Microangiopathy in patients with chronic myelogenous leukemia treated with interferon

Nailfold capillaries and myositis specific antibodies in anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis

OBJECTIVES

This study aimed to quantify nailfold capillary (NFC) abnormalities in anti-melanoma differentiation-associated gene 5 (MDA5)-positive dermatomyositis (DM) patients and to evaluate the association with clinical parameters, including serum biomarkers. In addition, we aimed to clarify the period leading to remission of NFC abnormalities during immunosuppressive treatment in patients with DM.

METHODS

A prospective observational study was conducted including patients (n = 10) who first visited Hiroshima University Hospital and were diagnosed with DM or clinically amyopathic dermatomyositis (CADM) with anti-MDA5 antibodies. We compared the NFC abnormalities detected by nailfold-video capillaroscopy (NVC), physical findings, blood tests, respiratory function tests, and vascular-related growth factors measured using a LEGENDplexTM Multi-Analyte Flow Assay Kit.

RESULTS

NFC abnormalities improved in all patients from 2-17 weeks after the initiation of immunosuppressive treatment. The NVC scores were inversely correlated with anti-MDA5 antibody titres at baseline. NVC scores and forced vital capacity (FVC) were positively correlated. Baseline with macrophage colony-stimulating factor (M-CSF) and stem cell factor (SCF) was correlated with anti-MDA-5 titres.

CONCLUSION

Our study suggests that NVC scores and disease activity are inversely correlated before treatment. Vascular-related growth factors, such as M-CSF and SCF, may be associated with the disease mechanism in patients with anti-MDA5 antibody-positive DM.

Endothelial dysfunction and decreased exercise tolerance in interferon-alpha therapy in chronic hepatitis C: relation between exercise hyperemia and endothelial function

BACKGROUND

We previously reported that reversible endothelial dysfunction is caused by interferon-alpha therapy (IFN) in patients with chronic hepatitis C. In experimental studies, limb blood flow during exercise is reported to be dependent on endothelium-derived nitric oxide.

HYPOTHESIS

The purpose of this study was to confirm the effect of IFN on endothelial function and to investigate whether exercise hyperemia is dependent on endothelial function in humans.

METHODS

We performed symptom-limited exercise treadmill testing and measured flow-mediated vasodilation (FMD, endothelium-dependent vasodilation) and sublingual glyceryl-trinitrate-induced dilation (GTN-D, 0.3 mg, endothelium-independent vasodilation) in the brachial artery by using high-resolution ultrasound in 10 patients with chronic active hepatitis C (age 53 +/- 11 years, 2 men, 8 women) before and immediately after administration of recombinant interferon 2b (10 million U/day) for 4 weeks.

RESULTS

There were no significant abnormal findings in any patients in routine studies of 24-h ambulatory electrocardiogram monitoring, two-dimensional echocardiography, and exercise treadmill testing both before and after treatment. Leg fatigue and exhaustion were the reasons for termination of exercise treadmill testing in each patient. Pressure rate product was calculated at rest and peak exercise. Interferon-alpha therapy significantly (p<0.05) decreased FMD (6.8 +/- 3.1 vs. 1.9 +/- 2.6%), exercise treadmill testing tolerance time (437 +/- 89 vs. 395 +/- 62 s) and peak pressure rate product (283 +/- 41 vs. 241 +/- 47 mmHg x beats/min x 10(-2)), but not GTN-D (13.4 +/- 5.4 vs. 17.0 +/- 5.5%). The change of FMD due to IFN significantly and highly correlated with exercise treadmill testing tolerance time (r = 0.86, p<0.001), but not with change of peak pressure rate product, suggesting that FMD is more closely related to the condition of the peripheral circulation than is cardiac performance.

CONCLUSION

These results suggest that IFN in patients with chronic hepatitis C impairs endothelial function and exercise tolerance, and that endothelial function might be at least partly involved in exercise hyperemia in humans.

