Nephrotic Syndrome in a Retroviral Disease Due to AA Amyloidosis: A Rare Presentation

Kidney disease poses a significant burden on individuals with HIV infection. In the pre-ART era, HIV-associated nephropathy (HIVAN) was the most common renal pathology identified in individuals with HIV. However, the widespread use of ART has led to changes in the spectrum of renal pathologies associated with HIV. HIV infection is an unclear cause of AA amyloidosis. Here, we report a rare case of an HIV-positive patient presenting with nephrotic syndrome which turned out to be AA amyloidosis on renal biopsy.

Intestinal Reactive Amyloid A (AA) Amyloidosis in a Patient With Multiple Myeloma: A Case Report and Literature Review

Amyloidosis is a rare group of disorders characterized by the extracellular deposition of misfolded protein aggregates that interfere with the function of the tissue affected. In some patients, the presenting symptom of monoclonal gammopathies, such as multiple myeloma, can be a gastrointestinal bleed with a further report of amyloidosis in gastrointestinal samples. In all the cases the pathology report is read as AL (light chain) amyloidosis. We present a case of a 57-year-old male patient with no medical history who debuted with gastrointestinal bleeding. A colonoscopy revealed a colonic ulcer with a pathologic diagnosis of amyloid A (AA) amyloidosis. Further investigation led to the finding of multiple myeloma (MM) with no evidence of systemic amyloidosis. Although there is little evidence in the literature of the association or even causative relationship between multiple myeloma and AA amyloidosis, our case highlights the importance of searching for an underlying monoclonal gammopathy like MM in a patient with a confirmed diagnosis of AA amyloidosis.

AA amyloidosis associated with Castleman disease: A case report and review of the literature

RATIONALE

AA amyloidosis (AA) is caused by a wide variety of inflammatory states, but is infrequently associated with Castleman disease (CD). CD describes a heterogeneous group of hematologic disorders that share characteristic lymph node histopathology. CD can present with a solitary enlarged lymph node (unicentric CD, UCD) or with multicentric lymphadenopathy (MCD), constitutional symptoms, cytopenias, and multiple organ dysfunction due to an interleukin-6 driven cytokine storm.

PATIENT CONCERNS

We are reporting a case of a 26-year-old woman with no significant past medical history who presented with a 3-month history of fatigue and an unintentional 20-pound weight loss.

DIAGNOSIS

A CT-scan of the abdomen and pelvis revealed hepatosplenomegaly and a mesenteric mass. Congo Red staining from a liver biopsy showed apple-green birefringence and serum markers were suggestive of an inflammatory process. Post-excision examination of the resected mass revealed a reactive lymph node with follicular hyperplasia with kappa and lambda stains showing polyclonal plasmacytosis consistent with CD.

INTERVENTIONS

The patient underwent surgery to remove the affected lymph node.

OUTCOMES

IL-6, anemia, leukocytosis, and thrombocytosis resolved or normalized 2 weeks after resection; creatinine normalized 9 months postsurgery. Twenty two months post-surgery her IFN-γ normalized, her fatigue resolved, her proteinuria was reduced by >90% and she had returned to her baseline weight.

LESSONS

Our case and literature review suggest that patients presenting with UCD or MCD along with organ failure should prompt consideration of concurrent AA amyloidosis.

Phagocyte depletion inhibits AA amyloid accumulation in AEF-induced huIL-6 transgenic mice

OBJECTIVE

Determine the role of phagocytosis in the deposition of acute phase SAA protein in peripheral organs as AA amyloid.

METHODS

AA amyloidosis was induced by injection of amyloid enhancing factor (AEF) in huIL-6 transgenic mice. Clodronate liposomes were injected at different times, and the amyloid load evaluated by Congo red birefringence staining and monitoring with the amyloid specific probe (125)I-labeled peptide p5R.

RESULTS

Injection of clodronate containing liposomes depleted Iba-1 positive and F4/80 positive phagocytic cells in liver and spleen for up to 5 days. Treatment prior to administration of intravenous AEF did not alter the pattern of deposition of the AEF in spleen, but inhibited the catabolism of the (125)I-labeled AEF. Clodronate treatment 1 day before or 1 day after AEF administration had little effect on AA amyloid accumulation at 2 weeks; however, mice treated with clodronate liposomes 5 days after AEF induction and evaluated at 2 weeks post-AEF induction showed reduced amyloid load relative to controls. At 6 weeks post-AEF there was no significant effect on amyloid load following a single clodronate treatment.

