Penicillin desensitization in the treatment of syphilis during pregnancy

The objective of this study was to compare patients' hospital course, complications, and charges for oral and intravenous (i.v.) desensitization regimens for the treatment of syphilis in the penicillin-allergic gravida. We performed a retrospective search of medical records at two tertiary-level teaching hospitals and reviewed the hospital course of penicillin-allergic gravidas who underwent penicillin desensitization. Between August 1988 and December 1995, 16 procedures for penicillin desensitization were carried out: 11 oral procedures, and 6 i.v. procedures. There were no significant differences between the patients in the oral and i.v. desensitization groups with respect to demographic characteristics, duration of time in a monitored bed, or length of hospital stay. The oral regimen was less expensive than the i.v. regimen ($144.06 vs. $319.48). In our experience, oral and i.v. regimens provide effective desensitization for the treatment of syphilis in penicillin-allergic gravidas. However, the oral route offers ease of administration and substantial cost savings, making it the preferred method.

Specificity of N-ethyl lysine of a monoclonal antibody to acetaldehyde-modified proteins prepared under reducing conditions

A monoclonal antibody has been developed that recognizes only protein-acetaldehyde (AA) adducts prepared under reducing conditions: 5 mM AA with 30 mM sodium cyanoborohydride overnight at 37 degrees. This monoclonal antibody is a mouse IgG2b that has been designated RT1.1. The primary adduct formed when proteins are exposed to acetaldehyde under reducing conditions is N-ethyl lysine (NEL). To examine the epitope specificity of RT1.1, inhibition ELISAs were developed using NEL and other possible inhibitors, such as arginine, ethylamine, lysine and proteins modified with AA under non-reducing conditions. RT1.1 (at half-maximum optical density, 50 ng/mL) was inhibited only by NEL and was independent of the carrier or the pH of the buffer used in the ELISA. Further evidence indicating that NEL is the epitope recognized by RT1.1 was obtained using mouse and human epidermal growth factor (EGF). Both proteins contain one alpha amino group but only the human-EGF contains lysine residues with epsilon amino groups. In experiments where these two proteins were modified with AA under reducing conditions, RT1.1 reacted only with human-EGF. These studies demonstrate that RT1.1 is specific for NEL that is formed by the ethylation of proteins with acetaldehyde under reducing conditions. Additionally, these studies demonstrate that the procedures and methods used herein may be useful for characterizing other antibodies prepared to AA-modified proteins under a variety of defined in vitro chemical conditions.

Detection of reduced acetaldehyde protein adducts using a unique monoclonal antibody

Acetaldehyde (AA), the major product of alcohol metabolism, has been shown to bind to proteins in vivo and form chemical adducts. These AA-protein adducts have been shown to alter protein structure and function and may result in tissue damage. Recent reports have shown that polyclonal antibodies can be produced that recognize proteins modified in vitro with AA in the presence of sodium cyanoborohydride (NaCNBH3), a strong reducing (R) agent. Antibodies prepared in this way have been shown to recognize proteins in the livers of rats fed alcohol chronically. Because multiple AA-protein adducts can be recognized by polyclonal antisera, and a variety of adducts may be formed in vitro or in vivo, this study was designed to develop monoclonal antibodies specific for proteins modified by AA. In addition, adducts formed under R conditions are probably chemically different than those formed under nonreducing (NR) conditions, and monoclonal antibodies may provide the specificity required to distinguish these chemical differences. Balb/c mice were immunized with bovine brain tubulin that was modified by treatment with 5 mM AA for 7 days under NR conditions. Sera from immunized animals were tested for antibody activity to the immunogen (protein-NR) and for cross-reactivity to protein-R and unmodified protein. Although the highest serum antibody titers were seen toward the NR adduct, antibodies to the R adduct were also detected. This activity difference was independent of the carrier protein, because NR and R bovine serum albumin, keyhole limpet hemocyanin, and actin also gave similar results when used as the adducted protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Association of integrase, matrix, and reverse transcriptase antigens of human immunodeficiency virus type 1 with viral nucleic acids following acute infection

