Familial encephalopathy with neuroserpin inclusion bodies.

We report on a new familial neurodegenerative disease with associated dementia that has presented clinically in the fifth decade, in both genders, and in each of several generations of a large family from New York State-a pattern of inheritance consistent with an autosomal dominant mode of transmission. A key pathological finding is the presence of neuronal inclusion bodies distributed throughout the gray matter of the cerebral cortex and in certain subcortical nuclei. These inclusions are distinct from any described previously and henceforth are identified as Collins bodies. The Collins bodies can be isolated by simple biochemical procedures and have a surprisingly simple composition; neuroserpin (a serine protease inhibitor) is their predominant component. An affinity-purified antibody against neuroserpin specifically labels the Collins bodies, confirming their chemical composition. Therefore, we propose a new disease entity-familial encephalopathy with neuroserpin inclusion bodies (FENIB). The conclusion that FENIB is a previously unrecognized neurodegenerative disease is supported by finding Collins bodies in a small kindred from Oregon with familial dementia who are unrelated to the New York family. The autosomal dominant inheritance strongly suggests that FENIB is caused by mutations in the neuroserpin gene, resulting in intracellular accumulation of the mutant protein.

Inducible nitric oxide synthase in the lung and exhaled nitric oxide after hyperoxia.

The effect of hyperoxia on nitric oxide (NO) production in intact animals is unknown. We described the effects of hyperoxia on inducible nitric oxide synthase (iNOS) expression and NO production in the lungs of rats exposed to high concentrations of oxygen. Animals were placed in sealed Plexiglas chambers and were exposed to either 85% oxygen (hyperoxic group) or 21% oxygen (negative control group). Animals were anesthetized after 24 and 72 h of exposure and were ventilated via a tracheotomy. We measured NO production in exhaled air (E(NO)) by chemiluminescence. The lungs were then harvested and processed for detection of iNOS by immunohistochemistry and Western blotting analysis. The same experiments were repeated in animals exposed to hyperoxia for 72 h after they were infused with L-arginine. We used rats that were injected intraperitoneally with Escherichia coli lipopolysaccharide to induce septic shock as a positive control group. Hyperoxia and septic shock induced expression of iNOS in the lung. However, E(NO) was elevated only in septic shock rats but was normal in the hyperoxic group. Exogenous infusion of L-arginine after hyperoxia did not increase E(NO). To exclude the possibility that in the hyperoxic group NO was scavenged by oxygen radicals to form peroxynitrite, lungs were studied by immunohistochemistry for the detection of nitrotyrosine. Nitrotyrosine was found in septic shock animals but not in the hyperoxic group, further suggesting that NO is not synthesized in rats exposed to hyperoxia. We conclude that hyperoxia induces iNOS expression in the lung without an increase in NO concentration in the exhaled air.

Maintenance of increased Bcl-2 expression in uterine leiomyomas after GnRH agonist therapy.

OBJECTIVE: To compare the immunohistochemical expression of Bcl-2 in uterine leiomyomas in patients undergoing myomectomy or hysterectomy with and without preoperative treatment with the gonadotropin-releasing hormone receptor agonist (GnRH-a) leuprolide acetate (LA). STUDY DESIGN: Retrospective case-control study. Seventeen patients with symptomatic uterine leiomyomata were included. Of the 17 patients, 7 were treated with LA (3.75 mg) in three monthly doses prior to myomectomy or hysterectomy. Ten patients who did not receive LA and underwent hysterectomy for leiomyomas served as controls. Formalin-fixed, paraffin-embedded archival tissue from 17 leiomyomas were immunostained with a monoclonal antibody against Bcl-2 protein. Positivity was scored semiquantitatively on a three-tier scale. RESULTS: Immunostaining for Bcl-2 protein was intense (2-3+) in 7 LA-treated and 10 untreated leiomyomas but was scarce (0-1+) in normal myometrial smooth muscle. CONCLUSION: Abundant expression of Bcl-2 protein may be responsible for the growth of leiomyomas by preventing apoptotic cell death. Its increased expression is maintained in GnRH-a-treated leiomyomas.

Prognostic markers in resected stage I and II non small-cell lung cancer: an analysis of 260 patients with 5 year follow-up.