Drug-induced vasculitis

Therapeutic agents from virtually every pharmacological class have been implicated in the development of drug-induced vasculitis. Clinical manifestations range from small vessel hypersensitivity vasculitis and leukocytoclastic vasculitis to clinical syndromes indistinguishable from classical systemic forms of vasculitis such as Wegener's granulomatosis, polyarteritis nodosa and Churg-Strauss syndrome (CSS). The exact pathogenic mechanisms involved remain to be elucidated; but both cell-mediated and humoral immunity appear to play important roles. Affected individuals may present with cutaneous involvement alone or life-threatening systemic involvement, which may result in severe and sometimes fatal illness. Since clinical presentation as well as serological and pathological parameters is identical to idiopathic forms of vasculitis, a high index of suspicion is necessary to accurately and expeditiously diagnose drug-induced vasculitis. Withdrawal of the offending agent alone is often sufficient to induce prompt resolution of clinical manifestations, obviating the need for systemic corticosteroids or more powerful forms of immunosuppression.

Vascular events associated with alpha interferon therapy

Alpha Interferon (IFN) is a biological agent used for the therapy of an increasing number of diseases, either as an established effective therapeutic tool or in the context of clinical trials. The use of IFN may be complicated by serious adverse reactions. We describe here the clinical course of a variety of vasculopathic complications in association with IFN-therapy in 12 patients with the diagnosis of chronic myeloid leukemia and 1 patient with malignant melanoma treated at our institute. Vascular manifestations in these patients include Raynaud's phenomena, digital ulcerations and gangrene, pulmonary vasculitis, pulmonary hypertension and thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS). These reactions occurred after 3 months to 3 years of 3-10 million units (MU) daily IFN therapy. Concomitant administration of hydroxyurea (HU) was noted in 5 patients. Discontinuation of IFN and initiation of immunosuppressive therapy brought about a complete resolution or arrested progression of these reactions. IFN-therapy may be complicated by severe vasculopathic/vasospastic complications that usually improve after its discontinuation. Possible underlying mechanisms for these complications are discussed. The early diagnosis of these complications may be vital and IFN should be immediately discontinued when early signs of these complications become evident.

Interferon-induced Raynaud's syndrome

OBJECTIVE

To review the clinical features, diagnosis, treatment, and outcome of interferon-induced Raynaud's phenomenon.

METHODS

The medical literature was reviewed from 1967 to November 2001 with the assistance of a MEDLINE search using the key words: Raynaud, Interferon, ischemia, thrombosis and necrosis. A qualitative review was performed after the articles were abstracted and the relevant information was summarized.

RESULTS

Twenty-four cases of interferon-induced Raynaud's phenomenon (including our patient) are described. Interpheron-alpha was the most common causative agent (14 cases). The symptoms appeared weeks to years after beginning treatment and varied from mild vasospasm to occlusion of digital arteries and tissue necrosis (14 cases), sometimes necessitating finger amputation (6 patients). Digital plethysmography, arteriography and capillaroscopy were valuable diagnostic tools. In 4 cases, cardiac, ophthalmic, or central nervous system drug-induced ischemia accompanied the peripheral Raynaud's phenomenon. Of the 15 cases with a documented outcome, withdrawal of the drug alone resulted in complete (6 patients) or partial (1 patient) recovery. In the others, supportive therapy was needed. The recovery period lasted from 2 weeks to 3 months. In 2 patients, continuation of treatment was possible.

CONCLUSIONS

Raynaud's phenomenon and related complications must be recognized as possible side effects of interferon therapy. Early diagnosis and withdrawal of the drug may prevent unnecessary morbidity and disability.

Drug-induced vasculitis

Many therapeutic agents, including recently introduced biologic response modifiers, can induce a variety of vasculitic manifestations ranging from small vessel hypersensitivity vasculitis and leukocytoclastic vasculitis to distinct vasculitic syndromes such as Wegener's granulomatosis, polyarteritis nodosa, and Churg Strauss syndrome. The pathogenic mechanisms remain to be defined and appear to be multifactorial, with cell-mediated and humural immune mechanisms playing important roles. Clinical presentation varies in severity from mild to severe and even fatal illness, can be self-limiting, or follows a more chronic protracted course. There are no significant differences in clinical presentation, serologic abnormalities, and pathologic findings with the idiopathic forms of vasculitis. However, it is extremely important to identify the offending drug because the discontinuation of the drug is often followed by a rapid improvement of the underlying vasculitic disorder.