Expression of keratins K6 and K16 in regenerating mouse epidermis is less restricted by cell replication than the expression of K1 and K10

Biosynthesis of the hyperproliferation-associated keratins K6 and K16 was studied in mouse epidermis following a single topical application of the tumour promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). An epidermal cell cohort was followed by pulse-labelling with the thymidine analogue 5-bromodeoxyuridine (BrdUrd). Mice were injected intraperitoneally with BrdUrd 1 h before a single topical application of TPA. TPA induced regenerative epidermal hyperplasia with hyperproliferation and shortened suprabasal transit time. The BrdUrd-labelled cell cohort was followed for 96 h after TPA-treatment by two-colour immunofluorescence staining with antibodies to BrdUrd, keratin K6 and K16. In control animals, K6 and K16 were found only in the hair follicles. K6 expression was immediately induced in all epidermal cell layers of TPA-treated epidermis, including actively replicating cells and it was expressed during the whole observation period. K16 was only present in post-mitotic cells and was transiently expressed 8-72 h after TPA treatment. Our results suggest that the expression of K6 and K16 is less restricted by cellular replication than the normally occurring K1 and K10 keratins.

Up-regulated epithelial expression of HLA-DR and secretory component in salivary glands: reflection of mucosal immunostimulation in sudden infant death syndrome

Human parotid glands from 55 forensic autopsy subjects, 1-12 mo of age, were examined by immunohistochemistry without knowledge about the cause of death. Various combinations of monoclonal or polyclonal antibody reagents of the following specificities were applied in two-color immunofluorescence analyses: HLA class I or II (DR, DP, or DQ); pan-T cell (CD3); leukocyte common antigen (CD45); and secretory component (poly-Ig receptor). Sudden infant death syndrome victims (n = 17) were shown to have significantly increased numbers of CD45+ stromal leukocytes and intensified epithelial expression of HLA-DR and secretory component as well as increased endothelial expression of both HLA class I and II (DR, DP, and DQ) determinants compared with controls (n = 31) who had died from noninfectious causes. Seven overtly infectious subjects (bronchopneumonia) showed still more up-regulated expression. This result suggested that enhanced stimulation of the local immune system exists in sudden infant death syndrome, with release of certain cytokines that are known to up-regulate epithelial expression of HLA-DR and secretory component.

Increased macrophage subset in inflammatory bowel disease: apparent recruitment from peripheral blood monocytes

Mucosal specimens from active Crohn's disease (ileum, n = 6; colon, n = 6), active ulcerative colitis (n = 9), normal ileum (n = 6), and normal colon (n = 6) were subjected to paired immunofluorescence staining for characterisation of macrophage subsets in situ. In the normal state, only few CD68+ macrophages (< 10%) expressing the myelomonocytic L1 antigen (calprotectin) were seen. In inflamed mucosa, especially near small vessels, the CD68+L1+ fraction increased with the degree of inflammation, near ulcers to median 65% (range 35-91%). Cells reactive with the monoclonal antibody RFD7 were also increased in inflammation but less than 5% of them costained for L1 antigen. It is concluded that L1 producing macrophages are distinct from the RFD7+ subset and probably recently recruited from peripheral blood monocytes. Like granulocytes, L1+ macrophages may be important in non-specific defence, providing calprotectin with putative anti-microbial and anti-proliferative properties.

Gluten stimulation of coeliac mucosa in vitro induces activation (CD25) of lamina propria CD4+ T cells and macrophages but no crypt-cell hyperplasia

