Presence of simian virus 40 in diffuse large B-cell lymphomas in Tunisia correlates with germinal center B-cell immunophenotype, t(14;18) translocation, and P53 accumulation.

Previously we have reported the presence of simian virus 40 DNA in 56% of diffuse large B-cell lymphomas in Tunisia. Here, we investigated the relationship between the status of simian virus 40 and t(14;18) translocation, germinal center status, and P53 and BCL2 expression to assess the clinical and biological relevance of simian virus 40 presence in diffuse large B-cell lymphomas. Therefore, we evaluated by immunohistochemistry the expression patterns of CD10, BCL6, MUM1, BCL2, and P53 in 86 diffuse large B-cell lymphomas (48 simian virus 40-positive and 38 simian virus 40-negative cases). The t(14;18) translocation was investigated by polymerase chain reaction. Immunostaining patterns for CD10, BCL6, and MUM1 were used to subclassify diffuse large B-cell lymphoma cases as germinal center or non-germinal center phenotypes. Germinal center phenotype, t(14;18), P53, and BCL2 expression were found in 71, 30, 55, and 65% of cases, respectively. Interestingly, germinal center phenotype, t(14;18), and P53 accumulation were found to be more frequent in simian virus 40-positive cases than in simian virus 40-negative ones (81, 44, 69 vs 58, 13, 37%; P=0.018, 0.002, and 0.003, respectively). However, there were no correlations between the presence of simian virus 40 and the expression of CD10, BCL6, MUM1 and BCL2, patient's age and gender, clinical stage, or the International Prognosis Index. Multivariate logistic regression analyses revealed that the germinal center phenotype, P53 accumulation, and t(14;18) were independent factors for simian virus 40 association (P=0.029, 0.006, and 0.014, respectively). There were no significant differences in overall survival regarding P53, BCL2, or t(14;18) status. However, patients with germinal center phenotype or low International Prognosis Index scores displayed a significantly better survival than those with non-germinal center phenotype or high International Prognosis Index scores (P=0.003 and 0.0001, respectively). These two prognosis factors remain independent in multivariate analyses (P=0.001 and <0.0001, respectively). Interestingly, among patients with germinal center phenotype, simian virus 40-positive subgroup displayed a significantly shorter survival than simian virus 40-negative subgroup (P=0.034). In summary, these findings support a role of simian virus 40 in the pathogenesis of diffuse large B-cell lymphomas. On other hand, they suggest that a significant proportion of diffuse large B-cell lymphoma cases with germinal center phenotype may result from early transformation by simian virus 40, mainly those harboring the t(14;18).Modern Pathology (2008) 21, 282-296; doi:10.1038/modpathol.3800993; published online 28 December 2007.     

Severe autoimmune hemolytic anemia caused by a warm IgA autoantibody directed against the third loop of band 3 (RBC anion-exchange protein 1)

BACKGROUND: Autoimmune hemolytic anemia associated with only IgA autoantibodies reacting optimally at 37 degrees C (WAIHA) is exceedingly rare. When identified, warm IgA autoantibodies specificities are usually directed to antigens of the Rh system. However, like IgG autoantibodies, the specificity of the majority of these antibodies is not identified. CASE REPORT: A case of a 3-year-old boy in whom a life-threatening IgA WAIHA occurred suddenly is reported. Following initial RBC transfusions and treatment with steroids at a dose of 3 mg per kg, which was slowly tapered, stabilization to a state of compensated hemolysis was achieved, persisting 4 months before complete resolution. There was no recurrence within a 16-month follow-up. STUDY DESIGN AND METHODS: The standard DAT in a gel column method with anti-IgG and anticomplement reagents was negative. However, the same method with an anti-IgA was strongly positive. RESULTS: The serum and the eluate obtained after acid elution reacted with all normal RBCs tested. Enzymatic treatment of panel RBCs by alpha-chymotrypsin and pronase abolished the reactivity. The reaction was completely inhibited by RBC incubation with four different MoAbs directed against the third extracellular loop of band 3, the RBC anion-exchange protein 1 (AE1), whereas MoAbs against other specificities showed no effect. CONCLUSIONS: This is the first report of an IgA autoantibody directed against the band 3 (AE1) protein and, more specifically, against the third loop. Moreover, this case underlines the importance of including IgA research in the initial diagnostic evaluation when a hemolytic anemia is suspected to be autoimmune and when IgG and complement are not detected on the patient's RBCs.     

Effect of donor CTLA-4 alleles and haplotypes on graft-versus-host disease occurrence in Tunisian patients receiving a human leukocyte antigen-identical sibling hematopoietic stem cell transplant

The CTLA-4 genetic variation, such as single nucleotide polymorphisms (SNPs) may be critical and can affect the functional activity of cells that initiate the graft-versus-host disease (GVHD) effects. The aim of this study is to examine the effect of donor CTLA-4 alleles and haplotypes for the -318C>T and the 49A>G polymorphisms on the occurrence of GVHD in Tunisians recipients of HSCs. A total of 112 patients and their 112 respective sibling donors of HSCs were enrolled in this study. All patients had either grades 0-I or grades II-IV acute GVHD, or chronic GVHD. The SNPs genotyping assay was performed using sets of sequence specific primers (SSP-PCR). The single marker association analysis showed that the 49G allele, in a genetic recessive model, may be a potential risk factor only for the chronic GVHD (p = 0.032, odds ratio [OR] = 2.58, 95% confidence interval = 1.05-6.32). The haplotypes analyses showed that the CTLA-4 -318C49G nucleotide combination is significantly associated with the incidence of chronic GVHD (p = 0.043, χ2 = 3.27). Donor CTLA-4 -318C49G haplotype may be a significant risk factor for developing chronic GVHD after allo-stem cell transplantation. We suppose that donor T cells expressing this haplotype in a homozygous state have higher proliferation than those expressing other haplotypes, especially after recognition of the recipient's minor histocompatibility antigens.     

