AL amyloidosis with a localized B cell neoplasia

Presentation and Outcomes of Localized Immunoglobulin Light Chain Amyloidosis: 14-Year Experience of an Academic Center

Localized light chain amyloidosis (loc-AL) is a rare disorder characterized by localized deposition of misfolded AL fibrils. There are limited data on patterns of disease presentation and long-term outcomes. In this study, we retrospectively reviewed 146 patients with loc-AL at our institution between January 1, 2010, and March 1, 2024. We excluded patients with evidence of systemic AL amyloidosis. We calculated local (PFSL) and systemic (PFSs) progression free survival (PFS) and overall survival (OS) using the Kaplan-Meier method. We found that loc-AL most commonly involved the respiratory (26%), gastrointestinal (17%), head and neck (17%) and genitourinary (10%) systems. Overall, 51% patients were asymptomatic at presentation, and 16% had a co-existent autoimmune disease. First line management included observation (52%), surgical resection (39%), chemotherapy (3%), and radiation (2%). Most patients (59%) had a response with first-line therapy. The median PFSL was ∼15 years (10-year PFSL 68%), and median OS was not reached (10-year OS 83%). None of the patients had progression to systemic amyloidosis. Seventeen patients had local recurrence and required second line therapy. In conclusion, loc-AL has an excellent prognosis and does not progress to systemic AL amyloidosis. Observation and/or surgical removal are usually adequate first-line approaches; however, a small proportion of patients can relapse locally requiring repeated interventions for symptom control.

Amyloid Light-Chain (AL) Amyloidosis of the Trachea Associated With an Indolent B-cell Neoplasm

We report the case of a 66-year-old woman who was diagnosed with localized tracheal amyloid light-chain (AL) amyloidosis caused by an underlying B-cell neoplasm. The diagnosis was confirmed through subsequent bronchoscopy and biopsies; however, she experienced a challenging episode of hypoxic respiratory failure that required intervention. Repeat bronchoscopies showed persistent subglottic stenosis and tracheobronchomalacia, which led to tracheal debulking surgery and additional interventions. The patient's treatment began with rituximab, zanubrutinib, and dexamethasone with outpatient follow-up. The rarity of tracheobronchial amyloidosis and its connection to B-cell malignancies are highlighted, emphasizing the challenges in diagnosis and the importance of tailored treatment strategies. The patient's clinical course, characterized by atypical respiratory symptoms, delayed diagnosis, and an evolving treatment approach, underscores the complexities of managing such a rare and intricate case.

Guidelines for non-transplant chemotherapy for treatment of systemic AL amyloidosis: EHA-ISA working group

BACKGROUND

This guideline has been developed jointly by the European Society of Haematology and International Society of Amyloidosis recommending non-transplant chemotherapy treatment for patients with AL amyloidosis.

METHODS

A review of literature and grading of evidence as well as expert recommendations by the ESH and ISA guideline committees.

RESULTS AND CONCLUSIONS

The recommendations of this committee suggest that treatment follows the clinical presentation which determines treatment tolerance tempered by potential side effects to select and modify use of drugs in AL amyloidosis. All patients with AL amyloidosis should be considered for clinical trials where available. Daratumumab-VCD is recommended from most untreated patients (VCD or VMDex if daratumumab is unavailable). At relapse, the two guiding principles are the depth and duration of initial response, use of a class of agents not previously exposed as well as the limitation imposed by patients' fitness/frailty and end organ damage. Targeted agents like venetoclax need urgent prospective evaluation. Future prospective trials should include advanced stage patients to allow for evidence-based treatment decisions. Therapies targeting amyloid fibrils or those reducing the proteotoxicity of amyloidogenic light chains/oligomers are urgently needed.

Localized light chain amyloidosis: A self-limited plasmacytic B-cell lymphoproliferative disorder

Immunoglobulin light chain amyloidosis can be either systemic or localized. Although these conditions share a similar name, they are strikingly different. Localized light chain amyloidosis has been challenging to characterize due to its lower incidence and highly heterogeneous clinical presentation. Here, we review the emerging literature, emphasizing recent reports on large cohorts of patients with localized amyloidosis, and provide insights into this condition's pathology and natural history. We find that patients with localized amyloidosis have an excellent prognosis with overall survival similar to that of the general population. Furthermore, the risk of progression to systemic disease is low and likely represents initial mischaracterization as localized disease. Therefore, we argue for the incorporation of more sensitive techniques to rule out systemic disease at diagnosis. Despite increasing mechanistic understanding of this condition, much remains to be discovered regarding the cellular clonal evolution and the molecular processes that give rise to localized amyloid formation. While localized surgical resection of symptomatic disease is typically the treatment of choice, the presentation of this disease across the spectrum of plasmacytic B-cell lymphoproliferative disorders, and the frequent lack of an identifiable neoplastic clone, can make therapy selection a challenge in the uncommon situation that systemic chemotherapy is required.

