Only a few cases of various glomerulonephropathies have been reported in patients with polycythemia vera. We report the case of a 72-year-old female with polycythemia vera in whom renal biopsy examination showed membranoproliferative glomerulonephritis (MPGN)-like lesion and glomerular expression of plasmalemmal vesicle-associated protein-1 (PV-1), a marker of glomerular capillary remodeling after injury. Prior to admission to our hospital for nephrotic syndrome, she had received hydroxyurea and phlebotomy. On admission, she was hypertensive with pretibial edema, hepatosplenomegaly, massive proteinuria (6.14 g/day), low serum albumin (2.9 g/dl), high fibrinogen, fibrin/fibrinogen degradation products and thrombomodulin levels, but with normal serum creatinine and complement levels. Microscopic examination of a renal biopsy demonstrated MPGN-like features with double contour and mesangial interposition. Electron microscopy showed subendothelial deposits, platelets attached to glomerular capillary walls and fibrin deposition. Immunofluorescence study identified IgM deposition along part of the capillary wall and mesangium. CD42b-positive platelets and megakaryocytes were detected in glomerular capillaries, accompanied with increased expression of platelet-derived growth factor receptor b and thrombomodulin in the mesangium and glomerular capillary, respectively. PV-1 was expressed along the glomerular capillary. Anti-platelet and anticoagulant combination therapy, together with the use of anti-hypertensive agents and hydroxyurea, resulted in improvement of the nephrotic syndrome. The findings suggested that activated platelets, enhanced coagulation state and endothelial damage may contribute to glomerulonephropathy associated with polycythemia vera.

The link between the nephrotic syndrome (NS) and malignancy was first described in 1922. In solid tumors, the NS is most often due to membranous glomerulonephropathy, whereas in common hematological malignancies, minimal-change disease predominates. Focal segmental glomerulosclerosis (FSGS) is among the least frequently reported renal lesion associated with malignancy.We report a case of the simultaneous diagnoses of FSGS and Hodgkin's lymphoma, and review the literature on various nephrotic glomerulonephropathies associated with common leukemia and lymphoma.Although nephrotic glomerulonephropathies rarely occur in association with acute leukemia, they have often been described in chronic lymphocytic leukemia (CLL). Membranoproliferative glomerulonephropathy and membranous glomerulonephropathy are the most common lesions observed in CLL. Nephrotic glomerulonephropathies have also been well documented among patients with lymphomas, in particular, Hodgkin's lymphoma. While minimal-change disease is most commonly found in association with Hodgkin's lymphoma, more diverse and complex renal lesions are associated with non-Hodgkin's lymphoma. FSGS remains a rare association with hematological malignancies.Nephrotic glomerulonephropathies are not only linked to solid-organ tumors, but also to hematological malignancies. A thorough evaluation, including a physical examination for lymphadenopathy and organomegaly, as well as a hematological evaluation, must be performed in all patients presenting with nephrotic glomerulonephropathies.

The experimental data and the study on human renal tissue in patients with glomerulonephropathies indicate that monocyte chemoattractant protein-1 (MCP-1) plays a main role in progression of inflammatory processes in kidney diseases. Monocytes/macrophages are multifunctional cells that may regulate matrix accumulation by producing transforming growth factor beta-1 (TGF-beta-1), which plays an important role in the progression of renal diseases. The present study was undertaken to evaluate the relationships between the immunoexpression of MCP-1, the number of CD68-positive cells, the immunoexpression of TGF-beta-1 and the extent of renal fibrosis as well serum creatinine level in patients with lupus nephritis. Using immunohistochemistry we analyzed the expression of MCP-1, TGF-beta-1 and the number of CD68+ cells in renal biopsy specimens in 17 patients with IV class of lupus nephritis and in 10 normal kidneys. Statistical analysis revealed significant increase in the tubulointerstitial MCP-beta immunostaining in lupus nephritis as compared to normal controls. In lupus nephritis the amount of glomerular and interstitial CD68+ cells was higher than in control group. None of the control sections have evidence of glomerular or tubulointerstitial immunoexpression of TGF-beta-1. In patients with lupus nephritis TGF-beta-1 was detected in the renal tubular epithelial cells and the interstitium, and to a lesser extent within glomeruli. The tubulointerstitial MCP-1 immunoexpression was significantly correlated with monocyte/macrophage interstitial infiltrates, the immunoexpression of TGF-beta-1 in tubuli and interstitium as well as serum creatinine. Moreover, the tubulointerstitial immunoexpression of TGF-beta-1 was significantly positively correlated with renal interstitial cortical volume and serum creatinine in patients with lupus nephritis. In summary, these data suggest that in lupus nephritis MCP-1 may play a role in modulating interstitial inflammatory process and in tubulointerstitial renal damage via TGF-beta-1 pathway.

