Monoclonal gammopathy of undeterminated significance and endoneurial IgG deposition: A case report

Monoclonal gammopathies of clinical significance (MGCS): In pursuit of optimal treatment

Monoclonal gammopathy of clinical significance (MGCS) represents a new clinical entity referring to a myriad of pathological conditions associated with the monoclonal gammopathy of undetermined significance (MGUS). The establishment of MGCS expands our current understanding of the pathophysiology of a range of diseases, in which the M protein is often found. Aside from the kidney, the three main organ systems most affected by monoclonal gammopathy include the peripheral nervous system, skin, and eye. The optimal management of these MGUS-related conditions is not known yet due to the paucity of clinical data, the rarity of some syndromes, and limited awareness among healthcare professionals. Currently, two main treatment approaches exist. The first one resembles the now-established therapeutic strategy for monoclonal gammopathy of renal significance (MGRS), in which chemotherapy with anti-myeloma agents is used to target clonal lesion that is thought to be the culprit of the complex clinical presentation. The second approach includes various systemic immunomodulatory or immunosuppressive options, including intravenous immunoglobulins, corticosteroids, or biological agents. Although some conditions of the MGCS spectrum can be effectively managed with therapies aiming at the etiology or pathogenesis of the disease, evidence regarding other pathologies is severely limited to individual patient data from case reports or series. Future research should pursue filling the gap in knowledge and finding the optimal treatment for this novel clinical category.

Corneal Densitometry and In Vivo Confocal Microscopy in Patients with Monoclonal Gammopathy—Analysis of 130 Eyes of 65 Subjects

Background: Corneal imaging may support an early diagnosis of monoclonal gammopathy. The goal of our study was to analyze corneal stromal properties using Pentacam and in vivo confocal cornea microscopy (IVCM) in subjects with monoclonal gammopathy. Patients and methods: In our cross-sectional study, patients with monoclonal gammopathy (130 eyes of 65 patients (40.0% males; age 67.65 ± 9.74 years)) and randomly selected individuals of the same age group, without hematological disease (100 eyes of 50 control subjects (40.0% males; age 60.67 ± 15.06 years)) were included. Using Pentacam (Pentacam HR; Oculus GmbH, Wetzlar, Germany), corneal stromal light scattering values were obtained (1) centrally 0–2 mm zone; (2) 2–6 mm zone; (3) 6–10 mm zone; (4) 10–12 mm zone. Using IVCM with Heidelberg Retina Tomograph with Rostock Cornea Module (Heidelberg Engineering, Heidelberg, Germany), the density of hyperreflective keratocytes and the number of hyperreflective spikes per image were manually analyzed, in the stroma. Results: In the first, second and third annular zone, light scattering was significantly higher in subjects with monoclonal gammopathy, than in controls (p ≤ 0.04). The number of hyperreflective keratocytes and hyperreflective spikes per image was significantly higher in stroma of subjects with monoclonal gammopathy (p ≤ 0.012). Conclusions: Our study confirms that increased corneal light scattering in the central 10 mm annular zone and increased keratocyte hyperreflectivity may give rise to suspicion of monoclonal gammopathy. As corneal light scattering is not increased at the limbal 10–12 mm annular zone in monoclonal gammopathy subjects, our spatial analysis provides evidence against the limbal origin of corneal paraprotein deposition. Using IVCM, stromal hyperreflective spikes may represent specific signs of monoclonal gammopathy.

Nerve biopsy: Current indications and decision tools

After initial investigation of patients presenting with symptoms suggestive of neuropathy, a clinical decision is made for a minority of patients to undergo further assessment with nerve biopsy. Many nerve biopsies do not demonstrate a definitive pathological diagnosis and there is considerable cost and morbidity associated with the procedure. This highlights the need for appropriate selection of patients, nerves and neuropathology techniques. Additionally, concomitant muscle and skin biopsies may improve the diagnostic yield in some cases. Several advances have been made in diagnostics in recent years, particularly in genomics. The indications for nerve biopsy have consequently changed over time. This review explores the current indications for nerve biopsies and some of the issues surrounding its use. Also included are comments on alternative diagnostic modalities that may help to supplant or reduce the use of nerve biopsy as a diagnostic test. These primarily include extraneural biopsy and neuroimaging techniques such as magnetic resonance neurography and nerve ultrasound. Finally, we propose an algorithm to assist in deciding when to perform nerve biopsies.

