Ruxolitinib is effective and safe in Japanese patients with hydroxyurea-resistant or hydroxyurea-intolerant polycythemia vera with splenomegaly

[Recommended diagnostics for pruritus affecting primary non-lesional skin]

BACKGROUND

Chronic pruritus affecting primary non-lesional skin (CPNL) manifests as a common symptom across a spectrum of diseases spanning various medical specialties. Given the diverse etiological factors involved, diagnosing the underlying condition poses a significant challenge.

OBJECTIVES

To provide a comprehensive overview of clinical, laboratory, and imaging diagnostics for CPNL.

MATERIALS AND METHODS

A thorough literature search on the diagnostics of chronic pruritus was conducted using PubMed with specific keywords "chronic pruritus AND non-lesional skin", "chronic itch AND non-lesional skin", "chronic pruritus AND diagnostics", "chronic itch AND diagnostics", "CKD-aP", "hepatic pruritus", "cholestatic pruritus", and "myeloproliferative neoplasms AND pruritus".

RESULTS

A systematic diagnostic approach is recommended for patients with CPNL, guided by the prevalence of pruritus-associated diseases. Initial basic diagnostics facilitate a cost-effective and focused evaluation during the initial medical assessment. Information pertaining to underlying diseases can be further refined through specialized diagnostic procedures.

CONCLUSIONS

CPNL often presents a diagnostic dilemma. Adopting a stepwise diagnostic strategy facilitates the identification of underlying etiologies, which is crucial for recognizing diseases and administering pruritus-specific pharmacotherapy.

Recent progress of JAK inhibitors for hematological disorders

JAK inhibitors are important therapeutic options for hematological disorders, especially myeloproliferative neoplasms. Ruxolitinib, the first JAK inhibitor approved for clinical use, improves splenomegaly and ameliorates constitutional symptoms in both myelofibrosis and polycythemia vera patients. Ruxolitinib is also useful for controlling hematocrit levels in polycythemia vera patients who were inadequately controlled by conventional therapies. Furthermore, pretransplantation use of ruxolitinib may improve the outcome of allo-hematopoietic stem cell transplantation in myelofibrosis. In contrast to these clinical merits, evidence of the disease-modifying action of ruxolitinib, i.e., reduction of malignant clones or improvement of bone marrow pathological findings, is limited, and many myelofibrosis patients discontinued ruxolitinib due to adverse events or disease progression. To overcome these limitations of ruxolitinib, several new types of JAK inhibitors have been developed. Among them, fedratinib was proven to provide clinical merits even in patients who were resistant or intolerant to ruxolitinib. Pacritinib and momelotinib have shown merits for myelofibrosis patients with thrombocytopenia or anemia, respectively. In addition to treatment for myeloproliferative neoplasms, recent studies have demonstrated that JAK inhibitors are novel and attractive therapeutic options for corticosteroid-refractory acute as well as chronic graft versus host disease.

Treatment of hydroxyurea-resistant/intolerant polycythemia vera: a discussion of best practices

Polycythemia vera (PV) is a burdensome, chronic myeloproliferative neoplasm characterized by activating mutations in Janus kinase 2, erythrocytosis, and bone marrow hypercellularity. The goals of treatment are to achieve hematocrit and blood count control to ultimately reduce the risk of thrombohemorrhagic events and improve PV-related symptoms. Treatment is risk-stratified and typically includes cytoreduction with hydroxyurea or interferon formulations in first line for high-risk disease. However, inadequate response, resistance, or intolerance to first-line cytoreductive therapies may warrant introduction of second-line treatments, such as ruxolitinib. In this review, I detail preferred treatment and patient management approaches following inadequate response to or intolerance of first-line treatment for PV.

[Systemic pruritus: what is new in diagnosis and treatment?]

BACKGROUND

Chronic pruritus is a common symptom of various systemic diseases. In particular, patients with chronic renal failure, hepatobiliary diseases, and myeloproliferative neoplasms are affected.

OBJECTIVES

The purpose of this review is to provide an overview of laboratory chemistry and imaging diagnostics as well as current and novel therapeutic approaches to pruritus of systemic diseases.

MATERIALS AND METHODS

An extensive PubMed search was performed.

RESULTS

To clarify the cause of chronic pruritus, a step-by-step diagnosis is recommended, which is based on the frequency of pruritus-associated diseases. A basic diagnosis enables a cost-effective and targeted clarification at the level of a general practitioner. Current topical and drug therapy recommendations of pruritus in chronic renal failure, hepatobiliary diseases, myeloproliferative neoplasms, and rarer causes are summarized. In addition, novel therapeutic approaches such as the κ‑opioid receptor agonist difelikefalin, bezafibrate, inhibitors of the ileal bile acid transporter (IBAT), and the JAK-STAT pathway are highlighted.

