Modulation of renal kallikrein by a high potassium diet in rats with intense proteinuria.

Injury of the renal tubulointerstitial compartment is recognized to play an important role in hypertension. Its damage may in turn, impair the activity of vasodepressor systems, like the kallikrein-kinin, in blood pressure regulation. The overload proteinuria model induces tubulointerstitial injury with activation of the renin-angiotensin system, but renal kallikrein and the development of hypertension have not received special attention. Sprague-Dawley rats received seven intraperitoneal doses of bovine serum albumin (BSA) 2 g/day under normosodic diet and were hydrated ad libitum. A second group received a high potassium diet to stimulate kallikrein production during the previous four weeks and while under BSA administration. A third one received potassium and BSA in the same schedule, but with the kinin B2 receptor antagonist, HOE140, added during the protein load phase. A control group received seven saline injections. Kallikrein protein was detected by immune labeling on renal sections and enzymatic activity in the urine. The BSA group showed massive proteinuria followed by intense tubulointerstitial damage. Blood pressure increased after the third dose in BSA animals, remaining elevated throughout the experiment, associated with significant reductions in renal expression and urinary activity of kallikrein, compared with controls. An inverse correlation was found between blood pressure and immunohistochemistry and urinary activity of kallikrein. Potassium induced a significant increase in both urinary activity and renal kallikrein expression, associated with significant reduction in blood pressure. The HOE140 antagonist blunted the antihypertensive effect of kallikrein stimulation in proteinuric rats. Loss of renal kallikrein, produced by tubulointerstitial injury, may participate in the pathogenesis of the hypertension observed in this model.

[Invasive hepatosplenic hyalohyphomycosis. Report of a case]. / Hialohifomicosis invasiva hepatoesplénica. Comunicación de un caso.

Invasive fungal infections are an increasingly common problem in patients with cancer and other vulnerable groups. We report a case of hepatosplenic hialohifomycosis probably by Aspergillus sp. In a patient with acute leukemia, and prolonged neutropenia, treated with corticosteroids and broad spectrum antibiotics. A review concerning diagnosis, clinical course and treatment of this condition is presented.

Overexpression of chemokines, fibrogenic cytokines, and myofibroblasts in human membranous nephropathy.

UNLABELLED: Overexpression of chemokines, fibrogenic cytokines, and myofibroblasts in human membranous nephropathy. BACKGROUND: Proteinuria plays a central role in the progression of glomerular disease, and there is growing evidence suggesting that it may determine tubular cell activation with release of chemokines and fibrogenic factors, leading to interstitial inflammatory reaction. However, most studies on this subject have been performed in experimental models, and the experience in human kidney biopsies has been scarce. We analyzed the tissue sections of patients with idiopathic membranous nephropathy (IMN), a noninflammatory glomerular disease that may follow a progressive disease with heavy persistent proteinuria, interstitial cell infiltration, and decline of renal function. METHODS: Paraffin-embedded biopsy specimens from 25 patients with IMN (13 progressive and 12 nonprogressive) were retrospectively studied by immunohistochemistry [monocyte chemoattractant protein-1 (MCP-1), regulated on activation normal T-cell expressed and secreted chemokine (RANTES), osteopontin (OPN), platelet-derived growth factor-BB (PD-GF-BB)] and in situ hybridization [MCP-1, RANTES, PDGF-BB, transforming growth factor-beta1 (TGF-beta1)]. Moreover, we studied the presence of myofibroblasts, which were identified by the expression of alpha-smooth muscle actin (alpha-SMA), the monocytes/macrophages (CD68-positive cells), and T-cell infiltration (CD4+ and CD8+ cells). All of the patients were nephrotic and without treatment at time of the biopsy. RESULTS: A strong up-regulation of MCP-1, RANTES, and OPN expression was observed, mainly in tubular epithelial cells, with a significant major intensity in the progressive IMN patients. A strong correlation between the mRNA expression and the corresponding protein was noted. The presence of these chemokines and OPN was associated with interstitial cell infiltration. TGF-beta and PDGF were also up-regulated, mainly in tubular epithelial cells, with a stronger expression in the progressive IMN, and an association with the presence of myofibroblasts was found. CONCLUSIONS: Patients with severe proteinuria and progressive IMN have an overexpression in tubular epithelial cells of the chemokines MCP-1, RANTES, and OPN and the profibrogenic cytokines PDGF-BB and TGF-beta. Because this up-regulation was associated with an interstitial accumulation of mononuclear cells and an increase in myofibroblastic activity, it is suggested that those mediators are potential predictors of progression in IMN. Finally, based on experimental data and the findings of this article, we speculate that severe proteinuria is the main factor responsible for the up-regulation of these factors in tubular epithelial cells.