Jejunal biopsy specimens from 10 patients with treated coeliac disease and seven non-coeliac controls were challenged in vitro with peptic-tryptic gluten digest. Mucosal T cells were examined in situ by three-colour immunofluorescence staining for expression of the activation marker CD25 (the p55 alpha-chain of interleukin-2 receptor) and the nuclear proliferation marker revealed by monoclonal antibody Ki-67. Intraepithelial T cells expressed CD25 rarely whereas the proportion of activated lamina propria T cells increased (P < 0.002) from median 2.8% (cultured with 20% fetal calf serum alone for 24-48 h) to 10.0% after 24 h with gluten (n = 10; range 1.1-17.4%) and to 10.4% after 48 h (n = 7; range 1.4-17.5%). Such gluten-induced increase of CD25+ T cells was not observed in specimens from non-coeliac control subjects. Crypt-cell hyperplasia and T-cell proliferation (Ki-67+) were observed neither in the coeliac nor in the control mucosae after gluten stimulation. Three-colour staining combining a polyclonal antibody reagent to CD3 and a monoclonal antibody to CD25 with a monoclonal antibody to CD45R0, CD4, CD8, the p75 beta-chain of interleukin-2 receptor, integrin alpha E beta 7, or HLA-DR showed that most of the CD25+ T cells (> 90%) were CD4+CD8-, co-expressed CD45R0 and the p75 beta-chain, and often also the integrin alpha E beta 7 but not HLA-DR. In addition to these activated T cells, a dominating population of CD25+CD3-CD4+ subepithelial pan-HLA-class II+ macrophages (CD68+) with variable expression of the p75 beta-chain was often induced by gluten challenge.

Do human Peyer's patches contribute to the intestinal intraepithelial gamma/delta T-cell population?

T-cell receptor gamma/delta+) (TcR gamma/delta+) lymphocytes in human Peyer's patches (PP) adjoining ileal mucosa were studied by monoclonal antibodies with paired immunofluorescence staining in situ and by flow-cytometric phenotyping of isolated cells. The proportion of gamma/delta+ T cells in the follicle-associated epithelium outside the M-cell areas (median 4.1%, range 2.2-30.1%) was similar to that in mucosal villous epithelium (median 4.4%, range 0.5-30.5%). Most intraepithelial gamma/delta cells (approximately 90%) expressed CD45R0 but only a few expressed CD8 (< 10%) and none L-selectin; a dominating subset (median 46%) employed the V delta 1/J delta 1 gene product (range 22-100%). The M-cell areas lacked gamma/delta cells but contained clustered CD20+ and CD3+ lymphocytes. The subepithelial PP dome area and interfollicular (T-cell) zones, as well as the mucosal lamina propria, contained very few gamma/delta cells (median 1.7%, range 0.4-8.9%) which were dominated (88-100%) by the V delta 2-encoded subset. Those in the dome area and lamina propria were often (approximately 75%) CD45R0+ (range 44-90%) while very few (approximately 2%) expressed L-selectin (range 0-15%). By contrast, CD45R0 expression on gamma/delta cells in the PP T-cell zones was relatively low (approximately 46%) and that of L-selectin relatively high (approximately 43%). In conclusion, TcR gamma/delta + cells are quite rare in human PP and belong mainly to the V delta 2-encoded subset, thus being different from most intraepithelial gamma/delta cells that probably have another origin. The L-selectin+ fraction of PP gamma/delta cells presumably represent newly recruited 'naive' T lymphocytes while CD45R0+ gamma/delta cells both in PP and lamina propria are probably antigen-primed.

Distribution of macrophages and granulocytes expressing L1 protein (calprotectin) in human Peyer's patches compared with normal ileal lamina propria and mesenteric lymph nodes

Antibodies to the cytosolic leucocyte L1 protein (or calprotectin) were examined for reactivity with macrophages, neutrophils, and eosinophils identified by paired immunofluorescence staining in sections of normal human ileal mucosa, including Peyer's patches. Macrophages were recognised by expression of the myelomonocytic antigen CD68 (monoclonal antibody KP1). Neutrophilic granulocytes were identified by their content of neutrophil elastase, and eosinophilic granulocytes by monoclonal antibody EG2. Virtually all CD68+ macrophages in normal lamina propria and Peyer's patches were L1- and the same was true for most extravasated macrophages in normal peripheral lymph nodes. Some mesenteric lymph nodes, however, and all peripheral lymph nodes with overt pathological processes (malignant lymphoma) contained many CD68+L1+ macrophages. Numerous L1+ cells were also localised to the crypt region and to some extent beneath the villous epithelium in normal lamina propria, but they were mainly identified as EG2+ eosinophils. Such cells were remarkably scarce or absent beneath the follicle associated epithelium in the dome region of Peyer's patches, where CD68+L1- macrophages were abundant. Also subepithelial and interfollicular CD68- interdigitating dendritic cells in Peyer's patches (recognised by antibody to S-100 protein) were usually unreactive with L1 antibody. The L1 protein shows a broad spectrum of antimicrobial activities in vitro, and its putative antiproliferative properties are interesting in relation to the immunosuppression postulated to take place in lamina propria. The virtual absence of L1 producing cells beneath the follicle associated epithelium in Peyer's patches may support the immunostimulatory function of these macrophage rich structures, which are held to be crucial for induction of specific mucosal immunity.