The amyloid proteome: a systematic review and proposal of a protein classification system

Amyloidosis is a disease caused by pathological fibril aggregation and deposition of proteins in different tissues and organs. Thirty-six fibril-forming proteins have been identified. So far, proteomic evaluation of amyloid focused on the detection and characterization of fibril proteins mainly for diagnostic purposes or to find novel fibril-forming proteins. However, amyloid deposits are a complex mixture of constituents that show organ-, tissue-, and amyloid-type specific patterns, that is the amyloid proteome. We carried out a comprehensive literature review on publications investigating amyloid via liquid chromatography coupled to tandem mass spectrometry, including but not limited to sample preparation by laser microdissection. Our review confirms the complexity and dynamics of the amyloid proteome, which can be divided into four functional categories: amyloid proteome-category 1 (APC1) includes exclusively fibrillary proteins found in the patient; APC2 includes potential fibril-forming proteins found in other types of amyloid; and APC3 and APC4 summarizes non-fibril proteins-some being amyloid signature proteins. Our categorization may help to systemically explore the nature and role of the amyloid proteome in the manifestation, progression, and clearance of disease. Further exploration of the amyloid proteome may form the basis for the development of novel diagnostic tools, thereby enabling the development of novel therapeutic targets.

Light Chain Amyloidosis (AL) Associated With B Cell Lymphoma a Single Center Experience

INTRODUCTION

Light chain (AL) amyloidosis and B-cell lymphoma represent 5% to 7% of all AL, Systemic amyloidosis, deposits in sites remote from the underlying lymphoma, and peritumoral amyloidosis deposition is within the immediate vicinity.

MATERIALS AND METHODS

We conducted a retrospectively study to identify and describe AL with B cell lymphoma at Princess Margaret Cancer Center from 01 January 1997 to 31 July 2019.

RESULTS

Thirty-five patients with AL and lymphoma, an incidence of 6, 2%, median age of diagnosis of 66 (range 47 to 86), majority male, most had underlying Waldestrom's Macroglobulinemia. 21 patients with peritumoral AL (PAL), and 15 with systemic AL. 42.8% of the patients had major organ involvement. 35% got treatment with Rituximab with alkylator, 20% received proteasome inhibitors, 17% patients were on a watch and wait approach, amyloid response showed very good partial response > 45.8%, and lymphoma ORR was 42.8%, with a median follow up of 31.5 months. A 36 month overall survival (OS) and progression-free survival (PFS) showed worse outcomes for heart involvement OS (P = .002), PFS (0.057) and IgM subtype OS (P = .02), PFS (0.01).

CONCLUSION

We have shown adverse outcome with IgM AL and to document a differences in OS and PFS not previously reported for PAL.

Monotypic Plasma Cell Proliferation of Uncertain Clinical Significance Mimicking Interstitial Cystitis: An Early Lesion of MALT Lymphoma?

We prospectively studied our institutional experience of bladder extranodal marginal zone (mucosa-associated lymphoid tissue [MALT]) lymphoma including bladder biopsies in which the possibility of MALT lymphoma was considered. We identified a subset of cases primary to the urinary bladder, presenting with prominent plasma cell infiltrates and symptoms mimicking bladder pain syndrome/interstitial cystitis. These proliferations were designated for this study as "monotypic plasma cell proliferation of uncertain clinical significance" (MPCP-US), as the features were insufficient for diagnosis of MALT lymphoma. We identified 33 patients, consisting of 22 cases of MPCP-US (6 of which were associated with amyloid deposition) and 11 cases of MALT lymphoma. MPCP-US was more prevalent in men (73%), a mass lesion was not identified at cystoscopy, and only 1 case had an accompanying urinary tract infection (4.5%). Histologically, MPCP-US presented as monotypic plasma cells arranged in a superficial band-like distribution in the lamina propria, predominantly kappa restricted (68%) and IgA+ or IgM+ (64% and 23%, respectively) and without a histologic mass of atypical B cells or plasma cells, not diagnostic for established MALT lymphoma or plasmacytoma. Secondary involvement of the bladder by other lymphoproliferative disorders was excluded and there was no evidence of progressive disease. MALT lymphomas are presented for comparison and our analysis demonstrated that MPCP-US represent a different clinicopathologic entity compared with classic MALT lymphoma. We present the first series of cases of MPCP-US. The recognition of this entity is fundamental to the development of management protocols to relieve intractable symptoms mimicking bladder pain syndrome/interstitial cystitis in these patients.