We have examined components of the preintegration complex of human immunodeficiency virus type 1 (HIV-1) and have analyzed features which govern the association of these components. HIV-1 nucleoprotein complexes, isolated from nuclear and cytoplasmic extracts of CD4+ cells after acute virus infection, contained viral RNA and DNA in association with viral matrix (MA), integrase (IN), and reverse transcriptase (RT) antigens but not capsid (CA) antigens and possessed integration activity in vitro. Association of IN but not RT or MA antigens with viral DNA was detergent-stable. Analysis of viral DNA synthesis and nuclear import of viral nucleoprotein complexes in the presence of a reversible RT inhibitor demonstrated that reverse transcription of viral RNA could be completed entirely in the host cell nucleus. Our studies demonstrate structural and functional features of the nucleoprotein (preintegration) complex of HIV-1 which are pertinent to the understanding of early events in the lentiviral life cycle.

Clinical and immunologic studies in reticular erythematous mucinosis and Jessner's lymphocytic infiltrate of skin

BACKGROUND

Little is understood about reticular erythematous mucinosis and Jessner's lymphocytic infiltrate of skin.

OBJECTIVE

Our purpose was to define reticular erythematous mucinosis and Jessner's lymphocytic infiltrate of skin further with focus on immunologic studies.

METHODS

In patients with reticular erythematous mucinosis and Jessner's lymphocytic infiltrate of skin, we measured circulating immune complexes before, during, and after therapy. We examined natural killer cells in a functional assay; we performed direct immunofluorescence and T- and B-cell marker studies in skin biopsy specimens.

RESULTS

The infiltrate in reticular erythematous mucinosis is composed of helper T cells. Circulating immune complexes are increased in both reticular erythematous mucinosis and Jessner's lymphocytic infiltrate of skin and decrease with hydroxychloroquine therapy and clinical clearing. Natural killer cell function is decreased in reticular erythematous mucinosis and Jessner's lymphocytic infiltrate of skin.

CONCLUSION

Changes in circulating immune complex titers accompanying therapy with hydroxychloroquine and clinical clearing, with recurrence of the condition and increase in circulating immune complexes on discontinuation of treatment, point to a possible relation between these events.

Enhanced immunosuppressive activity associated with metastatic lymphoma cells

Earlier reports from our laboratory showed that Abelson virus-induced, highly malignant and liver metastatic RAW117-H10 cells, but not the parental, less metastatic RAW117-P cells, inhibited both T-cell and B-cell mitogen-induced proliferation of syngeneic normal murine spleen cells. Similar inhibition was also noted when RAW117-H10 cell surface molecules extracted with butanol were used instead of whole tumor cells. In this report we describe the suppressive properties of the butanol-extracted RAW117-H10 cell surface molecules on other immune functions and the isolation/purification of a molecule from RAW117-H10 cell butanol extract which shows inhibitory activity. The immunosuppressive molecules also inhibit natural killer cell-mediated cytotoxicity, lymphokine-activated killer cell-mediated cytotoxicity, and bone marrow colony-forming unit-granulocyte-macrophage colony formation, but not colony-forming unit-fibroblast colony formation. The suppressive molecules inhibit interleukin 2 production by the T-lymphocytes. One of the molecules responsible for some of the immunosuppressive activity has been isolated and purified from butanol extracts of the metastatic RAW117-H10 cells by preparative isoelectrofocusing techniques. The suppressive molecule has an isoelectric point of 4.3 with an approximate molecular weight of 70,000. Metastatic RAW117-H10 lymphoma cells therefore express immunosuppressive molecules, which may facilitate their growth and metastasis in vivo.