We performed a retrospective analysis of potential prognostic markers in 260 patients with surgically resected stage I and II non small-cell lung cancer (NSCLC) with a minimum 5-year follow-up. Cox proportional hazard models and Wilcoxon tests were employed to analyze the effect of patient characteristics on survival and disease-free survival (DFS). In the univariate analysis, the following were significant predictors of shorter overall survival: N-stage (N1 vs N0) (p<0.001); T-stage (T2 vs T1) (p<0.001); antigen A (loss vs presence) (p<0.01); cough (present vs absent) (p=0.01); bcl-2 expression (positive vs negative) (p=0.03); age (>63.5 vs <63.5) (p=0.03); mucin (positive vs negative) (p<0.03). The following were significant predictors of shorter DFS: N-stage (p<0.001); T-stage (p=0.001); loss of antigen A (p=0.01); mucin expression (p<0.01); cough (p=0.02); Ki-67 expression (p=0.02) and negative bcl-2 expression (p=0.03). Analysis of survival difference for histologic subtype, degree of differentiation, aneuploidy, %S-phase, codon 12 K-ras mutation, and immunohistochemistry staining for Lewisy, p53, Rb, microvessel count, HER2, E-cadherin and neuroendocrine markers did not reach statistical significance. In multivariate analysis, the following predicted for shorter overall survival: N-stage (p<0.01), antigen A (p=0.01), age (p<0.01), and bcl-2 (p=0.05); and for DFS, N-stage (p<0.01), antigen A (p<0.01), Ki-67 (p=0.03), mucin (p=0.04) and T-stage (p=0.05). Of all the clinical-pathological, proliferative, and biological markers studied, only a few carried independent prognostic significance.

Prognostic significance of Lewis y antigen in resected stage I and II non-small cell lung cancer.

BACKGROUND: The role of Lewis y (Le(y)) antigen expression has been studied extensively in predicting the outcome of various malignancies. We evaluated the expression of Le(y) and its relationship to survival, disease-free survival and other clinicopathologic variables in patients with stage I and II non-small cell lung cancer (NSCLC). OBJECTIVE: To investigate the prognostic significance of Le(y) antigen expression in a large group of well characterized patients with resected stage I and II NSCLC. PATIENTS: Two hundred and sixty patients with surgically resected stage I (n = 193) and II (n = 67) NSCLC with at least 5-year follow-up were identified. RESULTS: The median survival for patients with negative expression of Le(y) (< 50% of cells that were positive) was 46 months, whereas for those with positive expression of Le(y) (> or = 50%), the median survival was 54 months (p = 0.99). The disease-free survival for patients with Le(y)(-) expression was 39 months and 34 months for patients with Le(y)(+) expression (p = 0.3). CONCLUSIONS: We found no relationship between loss of blood group antigen A and expression of Le(y). No statistically significant difference was found in survival between positive and negative expression of Le(y) antigen in patients with resected stage I and II NSCLC.

Characteristics of auto anti-idiotypic antibodies reactive with antibodies expressing the pathogenic idiotype, IdLNF1, in the (NZB x SWR)F1 model for lupus nephritis and its parental strains.

The F1 cross between SWR and NZB mice, SNF1, develops severe immune complex glomerulonephritis, in a similar manner to humans with systemic lupus erythematosus (SLE). Our previous data indicate that the idiotypically-related family of antibodies, IdLNF1 may play a role in the pathogenesis of this nephritis. The sera of SNF1 mice, but not NZB or SWR, contained high titers of IdLNF1+ IgG antibodies, which peaked at 22-24 weeks, coinciding with an increase in the CD4 to CD8 ratio of IdLNF1-reactive T cells and IdLNF1 Ig (IgG + IgM) deposition in the kidney glomerulus. Here, auto anti-IdLNF1 antibody levels were quantitated as the mice aged and were found to be significantly different in the three strains, particularly after 20 weeks of age. Moreover, auto anti-IdLNF1 antibody levels were decreased only in SNF1 mice at 20-24 weeks of age. Auto anti-IdLNF1 antibodies were purified by affinity chromatography; anti-IdLNF1 antibodies derived from SNF1 appeared to be of the Ab2 beta or gamma type, while those from SWR mice were Ab2 alpha. Thus, differences in the specificity of auto anti-idiotypic antibodies may be critical in the regulation of the IdLNF1 idiotype in SWR and SNF1 mice, and the development of nephritis in SNF1 mice.

Adenovirus infection of the renal allograft with sparing of pancreas graft function in the recipient of a combined kidney-pancreas transplant.

