The POEMS syndrome with coexisting endocrinopathy--case report

We present a case of a woman with unique multisystem disorder--POEMS syndrome and endocrine abnormalities coexisting with it. The POEMS acronym comprises the dominant features: polyneuropathy, organomegaly, endocrinopathy, monoclonal protein (M protein), skin changes. Association between plasma cell dyscrasia and polyneuropathy, was described in 1956 year by Crow. The main features were coined in the acronym POEMS by Bardwick in 1980 year. The polysymptomatic clinical picture, progressive course and no-concurrent manifestations of main features impede the diagnosis. In this case, the first symptoms were the sensomotor polyneuropathy, peripheral oedema, osteosclerotic bone lesions, skin changes, organomegaly. They preceded diagnosis by 3 years. The first endocrinopathy was hypothyroidism. Definite diagnosis was delayed because we couldn't detect the presence of M protein. Immunoelectrophoresis didn't detect it, but analysis by immunofixation detected M protein in serum and urine. Within 3 years of the first symptoms, she developed hypogonadism hypergonadotropic. At first, the monotherapy with corticosteroids was used, then--melfalan with prednisone. Due to the progression of the disease, a thalidomide was used in therapy (it is anti-VEGF agent). One of the side effects of the treatment of thalidomide is the progression of polyneuropathy, which was observed in this patient. After finishing this therapy she received chemotherapy. This case report imposes the necessity of constants observation of patients with POEMS syndrome because there is a possibility of their developing other disorders. In the event of coexistence polyneuropathy and plasma cell dyscrasia, this disease should be taken into consideration.     

Syndrome of plasma cell dyscrasia,polyneuropathy, and diabetes mellitus.

Multiple myeloma associated with sclerotic bone lesions and polyneuropathy represents a distinct subset of the plasma cell dyscrasias. We describe a case of biclonal gammopathy (the second case reported), insulin-resistant diabetes mellitus, and no evidence for anti-insulin receptor antibodies. After treatment with chemotherapy and irradiation, the diabetes resolved, the polyneuropathy lessened greatly, and the patient is alive without evidence of progression five years later. The reports of 95 other cases are reviewed. This syndrome occurs in younger patients (mean age, 48 years) and is frequently associated with organomegaly, endocrinopathies, and skin changes. Irradiation to the sclerotic bone lesions frequently lessens the neuropathy and endocrinopathies and may result in long-term remission. The mechanism of action leading to the systemic effects seen in this syndrome is unknown but is likely related to proteins secreted by the abnormal plasma cells.     

Anti-BCMA CAR-T cells for treatment of plasma cell dyscrasia: case report on POEMS syndrome and multiple myeloma

Background

POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes) syndrome still has no standard treatment. On the basis that both POEMS syndrome and myeloma have an underlying plasma cell dyscrasia, anti-myeloma therapy can be expected to be useful for POEMS syndrome. Chimeric antigen receptor T (CAR-T) cells targeting B cell maturation antigen (BCMA) has been used in the treatment of relapsed and refractory multiple myeloma (RRMM). No POEMS syndrome cases treated with anti-BCMA CAR-T cells have been reported.

Case presentation

Here, we, for the first time, report a POEMS syndrome case treated with anti-BCMA CAR-T cells. A 49-year-old female with incapacitating POEMS syndrome that progressed on lenalidomide treatment was enrolled in a phase I study involving anti-BCMA CAR-T cells (ChiCTR-OPC-16009113). Another patient with RRMM who had undergone six prior lines treatments was also enrolled in the study. They received infusions of anti-BCMA CAR-T cells. Both patients achieved a stringent complete response. Complete remission persisted in the patient with POEMS syndrome and lasted for 7.6 months before a relapse in RRMM patient. Both patients had toxicity consistent with the grade 1 cytokine release syndrome.

Conclusions

This is the first report of treatment by anti-BCMA CAR-T cells in POEMS syndrome. Our findings demonstrate the anti-BCMA CAR-T cell treatment may be a feasible therapeutic option for patients with POEMS syndrome and RRMM who do not respond well to traditional therapies.

Trial registration

ChiCTR-OPC, ChiCTR-OPC-16009113. Registered 29 August 2016.

