Hyperphosphorylation of autoantigenic targets of paraproteins is due to inactivation of PP2A.

Paratarg-7, a frequent autoantigenic target, and all other autoantigenic targets of human paraproteins molecularly defined to date are hyperphosphorylated in the respective patients compared with healthy controls, suggesting that hyperphosphorylation of autoantigenic paraprotein targets is a general mechanism underlying the pathogenesis of these paraproteins. We now show that hyperphosphorylation of paratarg-7 occurs because of an additional phosphorylation of Ser17, which is located within the paraprotein-binding epitope. Coimmunoprecipitation identified phosphokinase C ζ (PKCζ) as the kinase responsible for the phosphorylation of most, and phosphatase 2A (PP2A) as the phosphatase responsible for the dephosphorylation of all hyperphosphorylated autoantigenic targets of paraproteins. Single-nucleotide polymorphisms (SNPs) or mutations of PKCζ and PP2A were excluded. However, PP2A was inactivated by phosphorylation of its catalytic subunit at Y307. Stimulation of T cells from healthy carriers of wild-type paratarg-7 induced a partial and transient hyperphosphorylation between days 4 and 18, which was maintained by incubation with inhibitors of PP2A, again indicating that an inactivation of PP2A is responsible for the hyperphosphorylation of autoantigenic paraprotein targets. We conclude that the genetic defect underlying the dominantly inherited hyperphosphorylation of autoantigenic paraprotein targets is not in the PP2A itself, but in genes or proteins controlling PP2A activity by phosphorylation of its catalytic subunit.

Sjögren's syndrome associated with multiple myeloma.

There have been very few reported cases of multiple myeloma (MM) which had Sjögren syndrome (SS) as the first presentation. We report a 63-year-old Moroccan woman with IgA-lambda-type MM presenting as SS and who responded to anti-myeloma treatment. The patient, treated for SS, was admitted to our department for persistent and increasing thoracic pain. Clinical examination was normal. Laboratory investigations showed haemoglobin of 10 g/dL. Erythrocyte sedimentation rate was 80 mm/hr. Monoclonal spike was found in the betaglobulin region of the serum protein electrophoresis. Immunofixation identified it as IgA lambda and the level was 3.7 g/dL. The bone marrow contained 35 percent plasma cells, with atypical features. Radiographs showed diffuse lytic lesions. Treatment with vincristine, adriamycin and dexamethasone (VAD) was started and bisphosphonate was administered regularly. After three cycles of VAD therapy, the MM regressed without any evidence of SS symptoms. The development of MM in the setting of SS is unusual and the aetiopathogenic mechanism still unknown. However, some elements orient toward a common pathway for these two diseases, like the clinical remission of SS after treatment of the MM, such as described in our patient.

Hepatocytes derived from peripheral blood stem cells of granulocyte-colony stimulating factor treated F344 rats in analbuminemic rat livers.

BACKGROUND: hematopoietic stem cells (SCs) mobilized from the bone marrow (BM) into peripheral blood (PB) are reported to have ability to differentiate into various cell types. We investigated whether PB-SCs mobilized by treatment with granulocyte-colony stimulating factor (G-CSF) in normal rats can raise albumin-producing hepatocytes after transplantation within the liver of analbuminemic rats. MATERIALS AND METHODS: Fischer 344 rats (F344) were used as donors, and F344 congenic Nagase's analbuminemic rats (F344alb) as recipients. The donors were repeatedly treated with human recombinant G-CSF, and their PB mononuclear cells (MNCs) were infused into the portal veins of recipients immediately after 70% hepatectomy (PH). RESULTS: Although a few single and small clusters (less than five cells) of albumin positive (alb+) hepatocytes were seen in the livers of untreated F344alb and of the animals undergoing PH alone or transplantation of PB-MNCs with or without the prior G-CSF treatment, clusters consisting of more than 6 alb+ hepatocytes were only detected in the livers of recipients that received transplantation of mobilized PB-MNCs or BM-MNCs under the regenerating condition induced by PH. Sry3, a Y chromosome marker, could be detected corresponding to the alb+ clusters by in situ hybridization when male donors and female recipients were used. Moreover, normal albumin gene sequences were demonstrated in the microdissected alb+ clusters by polymerase chain reaction, and the serum albumin levels were elevated in the recipients. CONCLUSIONS: Hematopoietic SCs mobilized from BM into PB by the G-CSF treatment may raise hepatocyte colonies, when transplanted into regenerating livers.