Anticardiolipin antibodies in acute poststreptococcal glomerulonephritis and streptococcal impetigo.

Anticardiolipin (aCL) antibodies have been described in diverse clinical situations, linked to the risk of thrombosis in different vascular locations. They have been rarely studied in renal diseases, and occasionally they have been associated with glomerular thrombosis. We analyzed the incidence of aCL (isotypes IgG, IgA, and IgM) in samples, taken during the acute phase of the disease, from 27 well-documented patients having acute poststreptococcal glomerulonephritis. Twelve cases were positive on IgG testing, 1 case on IgA testing only, and no one was positive on IgM testing. A serological follow-up was performed with a second sample taken about 7 months later, for the patients initially positive on IgG testing showing persistence in 9. Clinical variables during the acute phase and after a follow-up period of 25 (range 6-89) months were analyzed for possible associations with the presence of these antibodies, but non was significantly related. Renal histopathological investigation did not reveal particular findings in the aCL-positive patients, and glomerular thrombosis was not found in any case. In addition, serum samples from 12 streptococcal impetigo patients without renal involvement were analyzed, showing similar incidence (4 positive on IgG testing, 1 of them positive on IgM testing as well, and no one positive on IgA testing) and titers of aCL antibodies. We conclude that the presence of aCL antibodies in acute poststreptococcal glomerulonephritis may be a marginal immunological phenomenon unrelated to the glomerular disease, triggered by the streptococcal infection.

Immunohistochemical localization of IL-8 and TGF-beta in streptococcal glomerulonephritis.

Acute poststreptococcal glomerulonephritis (APSGN) is characterized by diffuse glomerular hypercellularity, primarily as a result of accumulation of neutrophils (exudative glomerulonephritis), increase in intrinsic glomerular cells, and transient pathological mesangial matrix expansion. Cytokines and growth factors are supposed to play an important role as mediators of inflammation and as progression factors in various renal disorders. Interleukin-8 is a recently described cytokine, defined as a selective activator and chemoattractant of polymorphonuclear leukocytes (PMNL) and transforming growth factor (TGF)-beta plays a central role in the accumulation of pathological extracellular matrix in glomerulonephritis. This study analyzed the biopsies of ten patients with APSGN, using immunohistochemistry (avidin-biotin complex/horseradish peroxidase method) using monoclonal antibodies anti-IL-8, anti-TGF-beta 1, beta 2, beta 3. Controls consisted of non-immune mouse serum, or anti-TGF-beta preabsorbed with human recombinant TGF-beta. Compared with normal renal tissue, and minimal change disease, an increased glomerular IL-8 and TGF-beta staining was observed in all of the biopsies. Furthermore, in one patient, we observed a weak deposit of TGF-beta in tubulointerstitium. Immunoreactive IL-8 and TGF-beta in glomeruli was correlated with light microscopic and clinical features. There was a significant association (P < 0.05), between IL-8 glomerular immunoreactivity and neutrophil infiltration and between TGF-beta glomerular staining and mesangial matrix expansion. Otherwise, there was no correlation with the mesangial cellularity. It was concluded that increased protein expression of IL-8 and TGF-beta are observed in APSGN and may play a role in the acute glomerular inflammation.

Physical interaction between Langerhans cells and T-lymphocytes during antigen presentation in vitro.