Localized immunoglobulin light chain amyloidosis: Novel insights including prognostic factors for local progression

In localized light chain amyloidosis (locAL), amyloidogenic light chains (aLC) are produced and deposited locally by a B-cell clone. We present 293 patients with immunohistochemically confirmed locAL. Lung (nodular pulmonary) with 63 patients was the most involved organ. The aLC was λ in 217 cases (κ:λ ratio 1:3). A local B-cell clone was identified in 30% of cases. Sixty-one (21%) had a concomitant autoimmune disorder (cAD). A monoclonal component (MC) were present in 101 (34%) patients and were more frequent in subjects with cAD (51% vs 34%; P = .03). Cigarette smoking was more prevalent in lung locAL (54% vs 37%; P = .018). After a median follow-up of 44 months, 16 patients died and 5- and 10-years locAL progression-free survival (PFS) were 62% and 44%. Interestingly, locAL-PFS was shorter among patients with an identified clonal infiltrate at amyloid deposition site (40 vs 109 months; P = .02) and multinuclear giant cells and/or an inflammatory infiltrate resulted in longer locAL-PFS in lung involvement (65 vs 42 months; P = .01). However, no differences in locAL PFS were observed in patients with cAD, a MC and involved organ site. Treatment was administered in 163 (54%) patients and was surgical in 135 (46%). Median locAL-PFS after first treatment was 56 months. Responders had longer locAL-PFS (78 vs 17 months; P < .001). Three patients with lung locAL and a MC were diagnosed as systemic AL amyloidosis at follow-up. In summary, locAL pathogenesis seems to be heterogeneous and the clonal infiltrate leads local progression.

CT features in amyloidosis of the respiratory system - Comprehensive analysis in a tertiary referral center cohort

PURPOSE

Amyloidosis of the respiratory system is rare and challenging since imaging findings have several more prevalent alternative diagnoses. We analyze and quantify chest CT findings in a large tertiary referral center patient cohort with confirmed amyloidosis of the respiratory system.

METHODS

67 patients with histology-proven amyloidosis of the respiratory system and with available chest CT scans were retrospectively enrolled (years 2002-2018): 41 patients with local pulmonary parenchymal, 20 with local tracheobronchial, and 6 with systemic amyloidosis. CT was scored for findings like mass lesions, nodules, cysts, lymphadenopathy, calcifications and pleural, interstitial and tracheobronchial manifestations. Clinical data and imaging findings' frequencies among patients with local pulmonary parenchymal and tracheobronchial amyloidosis were compared.

RESULTS

Patients with local pulmonary parenchymal amyloidosis were older (67 vs. 56 years; P = 0.013) and less frequently symptomatic for cough (24% vs. 70%; P = 0.018) and bronchopulmonal infections (7% vs. 55%; P < 0.001) than patients with tracheobronchial amyloidosis. Local pulmonary parenchymal amyloidosis showed higher frequency of mass-like lesions (41% vs. 0%; P = 0.002) and nodules (95% vs. 20%; P < 0.001, with 10 or more nodules in 56% vs. 0%; P < 0.001 and predominantly pleura-associated in 32% vs. 0%; P = 0.02). Tracheobronchial amyloidosis leads to wall thickening of the bronchi (100% vs. 5%; P < 0.001) and the trachea (70% vs. 2%; P < 0.001). Systemic amyloidosis went along with a predominant alveolar septal pattern in 4 out of 6 patients.

CONCLUSION

Patients with local pulmonary parenchymal amyloidosis differ significantly from patients with tracheobronchial amyloidosis regarding clinical data and CT findings' frequencies. Being familiar with radiological manifestations of all three respiratory amyloidosis distribution patterns is essential to accelerate the diagnosis.

Nonlymphoplasmacytic lymphomas associated with light-chain amyloidosis

The authors report on the subset of AL amyloidosis patients with nonlymphoplasmacytic lymphoma, emphasizing a predominance of marginal zone lymphoma, frequent delay in diagnosis, and a generally poor prognosis.