Glomerular injury in end-stage liver disease--role of circulating IgG and IgM immune complexes

The relationship of IgG- and IgM-bound circulating immune complexes and immune dysfunction to glomerular injury was evaluated in 15 children with end-stage liver disease (ESLD) awaiting liver transplantation. Compared with age-matched controls, children with ESLD had significantly (P < 0.01) increased serum IgG, IgA, and IgM levels, as well as IgG- and IgM-bound circulating immune complexes. Furthermore, they showed a significant (P < 0.05) depression of C3 and C4 levels compared with controls. Hematuria occurred in 66% of children with ESLD, and the urinary protein/creatinine ratio was also significantly (P < 0.01) increased compared with controls (4.65 +/- 2.56 vs. 0.16 +/- 0.04 mg/mg). Light microscopy of renal biopsy tissue obtained from 6 children with ESLD at the time of transplantation demonstrated mesangial proliferation and expansion with basement membrane splitting. This was associated with subendothelial deposits on electron-microscopic examination, compatible with a diagnosis of membranoproliferative glomerulonephritis. By immunofluorescence, deposition of IgG, IgA, and IgM occurred in various combinations with co-deposition of complement fragments. We conclude that membranoproliferative glomerulonephritis is a common finding in children with ESLD, probably due to entrapment of circulating IgG- and IgM-bound immune complexes.

Production of serum amyloid A and C-reactive protein by HepG2 cells stimulated with combinations of cytokines or monocyte conditioned media: the effects of prednisolone

The hepatic production of the acute phase proteins in response to inflammatory cytokines, and the interaction of corticosteroids within this response, has been the subject of considerable recent research. In this study we have examined the effects of the corticosteroid prednisolone on the production of IL-1 alpha and IL-1 beta by lipopolysaccharide (LPS)-stimulated monocytes, and the ability of the monocyte conditioned media (MOCM) obtained under these conditions to induce human hepatoma HepG2 cells to produce serum amyloid A (SAA) and C-reactive protein (CRP). We also examined the production of SAA and CRP by HepG2 cells exposed to different combinations and concentrations of recombinant human (rh) IL-1 alpha, rhIL-1 beta, rhIL-6, recombinant human tumour necrosis factor-alpha (rhTNF-alpha) and prednisolone. The findings indicate: (i) prednisolone substantially inhibits the production of both IL-1 alpha and IL-1 beta by LPS-stimulated monocytes. The MOCM from prednisolone-treated monocytes induced less SAA and CRP production by HepG2 cells; (ii) IL-1 alpha and IL-1 beta both induced CRP and SAA synthesis by HepG2 cells, but only in the presence of IL-6. IL-1 beta was the more potent inducer for SAA production, but for CRP production IL-1 alpha and IL-1 beta were equivalent; (iii) prednisolone enhances the production of SAA by HepG2 cells, but does not enhance the production of CRP; (iv) TNF-alpha in the presence or absence of IL-6 and/or prednisolone did not induce the production of SAA or CRP by HepG2 cells. These findings offer a tenable solution to a disparate production of SAA compared with CRP in corticosteroid-treated cystic fibrosis (CF) patients.

Comparison of serum amyloid A and C-reactive protein as indicators of lung inflammation in corticosteroid treated and non-corticosteroid treated cystic fibrosis patients

Serum amyloid A (SAA) and C-reactive protein (CRP) levels were compared in 830 serum samples from 155 cystic fibrosis (CF) patients. Correlation coefficients were calculated for all samples (r = 0.73), for samples from non-corticosteroid treated (CFNS) patients (n = 698, r = 0.80), and for samples from corticosteroid treated (CFS) patients (n = 132, r = 0.35). SAA was the more sensitive indicator of pulmonary inflammation when SAA and CRP were compared to pulmonary function tests of 49 hospitalized patients at admission and discharge. CRP levels were significantly (p less than .05) lower at admission in CFS patients than in CFNS patients, whereas SAA levels were not significantly different between the two groups. All nine CFS patients hospitalized had elevated SAA levels (average 22 times above normal limits) at admission, while only six had elevated CRP levels (average 3.7 times above normal limits) at admission. In the 40 CFNS patients both SAA and CRP levels were significantly elevated at admission. In each case SAA and CRP levels declined as pulmonary functions improved with effective antimicrobial therapy. In three instances SAA levels increased during hospitalization while CRP levels did not. In each case, rising SAA levels indicated clinical deterioration associated with evolving resistance of P. aeruginosa which required a change in antibiotic therapy.

