Sally E. Self

IgA antiglomerular basement membrane nephritis associated with crohn's disease: a case report and review of glomerulonephritis in inflammatory bowel disease

A case of glomerulonephritis in a 35-year-old man with Crohns disease is described here. The patient presented with severe diarrhea, nephrotic range proteinuria, hematuria, microangiopathic hemolytic anemia, thrombocytopenia, hypocomplementemia, acute renal failure requiring hemodialysis, cryoglobulinemia, and extensive thrombotic gangrene of the distal upper and lower limbs. The patient did not respond to plasmapheresis and steroid therapy and died of upper gastrointestinal bleeding. Renal tissue obtained at autopsy showed IgA-mediated antiglomerular basement membrane crescentic glomerulonephritis. Linear staining of the glomerular basement membrane by non-IgG antibodies is quite unusual with only 11 cases previously reported in the worldwide literature, 8 caused by IgA. Glomerulonephritis is a rarely reported extraintestinal manifestation of inflammatory bowel disease, and there are only 24 previously described cases that are reviewed and summarized in this report. Glomerulonephritis occurred in the setting of active bowel inflammation in all cases, circulating immune complexes were found in nearly half the cases, and serum complements usually were normal. Renal insufficiency and nephrotic range proteinuria were typically present at the time of diagnosis of glomerulonephritis and most often improved in parallel with treatment of the gastrointestinal disorder. The histologic findings were varied and included membranoproliferative glomerulonephritis, mesangioproliferative glomerulonephritis, membranous nephropathy, IgA nephropathy, and IgM nephropathy. Thus, the authors present the first case of glomerulonephritis caused by antiglomerular basement membrane disease in association with inflammatory bowel disease.

Association of Serum Nitrate and Nitrite Levels With Longitudinal Assessments of Disease Activity and Damage in Systemic Lupus Erythematosus and Lupus Nephritis

OBJECTIVE Reactive intermediate production is an essential component of the innate immune response that is induced during disease activity in murine lupus. This study was undertaken to determine whether a marker of systemic nitric oxide (NO) production correlates with prospectively studied disease activity in human systemic lupus erythematosus (SLE) and lupus nephritis patients. METHODS Eighty-three SLE patients and 40 control subjects were studied longitudinally. The SLE group included 23 patients with lupus nephritis documented by renal biopsy and 26 with a history of lupus nephritis. During each visit, following a 24-hour low-nitrate diet, traditional markers of disease activity and damage were determined. Serum nitrate plus nitrite (NOx) levels were determined by chemiluminescence detection. RESULTS NOx levels were higher in SLE patients than in controls during the first visit. In univariate longitudinal analyses, NOx levels were associated with SLE Disease Activity Index scores. In multivariate analyses, NOx levels were associated with serum levels of C3 and creatinine and the urinary protein:creatinine ratio. Among patients with lupus nephritis, those with proliferative lesions had higher NOx levels, and higher NOx levels were associated with accumulation of renal damage and lack of response to therapy. CONCLUSION This is the first study to prospectively demonstrate longitudinal associations between serum NOx levels and markers of SLE and lupus nephritis disease activity. The more pronounced association with proliferative lupus nephritis and with longitudinal response to lupus nephritis therapy provides a rationale for the study of reactive intermediates as biomarkers of disease activity and therapeutic targets in proliferative lupus nephritis.

Comparative in vitro cytotoxic effects of taxol and its major human metabolite 6α-hydroxytaxol

Taxol is metabolized by the liver microsomal cytochrome P450 enzyme system into its principal metabolite 6α-hydroxytaxol (6HT). In the present in vitro studies 6HT was compared to taxol with respect to its effects on tubulin depolymerization, mitotic arrest, clonogenic survival and apoptosis in HL-60 cells. 6HT was generated by incubating taxol with human liver microsomes in a NADPH-generating system. HL-60 cells were incubated for 24 h with either taxol or 6HT, washed and placed in drug-free suspension or cultured for colony growth in agarose. For the suspension and colony culture growth of the cells, the IC50 concentrations of 6HT were 500±46 and 350±37 nM, while those of taxol were 3.2±0.2 and 2.8±0.5 nM, respectively. Immediately after a 24-h exposure of HL-60 cells to 50 nM taxol, electrophoresis of genomic DNA from HL-60 cells revealed an internucleosomal DNA fragmentation ‘ladder’. In addition, 39% of the cells were arrested in mitosis and 16% showed the morphologic features of apoptosis. In contrast, an identical treatment with 6HT resulted in the mitotic arrest of only 2.8% of the cells, with 4.0% displaying apoptosis (P<0.01); internucleosomal DNA fragmentation was not observed. 6HT was also significantly less effective than taxol in inhibiting the temperature-induced depolymerization of microtubules in a cell-free system. However, at equipotent concentrations, the effect of 6HT on tubulin depolymerization, mitotic arrest or apoptosis was similar to that of taxol. In addition, at concentrations of taxol or 6HT at or below their IC50, there was little tubulin depolymerization, mitotic arrest or apoptosis. The results presented here show that the biotransformation of taxol to 6HT substantially detoxifies taxol.

