p less than 0.001). PMNs seen histologically and in the BAL may be related to the time period examined. PMNs and lymphocytes observed throughout this 6-wk study support the idea that these cells may have an important role in the early events of asbestos lung injury.

In vitro cytotoxicity of chrysotile asbestos to human pulmonary alveolar macrophages is decreased by organosilane coating and surfactant

Human pulmonary alveolar macrophages were used to quantitate the cytotoxic effect of surface-altered chrysotile asbestos. Little difference was observed in mortality between chrysotile asbestos that was surface-treated to a 42% extent by a hydrophobic organosilane or untreated chrysotile. Little or no effect on mortality was observed when human pulmonary alveolar macrophages were cultured with untreated chrysotile or acid-leached asbestos in the presence of 10 mM dipalmitoyl lecithin. However, when human pulmonary alveolar macrophages were cultured with a hydrophobically-treated (to a 42% or 95% extent) chrysotile asbestos in the presence of 10 mM dipalmitoyl lecithin, a statistically significant decrease in mortality was observed compared to untreated chrysotile. No mutagenic activity was observed when V79 cells were cultured with acid-leached, or 42% hydrophobically-treated chrysotile asbestos, even when human pulmonary alveolar macrophages were included as an activation source. The 95% hydrophobically-treated and acid-leached chrysotile also exhibited decreased binding of benzo[a]pyrene compared to untreated chrysotile asbestos.

Suppression of the in vitro humoral immune response by chrysotile asbestos

The direct addition of UICC chrysotile B asbestos to spleen cell cultures produced a dose-dependent suppression of the antibody-forming cell (AFC) response to the T-dependent antigen, sheep erythrocytes. Concentrations of 0.1, 1, 10, and 100 micrograms/ml, which had no effect on either cell number or viability, suppressed the in vitro response by 12, 43, 71, and 95%, respectively. By separating spleen cells into nonadherent and plastic-adherent populations, the effects of asbestos on each cell type were studied utilizing reconstituted cultures. Treatment of adherent cells for 1 hr with asbestos and reconstitution with untreated nonadherent cells resulted in a dose-dependent suppression of the AFC response similar to that observed when asbestos was added to whole spleen cultures. Reconstitution studies were also conducted with spleen cell populations from animals administered asbestos in vivo. In cultures reconstituted with adherent cells from asbestos-treated mice and nonadherent cells from saline-treated animals, the AFC response was significantly suppressed. The T-dependent AFC response with reconstitution of adherent cells from saline-treated mice and nonadherent cells from asbestos-exposed animals was no different from reconstituted saline controls. Both adherent alveolar and pleural cells were capable of reconstituting the T-dependent AFC response with nonadherent spleen cells and demonstrated reduced immunological capability when exposed to asbestos fibers. The results of this investigation have identified the adherent spleen cell (macrophage) as the target cell type responsible for asbestos-induced immunosuppression of the in vitro T-dependent antibody-forming cell response.

Pathogenesis of pulmonary fibrosis induced by chrysotile asbestos. Longitudinal light and electron microscopic studies on the rat model

A single instillation of 1 mg chrysotile B with a fiber length between 0.05 and 0.2 micron in 0.1 ml tricaprylin was made via a polyvinyl catheter into the lower lobe of the right lung of 120 six-week-old Wistar rats under anesthesia. The animals were killed at intervals between five minutes and two years. The lower lobes of the right lung were investigated by light and electron microscopy. The process of pulmonary fibrosis induced by asbestos can be subdivided into four phases: these are the phase of phagocytosis (five to 15 min), the phase of granuloma formation (between one and two weeks), the phase of septal fibrosis (between two and six months) and finally the scar stage (after one year). After instillation of small asbestos fibers into the alveoli, a major proportion of these fibers is phagocytosed by alveolar macrophages after five minutes and leaves the lungs via the airways. A proportion of the fibers penetrates through the alveolar wall (mostly conveyed by type I pneumocytes) and reaches the interstitium of the lungs. There, the fibers are taken up by pulmonary tissue macrophages and giant cells. Within the phagolysosomes, the fibers are broken down into fragments less than 0.01 micron in length. Type II pneumocytes produce surfactant in excess. These cells become necrotic, tubular myelin and lamellar bodies pass into the alveoli and into the interstitium. Surfactant is phagocytosed by resident macrophages. These macrophages can break down. Besides asbestos and surfactant, mediators of fibrillogenesis are released. Macrophages following up from blood monocytes ingest surfactant and asbestos. This process is perpetuated up to complete scarring. After two years, small asbestos fibers less than 0.01 micron long are present in fibroblasts and pleural mesothelia.