Comparison of the use of bulk to micro culture of cell preparations for lymphokine-activated cytotoxicity assays

Different assay systems have been used to quantitate lymphokine-induced natural cytotoxic activity as a measure of immune status. This study compares the effects of inducing cytotoxicity in a bulk culture system, where effector cells are transferred to a micro culture well for assay, to a micro culture system where the effector cells are not transferred. The effector/target ratio for both the bulk and micro culture systems was calculated using the number of viable effector cells present at the time of target cell addition. After overnight incubation with interleukin-2 (IL-2), the lytic activity of murine spleen cells to targets using a micro culture system was increased two-fold over the bulk culture method. This increase was amplified further after 5 days of activation with IL-2, in that the micro culture system resulted in a four-fold increase in cytotoxic activity. The loss of some adherent cells in the bulk culture system did not explain the overall decrease in recovered cytotoxicity. The difference appeared to be related to cell loss during centrifugation. Therefore, the E/T ratios are different in the two systems if not corrected for the number of viable cells.

A monoclonal antibody sandwich immunoassay for serum amyloid A (SAA) protein

An antibody sandwich immunoassay using two purified rat monoclonal antibodies to human serum amyloid A was developed and used to measure serum amyloid A in human serum. The assay was specific, sensitive, reproducible, and reliable and does not require denaturation of the specimen prior to assay. Serum amyloid A purified by hydrophobic interaction chromatography of acute phase human serum afforded a reliable standard for the assay. A significant (r = 0.69) correlation for SAA and C reactive protein values was found for 180 patient samples analyzed.

Use of ethanol-eluted hydrophobic interaction chromatography in the purification of serum amyloid A

A two-step procedure for the purification of the acute-phase reactant serum amyloid A from serum is described. A hydrophobic interaction chromatography medium, octyl-Sepharose CL4B, eluted with increasing concentrations of EtOH was used as the first step in the purification. The concentrate from this step was applied to a gel filtration column of Sephacryl S-200 and eluted with 10% formic acid. The overall recovery of purified serum amyloid A from serum was 56%. This represents the first time that serum amyloid A has been purified without the use of high concentrations of guanidine or urea. The method presented could easily be scaled up to allow the purification of large quantities of serum amyloid A or readily adapted to the purification of other serum apolipoproteins.

Construction and use of a template block for radial immunodiffusion

Details for design and construction of template blocks for the increased sensitivity of radial immunodiffusion (RID) assays are described. The sensitivity of the template RID was 10-fold higher for quantifying albumin and 5-fold higher for IgG than the conventional RID with wells cut into the agarose. The system described in this communication resulted from the unit which provided the most consistent results from a variety of trials with different block thicknesses, chamber sizes and depths, and chamber arrangements.

Immunoglobulin subclasses in the urine of control and streptozotocin-induced diabetic rats and their role in the development of diabetic nephropathy

Fifty-nine streptozotocin-induced diabetic rats, not treated with insulin clearly demonstrated one of two protein excretion patterns based on urinary albumin and IgG excretion rates. 63% (35/59) of the diabetic rats developed significantly elevated albumin excretion rates (incipient proteinuria) when compared to age-matched control animals. This condition progressed to a highly elevated albuminuria and increased IgG excretion (overt proteinuria). Analysis of IgG subclass content in these diabetic proteinuric rat urines showed that there was a selective excretion of IgG2b into the urine at a time that correlated with the onset of overt proteinuria. This IgG subclass comprised approximately 75% of the total IgG excreted during progressive nephropathy (in some animals, 100%) and was unique as it was not the predominant subclass in the serum of this group of animals. The other 37% of the diabetic rats (22/59) did not develop either incipient or overt diabetic nephropathy. In fact, some animals in this group had statistically less albumin and/or IgG in their urine than control rats. The subclass IgG2c was detected sporadically in the urine of these diabetic non-proteinuric rats throughout the chronological study even though it was the IgG subclass that comprised the lowest serum concentration of all four IgG subclasses. In control rats (total of 19), urinary albumin and low levels of the subclass IgG2a were detected throughout the chronological study; both of which increased with the age of the rat. However, in contrast to diabetic rats, the subclasses IgG1 and IgG2b were not detected in the urine of control rats until late in the chronological study.(ABSTRACT TRUNCATED AT 250 WORDS)