Physical interaction between Langerhans cells and T cells is an essential requirement for antigen presentation. In this study we report the ultrastructural characteristics of the antigen-specific physical interactions that occur in vitro between murine Langerhans cells and T cells. Epidermal Langerhans cells enriched to 78% purity by a panning method were pulsed with 2,4-dinitrophenyl-Limulus polyphemus hemocyanin and co-incubated with syngeneic T lymphocytes primed in vivo with the same antigen. A substantial number of conjugates constituted by Langerhans cells surrounded by three or more lymphocytes were obtained after 60 min of incubation at 4 degrees C. Electron microscopy of the conjugates revealed that Langerhans cells and T lymphocytes interacted by two type of contacts. Type I was characterized by glycocalyx-glycocalyx interaction that occurred in relation to protrusions or microvilli of both cells. Type II was characterized by wide and tight areas of close apposition between Langerhans cells and T-lymphocyte plasma membranes. In these areas there were zones with intercellular bridges and small septilaminar junctions highly suggestive of gap junctions. An electron-immunogold procedure demonstrated the presence of DNP-LPH antigen on the type I contact. Our findings suggest that type I contact may represent the locus for antigen presentation whereas the type II contact may be involved in keeping adhesiveness between Langerhans cells and lymphocytes during antigen presentation.

[Rapidly progressive glomerulonephritis without immune deposits: detection of neutrophil anticytoplasmic antibodies]. / Glomerulonefritis rápidamente progresiva sin depósitos inmunes: detección de anticuerpos anticitoplasma de neutrófilos.

Antineutrophil cytoplasmic autoantibodies (ANCA), are serologic markers of disease in rapidly progressive glomerulonephritis without immune deposits (pauci-immune) and vasculitis, and could play a pathogenic role in these diseases. We communicate 5 patients with pauci-immune rapidly progressive glomerulonephritis; four of them in the evolution of necrotizing systemic vasculitis (Wegener's granulomatosis and microscopic polyarteritis) and one case with lesions limited to the kidney. All of them were associated with the presence of ANCA. The immunofluorescence pattern (cytoplasmic and perinuclear) and the antigenic specificity of ELISA assay, [antiproteinase-3 (PR-3) and antimyeloperoxidase (MOP)], are useful laboratory tools for the diagnosis and clinical management of these patients.

Antineutrophil-cytoplasmic-autoantibodies in poststreptococcal nephritis.

Sera from 210 patients with APSGN, were tested for the presence of ANCA (IgG-isotype). Indirect immunofluorescence (IF) on ethanol fixed human PMNs was used, and for those positive sera, ELISA kits for PR3 (Proteinase 3) and MPO (Myeloperoxidase) was performed. ANCA were detected in 9% (18 out of 210 cases) in a predominantly diffuse cytoplasmic staining pattern in 14 cases (77%), and in a perinuclear pattern in the remaining 4 cases (22%). Anti-MPO was found in 4 cases (C-ANCA 3; P-ANCA 1) and anti-PR3 was always negative. The presence of ANCA was significantly associated with a more severe glomerular disease as assessed by the serum creatinine value and the crescents formation. Longitudinal studies performed in 11 cases have shown that raised levels of these autoantibodies may persist for at least six months, without relationship with disease activity. Further studies are required to dilucidate the specificity of these autoantibodies, and if its presence is either an epiphenomenon of the heterogeneous humoral immune response in streptococcal infection, or they play some pathogenic role in APSGN.

Glomerular localization of platelet factor 4 in streptococcal nephritis.

Since platelet factor 4 (PF4), a cationic (pI 7.6) platelet secretory protein, binds avidly to glomerular polyanions both in vitro and in vivo, and is implicated in neutrophil chemotaxis, we studied by indirect immunofluorescence microscopy the presence of PF4 deposits in glomeruli of patients with poststreptococcal nephritis (APSGN). Goat antihuman PF4 serum was used as primary antibody and fluorescein-conjugated IgG fraction of rabbit antigoat IgG as second antibody. Controls consisted of nonimmune goat serum or anti-PF4 serum preabsorbed with human PF4, as primary antibodies. Glomerular deposits of PF4 were demonstrated in renal tissues obtained by biopsy in 14 of 20 patients studied; the deposits were particularly intense in 9 patients. PF4 was bound to the mesangium and to the capillary walls. There was a significant positive correlation between intraglomerular deposits of PF4 and the levels of proteinuria (p = 0.024). These findings provide further evidence for a role of platelets in the pathogenesis of APSGN and suggest that PF4 may contribute to alter the glomerular permeability in this disease.

Idiopathic membranous nephropathy, associated with HLA-DRw3 and not related to monocyte-phagocyte system Fc receptor dysfunction, in father and son.