Clonal diversity analysis using SNP microarray: a new prognostic tool for chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is a clinically heterogeneous disease. The methods currently used for monitoring CLL and determining conditions for treatment are limited in their ability to predict disease progression, patient survival, and response to therapy. Although clonal diversity and the acquisition of new chromosomal abnormalities during the disease course (clonal evolution) have been associated with disease progression, their prognostic potential has been underappreciated because cytogenetic and fluorescence in situ hybridization (FISH) studies have a restricted ability to detect genomic abnormalities and clonal evolution. We hypothesized that whole genome analysis using high resolution single nucleotide polymorphism (SNP) microarrays would be useful to detect diversity and infer clonal evolution to offer prognostic information. In this study, we used the Infinium Omni1 BeadChip (Illumina, San Diego, CA) array for the analysis of genetic variation and percent mosaicism in 25 non-selected CLL patients to explore the prognostic value of the assessment of clonal diversity in patients with CLL. We calculated the percentage of mosaicism for each abnormality by applying a mathematical algorithm to the genotype frequency data and by manual determination using the Simulated DNA Copy Number (SiDCoN) tool, which was developed from a computer model of mosaicism. At least one genetic abnormality was identified in each case, and the SNP data was 98% concordant with FISH results. Clonal diversity, defined as the presence of two or more genetic abnormalities with differing percentages of mosaicism, was observed in 12 patients (48%), and the diversity correlated with the disease stage. Clonal diversity was present in most cases of advanced disease (Rai stages III and IV) or those with previous treatment, whereas 9 of 13 patients without detected clonal diversity were asymptomatic or clinically stable. In conclusion, SNP microarray studies with simultaneous evaluation of genomic alterations and mosaic distribution of clones can be used to assess apparent clonal evolution via analysis of clonal diversity. Since clonal evolution in CLL is strongly correlated with disease progression, whole genome SNP microarray analysis provides a new comprehensive and reliable prognostic tool for CLL patients.

Cyclosporine‐induced hemolytic uremic syndrome and hemorrhagic colitis following renal transplantation

Nephrotoxicity remains one of the most common side‐effects of cyclosporine in the setting of transplantation. Acute reversible decreases in glomerular filtration rate and chronic irreversible renal damage are the most common manifestations, but hemolytic uremic syndrome and thrombotic thrombocytopenic purpura have been reported. Prognosis of cyclosporine‐associated de novo hemolytic uremic syndrome (CyA‐HUS) is poor, with nearly half of affected patients losing function in the transplanted kidney. Therapeutic options are limited, but good outcomes have been reported by switching patients from cyclosporine to tacrolimus. We report an unusual presentation of CyA‐HUS associated with hemorrhagic colitis following renal transplantation. The patient was successfully managed by switching from cyclosporine to tacrolimus.

Inducible Nitric Oxide Synthase Inhibitor SD-3651 Reduces Proteinuria in MRL/lpr Mice Deficient in the NOS2 Gene