Autonomous growth of lymphoid cells following IL-2 expression from retrovirus vectors containing HIV-1 trans-acting elements

The human immunodeficiency virus type I (HIV-1) possesses powerful regulatory elements that control the rate of replication of HIV-1 and subsequent processing of HIV-1 genes. We have used this regulatory mechanism to drive expression of foreign genes inserted in retrovirus vectors. This approach was used to express the human IL-2 gene in IL-2-dependent mouse CTLL-2 cells to determine the role of autonomous growth in maintaining proliferation of virus-infected T lymphocytes during HTLV-1-induced adult T-cell leukemia (ATL). Expression of IL-2 sequences in IL-2-dependent mouse CTLL-2 cells resulted in autonomous growth of IL-2-independent CTLL-2 clones. Endogenous expression of IL-2 appeared to interrupt normal constraints of growth in that these IL-2-independent clones showed reduced cell-density-dependent inhibition but not a tumorigenic phenotype. IL-2-independent CTLL-2 clones did not secrete detectable quantities of IL-2 into culture supernatant and exhibited reduced sensitivity to the inhibitory effects of both IL-2 and IL-2 receptor antibody. These results suggest that the IL-2 autocrine loop within these cells involves intracellular IL-2/IL-2 receptor binding. The apparent lack of IL-2 production and poor responsiveness to IL-2 or IL-2 antibodies displayed by cell lines from ATL patients may be explained by an intracellular IL-2/IL-2 receptor autocrine loop.

An enzyme-linked immunosorbent assay for the detection of antitetanus toxoid antibody using aluminum-absorbed coating antigen

An enzyme-linked immunosorbent assay (ELISA) for the detection of antitetanus antibodies was developed using aluminum-absorbed tetanus toxoid as the coating antigen. The assay was tested by measuring antitetanus antibody levels in serum obtained from subjects before and after immunization with the aluminum-absorbed tetanus suspension. The specificity of the antibodies for tetanus antigen was tested both before and after antitetanus activity was removed with tetanus antigen-coated beads. Also, the activities of the sera were compared with those of a commercially available test. Our results indicated that the aluminum-absorbed tetanus suspension can be coated onto standard polystyrene ELISA plates and used to measure antibody titers to tetanus toxoid.

Assessment of the role of the immunoglobulin isotypes in the development of diabetic nephropathy in untreated streptozotocin-induced diabetic rats

Thirty of 45 (67%) streptozotocin-induced male Sprague-Dawley diabetic rats developed microalbuminuria that progressed to overt proteinuria with increased concentrations of IgG in their urine. 33% (15/45) never developed albuminuria or IgG proteinuria. These percentages did not correlate with glucose control since none of the animals were treated with insulin and all demonstrated the same degree of hyperglycemia. Indirect immunofluorescent antibody staining of frozen tissue sections from the kidneys of rats that developed overt proteinuria stained for IgM (67%), C3 (93%), IgG2b (93%) and IgG2c (60%). Non-proteinuric diabetic kidneys stained for IgM (80%), C3 (67%) IgG2b (67%) and IgG2c (87%). Control kidney sections demonstrated no consistent staining pattern. The occurrence and concentration of the different immunoglobulin isotypes, eluted from frozen sections with immune complex dissociating buffers, mimicked that which was observed by immunofluorescence. When urine or serum from the same rat or a rat of a different group was incubated with kidney sections eluted of all immunoglobulin, indirect immunofluorescent staining demonstrated antibody activity corresponding to the original staining pattern observed for each animal group prior to elution. The most consistent observation was that the diabetic rats that developed proteinuria were positive for IgG2b staining in their kidney sections; whereas, those that did not develop proteinuria stained predominantly for IgG2c. From this data, we suggest that the progression of diabetic nephropathy may depend on whether a specific IgG subclass response is elicited.