Duodenal intraepithelial gamma/delta T cells and soluble CD8, neopterin, and beta 2-microglobulin in serum of IgA-deficient subjects with or without IgG subclass deficiency

Expression of the gamma/delta T cell receptor (TCR) on CD3+ intraepithelial lymphocytes (IELs) was studied by two-colour immunofluorescence in duodenal tissue sections from healthy (n = 6) or infection-prone (n = 7) subjects with selective IgA deficiency (IgAD), and subjects (n = 4) with combined IgAD and IgG subclass deficiency. TCR gamma/delta+ IEL proportions in selective IgAD subjects (median 6.3%, range 1.0-41%) and in those with combined deficiency (median 4.5%, range 1.2-33%) were well within the range (0.3-38%) for histologically normal controls (n = 11), but the healthy IgAD subgroup tended to show raised TCR gamma/delta+ IEL proportions (median 13.6%) compared with the other two subgroups. Also the number of TCR gamma/delta+ IELs per intestinal length unit was relatively high (median 13.9/mm) in the healthy IgAD subjects, and significantly raised (P < 0.03) compared with controls (median 3.2/mm). Paired staining revealed that most TCR gamma/delta+ IELs in both selective IgAD (98%) and combined deficiency (99%) were CD8-, and a large fraction (median 84% and 63%, respectively) expressed the V delta 1/J delta 1-encoded epitope. The total number of CD3+ IELs (mostly CD8+) was similar to controls. IgAD subjects, and especially the healthy subgroup, had significantly increased serum concentrations of soluble CD8 (P < 0.0002), neopterin (P < 0.005), and beta 2-microglobulin (P < 0.007), which was similar to our previous observations in common variable immunodeficiency, and probably reflected stimulation of cell-mediated immunity. In addition, the increased TCR gamma/delta+ IELs might reflect a component of compensatory surface protection in the healthy IgAD subgroup.

Glandular distribution of immunoglobulins, J chain, secretory component, and HLA-DR in the human endometrium throughout the menstrual cycle

Two-colour immunofluorescence was used to study components of the secretory immune system in the endometrium. Tissue sampling was performed in the follicular, ovulatory and luteal menstrual phase from women admitted for laparoscopic sterilization. The specimens were prepared for immunohistochemistry by a method that removes most extracellular immunoglobulin (Ig). The stroma contained only a few Ig-producing immunocytes, but was rich in HLA-DR positive cells. Most of the IgA- and IgM-producing immunocytes also expressed J chain, which is necessary for the generation of polymeric Ig (poly-Ig) with affinity for epithelial secretory component (SC or poly-Ig receptor). Throughout the menstrual cycle there was increasing accumulation of Ig within the endometrial glands, with preferential apical and intraluminal occurrence of IgA and IgM, usually along with J chain and SC. It is likely that some monomeric IgA (without J chain) and IgG enter the endometrial glands by passive diffusion from the stroma, but there is clearly an additional active external poly-Ig transport. Some of the glands stained for HLA-DR irrespective of the menstrual phase or degree of SC expression. Our findings suggest that active SC-mediated external transport of serum-derived (and to some extent locally produced) poly-Ig is enhanced in the luteal phase, and that SC and HLA class II molecules are differently regulated in the endometrial glands.