Uterine leiomyoma with massive lymphoid infiltration: case report

Uterine leiomyoma with massive lymphoid infiltration is a rare and unusual pathological finding; only 20 cases have been reported in the literature. We report a case of this unusual lesion in a 35-year-old woman who underwent a myomectomy. On gross examination, the tumor was of white color and firm consistency. Histological sections showed interlacing bundles of spindle shaped cells of low density with moderate to severe lymphocytic infiltrate associated to lymphoid follicles and few plasma cells. Immunohistochemically, the diffusely infiltrating lymphoid cells were predominantly of T cell phenotype. The interspersed spindle shaped cells were positive with alpha smooth muscle actin, desmin and h-caldesmon. The cause of this unusual lesion is not clear, but the recognition of its distinct histological features is important to avoid possible confusion with differential diagnosis including malignant lymphoma, inflammatory pseudotumor and pyomyoma.     

Minor histocompatibility antigens in Tunisians: could platelet endothelial cell adhesion molecule 1 marker be one of them?

Platelet endothelial cell adhesion molecule 1 (PECAM-1/CD31) is one of the human minor histocompatibility antigens that are the main targets of alloreactive T-cells after hematopoietic stem cells or solid organs transplantation. In order to investigate its polymorphism in Tunisians, three single nucleotide polymorphisms (SNPs) (rs668, rs12953 and rs1131012) were selected to perform an allele and haplotype analysis. Hundred-and-forty-two healthy and unrelated subjects were enrolled in this survey. Genomic DNAs were extracted using salting out method. SNP genotyping assays were performed with home-designed sequence-specific primers polymerase chain reaction (SSP-PCR). As a result, molecular analysis showed that PECAM-1 is one of the most polymorphic markers in the Tunisian population because minor allele frequency was 0.3, and minimum haplotype frequency was 0.03. A low linkage disequilibrium (D' = 0.45) between rs12953 and rs1131012 was noticed, although all other loci were in the Hardy-Weinberg equilibrium (minimum P value = 0.07). The frequencies were close to those reported in African-American and Caucasian groups.     

Combined vesicovaginal and rectovaginal fistulas associated with a vaginal foreign body

Long-duration intravaginal foreign bodies are a rare entity, but may cause serious complications to the bladder or rectum. We describe a 22-year-old woman who presented with a calcified pelvic mass caused by a long-duration intravaginal foreign body complicated by perforation into the bladder and rectum. The vesicovaginal and rectovaginal fistulas were simultaneously repaired by suprapubic approach after retrieval of the foreign body during the same procedure.     

Osteomalacia in a patient with primary intestinal lymphangiectasis (Waldmann's disease)

Primary intestinal lymphangiectasis (PIL), also known as Waldmann's disease, is a rare protein-losing enteropathy characterized by abnormal enlargement of the lymphatic ducts in the bowel wall. The symptoms usually start in early infancy. We report a case of osteomalacia in a 63-year-old patient with delayed-onset of PIL, for which she was on dietary treatment. She presented with a 3-year history of mechanical pain in the back and pelvis. Mild ascites and edema with functional impairment of the lower limbs were noted. The neurological evaluation was normal. Blood tests showed hypocalcemia, hypophosphatemia, alkaline phosphatase elevation, and evidence of intestinal malabsorption. Radiographs of the pelvis disclosed a fracture, Looser's zones in the iliopubic rami and left femoral neck, and a washed-out appearance of the vertebras. Dual-energy X-ray absorptiometry showed bone loss with T-score values of -1.2SD at the lumbar spine and -2.5SD at the femoral necks. A diagnosis of osteomalacia related to vitamin D deficiency was given. Serum 25-OH-vitamin D was 18.2ng/ml (normal, 20-40ng/ml) and serum parathyroid hormone was 620pg/ml (normal, 15-65pg/ml), suggesting secondary hyperparathyroidism. Intramuscular vitamin D was given, together with oral calcium and an adequate diet. At follow-up 8 months later, small improvements were noted in the symptoms and absorptiometry findings.     

Epidemiology and risk factors for corneal graft rejection

Objective

The aim of this study was to evaluate the frequency and main risk factors for corneal graft rejection.

Patients and Methods

This retrospective study included 285 eyes in 256 patients who underwent a penetrating keratoplasty (KPT) from January 1995 to December 2004. The minimum follow-up was 12 months to evaluate graft evolution. Except for complications, the follow-up was weekly, then monthly for 6 months, and ultimately quarterly during the first year. Thereafter the follow-up was performed semi-annually. Patients were informed about the functional signs for which they have to urgently consult.

Results

Immunologic rejection of the corneal graft occurred in 128 KPT in 112 patients (rejection frequency = 41%). The identified main risk factors were new vascularization of the recipient cornea over 2 or more quadrants, corneal opacity due to an infectious origin, posttraumatic corneal opacity or congenital glaucoma, graft diameter >8 mm, and therapeutic KPT.

Conclusions

Rejection of the corneal graft is the primary cause of KPT failure. One out of 2 graft failures was due to rejection. Two criteria are unanimously recognized as risk factors for rejection: neovascularization of recipient cornea and antecedents of corneal rejection. The rejection must be treated early to not endanger graft success, which imposes a close follow-up for grafted patients.