IgG subclasses in gingival crevicular fluid from active versus stable periodontal sites

Since IgG subclasses are common immunoglobulins associated with the periodontium and have different biological characteristics, these subclasses were measured in gingival crevicular fluid (GCF) from periodontally active (greater than or equal to 2 mm clinical attachment loss within three months of sample) versus clinically similar but stable or healthy sites. A sandwich enzyme-linked immunosorbent assay (ELISA) using monoclonal antibodies was performed to quantitate IgG subclass and albumin concentrations in serum and interproximal GCF samples from at least one each of the three disease categories from each of 20 periodontal maintenance patients. Although much variability existed among sites, mean IgG1 (p less than 0.05) and IgG4 (p less than 0.01) concentrations were higher in GCF from active periodontitis areas than stable sites, even though both had similar clinical characteristics. When IgG subclass concentrations were adjusted per mg albumin, both IgG1 and IgG4 levels in GCF from active sites were still significantly elevated over stable areas (p less than 0.05). Mean adjusted concentrations in GCF were generally greater than in serum, especially for IgG4 (active site GCF:serum = 24.2:1). GCF IgG4 concentrations may be useful as an indicator of the immunopathological changes which occur in active periodontitis.

Protection of mice against the lethal effect of an intraperitoneal infection with Haemophilus (Actinobacillus) pleuropneumoniae after vaccination with capsular proteins

Haemophilus (Actinobacillus) pleuropneumoniae Serotypes 5 and 7 capsular antigens (CA-1) were precipitated from culture supernatants with N-cetyl-N,N,N,-trimethylammonium bromide (Cetavlon). CA-1 contained a carbohydrate to protein ratio of 2:1 for Serotype 5 and 3:1 for Serotype 7. Glucosamine and uronic acid were detected in CA-1 from both serotypes suggesting that the capsule contained hyaluronic acid. All mice immunized intraperitoneally with CA-1 vaccine were protected from death when challenged with 10X the LD50 of the homologous but not the heterologous serotype. Oil adjuvants and the use of young (6 h) cultures were necessary for CA-1 vaccines to be protective. Deproteinization of CA-1 with chloroform and butanol followed by pronase treatment resulted in failure to protect mice from death. The protective capsular protein antigen in CA-1 vaccine may not originate from the outer membrane (OM) since repeated washing of the OM to elute the capsular protein antigen rendered the OM vaccine completely nonprotective for mice. Vaccines prepared from cell-wall lipopolysaccharide also were nonprotective for mice. Passive immunization of mice with anti-CA-1 antibody produced in rabbits to Serotype 5 was highly protective (P less than 0.01) for mice when challenged with 10X the LD50 of the homologous serotype.

In situ lymphocyte subpopulations from active versus stable periodontal sites

The purpose of this study was to evaluate lymphocyte subset densities and distributions within gingival biopsies from active sites (greater than or equal to 2 mm clinical attachment loss within three months of biopsy) versus clinically similar but stable or healthy sites. Small interproximal gingival biopsies representing at least one of each of the above categories were obtained from each of 20 periodontal maintenance patients. Serial cryostat sections displaying a cross section of the gingiva were labeled with monoclonal antibodies for (1) pan T cells, (2) T cytotoxic/suppressor cells, (3) T helper/inducer cells and (4) pan B cells and were developed using an avidin-biotin-peroxidase system. Lymphocyte populations were enumerated in repeatable fields from the sulcular, middle and oral one-third of each section. Relative proportions of the same lymphocyte subsets were analyzed in peripheral blood samples from the same patients using direct immunofluorescence. Pan B cells were significantly more prevalent in infiltrates from active sites than in stable (P less than 0.05) or healthy (P less than 0.01) sites. The T/B cell ratio was also significantly lower in active than stable biopsies (P less than 0.05), and in active biopsies versus blood (P less than 0.05). The T helper/T suppressor cell ratio did not vary significantly between blood and any gingival tissue disease group or location, but a trend toward lower relative numbers of T helper cells in the sulcular infiltrates of active sites was noted. These results support the premise that active periodontal sites display elevated B cell populations and abnormal immune regulation possibly involving the T helper cell subset.