     

Association of Low Prostate-Specific Antigen Concentration and Panhypopituitarism

ObjectiveTo report the association of undetectable or very low prostate-specific antigen (PSA) concentrations with hypopituitarism.MethodsWe present a case series of 4 patients with low or undetectable PSA concentrations and associated panhypopituitarism and summarize the clinical presentation and pertinent laboratory and radiologic findings. We review related literature and discuss possible mechanisms explaining the described association.ResultsFour men with PSA values below the second percentile of a healthy population had hypopituitarism. In 3 men, low PSA concentrations were noted before large pituitary tumors were diagnosed. No man had headaches, visual problems, or other symptoms that were severe enough to prompt a search for tumor. All 4 patients had undetectable total testosterone levels. Luteinizing hormone and follicle-stimulating hormone levels were low to low-normal in 3 of the 4 patients. Baseline growth hormone level was low in 1 patient and undetectable in the other 3. The insulinlike growth factor 1 concentration was less than 73 ng/mL in each patient.ConclusionsWe believe that the association of low PSA concentrations and hypopituitarism is not incidental and that the extremely low PSA values in this case series were a consequence of both gonadal and growth hormone deficiency. We suggest that low PSA is a marker of combined profound testosterone and growth hormone deficiency in men with panhypopituitarism. This marker is important because PSA is frequently measured during routine health care visits; a low concentration may be the first clue to the presence of hypopituitarism in an otherwise asymptomatic patient. (Endocr Pract. 2008;14:432-436)     

Repairing a "broken heart" with hormone replacement therapy: case report of cardiogenic shock due to undiagnosed pituitary insufficiency

ObjectivesTo indicate cardiogenic shock as a very rare but serious clinical consequence of untreated panhypopituitarism attributable to Sheehan syndrome; to emphasize the importance of eliciting a detailed endocrine and obstetric history in women presenting with idiopathic heart failure; to highlight the diagnostic shortcomings of screening for thyroid dysfunction solely with thyroidstimulating hormone determinations; and to report the reversibility of severe heart failure induced by longterm pituitary insufficiency.MethodsDescribed is a case report of a 35yearold woman who presented with severe congestive heart failure, hypotension, and confusion. Her 2dimensional echocardiogram revealed appreciable systolic and diastolic dysfunction. In screening for possible endocrine causes of heart failure, a normal thyroidstimulating hormone level of 0.72 mIU/L (reference range, 0.35 to 5.5) was unremarkable; however, a profoundly low free thyroxine level of 0.12 ng/dL (reference range, 0.9 to 1.8) led clinicians to pursue a workup of central hypothyroidism.ResultsEndocrine testing confirmed the presence of panhypopituitarism and adrenal insufficiency. Magnetic resonance imaging of the brain revealed empty sella syndrome. Further questioning of the patient revealed a history of extensive postpartum bleeding 15 years earlier, failure to lactate, and secondary amenorrhea—all consistent with undiagnosed Sheehan syndrome. In the hospital, the patient was treated with intravenously administered corticosteroids and levothyroxine. Her mental status and symptomatic heart failure improved dramatically. After 9 months of oral levothyroxine and glucocorticoid therapy, the patient remained asymptomatic, and repeated echocardiography indicated completely normalized cardiac function.ConclusionSevere heart failure and cardiogenic shock can be a very rare (but fortunately reversible) complication of longstanding panhypopituitarism resulting from undiagnosed Sheehan syndrome. (Endocr Pract. 2012;18:e26e31)     

Serum Matrix Metalloproteinase-9 Levels in the Diagnosis of Functioning Adrena Tumors