Several studies have demonstrated the effectiveness of arginine analog nitric oxide synthase (NOS) inhibitor therapy in preventing and treating murine lupus nephritis. However, MRL/MpJ-FASlpr (MRL/lpr) mice lacking afunctional NOS2 (inducible NOS [iNOS]) gene (NOS2−/−) develop proliferative glomerulonephritis in a fashion similar to their wild-type (wt) littermates. This finding suggests that the effect of arginine analog NOS inhibitors is through a non-iNOS-mediated mechanism. This study was designed to address this hypothesis. NOS2−/− mice were given either vehicle or a NOS inhibitor (SD-3651) to determine if pharmacological NOS inhibition prevented glomerulonephritis, using wt mice as positive controls. Urine was collected fortnightly to measure albumin. At the time of full disease expression in wt mice, all mice were killed, and renal tissue was examined for light, immunofluorescence, and electron microscopic evidence of disease. Serum was analyzed for anti-double-stranded DNA antibody production. NOS2−/− mice had higher serum anti-double-stranded DNA antibody antibody levels than those of wt mice. SD-3651 therapy reduced proteinuria, glomerular immunoglobulin G deposition, and electron microscopic evidence of podocytopathy and endothelial cell swelling without affecting proliferative lesions by light microscopy. These studies confirm that genetic iNOS deficiency alone is insufficient to prevent proliferative glomerulonephritis and suggest that iNOS activity may inhibit autoantibody production. These results also suggest that SD-3651 therapy acts via a non-iNOS-mediated mechanism to prevent endothelial cell and podocyte pathology. Studies that elucidate this mechanism could provide a useful drug target for the treatment of nephritis.

Autoantibody Testing for Autoimmune Disease

The proper use and interpretation of serologic testing for diagnosing autoimmune diseases presents a challenge to clinicians for several reasons. Most laboratory tests for autoimmune disease are significantly less than 100% sensitive or specific. In addition, different techniques for the same antibody test may give different results, such as indirect immunofluorescence and multiplex bead assay for antinuclear antibody. Autoantibody testing should only be performed in the context of the clinical workup of patients who have a reasonable likelihood of having the disease for which the testing is relevant. Otherwise, the predictive value of a positive test is too low. Particularly with antinuclear antibody and antineutrophil cytoplasmic antibody testing, clinicians must know the methodology through which the tests are being performed, and should develop a relationship with the laboratory pathologist so that inconsistent or surprising results can be investigated.

Utility of percutaneous renal biopsy in chronic kidney disease

Background:  We tested the hypothesis that patterns of serum creatinine concentrations (S‐cr) prior to percutaneous renal biopsy (PRB) predict the utility of PRB in safely making renal diagnoses, revealing treatable disease, and altering therapy in chronic kidney disease patients.

Kidney-limited thrombotic microangiopathy in patients with SLE treated with romiplostim

We present the case of a 19 year-old Caucasian female with history of systemic lupus erythematosus (SLE) and normal baseline kidney function who developed severe acute renal failure following treatment of thrombocytopenia with the thrombopoietic agent romiplostim. Percutaneous kidney biopsy revealed thrombotic microangiopathy (TMA) without immune complex lupus glomerulonephritis. We discuss pathogenesis and differential diagnosis of TMA in patients with SLE and raise concerns regarding the use of thrombopoietic agents in such patients. Based on favorable long-term outcome in our case aggressive treatment and in particular prolonged use of plasma exchange in these patients are advocated.

Characterization of Mast Cell Activation Syndrome

Background: Mast cell activation syndrome (MCAS), a recently recognized nonneoplastic mast cell disease driving chronic multisystem inflammation and allergy, appears prevalent and thus important. We report the first systematic characterization of a large MCAS population. Method: Demographics, comorbidities, symptoms, family histories, physical examination and laboratory findings were reviewed in 298 retrospective and 115 prospective patients with MCAS. Blood samples from prospective subjects were examined by flow cytometry for clonal mast cell disease and tested for cytokines potentially driving the monocytosis frequent in MCAS. Results: Demographically, white females dominated. Median ages at symptom onset and diagnosis were 9 and 49 years, respectively (range: 0‐88 and 16‐92, respectively) and median time from symptom onset to diagnosis was 30 years (range: 1‐85). Median numbers of comorbidities, symptoms, and family medical issues were 11, 20, and 4, respectively (range: 1‐66, 2‐84, and 0‐33, respectively). Gastroesophageal reflux, fatigue and dermatographism were the most common comorbidity, symptom and examination finding. Abnormalities in routine laboratories were common and diverse but typically modest. The most useful diagnostic markers were heparin, prostaglandin D2, histamine and chromogranin A. Flow cytometric and cytokine assessments were unhelpful. Conclusions: Our study highlights MCASs morbidity burden and challenging heterogeneity. Recognition is important given good survival and treatment prospects.