Photodisruption of intraocular gas bubbles

During gas-fluid exchange bubbles can form in the vitreous cavity. These bubbles can interfere with visualization of the fundus for retinal examination, photocoagulation, or cryopexy. We used the Nd:YAG laser to eliminate these bubbles in vitro and in two patients.

Isolation and characterization of circulating immune complexes from patients with pneumococcal pneumonia

Circulating immune complexes (CIC) were isolated from serum samples from patients with bacteremic and nonbacteremic pneumococcal pneumonia. Overall, 63% (26 of 41) of patients with pneumococcal pneumonia had elevated levels of immunoglobulin G (IgG)-containing CIC. IgM-containing CIC were identified in samples from only three patients. Serum samples from nonbacteremic patients contained significantly higher levels of IgG-containing CIC (96.6 +/- 111.7 micrograms/ml) than did samples from bacteremic patients (31.7 +/- 26.9 micrograms/ml) during week 1 in hospital (P less than 0.05). Immune complexes levels did not correlate with IgG concentrations in serum or anticapsular antibody levels. Immune complexes from nonbacteremic patients had sedimentation coefficients of greater than 19s by density gradient ultracentrifugation. In contrast, CIC from bacteremic patients had smaller coefficients, of between 9s and 14s. Pneumococcal capsular antigens were identified in concentrated dissociated CIC from both patient groups by counterimmunoelectrophoresis.

Immunoglobulin isotypes in the circulating immune complexes of diabetic rats with and without proteinuria: a chronological study

Circulating immune complexes (CIC) have been postulated to contribute to the development of the secondary complications of diabetes mellitus. Therefore studies were performed to determine whether CIC are the cause of the consequence of the development of diabetic nephropathy. This was done by comparing the occurrence and concentration of CIC containing the different isotypes of immunoglobulins in control rats to those detected in streptozotocin-induced (Sz) diabetic rats that developed albuminuria (Group I) and that did not develop albuminuria (Group II). Only CIC containing IgM, IgG2b and IgG2c were detected in diabetic rats. By staging Group I albuminuric diabetic rats to a clinical reference point of albuminuria, there was no correlation between the occurrence or concentration of CIC containing any isotype of immunoglobulin and the onset of albuminuria. In all Group I albuminuric diabetic rats, the occurrences of all CIC were variable and their concentrations fluctuated during the development and early progression of nephropathy. However, after this group of diabetic rats progressed to overt nephropathy (marked by albuminuria and IgG proteinuria), CIC could be demonstrated in 100% of the animals. In diabetic rats that did not develop albuminuria (Group II), CIC containing IgG2b occurred earlier and more often than in Group I albuminuric rats. Similarly, the subclass IgG2c was detected in the CIC of Group II non-albuminuric rats more frequently and in higher concentrations than in Group I albuminuric rats. CIC containing IgM were detected in all 3 animal groups, however, in higher concentrations and occurrences in Group II non-albuminuric rats as compared to control and Group I albuminuric rats. The consistent elevation in CIC after the development of diabetic nephropathy, suggests that the CIC containing any immunoglobulin isotype either result from diabetic kidney, or from other deteriorating conditions associated with the diabetic state. The data also suggests that CIC are not involved in the onset or progression of diabetic nephropathy regardless of the isotypes of immunoglobulins contained within the CIC. However, there is an isotypic restriction in the immunoglobulins detected in the CIC of diabetic rats (IgM, IgG2b and IgG2c) that may signal some involvement of the immune system in the development of diabetic nephropathy.