CONCLUSIONS

Chronic pruritus in systemic diseases can be a diagnostic challenge. A staged diagnostic approach facilitates identification of the underlying disease. Improved pathophysiological understanding has led to the first approved therapeutic options for chronic kidney disease-associated and hepatic pruritus.

Volumetric Splenomegaly in Patients With Polycythemia Vera

BACKGROUND

Non-palpable splenomegaly in patients with polycythemia vera (PV) has seldom been addressed. In this retrospective study, we evaluated non-palpable, volumetric splenomegaly defined based on age- and body surface area (BSA)-matched criteria in patients with PV diagnosed according to the 2016 World Health Organization diagnostic criteria.

METHODS

Patients with PV who underwent abdominal computed tomography (CT) and who had palpable splenomegaly at diagnosis from January 1991 to December 2020 at Chungnam National University Hospital were enrolled. The spleen volume of each patient was determined by volumetric analysis of abdominal CT and adjusted for the patient's age and BSA. Then the degree of splenomegaly was classified as no splenomegaly, borderline volumetric splenomegaly, overt volumetric splenomegaly, or palpable splenomegaly.

RESULTS

Of the 87 PV patients enrolled, 15 (17.2%) had no splenomegaly, whereas 17 (19.5%), 45 (51.7%), and 10 (11.5%) had borderline volumetric, overt volumetric, and palpable splenomegaly, respectively. The degree of splenomegaly did not affect the cumulative incidence of thrombotic vascular events (10-year incidence: 7.7%, 0%, 22.3%, and 50.7%, respectively, P = 0.414). By contrast, splenomegaly tended to adversely affect myelofibrotic transformation (10-year cumulative incidence: 0%, 0%, 7.1%, and 30.3%, respectively, P = 0.062). Moreover, the cumulative incidence of myelofibrotic transformation was significantly higher in patients with overt volumetric or palpable splenomegaly than those with no or borderline volumetric splenomegaly (10-year incidence: 0% vs. 10.3%, respectively; 15-year incidence: 0% vs. 26.3%, respectively, P = 0.020). Overall survival (OS) differed among patients with different degrees of splenomegaly (15-year OS: 100%, 78.6%, 71.7%, and 51.9%, respectively, P = 0.021).

CONCLUSION

The degree of splenomegaly, including volumetric splenomegaly, based on age- and BSA-matched reference spleen volumes at diagnosis reflects disease progression in PV patients. Therefore, volumetric splenomegaly should be evaluated at the time of diagnosis and taken into consideration when predicting the prognosis of patients with PV.

[Pruritus in systemic diseases : Common and rare etiologies]

Chronic pruritus is a symptom of various internal disorders. In contrast to dermatological diseases, pruritus does not present with primary skin alterations in these patients. However, intense scratching my cause secondary skin changes such as abrasion, excoriation, prurigo nodularis, or in rare cases even scarring. The most common internal causes for chronic pruritus are chronic kidney disease, hepatobiliary, and hematological disorders as well as adverse drug reactions. Pruritus is less commonly seen in patients with endocrine or metabolic diseases, malabsorption syndromes, infectious diseases, and solid tumors. The pathogenesis of pruritus in these disorders remains largely elusive, albeit first insights have been gained for uremic and cholestatic pruritus. Antipruritic treatment is therefore symptomatic in most cases and may represent a clinical challenge. The calcium channel blockers gabapentin and pregabalin have the best proven efficacy in chronic kidney disease associated pruritus. In Japan, nalfurafine, a κ-opioid receptor agonist, has been licensed for this indication. UVB light may also attenuate uremic symptoms. In patients suffering from hepatobiliary disorders the sequestrant cholestyramine and the enzyme inducer rifampicin are effective. Furthermore, bezafibrate, the μ‑opioid receptor antagonists and, in Japan, nalfurafine may be used to ameliorate cholestatic pruritus. So far, no randomized controlled trials have been performed for chronic itch in other internal disorders. Antipruritic treatment is symptom-based with a focus on the effective therapy of the underlying disease.

Possible roles of basophils in chronic itch

Basophils are blood granulocytes and normally constitute <1% of blood peripheral leucocytes. Basophils share some morphological and functional similarities with mast cells, and basophils were once regarded as redundant and negligible circulating mast cells. However, recent studies reveal the indispensable roles of basophils in various diseases, including allergic and pruritic diseases. Basophils may be involved in itch through the mediation of a Th2 immune response, interaction with other cells in the skin and secretion of a wide variety of itch-related mediators, for example histamine, cytokines and chemokines (IL-4, IL-13, IL-31 and TSLP), proteases (cathepsin S), prostaglandins (PGE2 and PGD2), substance P and platelet-activating factor. Not only pruritic skin diseases (eg, atopic dermatitis, irritant contact dermatitis, chronic urticaria, prurigo, papulo-erythroderma of Ofuji, eosinophilic pustular folliculitis, scabies, tick bites and bullous pemphigoid) but also pruritic systemic diseases (eg, primary sclerosing cholangitis and polycythemia vera) may be affected by basophils.