We report a case of adenovirus infection of the renal allograft in a combined kidney/pancreas transplant recipient. The clinical presentation was renal allograft failure, which eventually reversed. The pancreatic graft function remained stable. A renal biopsy showed massive tubular necrosis associated with a prominent granulomatous reaction. The process had a striking regional distribution within the kidney with the injury and inflammation limited to the outer medulla. Adenovirus type 11 was isolated from renal tissue by culture, and adenovirus was demonstrated by immunofluorescence and electron microscopy in the kidney biopsy. Immunosuppression may result in unusual patterns of response to infectious agents. This case demonstrated tropism of the adenovirus to only selected tubules within the kidney, with sparing of other organ function including, specifically, the pancreas allograft. The differential diagnosis of a granulomatous reaction in the transplant kidney must be expanded to include viral infection, in particular, adenovirus.

Comparative analysis of antibody and cell-mediated autoimmunity to transaldolase and myelin basic protein in patients with multiple sclerosis.

Antibody and T cell-mediated immune responses to oligodendroglial autoantigens transaldolase (TAL) and myelin basic protein (MBP) were examined in patients with multiple sclerosis (MS). Immunohistochemical studies of postmortem brain sections revealed decreased staining by MBP- and TAL-specific antibodies in MS plaques, indicating a concurrent loss of these antigens from demyelination sites. By Western blot high titer antibodies to human recombinant TAL were found in 29/94 sera and 16/23 cerebrospinal fluid samples from MS patients. Antibodies to MBP were undetectable in sera or cerebrospinal fluid of these MS patients. Proliferative responses to human recombinant TAL (stimulation index [SI] = 2.47+/-0.3) were significantly increased in comparison to MBP in 25 patients with MS (SI = 1.37+/-0.1; P < 0.01). After a 7-d stimulation of PBL, utilization of any of 24 different T cell receptor Vbeta gene segments in response to MBP was increased less than twofold in the two control donors and six MS patients investigated. In response to TAL-H, while skewing of individual Vbeta genes was also less than twofold in healthy controls, usage of specific Vbeta gene segments was differentially increased ranging from 2.5 to 65.9-fold in patients with MS. The results suggest that TAL may be a more potent immunogen than MBP in MS.

Blood group antigen A and flow cytometric analysis in resected early-stage non-small cell lung cancer.

The loss of blood group antigen A on tumor tissue has been reported to be a strong adverse prognostic marker for patients with resected non-small cell lung cancer (NSCLC). Results have varied with respect to the prognostic significance of flow cytometric data. We sought to confirm the prognostic significance of blood group antigen A loss and flow cytometry in a large cohort of patients with early-stage NSCLC. Two hundred and sixty patients with surgically resected stage I (n = 193) and II (n = 67) NSCLC with at least a 5-year follow-up were identified. Using paraffin-embedded primary tumor, immunohistochemical stains for blood group antigen A were performed on 90 patients with blood type A or AB. The DNA index and percentage of cells in S phase were successfully obtained on 188 and 152 patients, respectively. The median survival time of the patients with primary tumors negative for blood group antigen A was 38 months (n = 36), compared with 98 months (n = 54) for those with antigen A-positive tumors (P < 0.01). The median disease-free survival times for antigen A-negative and -positive tumors were 26 months and 98 months, respectively (P < h 0.01). The median survival time of the patients with aneuploid tumors was 51 months (n = 131), compared with 50 months (n = 57) for those with diploid tumors (P = 0.42). The median survival time of the patients with S phase >8% was 44 months (n = 105), compared with 60 months (n = 47) for those with S phase

False-positive antineutrophil cytoplasmic antibody in aspergillosis with oxalosis.

Although highly specific for Wegener's granulomatosis and other vasculitides, false-positive antineutrophil cytoplasmic antibody is occasionally encountered in other nonvasculitic conditions. We report a case of clinically suspected Wegener's granulomatosis with a large pulmonary cavity, renal failure, and positive cytoplasmic antineutrophil cytoplasmic antibody reaction. The patient died before initiation of immunosuppressive therapy. Postmortem examination revealed pulmonary aspergillosis due to Aspergillus niger, with extensive pulmonary and renal oxalosis, which lead to renal failure. The possible role of oxalosis in the pathogenesis of false-positive antineutrophil cytoplasmic antibody reaction is discussed.

IdLNF1-specific T cell clones accelerate the production of IdLNF1 + IgG and nephritis in SNF1 mice.