ObjectiveTo investigate whether serum matrix metalloproteinase-9 (MMP-9) levels can be used as a diagnostic tool in determining the functioning status of benign adrenal tumors.MethodsIn this case-control study, medical records of patients with adrenal tumors who consecutively presented to an endocrinology clinic between August 2005 and October 2008 were evaluated. Operation was recommended when the incidentaloma was larger than 4 cm or when a hypersecreting tumor was suspected. A control group of healthy persons matched for age, body mass index, and sex was also enrolled. Patients underwent routine endocrinologic examinations. MMP-9 levels were compared preoperatively and postoperatively. Findings were compared among patients with functioning adrenal tumors, patients with nonfunctioning adrenal tumors, and control participants.ResultsOf 370 patients with adrenal tumors, 50 with adrenal incidentaloma met the inclusion criteria. Twenty- five healthy individuals were enrolled as controls. Group 1 included 20 patients with functioning adrenal tumors (14 with Cushing syndrome and 6 with pheochromocytoma), and Group 2 included 30 patients with nonfunctioning adrenal tumors. MMP-9 levels were higher in patients with nonfunctioning adrenal tumors and functioning adrenal tumors than in control participants (P < .001). MMP-9 levels in patients with functioning adrenal tumors were significantly higher than those in patients with nonfunctioning adrenal tumors (P = .002). After operation, levels decreased significantly in patients with Cushing syndrome and in those with pheochromocytoma; however, patients with Cushing syndrome and pheochromocytoma had similar MMP-9 levels preoperatively and postoperatively. No significant linear correlation existed between tumor volume and MMP-9 levels. A significant positive correlation was determined between preoperative MMP-9 concentrations and 24-hour urinary fractionated metanephrine and epinephrine (r = 0.938, P = .006; r = 0.965, P = .002, respectively), between MMP-9 levels and baseline cortisol levels (r = 0.402, P = .003), and between MMP-9 levels and cortisol levels obtained after dexamethasone suppression testing (r = 0.357, P = .006).ConclusionOur data suggest that serum MMP-9 levels may be useful in differentiating benign subclinical functioning adrenal tumors from benign nonfunctioning adrenal tumors. (Endocr Pract. 2010;16:419-427)     

Cerebral and ocular abnormalities with anterior pituitary insufficiency of familial nature

Three families presenting one or several cases of brain or ophthalmic abnormalities and an hypopituitarism at least by one of the members have been observed. In the first family, the mother and one of her sons present bilateral choroidoretineal coloboma with amblyopia; one of these two suffers as well from panhypopituitarism. In the second family two premature twins, a brother and his sister, present a syndrome with hypophyseal dwarfism and ophthalmic abnormalities, consisting in the boy's case in an peripapillary depigmentation with no visible sight trouble whereas girl's is showing an extreme microphthalmia with major mental retardation. In the third family two 2nd degree cousins present a panhypopituitarism but only one of the two reveals through neuroradiological investigations corpus callosum and septum lucidum agenesia. The karyotype is normal in all the cases. An hereditary mechanism appears clearly in the first family. It is possible in the second, probable in the third one.     

Long-Standing Undiagnosed Sheehan Syndrome Presenting as Polymorphic and Monomorphic Ventricular Tachycardia: A Case Series of 2 Patients

ObjectiveTo describe 2 cases of Sheehan syndrome presenting with ventricular tachycardia.MethodsIn this case series, we present 2 cases of Sheehan syndrome presenting with ventricular tachycardia, which is an extremely rare complication of Sheehan syndrome. We review the literature for cases of panhypopituitarism presenting with ventricular tachycardia and also review the pathophysiologic mechanisms underlying development of ventricular tachycardia in these patients.ResultsTwo female patients presented with ventricular tachycardia. One patient had monomorphic and the other had polymorphic ventricular tachycardia. On further workup, both patients were found to have panhypopituitarism. Due to past history of postpartum hemorrhage, both patients were suspected of having Sheehan syndrome as the cause of panhypopituitarism. Electrocardiogram revealed prolonged QT interval. Both patients were started on hormone replacement therapy. Both patients responded well initially and were discharged home. One of the patients is alive and healthy at the time of this report. However, the other patient was readmitted with seizures a few days after discharge and unfortunately died of sudden cardiac arrest.ConclusionUntreated cases of Sheehan syndrome can present with fatal ventricular tachycardia. Hormone replacement in these patients can treat and prevent fatal arrhythmias. (Endocr Pract. 2014;20:e211-e214)     

Bone Marrow Hypoplasiaresponsive to Testosterone Therapyin a Patient with Panhypopituitarism:Need for Adherence to Androgen Replacement