Ocular Signs and Ocular Comorbidities in Monoclonal Gammopathy: Analysis of 80 Subjects

Purpose

To examine the ocular signs of monoclonal gammopathy and to evaluate ocular comorbidities in subjects with monoclonal gammopathy. Patients and Methods. We analyzed patients from two large referral hematology centers in Budapest, diagnosed and/or treated with monoclonal gammopathy between 1997 and 2020. As a control group, randomly selected individuals of the same age group, without hematological disease, have been included. There were 160 eyes of 80 patients (38.75% males; age 67.61 ± 10.48 (range: 38-85) years) with monoclonal gammopathy and 86 eyes of 43 control subjects (32.56% males; age 62.44 ± 11.89 (range 37-86) years). The hematological diagnosis was MGUS in 9 (11.25%), multiple myeloma in 61 (76.25%), smoldering myeloma in 6 (7.50%), and amyloidosis or Waldenström macroglobulinemia in 2 cases (2.50%-2.50%). Before detailed ophthalmic examination with fundoscopy, 42 subjects with gammopathy (52.50%) and all controls filled the Ocular Surface Disease Index (OSDI) questionnaire.

Results

The OSDI score and best-corrected visual acuity (BCVA) were significantly worse in subjects with monoclonal gammopathy than in controls (p=0.02; p=0.0005). Among gammopathy subjects, we observed potential corneal immunoglobulin deposition in 6 eyes of 4 (3.75%) patients. Ocular surface disease (p=0.0001), posterior cortical cataract (p=0.01), and cataract (p=0.0001) were significantly more common among gammopathy subjects than in controls (χ ² test).

Conclusions

Ocular surface disease and cataract are more common, and BCVA is worse in patients with monoclonal gammopathy than in age-matched controls. Therefore, and due to the potential ocular signs and comorbidities of monoclonal gammopathy, we suggest a regular, yearly ophthalmic checkup of these patients to improve their quality of life.

[Chronic inflammatory demyelinating polyneuropathy: Diagnosis and therapeutic update]

Chronic inflammatory demyelinating polyradiculoneuropathies are acquired demyelinating neuropathies belonging to the group of autoimmune neuropathies. Since specific biological markers are present in less than 10% of cases, the diagnosis is based on the clinical and electrophysiological analysis of each patient. Furthermore, a decision-making algorithm ranking all other available paraclinical tools will guide the physician to the diagnosis of atypical forms. In nearly 80% of cases, these dysimmune neuropathies are responsive to first-line treatments, namely intravenous immunoglobulins, corticosteroids and plasma exchanges. A second line treatment may be proposed in case of no response, intolerance or inaccessibility to the three reference treatments. While some immunosuppressants or monoclonal antibodies can sometimes be very effective, there is currently no predictive marker or recommendation available to determine which treatment will be most appropriate for which patient.

Longitudinal extensive transverse myelitis with an abnormal uFLC ratio in a pediatric patient: Case report and literature review

RATIONALE

The serum and urine-free light chain (sFLC/uFLC) ratios of kappa (κ) to lambda (λ) serve as biomarkers for plasma cell disorders, especially multiple myeloma. However, to our best knowledge, the ratios have not been appropriately assessed for acute transverse myelitis (ATM).

PATIENT CONCERNS

We present a 12-year-old boy who had sudden onset low back pain following paralysis of his 4 extremities and disturbance consciousness. Magnetic resonance imaging (MRI) of the brain and spine indicated diffuse hyperintensity in T2-weighted images from the cervical spinal cord to the conus medullaris. An abnormal serum M-peak and uFLC ratio were detected in acute stage.

DIAGNOSES

Based on the image findings, laboratory findings, and physical examination results, the diagnosis of acute transverse myelitis was established.

INTERVENTIONS AND OUTCOMES

With the treatment of pulse therapy and 5 courses of plasmapheresis, the patient had improvement in expanded disability status scale (EDSS) score from 9 to 5. Besides, the κ/λ ratio was also returned within the normal range.

LESSON

The case presented an unusual phenomenon of transient abnormal κ/λ ratio combined with an M-peak in the acute course of longitudinally extensive transverse myelitis (LETM), which revealed FLC ratio recovering accompany with the improvement of disease. Further studies are required to identify the association between ATM and monoclonal gammopathy of undetermined significance (MGUS).