Membranoproliferative glomerulonephritis, with or without cryoglobulinemia, and membranous glomerulonephritis are the best characterized glomerulonephropathies associated with hepatitis C virus (HCV) infection. Other more unusual patterns of glomerular injury, including IgA nephropathy, focal segmental glomerulosclerosis, crescentic glomerulonephritis, fibrillary glomerulonephritis, immunotactoid glomerulopathy, and thrombotic microangiopathy, have also been associated with HCV infection, but primarily on an anecdotal basis. It remains uncertain whether the patterns of glomerular injury seen in HCV infected patients, particularly the unusual patterns, represent a disease process specifically related to HCV infection or whether they represent nonspecific patterns of injury due to other causes that happen to occur in HCV-infected patients. We examine this issue by reviewing the epidemiological and pathological evidence in the literature that either supports or refutes a specific relationship between HCV and the pattern of glomerular injury. We also include our experience with 31 HCV-infected patients. In addition, the pathogenesis of HCV-associated glomerulonephropathies is discussed with an emphasis on the significance of detecting HCV in renal biopsies by reverse transcriptase-polymerase chain reaction.

The pathogenetic concept of renal hyperperfusion and hyperfiltration in inducing glomerular pathology and disease progression documented in the renal ablation model in experimental animals to mimic renal disease with reduced nephron mass has recently been challenged. In contrast to the above, the intrarenal hemodynamic study in a variety of chronic glomerulonephropathies reveals a unique characteristic of renal hypoperfusion rather than hyperperfusion. This is associated with an elevated renal arteriolar resistance and reductions in renal plasma flow and peritubular capillary blood flow. The magnitude of reduction in peritubular capillary blood flow is inversely proportional to the degree of tubulointerstitial disease and tubular dysfunction. A progressive reduction in the vascular space due to nonvascular expansion with disease progression supports the concept of hypoperfusion of a whole kidney as well as a single nephron. In accordance with the renal ablation model and early diabetes mellitus, a similar hypoperfusion pattern is also subsequently observed in the chronic stage of renal ablation model in animals and late diabetic nephropathy. The disparity between the hyperperfusion and hypoperfusion in inducing renal disease progression can be enlightened by the Noble Truth of Lord Buddha stating "The Middle Tract is The Balance of Nature". Further support of this conceptual view of renal hypoperfusion as a determinant of tubulointerstitial disease and disease progression is in accordance with the therapeutic benefit with an enhanced-renal-perfusion formula per se in a variety of chronic glomerulonephropathies.

It has been demonstrated that cultured mesangial cells (MC) express latent transforming growth factor (TGF)-beta binding protein (LTBP) mRNA, and that LTBP might be essential for the extracellular matrix (ECM) accumulation stimulated by TGF-beta in cultured MC. We performed a study to test the pathophysiological role of LTBP in mesangial ECM accumulation in human glomerulonephropathies. The expression of LTBP in 64 renal biopsies of patients with renal diseases was examined by immunohistochemical staining with the specific antibody raised against human LTBP. The biopsy specimens were divided into three groups: Group 1, IgA nephropathy; Group 2, IgA negative mesangial proliferative glomerulonephritis, which mainly consisted of diabetic nephropathy and lupus nephritis; and Group 3, non-proliferative nephropathy, which consisted of minimal change and membranous nephropathy. Immunohistochemical staining of LTBP was significantly detected in mesangial/paramesangial area of glomerulus in Group 1, but not observed in Group 2 or Group 3. The intensity of staining was well related to the grade of mesangial ECM accumulation in Group 1. These findings suggest that the LTBP-TGF-beta complex may play a pivotal role in ECM accumulation in IgA nephropathy, and that modification of LTBP-ECM interaction might provide a new therapeutic strategy against the progression of glomerulosclerosis.