ObjectiveTo describe the case of a young Saudi male patient with long-term panhypopituitarism and pancytopenia attributable to poor adherence to androgen replacement therapy, which resolved after institution of testosterone treatment and recurred after another interval of poor adherence to recommended therapy.MethodsWe present the clinical and laboratory data before and after treatment with testosterone. In addition, the corresponding histologic changes in the bone marrow are illustrated.ResultsAfter resection of a hypothalamic glioma, panhypopituitarism developed in a 14-year-old Saudi boy. At age 22 years, he had shunt-related meningitis. He was then noted to have pancytopenia, with a platelet count of 54 × 10³/μL, a hemoglobin concentration of 6.9 g/dL, and a leukocyte count of 2.7 × 10³/μL. After treatment of sepsis, the pancytopenia persisted. No underlying cause was detected. Bone marrow biopsy showed a hypocellular marrow with dysplastic megakaryocytes. The patient’s family indicated that he had not been taking his testosterone therapy. Testosterone decanoate (250 mg) was administered intramuscularly daily for 3 days. His platelet count increased to 74 × 10³/μL. Maintenance therapy with testosterone once weekly for 3 weeks and then once every 3 weeks resulted in improved hematologic findings. Repeated bone marrow biopsy after 6 weeks showed normocellular marrow, with disappearance of the megakaryocytic dysplasia. The patient again discontinued his testosterone treatment, and the hematologic abnormalities recurred but were again corrected after supervised testosterone therapy.ConclusionThis case emphasizes the importance of androgen replacement therapy in patients with hypopituitarism, not only for sexual potency, bone strength, and quality of life but also for normal bone marrow function. (Endocr Pract. 2008;14:229-232)     

Panhypopituitarism secondary to a macroprolactinoma manifesting with pancytopenia:case report and literature review

ObjectiveTo present a case of pancytopenia associated with hypopituitarism secondary to a macroprolactinoma.MethodsWe report the clinical features on presentation and results of laboratory investigation. Findings on magnetic resonance imaging are illustrated. The response to hormone replacement therapy is summarized.ResultsA 46-year-old man was referred with pancytopenia and secondary hypothyroidism. Laboratory investigation revealed hypopituitarism and a substantially increased prolactin level. Magnetic resonance imaging of the head demonstrated a macroprolactinoma. Hematologic investigation disclosed no other cause for the pancytopenia. Hormone replacement therapy was initiated with hydrocortisone, levothyroxine, and testosterone. Cabergoline was used to induce regression of the prolactinoma. A rapid improvement was seen in the cytopenias, with normalization of the blood cell counts after 8 months of treatment. This result has been sustained during 29 months of follow-up.ConclusionPancytopenia associated with hypopituitarism has been reported in the literature as a rare occurrence limited to isolated case reports, predominantly associated with Sheehan syndrome. To our knowledge, this is the first reported case of pancytopenia macroprolactinoma. This finding is noteworthy because associated with a prolactin alone has been reported to support hematopoiesis in animal studies. (Endocr Pract. 2011;17:e32-e36)     

Generation of mice with a conditional null fraser syndrome 1 (Fras1) allele

Summary: Fraser syndrome (FS) is an autosomal recessive disease characterized by skin lesions and kidney and upper airway malformations. Fraser syndrome 1 (FRAS1) is an extracellular matrix protein, and FRAS1 homozygous mutations occur in some FS individuals. FRAS1is expressed at the epithelial‐mesenchymal interface in embryonic skin and kidney. blebbed mice have a null Fras1 mutation and phenocopy human FS. Like humans with FS, they exhibit a high fetal and neonatal mortality, precluding studies of FRAS1 functions in later life. We generated conditional Fras1 null allele mice. Cre‐mediated generalized deletion of this allele generated embryonic skin blisters and renal agenesis characteristic of blebbed mice and human FS. Targeted deletion of Fras1 in kidney podocytes circumvented skin blistering, renal agenesis, and early death. FRAS1 expression was downregulated in maturing glomeruli which then became sclerotic. The data are consistent with the hypothesis that locally produced FRAS1 has roles in glomerular maturation and integrity. This conditional allele will facilitate study of possible role for FRAS1 in other tissues such as the skin. genesis 50:892–898, 2012. © 2012 Wiley Periodicals, Inc.     

A monoclonal anti-idiotypic antibody against a human monoclonal IgM with specificity for myelin-associated glycoprotein

A human monoclonal IgM lambda antibody, directed against MAG, obtained from a patient with polyneuropathy associated with a gammopathy, was used as an immunogen to generate mouse monoclonal anti-idiotype antibodies. One hybridoma antibody, designated A8F2, reacts uniquely with the M-IgM of the patient, shows high affinity binding to the patient's M-IgM, and dose-dependently inhibits binding of the patient's M-IgM to its specific antigen MAG. Thus, A8F2 is a monoclonal anti-idiotype antibody that recognizes a region of the MAG binding site of the patient's IgM. Use of this anti-idiotype antibody in a competition RIA revealed the presence of naturally occurring anti-idiotype in the patient's serum. Because anti-idiotype antibodies may be part of a mechanism for down-regulation of antibody production, the use of A8F2 to induce a specific immunosuppression should be considered.     