CONCLUSION

Macrophages have been shown to be instrumental in both accumulation and clearance of AA amyloid after cessation of inflammation. Our data indicate that when SAA protein is continuously present, depletion of phagocytic cells during the early course of the disease progression temporarily reduces amyloid load.

Influence of the carboxy terminus of serum amyloid A on protein oligomerization, misfolding, and fibril formation

The fibrillar deposition of serum amyloid A (SAA) has been linked to the disease amyloid A (AA) amyloidosis. We have used the SAA isoform, SAA2.2, from the CE/J mouse strain, as a model system to explore the inherent structural and biophysical properties of SAA. Despite its nonpathogenic nature in vivo, SAA2.2 spontaneously forms fibrils in vitro, suggesting that SAA proteins are inherently amyloidogenic. However, whereas the importance of the amino terminus of SAA for fibril formation has been well documented, the influence of the proline-rich and presumably disordered carboxy terminus remains poorly understood. To clarify the inherent role of the carboxy terminus in the oligomerization and fibrillation of SAA, we truncated the proline-rich final 13 residues of SAA2.2. We found that unlike full-length SAA2.2, the carboxy-terminal truncated SAA2.2 (SAA2.2ΔC) did not oligomerize to a hexamer or octamer, but formed a high molecular weight soluble aggregate. Moreover, SAA2.2ΔC also exhibited a pronounced decrease in the rate of fibril formation. Intriguingly, when equimolar amounts of denatured SAA2.2 and SAA2.2ΔC were mixed and allowed to refold together, the mixture formed an octamer and exhibited rapid fibrillation kinetics, similar to those for full-length SAA2.2. These results suggest that the carboxy terminus of SAA, which is highly conserved among SAA sequences in all vertebrates, might play important structural roles, including modulating the folding, oligomerization, misfolding, and fibrillation of SAA.

AA amyloidosis in the renal allograft: a report of two cases and review of the literature

AA amyloidosis is a disorder characterized by the abnormal formation, accumulation and systemic deposition of fibrillary material that frequently involves the kidney. Recurrent AA amyloidosis in the renal allograft has been documented in patients with tuberculosis, familial Mediterranean fever, ankylosing spondylitis, chronic pyelonephritis and rheumatoid arthritis. De novo AA amyloidosis is rarely described. We report two cases of AA amyloidosis in the renal allograft. Our first case is a 47-year-old male with a history of ankylosing spondylitis who developed end-stage renal disease reportedly from tubulointerstitial nephritis from non-steroidal anti-inflammatory agent use. A biopsy was never performed. One year after transplantation, AA amyloidosis was identified in the femoral head and 8 years post-transplantation, AA amyloidosis was identified in the renal allograft. He was treated with colchicine and adalimumab and has stable renal function at 1 year-follow-up. Our second case is a 57-year-old male with a long history of intravenous drug use and hepatitis C infection who developed end-stage kidney disease due to AA amyloidosis. Our second patient's course was complicated by renal adenovirus, pulmonary aspergillosis and hepatitis C with AA amyloidosis subsequently being identified in the allograft 2.5 years post-transplantation. Renal allograft function remains stable 4-years post-transplantation. These reports describe clinical and pathologic features of two cases of AA amyloidosis presenting with proteinuria and focal involvement of the renal allograft.

Amiloidosis, a mysterious disease, still underestimated

Amyloidosis, 150 years after being identified, still remains a mysterious disease, full of mystery, question marks and challenges, almost always ignored from the start, with terrible symptoms and terrible prognosis. The mechanics of the formation. persistence and setting of the amyloid fibrils are still under discussion. This article wishes to point out some of the main characteristics of this disease and the involved proteins by referring to the history. The pathogenesis, the histology, the diagnosis and a few aspects of the prognosis of this disease in the hope that future research will bring to light the answers for the mystery of amyloidosis along with more efficient therapies.