A glomerular endothelial function with its hemodynamic impact is proposed to determine disease progression. In the clinical settings associated with an intact endothelial function, such as minimal-change steroid-sensitive nephrosis, the early phase of diabetes mellitus and the early stage of an experimental model of renal ablation in animals, it was observed that adequate renal perfusion correlates with the intact structure and function of the nephron with no evidence of disease progression. In contrast, the clinical settings associated with endothelial dysfunction, such as chronic glomerulonephropathy, the late stage of diabetes mellitus and a renal ablation model in animals, are usually associated with a reduction in renal perfusion. The magnitude of renal hypoperfusion observed in all forms of chronic glomerulonephropathies is proportional to the degree of clinical severity. A progressive pattern of renal hypoperfusion is uniquely observed when disease severity progresses. In this context, a new therapeutic maneuver aiming to improve renal perfusion is proposed for treating glomerulonephropathy with disease progression and preventing it from developing to end-stage renal disease.

Eight patients between the ages of 5 and 26 years developed a rapid decline of renal function with a period of oliguria or anuria which ranged between 1 and 21 days. The initial assessment of renal function revealed a severe degree of glomerular, tubular, and vascular abnormalities. The magnitude of the renal dysfunction was quantified and expressed in terms of a clinical score. The degree of glomerular and tubular dysfunction was inversely proportional to the renal plasma flow and peritubular capillary blood flow, respectively. Similar findings have been observed in a variety of other glomerulonephropathies where a relationship exists between the reduction of peritubular capillary blood flow and the severity of the tubulointerstitial disease. Evidence to support the position that the reduction of peritubular capillary blood flow plays a primary role in inducing tubulointerstitial disease is as follows: (i) A reduction of peritubular capillary blood flow has been documented in mesangial proliferative nephrosis with steroid resistance prior to the detection of tubulointerstitial disease. (ii) Ischemic insults are capable of inducing tubulointerstitial disease in the experimental setting of renal artery occlusion in animals. (iii) As demonstrated in the present report, an improvement of tubular function can be achieved following an increase in peritubular capillary blood flow with therapy designed to enhance renal perfusion.

Eight patients aged between 5 and 26 years developed rapid deterioration of renal function and became oliguric/anuric with duration ranging from 1 to 21 days. The initial functional assessment revealed severe degree of glomerular, tubular, and vascular dysfunctions. The magnitude of renal dysfunction was quantified and expressed in terms of a clinical score. The degree of glomerular and tubular dysfunctions were inversely proportional to the renal plasma flow and peritubular capillary blood flow (PTCB), respectively. Similar findings have been observed in a variety of severe glomerulonephropathies. In this aspect, it is likely that the reduction of peritubular capillary blood flow and tubulointerstitial disease are interrelated. Further evidence to support the primary role of reduction of PTCB in inducing tubulointerstitial disease is provided by the following: (a) Reduction of PTCB is documented in mesangial proliferative nephrosis with steroid resistance prior to the detection of tubulointerstitial disease. (b) Ischemic insult can induce tubulointerstitial disease in experimental setting of renal artery occlusion in animal, (c) Improved tubular function can be achieved following the increase in PTCB with the enhanced renal perfusion therapy.

Of the 4,776 first grafts recorded in the pediatric European Dialysis and Transplant Association (EDTA) registry, 2,113 were reported to have failed and 5.6% of graft failures were related to a recurrence of primary renal disease. Nephrotic syndrome with focal and segmental glomerulosclerosis was the main renal disease prone to recur because recurrence represented 20% of the causes of graft failure in these patients; an even higher proportion was reported in a single-center experience in Europe. Other glomerulonephropathies, such as membranoproliferative glomerulonephritis and Berger's disease, were also reported to be the cause of graft failure by means of recurrence in a proportion similar to focal and segmental glomerulosclerosis. The usual recurrence of primary oxaluria was the cause of close to 50% of graft failure in this disease. Finally, hemolytic uremic syndrome recurred rarely with the graft in the EDTA registry, which is the opposite of what was reported in the United States.