Efforts in diagnosing early leprosy using serological techniques

Skin scrapings obtained from the lesions of leprosy patients of all types showed 96 % positivity to the serum antibody competition test using monoclonal antibody (ML04)to 35 kDa antigen of Mycobacterium leprae. Further, in vitro culture of full thickness skin biopsies from lepromatous patients were noted to release IgG antibodies toM. leprae with a peak antibody response at 48 h. The significance of this local antibody response toM. leprae in skin has been discussed for its possible use in diagnosing early leprosy.     

Revealing serum lipidomic characteristics and potential lipid biomarkers in patients with POEMS syndrome

POEMS syndrome is a rare plasma cell dyscrasia with distinct lipid metabolism abnormalities at disease onset. However, the serum lipidomic characteristics in patients with POEMS syndrome were not investigated. The study performed an untargeted lipidome screening by liquid chromatography-tandem mass spectrometry (LS-MS/MS) in the pre- and post-treatment serum of 24 patients with POEMS syndrome, together with the serum of 24 paired healthy controls. Patients with POEMS syndrome had a distinct serum lipid composition compared with healthy controls, and a 3-lipid model had a predictive accuracy of 93.5% in distinguishing patients and healthy controls consisting of fatty acyl 17-oxo-20Z-hexacosenoic acid, phosphatidylcholine(16:0/18:1(9Z)) and sterol lipid 5b-pregnanediol. Four lipids including 17-oxo-20Z-hexacosenoic acid (r = 0.423, P = .040) were correlated with risk stratification, and 2 lipids including Cer(d18:0/13:0) were inversely related to serum vascular endothelial growth factor level (r=−0.465, P = .022). Eleven lipids were related to disease activity, including arachidonic acid which was inversely related and lysoPC(20:4) which was positively related. The study indicated a distinct lipid characteristic profile of patients with POEMS syndrome different from healthy controls and identified several lipids that may serve as potential diagnostic markers and monitors of therapeutic efficacy, as well as indicating potential metabolism pathways involved in the pathological process.     

A Case of Hypercalcemia Associated with Castleman Disease

ObjectiveTo present a case of hypercalcemia associated with Castleman disease.MethodsThe details of case presentation, evaluation, diagnosis, and treatment are reviewed in a 25-year-old woman with severe hypercalcemia, joint pain, conjunctival injection, and lymphadenopathy.ResultsEndocrinopathies such as primary hyperparathyroidism were ruled out. Infectious and rheumatologic laboratory evaluations revealed normal results. On a whole-body scan, the patient was noted to have diffusely increased osseous uptake in conjunction with increased periarticular uptake, consistent with a metabolic superscan. After extensive evaluation, the patient underwent a right axillary lymph node biopsy and was found to have multicentric Castleman disease. She was treated with high-dose corticosteroids and eventually immunomodulators to help control her disease.ConclusionTo the best of our knowledge, this is the first published case report demonstrating hypercalcemia in association with Castleman disease. The pathologic mechanism is likely bone turnover mediated by cytokines such as interleukin-6. (Endocr Pract. 2010;16:1007-1011)     

Idiopathic Hypertrophic Pachymeningitis Resulting in Delayed Panhypopituitarism

ObjectiveTo describe an adult man with idiopathic hypertrophic pachymeningitis (IHPM) that progressed to involve the pituitary gland and caused hypopituitarism 6 years after the onset of the first symptom.MethodsWe describe the slow 6-year progression of IHPM in a man being treated with steroids, radiation, and antineoplastic medications and present clinical, pathologic, and imaging data. The pertinent literature is also reviewed.ResultsA 35-year-old man who presented with headaches, pain, and sensory loss on the right side of his face had thickened, infamed dura without granulomas. Initially, the right middle fossa, the lateral wall of the right cavernous sinus, and the tentorium were involved. Results from a dural biopsy specimen were consistent with IHPM. His symptoms were only partially controlled with continuous high-dose steroids, cyclophosphamide, azathioprine, and radiation therapy. IHPM was diagnosed based on findings from an open brain biopsy. Other pathologic causes of inflammatory dural thickening were excluded. Six years after the onset of the first clinical manifestation of IHPM, the patient developed panhypopituitarism. Magnetic resonance imaging showed that the inflammatory process had invaded the pituitary gland. IHPM was confirmed by findings from transsphenoidal biopsy.ConclusionIHPM is a rare disorder characterized by an unexplained inflammatory thickening of the dura at the skull base. The usual clinical symptoms are intractable headache and cranial nerve palsies. Physicians must be aware that IHPM can be slowly progressive despite attempted treatment, and that the disease process can invade the sella with dysfunction of both the anterior and the posterior pituitary gland. (Endocr Pract. 2007;13:481-486)     

