IgA-dominant acute poststaphylococcal glomerulonephritis complicating diabetic nephropathy.

Two pathological patterns of acute poststaphylococcal glomerulonephritis are well defined and include (1) an acute proliferative and exudative glomerulonephritis closely resembling classical acute poststreptococcal glomerulonephritis in patients with Staphylococcus aureus infection and (2) a membranoproliferative glomerulonephritis in patients with Staphylococcus epidermidis infection secondary to ventriculovascular shunts. In this study, we report a novel immunopathologic phenotype of immunoglobulin (Ig) A-dominant acute poststaphylococcal glomerulonephritis occurring in patients with underlying diabetic nephropathy. Five patients with type 2 diabetes presented with acute renal failure occurring after culture-positive staphylococcal infection. Renal biopsy disclosed an atypical pattern of acute endocapillary proliferative and exudative glomerulonephritis with intense deposits of IgA as the sole or dominant immunoglobulin, mimicking IgA nephropathy. The deposits were predominantly mesangial in distribution with few subepithelial humps. All five cases occurred superimposed on well-established diabetic nephropathy. Outcome was poor with irreversible renal failure in four of five (80%) cases. The possible pathophysiological basis of this atypical form of acute poststaphylococcal glomerulonephritis in diabetic patients is explored. Proper recognition of this entity is needed to avoid an erroneous diagnosis of IgA nephropathy, with corresponding therapeutic and prognostic implications.

Immunologic and tissue biocompatibility of flexible/stretchable electronics and optoelectronics.

Recent development of flexible/stretchable integrated electronic sensors and stimulation systems has the potential to establish an important paradigm for implantable electronic devices, where shapes and mechanical properties are matched to those of biological tissues and organs. Demonstrations of tissue and immune biocompatibility are fundamental requirements for application of such kinds of electronics for long-term use in the body. Here, a comprehensive set of experiments studies biocompatibility on four representative flexible/stretchable device platforms, selected on the basis of their versatility and relevance in clinical usage. The devices include flexible silicon field effect transistors (FETs) on polyimide and stretchable silicon FETs, InGaN light-emitting diodes (LEDs), and AlInGaPAs LEDs, each on low modulus silicone substrates. Direct cytotoxicity measured by exposure of a surrogate fibroblast line and leachable toxicity by minimum essential medium extraction testing reveal that all of these devices are non-cytotoxic. In vivo immunologic and tissue biocompatibility testing in mice indicate no local inflammation or systemic immunologic responses after four weeks of subcutaneous implantation. The results show that these new classes of flexible implantable devices are suitable for introduction into clinical studies as long-term implantable electronics.