Angioimmunoblastic lymphadenopathy with dysproteinemia following doxycycline administration.

Angioimmunoblastic lymphadenopathy with dysproteinemia (AILD) is a primary lymphoproliferative T-cell disorder, currently classified as a peripheral T-cell non-Hodgkin's lymphoma. AILD is characterized by generalized lymphadenopathy, hepatosplenomegaly, immunological abnormalities, polyclonal hypergammaglobulinemia and anemia. We report a case of AILD in an 80-year-old male who presented with a generalized pruritic maculopapular eruption and fever following doxycycline administration. The maculopapular rash progressed to formation of confluent nodules, plaques and finally erythroderma with lymphadenopathy and hepatosplenomegaly. Blood analysis revealed an elevated erythrocyte sedimentation rate and polyclonal hypergammaglobulinemia. Lymph node biopsy showed almost complete effacement of the nodal architecture with diffuse proliferation of small vessels forming an arborizing network, surrounded by atypical lymphocytes, usually CD3+ CD4+ and occasionally CD3+ CD8+. There were also larger cells (immunoblastic shape) that displayed CD20 positively, some scattered plasma cells, and eosinophils. Histology of a cutaneous lesion showed spongiosis and infiltration of the epidermis by atypical lymphocytes with large hyperchromatic nuclei, perivascular dermal lymphocytic infiltrate (CD3+) mixed with plasma cells and occasional large immunoblasts (CD20+). During hospitalization the patient developed hemolytic anemia (Coombs positive) and lung metastases. The prognosis of AILD is generally poor, with a median survival of less than 20 months. Our patient died two and a half months after the diagnosis was made due to sepsis caused by Staphylococcus aureus isolated in hemoculture.

Cytoplasmic cytokines in lymphoproliferative disorders: multiple cytokine production in angioimmunoblastic lymphadenopathy with dysproteinemia.

Cytokines play an important role in the pathogenesis of lymphomas via autocrine or paracrine mechanisms, or both. Here we determined the proportion of CD3-positive T lymphocytes containing various types of cytokines in enlarged lymph nodes. Lymph nodes were obtained from 16 patients with various lymphoproliferative disorders, including 3 cases with angioimmunoblastic lymphadenopathy with dysproteinemia (AILD), 3 cases with adult T cell leukemia/lymphoma (ATLL), 2 cases with T-cell nonspecific malignant lymphoma (T-ML), 3 cases with B-cell diffuse large malignant lymphoma (BDL), 3 cases with histiocytic necrotizing lymphadenitis (HNL), and 2 cases with non-specific lymphadenitis (NSL). The percentages of T lymphocytes positive for cytoplasmic cytokines IL-2, IL-4, IL-5, IL-6, IL-13, TNF-alpha, and INF-gamma were determined. The percentage of INF-gamma positive T lymphocytes was high in reactive lymphadenopathy of NSL and HNL. AILD showed a high proportion of TNF-alpha positive T-lymphocytes, and in addition, the percentages of IL-2, IL-4, IL-5, IL-6, IL-13 and INF-gamma positive T-lymphocytes were relatively higher than in other diseases. Our results supported the state of multiple hypercytokinemia typically seen in AILD and suggested that the source of the cytokines is the lymph nodes. Our results also suggested that multiple cytokine networks play an important role in the clinical and histopathological features of AILD. Modulation of the cytokine network may be the logical objective in future therapeutic strategies designed for AILD.

Seropositive rheumatoid arthritis with dermatomyositis sine myositis, angioimmunoblastic lymphadenopathy with dysproteinemia-type T cell lymphoma, and B cell lymphoma of the oropharynx.

Angioimmunoblastic lymphadenopathy with dysproteinemia (AILD) is a rare lymphoproliferative disorder that often progresses to high grade T cell lymphoma. We describe a 63-year-old woman with longstanding seropositive rheumatoid arthritis who developed fever, cutaneous findings of dermatomyositis, a diffuse pruritic maculopapular rash, enlarged lymph nodes, polyclonal elevated serum gammaglobulins, and an IgG lambda paraprotein. Lymph node biopsies yielded tissue with characteristic changes of AILD and T cell lymphoma. Interleukin 6 (IL-6) was present during the early, active phase of disease, and circulating IL-6 and IL-2 were detected one month before tumor recurrence. Two years after AILD and T cell lymphoma were diagnosed, she developed a B cell lymphoma that involved the oropharynx.