The in vitro cytotoxicity of asbestos fibers: I. P388D1 cells

In this study, the cytotoxicity of 13 fibrous samples of known fiber number and dimensions has been established in P388D1 cells. The cells were exposed in vitro to dust concentrations of 10 or 50 micrograms/ml and, after incubation for 24 or 48 hours, any changes in cellular viability, lactate dehydrogenase, and glucosaminidase levels were determined. In general, there was a close association between the reduction in cellular viability and the loss of intracellular enzymes induced by each dust, the chrysotile asbestos samples proving more cytotoxic than the amphiboles. The cytotoxicity of the fibrous dusts was shown to be related to the number of fibers greater than 8 micron in length in the samples.

Increased release of hydrogen peroxide and superoxide anion from asbestos-primed macrophages. Effect of hydrogen peroxide on the functional activity of alpha 1-protease inhibitor

The ability of asbestos-elicited murine peritoneal macrophages to release superoxide anion and hydrogen peroxide, following in vitro triggering, has been investigated. The asbestos-elicited macrophages produced increased levels of superoxide and hydrogen peroxide compared to control macrophages and similar levels to those produced by Corynebacterium parvum elicited macrophages. The supernatants from asbestos-elicited macrophages which had been triggered in vitro were capable of impairing the ability of alpha 1-protease inhibitor to inhibit elastase function. The catalase sensitivity of this effect showed it to be due to hydrogen peroxide.

Asbestos-induced chemiluminescence response of human polymorphonuclear leukocytes

Products of the oxidative metabolism of polymorphonuclear leukocytes (PMN), namely hydrogen peroxide and superoxide, may play a role in tissue injury at sites of inflammation. Oxidant production by PMN was measured by the luminol-enhanced chemiluminescence (CL) of cells exposed in vitro to asbestos fibers. Human peripheral blood PMN were incubated with 1-1000 micrograms/ml of UICC chrysotile B asbestos fibers opsonized with either normal or heat-inactivated human serum. CL was measured over 210 min and revealed a peak response at 45 min; this response was delayed in comparison to control CL induced by Staphylococcus aureus (5-10 min) and represented approximately 50% of that of the latter. Although maximal CL was generated by asbestos concentrations of 100-500 micrograms/ml, significant CL was observed at concentrations as low as 0.5-1 micrograms/ml. Opsonization of asbestos fibers with heat-inactivated serum markedly depressed CL responses, suggesting that complement activation by asbestos fibers may be important in the generation of CL by PMN. In view of the previously reported accumulation of PMN in the lungs of asbestos-exposed animals, this study suggests that oxidant production by PMN may mediate some of the pathological effects of asbestos fibers.

Reaction of rat lungs to inhaled chrysotile asbestos following acute and subchronic exposures

Inhalation of asbestos fibers can cause fibrotic and neoplastic diseases in the lung. The early in vivo interactions between fibers and lung tissue that initiate these diseases have received little study. Male and female Fischer 344 rats were placed in inhalation chambers and exposed to 9.06 +/- 1.83 mg/m3 (average respirable mass) of chrysotile asbestos for 1 hr, 1 day, 7 hr/day for 5 days, or 5 days/week for 3 months. Qualitative examination of the tissue showed that, after 1 day, fibers were found not only in the alveolar macrophages, but also in the epithelium and interstitium of the alveolar region. After 3 months, numerous fibers were present in the epithelium and interstitium. Morphometric analysis of this tissue showed that these compartments were also the most significantly changed as a result of asbestos exposure. The majority of epithelial changes were attributable to a 57% increase in the number of type II cells and a 90% increase in their average cell volume. The interstitial cell population increased 58% with a 40% increase in the average cell volume. There was no significant increase in the volume of noncellular interstitium. A morphologic characterization of the interstitial cells showed that interstitial macrophages accounted for almost the entire increase in this population and that 88% of the fiber-containing cells were macrophages. Several interstitial macrophages contained membrane-bound inclusions which were shown by x-ray energy spectrometry to be microcalcifications. They were composed of rings of calcium phosphate granules around asbestos fibers. These microcalcifications may indicate sublethal cell injury caused by the presence of asbestos fibers in the cell cytoplasm. Fibers which enter but do not kil alveolar cells may be an essential component for the pathogenesis of lung disease caused by asbestos inhalation.