Immunohistochemical demonstration of vitronectin in association with elastin and amyloid deposits in human kidney

The multifunctional glycoprotein vitronectin, also called serum spreading factor and S-protein of complement, is a potent inducer of cell adhesion and spreading in vitro, and also has a regulatory function in the complement and coagulation pathways. It is present both in plasma and tissue. Recently, vitronectin immunoreactivity was demonstrated in the elastic fibres of normal human skin. Normal and amyloid kidney tissue was investigated for vitronectin immunoreactivity using polyclonal and monoclonal antibodies in an avidin-biotin-peroxidase complex technique and in an alkaline phosphatase anti-alkaline phosphatase complex technique. Vitronectin was found in the elastic layers of normal vessel walls, and in glomerular sclerotic lesions in cases of benign nephrosclerosis, but not in normal glomeruli. Strong specific vitronectin immunoreactivity was found in the amyloid deposits in kidneys from cases with amyloid A type amyloidosis, and in cases with amyloid light chain type amyloidosis. Structures immunostainable with anti-amyloid A antiserum were invariably immunostainable with anti-vitronectin. An antiserum against serum amyloid P component stained the same structures as did the anti-vitronectin antibodies, and in addition stained normal glomerular basement membranes. In conclusion, vitronectin immunoreactivity was demonstrated in elastic tissue, in amyloid deposits and in sclerotic lesions in human kidney.     

Endocrine Dysfunction in A Patient with Phace Syndrome,Including Port-Wine Stain of the Right Periorbital Area

ObjectiveTo report a case of PHACE syndrome— Posterior fossa brain abnormalities, Hemangioma (usually facial), Arterial anomalies, Coarctation of the aorta along with cardiac defects, and Eye abnormalities—in a 16-yearold female patient with a port-wine stain of the right periorbital area present since birth in conjunction with hypoplasia of the contralateral internal carotid artery.MethodsThyroid-stimulating hormone, free thyroxine, and growth hormone (GH) levels were measured, and insulin-induced hypoglycemia and arginine infusion tests were done. Radiologic investigations included sagittal enhanced T1-weighted magnetic resonance imaging of the brain and the pituitary gland as well as computed tomography and magnetic resonance angiography of the head and neck.ResultsThe patient had a normal karyotype. Her height and weight were below the 5th percentile for her chronologic age, and she had amenorrhea. Laboratory investigations revealed both thyroid and GH deficiencies and confirmed the diagnosis of hypogonadotropic hypogonadism. The imaging studies showed a right intraorbital hemangioma as well as an enhancing mass in the right internal auditory canal at the cerebellopontine angle, consistent with a posterior fossa hemangioma. Initiation of both thyroid and GH replacement therapy improved her growth rate and yielded a good clinical outcome.ConclusionIn patients with facial or neck hemangiomas, PHACE syndrome should be suspected, and brain imaging and cardiac, ophthalmologic, and endocrinologic evaluations are recommended to screen for other potential PHACE abnormalities. (Endocr Pract. 2010;16:255-259)     

Variability of plasma viscosity in monoclonal IgM gammopathies.

Hyperviscosity syndromes can caused by both plasmatic and cellular factors. We have studied 20 patients affected by IgM gammopathy of different origin and 12 healthy subjects matched for sex and age, in order to evaluate the relation between paraprotein levels and plasma viscosity. We have observed a significant plasma viscosity increase only in 14 patients with monoclonal IgMk gammopathy. In the same patients was also evident an hyperviscosity syndrome. In the other 6 patients, with monoclonal IgM or polyclonal gammopathy and without clinical symptoms, plasma viscosity was only slightly increased. We have also observed a significant correlation between IgM and light chains (kappa, lambda) serum level and increased plasma viscosity. These results suggest that one can't consider all IgM gammopathies as cause of hyperviscosity syndrome.