We have shown that antibodies bearing a nephritogenic idiotype (IdLNF1) are important in the pathogenesis of autoimmune glomerulonephritis in the (NZB x SWR)F1 hybrid, SNF1. A significant shift in the ratio of CD4+ to CD8+ IdLNF1-specific T lymphocytes, in favour of CD4+ IdLNF1-specific T cells, occurred at 22-24 weeks of age in the SNF1 and correlated with an increase in serum IdLNF1 + IgG and its deposition in the kidney. Recently, we reported the characteristics of six IdLNF1-specific T cell clones (CD3+CD4+CD8-V beta 17a+) derived from 22-week-old SNF1 mice which proliferated in response to IdLNF1 + Ig and augmented IdLNF1 + IgG production when mixed with SNF1 B cells in vitro. No increase in the production of anti-DNA antibodies was seen. Here we report results of the adoptive transfer of three of these clones, A1, B6 and D2, into 6-8-week-old SNF1 mice. Serum immunoglobulin (Ig) (IgG and IgM) levels did not differ from those of age-matched unmanipulated SNF1 up to and including 35 days post-injection. Similarly, total IdLNF1 + Ig levels did not vary significantly among the groups until 28 days post-injection. However, elevated levels of IdLNF1 + IgG were observed as early as 7 days post-injection in mice receiving clone B6 and 21 days post-injection in mice receiving clone D2. This was in sharp contrast with the results obtained in mice treated with clone A1 or unmanipulated SNF1 mice, which did not express IdLNF1 + IgG during this period. Digital image analysis of the kidney glomeruli of mice receiving T cell clones B6 or D2 demonstrated a significantly (P < 0.05) higher level of IdLNF1 + Ig deposition and glomerulonephritis than age-matched unmanipulated SNF1 mice or mice which had received clone A1. Interestingly, there was no statistically significant difference in the production of anti-ssDNA or dsDNA antibodies with the treatments. Mean survival for mice treated with T cell clones B6 and D2 was significantly (P < or = 1 x 10(-6)) shorter compared to unmanipulated SNF1 mice, while that of mice which had received T cell clone A1 was significantly (P < or = 3 x 10(-6)) longer, as determined by chi-squared analysis. The overall survival of mice treated with clones B6 and D2 did not differ from that of unmanipulated mice; however, mice treated with clone A1 survived significantly (P < or = 0.05) longer.(ABSTRACT TRUNCATED AT 400 WORDS)

Oligodendrocyte-specific expression and autoantigenicity of transaldolase in multiple sclerosis.

Although the etiology of multiple sclerosis (MS) is unknown, there is compelling evidence that its pathogenesis is mediated through the immune system. Molecular mimicry, i.e., crossreactivity between self-antigens and viral proteins, has been implicated in the initiation of autoimmunity and MS. Based on homology to human T cell lymphotropic virus type I (HTLV-I) a novel human retrotransposon was cloned and found to constitute an integral part of the coding sequence of the human transaldolase gene (TAL-H). TAL-H is a key enzyme of the nonoxidative pentose phosphate pathway (PPP) providing ribose-5-phosphate for nucleic acid synthesis and NADPH for lipid biosynthesis. Another fundamental function of the PPP is to maintain glutathione at a reduced state and, consequently, to protect sulfhydryl groups and cellular integrity from oxygen radicals. Immunohistochemical analyses of human brain sections and primary murine brain cell cultures demonstrated that TAL is expressed selectively in oligodendrocytes at high levels, possibly linked to production of large amounts of lipids as a major component of myelin, and to the protection of the vast network of myelin sheaths from oxygen radicals. High-affinity autoantibodies to recombinant TAL-H were detected in serum (25/87) and cerebrospinal fluid (15/20) of patients with MS. By contrast, TAL-H antibodies were absent in 145 normal individuals and patients with other autoimmune and neurological diseases. In addition, recombinant TAL-H stimulated proliferation and caused aggregate formation of peripheral blood lymphocytes from patients with MS. Remarkable amino acid sequence homologies were noted between TAL-H and core proteins of human retroviruses. Presence of crossreactive antigenic epitopes between recombinant TAL-H and HTLV-I/human immunodeficiency virus type 1 (HIV-1) gas proteins was demonstrated by Western blot analysis. The results suggest that molecular mimicry between viral core proteins and TAL-H may play a role in breaking immunological tolerance and leading to a selective destruction of oligodendrocytes in MS.

Affinity studies of human anti-MAG antibodies in neuropathy.