Analysis of depressed cell-mediated immunity in asbestos workers

To explore the mechanisms of asbestos-related perturbations of the immune system, we evaluated the in vitro cell-mediated immunity of five asymptomatic asbestos workers with hypergammaglobulinemia and decreased T-cell numbers. These results were compared with those in 10 matched controls. Analysis of T-lymphocyte populations revealed decreased absolute numbers of OKT4+ (helper/inducer) T cells in the peripheral blood and phytohemagglutinin (PHA)-stimulated mononuclear cell cultures of the workers. When chrysotile asbestos was added to PHA cultures, expansion of OKT4+ cell populations was disproportionately inhibited in workers' cultures. Furthermore, control proliferative responses to PHA became indistinguishable from initial worker responses. These effects were incompletely explained by the cytotoxic effects of asbestos on cultured lymphocytes. We conclude that both in vivo and in vitro exposure of mononuclear cell populations to asbestos may lead to a diminution of helper-inducer T-cell numbers. In asbestos-exposed individuals, this latter lymphocyte subpopulation appears to be especially sensitive to in vitro asbestos exposure. Although the clinical implications of these findings are unclear, we hypothesize that many of the immunologic abnormalities that occur in asbestos workers could be explained by direct asbestos effects on the OKT4+ immunoregulatory population.

Concanavalin A receptors and capping in control and activated macrophages

Macrophages activated in vivo with Corynebacterium parvum and asbestos showed an increased sub-population of cells which capped spontaneously on incubation with fluoresceinated Concanavalin A compared to saline-induced control macrophages. This capping was unaffected by colchicine but was inhibited by cytochalasin B. The spontaneous capping of activated macrophages did not appear to be directly related to the total number of Concanavalin A receptors as measured by specific 125I-labelled Concanavalin A binding to activated and control macrophages. Capping also did not appear to be related to the position of Concanavalin A receptors as judged by trypsin accessibility of bound 125I-labelled Concanavalin A.

Role of alveolar macrophages in asbestosis: modulation of neutrophil migration to the lung after acute asbestos exposure

After intratracheal injection of short chrysotile asbestos fibres in guinea-pigs an intense neutrophil alveolitis was observed within three days. Evaluation by bronchoalveolar lavage of the inflammatory and immune effector cells producing the alveolitis by three days showed an increased proportion of polymorphonuclear leucocytes, which comprised 21% +/- 3% of the total leucocytes compared with 9% +/- 2% for the controls (p less than 0.05), persisting for at least six weeks (after which time the polymorphonuclear leucocytes comprised 28% +/- 2% compared with 7% +/- 1% for the controls: p less than 0.05). One mechanism by which asbestos fibres may cause polymorphonuclear leucocytes to be attracted to the alveolar structures is by induced release of neutrophil chemotactic factor by alveolar macrophages. When exposed in vitro to short or intermediate chrysotile fibres or amosite or crocidolite fibres guinea-pig alveolar macrophages released appreciable amounts of neutrophil chemotactic factor. The release of this chemotactic factor was augmented when the asbestos fibres had been previously exposed to normal serum. The chemotactic factor was lipid soluble, and was similar to the neutrophil chemotactic factor spontaneously released by alveolar macrophages recovered from guinea-pigs exposed in vivo to short chrysotile fibres. These observations suggest that alveolar macrophages may play an important part in the early stages of asbestosis by modulating the migration of neutrophils to the lung.

Drug-induced lipidosis and the alveolar macrophage

The alveolar macrophage is the principal component of the defense mechanisms of the lung. As a result, alterations in its function can predispose the host organism to pulmonary disease or damage. This cell shows toxic responses to a wide variety of chemicals which are delivered to the lungs by either inhalation or via the systemic circulation. In this regard, this review will focus on the effects of a group of cationic amphiphilic drugs which when administered to humans and animals causes a lysosomal storage disorder of lipids, principally phospholipids, in alveolar macrophages. The susceptibility to the disorder is species-dependent and can be induced in fetal, neonatal and adult animals. Evidence exists that the accumulation of lipids within the cells occurs as a result of an impairment in lipid catabolism, however, not all of the available data are consistent with this theory. In light of this, other mechanisms to explain the etiology of this lipidosis are discussed. Associated with the increase in lipid content within the cell, striking morphological, biochemical and functional changes occur to the alveolar macrophage. Available data indicate that afflicted cells have an increased phagocytic activity and exhibit enhanced killing of one strain of bacteria. While these data suggest an enhancement in certain cellular functions, inadequate information presently exists to allow conclusions to be drawn concerning the consequences of this disorder.