Distribution and phenotypes of duodenal intraepithelial gamma/delta T cells in patients with various types of primary B-cell deficiency

Expression of the gamma/delta T-cell receptor (TCR) on CD3+ intraepithelial lymphocytes (IEL) was studied in situ by two-color immunofluorescence on duodenal tissue sections from 34 infection-prone, adult patients with various types of primary hypogammaglobulinemia, classical Bruton's, Bruton-like or congenital, and common variable immunodeficiency. TCR gamma/delta+ IEL proportions (median 4.3%, range 0.3-43.3%) were within the range (0.3-38.3%) for histologically normal controls (n = 11), and there was no significant difference between the three patient categories. The total number of CD3+ IEL (mostly CD8+) per intestinal length unit was significantly higher (P < 0.004) in patients than in controls. In addition, TCR gamma/delta+ IEL per length unit, as well as TCR gamma/delta+ IEL proportions, were significantly increased (P < 0.008 and P < 0.05) in 14 patients with intestinal villous atrophy. Paired staining revealed that most (approximately 94%) TCR gamma/delta+ IEL in B-cell deficiency were CD8-, and a large fraction (approximately 67%) expressed the V delta 1/J delta 1-encoded epitope. No relationship was found between CD3+ or TCR gamma/delta+ IEL and the number of CD3+, CD4+, CD8+, and B lymphocytes or the CD4:CD8 ratio in peripheral blood. TCR gamma/delta+ IEL thus appeared to maintain a normal distribution in B-cell deficiency, except for being increased in patients with villous atrophy. Enhanced T-cell-mediated immunity, as possibly reflected by the numerical increase of CD3+ IEL, might compensate for a deficient mucosal B-cell system.

B-cell activation in duodenal mucosa after oral cholera vaccination in IgA deficient subjects with or without IgG subclass deficiency

Alterations in duodenal Ig-producing cells induced by two oral cholera vaccinations were studied by two-colour immunofluorescence in mucosal tissue sections from adults with selective IgA deficiency (IgAD), either with (n = 7) or without (n = 9) frequent infections, infection-prone patients with combined IgAD and IgG subclass deficiency (IgGSD) (n = 7), and normal control subjects (n = 11). The proportion of IgG-producing cells prior to immunization tended to be lower in the symptomatic IgAD subjects than in the clinically healthy ones. In the first subgroup the absolute number of IgG cells per intestinal length unit was significantly increased after immunization (P < 0.04), and this tendency was also observed in the healthy IgAD subjects (6/9) and in those with combined deficiency (5/7). Very few IgAD subjects responded with an increase of IgM-producing cells. The normal controls responded variably in all major immunocyte classes, in the order IgA > IgG > IgM. Compared with these controls, the patients with combined IgAD and IgGSD showed significantly increased IgG1 (P < 0.01) and reduced IgG2 (P < 0.006) proportions, which was in accordance with their serum subclass levels. Our study showed that oral cholera vaccination preferentially activates intestinal IgG-producing cells in IgAD subjects. This result agreed with data recently obtained by ELISPOT in the same patients with regard to antibody-forming cells specific for cholera toxin. Both methods suggested that IgG rather than IgM antibodies are elicited as compensation for a lacking IgA response. However, our overall results showed that intestinal B-cell activation is quite variable after oral cholera vaccination. Although such vaccination might be of importance for enhancing mucosal immunity also in IgAD patients, a concurrent gut disease could possibly be aggravated by IgG-mediated mucosal immunopathology in the absence of anti-inflammatory IgA antibodies.

[Meningitis and septic shock as acute, fatal conditions]

Meningitis and septic shock represent an acute inflammatory response in the subarachnoid space and the vascular tree respectively. Specific molecules in the bacterial outer membrane and exotoxins induce the inflammatory response through various mediator systems. The septic shock is caused by reduced vascular resistance and capillary leakage. Meningitis leads to altered brain metabolism, oedema and circulatory disturbance, which ultimately cause hypoxia. The general practitioner should be aware of the atypical symptomatology of meningitis in infants. Septic shock is related to meningococcal infections, pneumococcal infections in splenectomized persons and toxic shock syndromes. The authors give various advice concerning diagnosis, initial treatment and transport before admission to hospital.