Human IgM anti-myelin associated glycoprotein (MAG) antibodies from patients with neuropathy bind to oligosaccharide determinants shared by MAG and several other glycoconjugates in peripheral nerve. The apparent affinities of human anti-MAG antibodies were determined by an ELISA system which measures free antibody concentration at equilibrium in solution. Intact MAG, which bears multiple antigenic oligosaccharides, and monovalent oligosaccharides generated by pronase digestion of MAG were used as antigen. The human antibodies bound to intact MAG with dissociation constants of between 2.5 x 10(-10) M and 2.1 x 10(-7) M, and to the monovalent oligosaccharides with up to 100-fold lower affinities. Reduction of the pentameric IgM to its monomeric counterpart reduced its affinity to intact MAG 5-fold, but its avidity for immobilized MAG was reduced 500-fold as determined by ELISA. These studies show that IgM Anti-MAG antibodies exhibit relatively low intrinsic affinities for the oligosaccharide antigen, but their affinities and avidities are significantly increased by the multivalent nature of the antibody-antigen interaction.

The prognostic significance of neuroendocrine markers and carcinoembryonic antigen in patients with resected stage I and II non-small cell lung cancer.

Non-small cell lung cancer with neuroendocrine differentiation may represent a subset of patients with a more aggressive (like small cell lung cancer) or less aggressive (like carcinoid) biological behavior. To investigate their prognostic significance, immunohistochemical stains for 4 neuroendocrine markers (neuron-specific enolase, chromogranin A, Leu-7, and synaptophysin) and carcinoembryonic antigen (CEA) were studied in 260 patients with surgically resected stage I and II non-small cell lung cancer. The following percentages of cases were positive for each marker: neuron-specific enolase, 70.0%; chromogranin A, 14.2%; Leu-7, 7.7%; synaptophysin, 11.2%; and CEA, 68.5%. Sixty-one (23.5%) were positive for > or = 2 neuroendocrine markers. When compared to adenocarcinoma, squamous cell carcinoma displayed lower positivity for CEA and > or = 2 neuroendocrine markers. There was no significant difference in stage, site of relapse (distant versus local), disease-free, or overall survival for each marker individually or for those with > or = 2 neuroendocrine markers. Multivariate analysis showed that higher nodal stage (N1 versus N0), tumor stage (T2 versus T1), older age, and the presence of mucin predicted for poorer overall survival. Neuroendocrine markers and CEA were not of prognostic significance in this group of patients with resected stage I and II non-small cell lung cancer.

Treatment with antibody reactive with the nephritogenic idiotype, IdLNF1, suppresses its production and leads to prolonged survival of (NZB x SWR)F1 mice.

The F1 progeny of the cross between SWR and NZB mice (SNF1) develop severe immune complex glomerulonephritis, similar to that seen in human SLE. An idiotypically-related family of nephritic antibodies (IdLNF1) has been shown to be important in the pathogenesis of autoimmune glomerulonephritis in these mice. Interestingly, the majority of IdLNF1+ antibodies do not bind DNA. Here, we sought to examine whether regulation of the expression of this idiotype was important in the development of lupus nephritis and to identify the mechanisms regulating its expression. In the present study, biweekly injections of SNF1 mice with 100 micrograms of rabbit anti-IdLNF1 antibodies, beginning at 8 to 10 weeks of age, resulted in significant P < or = 0.05) suppression of IdLNF1+ Ig(G+M) and IgG production. The decrease appeared to be mediated via significant (P < or = 0.05) decreases in the percentage of IdLNF1-expressing B cells and CD4+ IdLNF1-specific T cells in the treated SNF1 mice compared to the controls. This was accompanied by a significant (P < or = 0.005) increase in survival with delayed onset of glomerulonephritis. Surprisingly, there was no difference in the incidence of anti-DNA antibody production between the treated and control SNF1 mice. These results support the hypothesis that dysregulation of pathogenic idiotypes, not confined to anti-DNA antibody idiotypes as had been shown in previous studies, may contribute to the development of SLE.

Pleomorphic fibrohistiocytoma of the breast: a potential pitfall in breast biopsy interpretation.

We describe a benign mammary mesenchymal tumour with atypical stromal giant cells in the contralateral breast of a 66-year-old woman with infiltrating ductal carcinoma. The clinical, morphological and immunohistochemical features of this tumour suggest a pleomorphic variant of fibrous histiocytoma. This benign lesion represents a possible pitfall in breast pathology when interpreting a frozen section or fine needle aspiration biopsy.

erbB-2 and myc oncoproteins in sera and tumors of breast cancer patients.