Angioimmunoblastic lymphadenopathy with dysproteinemia--lack of a prognostic value of clear cell morphology.

It has been suggested that angioimmunoblastic lymphadenopathy with dysproteinemia (AILD) is closely related to peripheral T cell lymphoma (PTCL). However, the clinical course of AILD-like PTCL is notoriously unpredictable. A minor portion of patients enjoyed prolonged remission with steroid-only treatments (indolent AILD) while most others died rapidly despite the use of intensive chemotherapy (aggressive AILD). Recently, it has been suggested that histological features such as the presence or absence of clear cells and convoluted cells are of high prognostic value. The validity of this observation was addressed in this study. Eighteen patients who presented between 1977 and 1994 at the National Taiwan University Hospital were retrospectively studied. There were 11 men and 7 women, with a median age of 47 years. Twelve patients had received various regimens of systemic chemotherapy, and the other 3 patients had been treated with steroids alone. Eight patients had indolent AILD and 6 aggressive AILD. The follow-up period in 4 patients was too short to be analyzed. The histopathology of these cases was divided, according to the criteria of Aozasa et al., into group I (neither cells), 4 patients; group II (only convoluted cells), 1 patient, and group III (clear cells with or without convoluted cells), 13 patients. Contrary to others, our data revealed that group III patients were doing better than group I patients. Univariate analysis of other pertinent clinical features, including sex, age, lymphadenopathy, B symptoms, hepatosplenomegaly, hypergammaglobulinemia, elevated serum lactate dehydrogenase, and treatment regimens, revealed none of them to be prognostically relevant. However, patients who had achieved complete remission by steroids or other systemic chemotherapy had a significantly better prognosis than those who had not. Together, these preliminary data suggested that (1) the presence or absence of clear cells and convoluted cells failed to predict the clinical behavior, and (2) induction of complete remission by steroids or other chemotherapeutic agents is an important prognostic index.

[Cryptococcosis in a female patient with angioimmunoblastic lymphadenopathy and dysproteinemia]. / Criptococcosi in una paziente affetta da linfoadenopatia angioimmunoblastica con disproteinemia.

A case of a 72-year-old woman affected by angioimmunoblastic lymphadenopathy with dysproteinemia is described. She was admitted to the hospital for serious cutaneous lesions and dementia. The patient had been treated with corticosteroids for the previous two years. Cryptococcosis was diagnosed by cutaneous biopsy. Antimycotic therapy together with corticosteroid withdrawal cured the cutaneous lesions and improved her psychiatric symptoms.

[Clinical and morphological findings in 2 cases of angioimmunoblastic lymphadenopathy with dysproteinemia]. / Rilievi clinici e morfologici in due casi di linfoadenopatia angioimmunoblastica con disprotidemia o LAID.

Two autopsy cases of angioimmunoblastic lymphadenopathy with dysproteinemia were examined. Clinical and morphological data did not differ greatly from those in other cases of the literature: patients died two and three months after the onset of the symptoms. The autopsy findings included moderately enlarged generalized lymph nodes, hepatosplenomegaly and lungs involvement. Microscopically the most prominent change was the vascular proliferation with pleiomorphic cellular infiltration.

Studies on the relationship between proteinuria and glomerular ultrastructural change in hyperalbuminaemic female Wistar rats.

Increased albumin filtration was shown to cause glomerular epithelial cell foot process loss in female Wistar rats made hyperalbuminaemic by means of a series of intraperitoneal bovine albumin injections. It appeared to act by stimulating glomerular epithelial cell endocytosis with the result that protein droplets and vacuoles accumulated within the epithelium causing marked cytoplasmic swelling which forced the foot processes to spread out and fuse. The severity of this glomerular ultrastructural damage rose with increasing bovine albumin dose and correlated well with induced proteinuria.

Peripheral neuropathy in angioimmunoblastic lymphadenopathy with dysproteinaemia.

A case of angioimmunoblastic lymphadenopathy with dysproteinaemia complicated by a subacute peripheral neuropathy is described. Clinically the neuropathy was mainly motor, but pain and paraesthesiae in the legs were also present. Sural nerve biopsy indicated decreased numbers of myelinated fibres, mainly the largest, without actual signs of degeneration or regeneration. However, the occurrence of denervation bands indicated that degeneration had led to loss of myelinated fibres.