Familial idiopathic membranous nephropathy, an immune-complex-associated glomerulopathy, has not been previously reported in father and son, despite its striking immunogenetic correlation, especially with HLA-DR3. As a dysfunction of the monocyte-phagocyte system (MPS), it has been observed linked to DR3 antigen, so we studied the MPS Fc receptor function in a father and his son with a histologically proven membranous nephropathy, associated with the haplotype A9-B35-DR3-DQw2. The Fc receptor function of the MPS was examined by measuring the clearance of IgG-sensitized, 51Cr-labeled erythrocytes and by measuring the ability of isolated monocytes to ingest autologous red blood cells coated with IgG anti-Rh (D) antibody. Immune clearance and in vitro phagocytosis was normal in both patients and not related to their levels of immune complexes (as measured by ELISA C1q and Conglutinin solid-phase binding assay). This report suggest that genetic factors may play an important role in the development of membranous nephropathy, and it seems not to be related to a dysfunction of MPS as measured by these tests.

Cellular and subcellular distribution of 2,4-dinitrophenyl groups in mouse epidermis and regional lymph nodes after epicutaneous application of 2,4-dinitrofluorobenzene.

The cellular and subcellular distribution of 2,4-dinitrophenyl (DNP) groups in the epidermis and regional lymph nodes of the mouse was investigated after epicutaneous application of 2,4-dinitrofluorobenzene (DNFB) to sensitized and non-sensitized mice. The peroxidase-antiperoxidase method and the immunogold technique were used to visualize the DNP groups at both light and electron microscopic levels. The highest intensity of immunolabelling was found on tonofilaments of keratinocytes present in the upper layers of the epidermis. On the other hand, in vitro experiments showed that DNFB has the capacity to bind keratin which, together with immunocytochemistry, suggests that this molecule may be one of the skin protein carriers for DNFB. In addition, intense immunostaining for DNP was observed in the Golgi area of some epidermal Langerhans cells. Cells immunoreactive to DNP were also observed in the marginal sinus of cervical lymph nodes 6, 12 and 24 h after challenge. Immunoelectron microscopy revealed immunoreactive DNP groups in phagosomes of Langerhans cells at this site. The present findings support the hypothesis that the hapten DNFB penetrates passively into the cytoplasm of Langerhans cells, concentrates in the Golgi area and, during the migration of Langerhans cells to the lymph nodes, it is probably processed in the lysosomes before its presentation to T lymphocytes.

[Clinical course in 51 patients with idiopathic membranous glomerulopathy]. / Estudio de la evolución de 51 pacientes con glomerulopatía membranosa idiópatica.

51 patients, mainly adults, with idiopathic membranous glomerulonephropathy were studied to evaluate their clinical course and long-term prognosis. Glomerular lesions were classified into four groups, according to Ehrenreich and Churg: 5 had type I, 19 type II, 20 type III and 7 type IV lesions. The onset was marked by a nephrotic syndrome in 47 patients (92%). Hypertension was present in 41% and the serum creatinine was over 2 mg/dl in 17%. During the follow-up period (mean 42 months) clinical remission occurred in 7 cases, clinical improvement in 4 patients, renal insufficiency in 11 patients (with end-stage renal failure in 10 and the condition remained unchanged in 29 cases. The actuarial life-table survival at 5 and 15 years was 80% and 56% respectively, excluded the 5 patients with renal vein thrombosis. The retrospective comparison in patients who did (n = 29) or did not (n = 22) receive corticosteroids, shows a favorable outcome of treated patients. Poor prognostic indicators were: impaired renal function at time of diagnosis, and advanced histologic staging.

Immunocytochemical demonstration of Langerhans' cells in smears and pellets of exfoliated cells from human exocervices.

Immunocytochemical staining with OKT6 monoclonal antibody and S-100 protein antiserum was used to reveal Langerhans' cells in smears and/or pellets of exfoliated cells from uterine cervices (normal and with squamous carcinoma). Immunoreactive Langerhans' cells were found exclusively in smears and pellets of cervices with squamous carcinoma. Langerhans' cells, which appear as rounded cells, showed a peripheral ring of intense fluorescence with OKT6 antibody whereas the entire cell stained with S-100 protein antiserum. The presence of Langerhans' cells among cells exfoliated from exocervical squamous carcinoma can be explained by the increased density of these cells in tissue with neoplastic changes.