This study compares the prevalence of elevated serological levels of erbB-2 and myc proteins in 36 breast cancer patients and 25 healthy, ambulatory female controls. The controls were frequency matched to the cases by age and ethnicity. Oncoprotein levels were determined blind to the "case-control status" of the individual from whom the specimen was derived. Corresponding tissue levels were examined in tumors of the 13 cases from whom sufficient tissue was available. Serum oncoproteins were elevated as follows: erbB-2 in one control (4%) compared with nine cases (25%; PFisher's exact = 0.03); myc in no control (0%) compared with seven cases (19%; PFisher's exact = 0.02). Elevated serum levels of erbB-2 or myc oncoproteins were detected in four of the seven cases (57.1%) of in situ cancer without evidence of infiltration. In all cases with elevated serum oncoproteins where tumor tissue was available, the corresponding protein was elevated in the tumor. The three cases who had elevated preoperative serum oncoprotein levels and from whom it was possible to procure postoperative specimens had normal postoperative serum oncoprotein levels. We conclude that (a) erbB-2 and myc oncoproteins are elevated in a proportion of breast cancer patients, (b) the tumor seems to be the source of the serum elevation, and (c) these proteins may be useful as part of a panel of biomarkers of early malignant disease.

Experimental paraprotein neuropathy, demyelination by passive transfer of human IgM anti-myelin-associated glycoprotein.

Circulating monoclonal IgM antibodies that react with myelin-associated glycoprotein are strongly associated with a specific type of human peripheral nerve demyelination. There has been great interest in this syndrome because, if the paraprotein could be shown to cause the demyelination, then it would be the first proven example of antibody-mediated demyelination in humans. Systemic transfusion of chickens with monoclonal IgM antibody isolated from one of these patients produced peripheral demyelination highly characteristic of the human syndrome. The experimental lesion consists of segmental demyelination and remyelination with minimal inflammation, specific antibody bound to myelin, and widening of the myelin lamellae. In the experimental model, antibody is concentrated in specialized myelin structures, the nodes of Ranvier, and Schmidt-Lanterman incisures, suggesting that myelin-associated glycoprotein may be the antigenic target in vivo. This demonstration that human myelin-associated glycoprotein antibodies cause demyelination in vivo is the final information needed to prove that this type of human demyelination is antibody mediated. This strengthens the proposition that nerve antibodies, present in other human neurological syndromes, may also cause disease.

Large scale recovery of biologically active IgM (95% pure) from human plasma obtained by therapeutic plasmapheresis.

We have developed a large scale (10 g/batch) non-chromatographic method for the collection of IgM directly from plasma obtained from therapeutic plasmapheresis of patients. The technique uses sequential precipitations from ammonium sulfate and polyethylene glycol, and gives high yields of undenatured IgM antibodies. The biological activity of IgM prepared by this method has been demonstrated by systemically transfusing animals with the antibody and producing a demyelinating syndrome very similar to the antibody donor. Control IgM preparations exhibited no toxicity after daily injections of antibody for 8 weeks, showing that the method gives antibody with excellent bio-compatibility (Tatum, 1989). The method, which is effective for monoclonal and polyclonal antibodies, is useful when large amounts of antibodies are needed for passive transfer or other studies.

The onset of nephritis in the (NZB x SWR)F1 murine model for systemic lupus erythematosus correlates with an increase in the ratio of CD4 to CD8 T lymphocytes specific for the nephritogenic idiotype (IdLNF1).

An idiotypically related family of nephritogenic antibodies (IdLNF1) has been shown to be important in the pathogenesis of autoimmune glomerulonephritis in the (NZB x SWR)F1 hybrid, SNF1. Idiotype-specific T lymphocytes which modulate expression of antibody bearing that idiotype may be important in the pathogenesis of systemic lupus erythematosus (SLE). Here, IdLNF1-reactive T lymphocytes were not only found to be present in the NZB, SWR, and SNF1, but a significantly (P < or = 0.05) greater number of IdLNF1-reactive Thy 1.2+ splenic lymphocytes were observed as early as 12 weeks of age in the SNF1. Further, a significant shift in the ratio of CD4+ to CD8+ IdLNF1-reactive T lymphocytes in favor of CD4+ IdLNF1-reactive T cells was observed at 20 to 24 weeks of age only in the SNF1. This shift correlated with an increase in IdLNF1+IgG, and deposition of IdLNF1 bearing immunoglobulin in the kidney glomeruli. These observations suggest a role for idiotype-specific T lymphocytes in the induction of glomerulonephritis in this murine model of SLE.