Increased epithelial expression of HLA-DQ and HLA-DP molecules in salivary glands from patients with Sjögren's syndrome compared with obstructive sialadenitis

Salivary gland specimens from 10 patients with primary Sjögren's syndrome (pSS) were examined by two-colour immunofluorescence with various combinations of monoclonal and polyclonal antibody reagents of the following specificities: human leucocyte antigen (HLA) class I and II (DR, DP and DQ), CD3, CD45 (leucocyte common antigen), various cytokeratins, and factor VIII-related antigen. Tissue specimens from 10 normal glands and 10 glands with obstructive sialadenitis (no known autoimmunity) served as controls. Only some intercalated ducts and scattered acini of the normal major glands expressed HLA class II determinants (< 5% of total epithelial area); the relative proportion of positive elements indicated differential expression (DR > DP > DQ). SS glands contained substantial T cell infiltrates and increased numbers of activated (DR+) T cells; adjacent epithelium showed extensive differential expression of HLA class II determinants (DR > DP > DQ). Glands with obstructive sialadenitis showed similarly increased epithelial expression of HLA-DR but with surprisingly small amounts of concomitant HLA-DP and -DQ expression. Epithelial HLA class II expression probably depends on cytokines as an inductive event, which is not unique for SS but particularly prominent in this disorder. Our results suggest that epithelial expression of HLA-DP or -DQ, rather than -DR, might be a prerequisite for the autoimmune process of SS to develop in genetically susceptible individuals.

Epithelial deposits of immunoglobulin G1 and activated complement colocalise with the M(r) 40 kD putative autoantigen in ulcerative colitis

The intestinal expression pattern and general tissue distribution of the M(r) 40 kD putative epithelial autoantigen in ulcerative colitis were re-examined by in situ two and three colour immunofluorescence staining including the murine monoclonal antibody 7E12H12. The intestinal distribution was also compared with the epithelial codeposition of IgG1 and activated complement (C3b and terminal complement complex) seen selectively in ulcerative colitis. The M(r) 40 kD antigen was found for the first time in goblet cells of normal terminal ileum and proximal colon but not in rectal goblet cells. By contrast, colonic enterocytes expressed this antigen apically with increasing intensity in a distal direction, expanding to intense cytoplasmic expression in rectal enterocytes. The antigen was also expressed by the epithelium of the fallopian tubes, major bile ducts, gall bladder, and epidermis but not by proximal gastrointestinal tract epithelium or 13 other extra-gastrointestinal organs. Activated complement and IgG1 often colocalised with the M, 40 kD antigen apically on the surface epithelium in active ulcerative colitis but not in Crohn's disease. Our results support the idea that an autoimmune response to this antigen, leading to complement activation mediated by IgG1, is a possible pathogenetic mechanism for epithelial damage and persistent inflammation in ulcerative colitis.

Hereditary tyrosinemia type I. Self-induced correction of the fumarylacetoacetase defect

Two Norwegian patients with chronic tyrosinemia type I showed > 50% residual fumarylacetoacetase activity in liver samples obtained during liver transplantation. The enzyme characteristics of both patients were comparable with those of a normal control. Immunohistochemistry on liver sections from these patients and from three other Norwegian tyrosinemia patients revealed a mosaicism of fumarylacetoacetase immunoreactivity corresponding completely or partly to some of the regenerating nodules. This appearance of enzyme protein is presumably induced by the disease process. The mechanism involved remains unclear and could be caused by a genetic alteration, regained translation of messenger RNA, or to enhanced stability of an abnormal enzyme.