Ultrastructural characteristics of the contact zones between Langerhans cells and lymphocytes.

The present work was carried out to look for the ultrastructural substrate of the contact zones between Langerhans cells and lymphocytes. A high resolution electron microscopic analysis of the contact zones between Langerhans cells and lymphocytes was performed. The material used for this study was obtained from experimental contact dermatitis in mice, and human cervical squamous carcinoma and mycosis fungoides. Three types of cell-cell binding were found. Type I is a junction-like structure characterized by the presence of intercellular bridges. It is suggested that this contact might represent a fixation mechanism between the two cells. Type II is characterized by a glycocalyx-glycocalyx continuity. An immunological function--recognition and antigen presentation--is proposed for this type of contact. Type III is a septilaminar tight contact area which seems to be a gap junction. It is suggested that all these types of physical contact might be the morphological expression of interaction between antigen presenting cells and lymphocytes.

Anatomical relationship between kallikrein-containing tubules and the juxtaglomerular apparatus in the human kidney.

Current evidence suggests a functional and biochemical link between the renin and the kallikrein systems. The purpose of this work was to study the localization of kallikrein along the human nephron to elucidate whether there exists an anatomical base for such interrelation. Serial sections of human kidney tissue were stained by immunocytochemical methods with antisera against kallikrein. Kallikrein immunostaining was observed exclusively in segments of the distal nephron lying in the cortical labyrinths and forming arcades in its distal portion. Consistently the tubules containing kallikrein established a close anatomical relationship with the afferent arteriole of the juxtaglomerular apparatus providing an anatomical base for an interaction between the renin and kallikrein systems in the human kidney.

Ultrastructural characteristics of the interdigitating dendritic cell in dermatopathic lymphadenopathy of mycosis fungoides patients.

The ultrastructure of interdigitating dendritic cells in dermatopathic lymphadenopathy from patients with mycosis fungoides was investigated. The most remarkable findings were: a marked hypertrophy of the smooth endoplasmic reticulum with a peculiar concentric arrangements of the cisternae around lipid droplets, an abundance of cytoplasmic lipid droplets and the presence of paranuclear chromatoid-like bodies. It is suggested that these ultrastructural features may correspond to some unknown functional capability of the interdigitating dendritic cell.

Langerhans' cell density in the normal exocervical epithelium and in the cervical intraepithelial neoplasia.

A morphometric analysis was performed of the Langerhans' cell density in epithelial sheets obtained from normal exocervices and from exocervices with squamous carcinoma. Laminae of exocervices with squamous carcinoma that showed cervical intraepithelial neoplasia (CIN) were classified according to its predominant degree of severity as CIN I, CIN II and CIN III or as normal when no neoplastic changes were found. Laminae with CIN showed a higher Langerhans' cell density than the laminae from normal exocervices and than the normal laminae of exocervices with carcinoma. The magnitude of the increase of Langerhans' cell density and the degree of severity of the neoplastic changes appear as closely related phenomena. An increase of the more ramified types of Langerhans' cell in the laminae containing CIN was found, with the most ramified being more frequent in the most severe lesions.

Cytochemistry and ultrastructure of normal and neoplastic cells exfoliated from the human uterine cervix.

Cells exfoliated from the uterine exocervix from normal women at different stages of the reproductive period and from patients with invasive carcinoma were studied. Cell pellets were fixed in aldehydes and two different concentrations of OsO4, and embedded in methacrylate or Epon. Semithick sections were used for general light microscopic study and for the visualization of glycogen. Ultrathin sections were used for conventional electron microscopy, high resolution analysis of the plasma membrane, and the demonstration of glycogen and cell surface glycoconjugates by the Thiery method. Semithick sections stained with the Thiery method and viewed under the electron microscope were used for the study of surface projections. Based on the size, shape, nuclear characteristics, amount and distribution of glycogen, type of surface protrusions, density and distribution of surface glycoconjugates, and plasma membrane fine structure, the cells exfoliated from all normal uterine cervices were grouped into five cell types. It is suggested that these types correspond to cells located in the different layers of the exocervical epithelium and, consequently, represent different degrees of normal differentiation. The plasma membrane of carcinoma cells shared most of the characteristic of that of the least differentiated normal cells, indicating an early deviation of the differentiation process in carcinoma cells.