Immune modulation of adhesion molecules ICAM-1 (CD54) and LFA-3 (CD58) in human hepatocytic cell lines

Interactions between leukocytes such as T cells and accessory or target cells are promoted by adhesion molecules, in particular intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-3 (LFA-3). Hepatocytes are usually negative for these surface membrane proteins which, however, may be up-regulated in inflammatory processes within the liver. Because the regulatory signals for, and tissue distribution of, these adhesion molecules vary among different tissues, expression of ICAM-1 and LFA-3 was studied in the Hep-G2 and SK-Hep-1 human hepatocytic cell lines in vitro. Low, constitutive membrane expression of the two molecules was detected in both cell lines. ICAM-1, but not LFA-3, was rapidly up-regulated by interleukin-1 (IL-1), tumor necrosis factor-alpha (TNF), and to some extent by interferon-gamma (IFN) and IL-6, whereas IL-4 had variable low effects, if any. Considerable synergism on ICAM-1 protein levels was observed after stimulation with TNF, IL-1, and IFN, whereas co-incubation with actinomycin D abolished these effects. ICAM-1 mRNA levels increased 16-20 times after cytokine incubation. Our data indicated that hepatocytes share the regulatory pathways for ICAM-1 described for several other cell types. Absence of these molecules in vivo may reflect a dominance of negative modulation signals in the normal liver, which might also explain the low levels of HLA class I molecules.

Interleukin-8 in serum and cerebrospinal fluid from patients with meningococcal disease

To evaluate the role of interleukin (IL)-8 in meningococcal disease, a solid-phase double-ligand ELISA was used to quantitate IL-8 in sera and cerebrospinal fluid (CSF) from patients with meningococcal meningitis, bacteremia, or both with or without septic shock. IL-8 was demonstrated in sera from 28 of 62 patients; levels were significantly higher in patients with septic shock without meningitis (median, 36.1 ng/mL) than in patients with other manifestations (median, < 0.02 ng/mL), and 4 of 5 patients who died had high levels. IL-8 was detected in all 27 CSF samples. Serum IL-8 levels correlated highly significantly with those of IL-6 (r = .83) and tumor necrosis factor (TNF; r = .64), while the correlations between corresponding CSF levels were less pronounced (r = .43 and r = .38, respectively) but still significant. Serum IL-8 levels were highest in patients with a symptom history < 12 h. The elimination rate of IL-8 from serum varied and was similar to that of IL-6 and TNF. IL-8 appears to participate in the complex cytokine network during the initial phase of systemic meningococcal infections.

Activated T lymphocytes in the celiac lesion: non-proliferative activation (CD25) of CD4+ alpha/beta cells in the lamina propria but proliferation (Ki-67) of alpha/beta and gamma/delta cells in the epithelium

In order to identify any dominating subset of activated T cells in the celiac lesion, we examined CD3+, CD4+, CD8+ and T cell receptor (TcR) gamma/delta+ lymphocytes in jejunal cryosections from 25 patients with celiac disease and 10 controls by three-color immunofluorescence staining for expression of the nuclear proliferation marker detected by monoclonal antibody (mAb) Ki-67 and the p55 alpha chain of interleukin-2 receptor (CD25). mAb Ki-67+ intraepithelial lymphocytes (IEL) were exclusively observed in celiac patients. The median proportion of CD3+ IEL positive for Ki-67 increased from nil in controls to 4.5% in partly treated (range 0-19.0%; n = 10; p = < 0.05) and 12.8% in untreated celiac disease (range 4.0-30.7%; n = 15; p < 0.005). Only 1.5% of CD3+ subepithelial T cells expressed the Ki-67 marker in celiac disease (range 0-9.5%). Two- and three-color staining combining mAb to CD3 and Ki-67 with mAb to CD4, CD8 or TcR delta showed that both TcR alpha/beta+ CD8+ and TcR gamma/delta+ (but not CD4+) mucosal T cells proliferated in the epithelium. By contrast, CD25 were almost exclusively expressed on CD4+ T cells in the lamina propria. The percentage of CD25+ T cells increased significantly from 1.7% in controls (range 0-2.9%) to 7.5% in partly treated (range 0.8-17.8%, p < 0.002), and to 14.65% in untreated celiac disease (range 3.9-21%, p < 0.002). These results suggest that gluten ingestion in celiac disease induces proliferative activation of TcR alpha/beta+ CD8+ and TcR gamma/delta+ IEL but non-proliferative activation (lymphokine production?) of lamina propria CD4+ T cells.

Interferon-gamma stimulation of messenger RNA for human secretory component (poly-Ig receptor) depends on continuous intermediate protein synthesis

Secretory component (SC or poly-Ig receptor) plays a key role in mucosal external body fluids. The aim of this study was to elucidate the molecular events underlying IFN-gamma-dependent up-regulation of SC. Using a human SC cDNA clone isolated by our laboratory, we found that IFN-gamma up-regulated SC mRNA levels in a time- and concentration-dependent manner. Moreover, in situ hybridization showed a striking increase of SC mRNA-positive HT-29 cells after IFN-gamma treatment. Inhibition with 5,6-dichloro-1-beta-ribofuranosyl-benzimidazole (DRB) indicated a half-life for IFN-gamma-induced SC mRNA of approximately 1 h. Cycloheximide (CHX) abolished the IFN-gamma-induced accumulation of SC mRNA in a reversible manner; the time-course suggested that de novo synthesis of protein factor(s) with a turnover time shorter than 6 h was required for accumulation of SC message. IFN-gamma-stimulated up-regulation of SC expression therefore appears to depend on molecular events similar to those taking place for the activation of several other genes in the Ig supergene family.

Oral candidiasis is associated with low levels of parotid calprotectin in individuals with infection due to human immunodeficiency virus

The level of the antifungal leukocyte protein calprotectin was determined in parotid saliva from 44 individuals with infection due to human immunodeficiency virus (HIV) and 19 healthy HIV-seronegative controls. Nine of the HIV-infected subjects suffered from oral candidiasis. Similar calprotectin levels were found in subjects with HIV infection as a whole group and in controls. When HIV-infected individuals with or without oral candidiasis were compared, the calprotectin level was significantly lower in the former group (67 micrograms/L vs. 216 micrograms/L). We suggest that calprotectin may play a role in the defense against oral candidal infections in HIV-infected patients, although several other antimicrobial factors also are probably operative.

Increasing values of serum acid phosphatase in a child with Mycoplasma pneumoniae-associated hemophagocytic histiocytic syndrome

We describe a 3 1/2-year-old boy with disseminated histiocytic disease probably induced by Mycoplasma pneumoniae. In this patient, acid phosphatase was elevated in serum and was also detected histochemically in the infiltrating histiocytes. The serum acid phosphatase levels increased as his histiocytosis progressed, apparently mirroring the activity of the disease. This observation suggests that serum acid phosphatase levels should be evaluated further to determine whether they will be a useful indicator of disease in children with different histiocytosis syndromes.

Alpha-chain disease: analysis of alpha-chain protein and secretory component in jejunal fluid

BACKGROUND

It is unclear why different forms of alpha-chain disease protein appear in intestinal fluid. This was studied in a 23-year-old Mauritanian man in whom alpha-chain disease was diagnosed localized to the duodenum and jejunum, nasopharynx, and bone marrow.

METHODS

The duodenal infiltrate was studied by immunohistochemistry. Forms of alpha chain-containing proteins in serum and jejunal fluid were analyzed by ultracentrifugation and radioimmunoassays.

RESULTS

The infiltrating cells contained alpha-1 chain but no light chains, and approximately 66% showed variable expression of J chain. Serum contained a large fraction of monomeric alpha-chain disease protein, whereas both monomeric and heavier forms appeared in jejunal fluid. Some of the latter were bound to secretory component, and the fluid contained virtually no free component.

CONCLUSIONS

Linkage of polymeric alpha-chain disease protein to secretory component depends on balanced synthesis of alpha chains and J chain in the proliferating B cells, giving rise to polymers with binding site for secretory component expressed as an epithelial receptor. Insufficient receptor-mediated transport capacity (either relative and/or because of intestinal crypt reduction) results in passive external transfer of polymers without bound secretory component along with leakage of serum-derived or locally produced monomeric alpha-chain disease protein, the latter presumably originating from immunocytes with little or no J-chain synthesis.