Familial hemophagocytic lymphohistiocytosis associated with disseminated T-cell lymphoma: a report of two siblings

Fatal familial hemophagocytic lymphohistiocytosis with perforin gene (PRF1) mutation and EBV-associated T-cell lymphoproliferative disorder of the thyroid

Familial hemophagocytic lymphohistiocytosis (FHL) is a rare fatal autosomal recessive disorder of immune dysregulation. The disease presents most commonly in the first year of life; however, symptomatic presentation throughout childhood and adulthood has also been identified. Biallelic mutation in the perforin gene is present in 20%–50% of all cases of FHL. Secondary hemophagocytic lymphohistiocytosis (HLH) in association with hematological malignancies is known; however, whether mutations in HLH-associated genes can be associated with FHL and hematolymphoid neoplasms is not well documented. Also, Epstein–Barr-virus- (EBV) positive systemic T-cell lymphoproliferative disease (SE-LPD) in the setting of FHL is not clearly understood. Here, we present the case of a young boy who presented with typical features of childhood FHL harboring the perforin gene (PRF1) mutation, and had SE-LPD diagnosed on autopsy, along with evidence of recent EBV infection. The patient expired due to progressive disease. Five siblings died in the second or third decade of life with undiagnosed disease. Genetic counseling was provided to the two surviving siblings and parents, but they could not afford genetic testing. One surviving sibling has intermittent fever and is on close follow-up for possible bone marrow transplantation.

Clonal dissemination of T-lymphocytes in scid mice from familial hemophagocytic lymphohistiocytosis

BACKGROUND

Although familial hemophagocytic lymphohistiocytosis (FHL) has been considered a disorder of T-cell dysfunction, there is no evidence of the clonal origin of T-cells in this disease.

PROCEDURE

We engrafted mononuclear cells (MNCs) from five FHL patients into scid mice and examined the infiltration of human cells in mouse organs. The characterization of human cells that infiltrated in the mouse organs was then performed.

RESULTS

A diffuse infiltration of human lymphoid cells was detected in scid mice treated with 1 x 10(6) MNCs from one of the five patients. These cells were positive for HLA-DR and CD3, but negative for CD4, CD8, CD20, and CD68, suggesting the infiltration of double negative (DN) T-cells. The MNCs from the other four patients induced murine lymphoma-like disease; T-cell lymphoma in one and lymphoma of unknown origin in three. The characterization of these human DN T-cells was performed. The analysis of the Vbeta repertoire showed no preferential usage of the Vbeta family in MNCs, while the dominant expression of Vbeta13 was detected in T-cells infiltrating in the spleen and lung. A Jbeta analysis showed the restricted usage of Jbeta1.2 for Vbeta13 in these cells, and the clonality of Vbeta13-Jbeta1.2 fragment was confirmed by a single-strand confirmation polymorphism analysis. The analysis of the Valpha repertoire showed that Valpha24 was exclusively used in these DN T-cells, but no usage of JalphaQ for Valpha24 was observed.

CONCLUSIONS

A clonal expansion of T-cells was induced in scid mice by the engraftment of MNCs from an FHL patient. The infiltration of DN alphabeta T-cells bearing invariant Valpha24 T-cell receptor in mouse organs may provide a useful clue to the pathogenesis of FHL. In the patients whose MNCs induced murine lymphoma-like disease, some cytokines or unknown factors that stimulate the growth and the tumorigenicity of murine lymphocytes might be produced by the MNCs engrafted in scid mice. Further study is needed to confirm the validity of our experimental approach and the findings observed in scid mice by using more FHL samples.

Adenosine endogenously released during early reperfusion mitigates postischemic myocardial dysfunction by inhibiting platelet adhesion

The purpose of this study was to investigate platelet effects on postischemic heart function in conjunction with adenosine effects on intracoronary platelet adhesion. Homologous platelets were infused into the coronaries of isolated guinea pig hearts, either during low-flow ischemia or during reperfusion, and external heart work (EHW) and intracoronary platelet adhesion were determined. In most experiments, thrombin was added to the perfusate. The influence of endogenous adenosine was studied by use of the uptake blocker dipyridamole and the unspecific adenosine-receptor blocker theophylline, the A1-receptor blocker 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), and the A2-receptor blocker 3,7-dimethyl-1-propargylxanthine (DMPX). The importance of nitric oxide and prostaglandin I2 (PGI2) was tested by using nitro-L-arginine (NOLAG) and indomethacin, respectively. When platelets were applied with thrombin during low-flow ischemia, EHW recovered to only 63 +/- 4% of the preischemic value, as compared with 89 +/- 3% without platelets (p < 0.05). Despite thrombin, platelets incurred no significant functional loss when applied in the first minute of reperfusion (but again in the fifth minute); however, when theophylline was also present, recovery of EHW amounted to only 42 +/- 12%. Intracoronary adhesion of platelets was negligible without thrombin, and highest during low-flow ischemia with thrombin (35 +/- 3% of the applied number). No adhesion occurred during the first minute of reperfusion, whereas in the fifth minute, adhesion was again 20.8 +/- 4%. Dipyridamole increased adenosine release and attenuated adhesion at this time. Theophylline increased adhesion in the first minute of reperfusion (33 +/- 6.4%), whereas NOLAG and indomethacin proved to be ineffective. DPCPX and DMPX each increased platelet retention during the first minute of reperfusion, their effects being additive. Intracoronary adhesion of platelets induced by thrombin in isolated hearts can reduce postischemic recovery of heart function. During reperfusion, but not during low-flow, endogenous adenosine can prevent platelet adhesion and loss of myocardial function, an action mediated both by A1- and A2-receptor-dependent mechanisms.

Partial V(D)J recombination activity leads to Omenn syndrome

Genomic rearrangement of the antigen receptor loci is initiated by the two lymphoid-specific proteins Rag-1 and Rag-2. Null mutations in either of the two proteins abrogate initiation of V(D)J recombination and cause severe combined immunodeficiency with complete absence of mature B and T lymphocytes. We report here that patients with Omenn syndrome, a severe immunodeficiency characterized by the presence of activated, anergic, oligoclonal T cells, hypereosinophilia, and high IgE levels, bear missense mutations in either the Rag-1 or Rag-2 genes that result in partial activity of the two proteins. Two of the amino acid substitutions map within the Rag-1 homeodomain and decrease DNA binding activity, while three others lower the efficiency of Rag-1/Rag-2 interaction. These findings provide evidence to indicate that the immunodeficiency manifested in patients with Omenn syndrome arises from mutations that decrease the efficiency of V(D)J recombination.

Heterogeneity of immune markers in hemophagocytic lymphohistiocytosis: comparative study of 9 familial and 14 familial inheritance-unproved cases

PURPOSE

Although immune dysfunction is suspected in patients with hemophagocytic lymphohistiocytosis (HLH), the difference between immune dysfunction in patients with familial erythrophagocytic lymphohistiocytosis (FEL) and familial inheritance-unproved lymphohistiocytosis (FIU) remains unknown. The aim of this study was to determine useful markers to distinguish patients with FEL from those with FIU.

PATIENTS AND METHODS

Clinical features and laboratory findings, especially natural killer (NK) cell activity and the relative frequencies of peripheral blood mononuclear cell (PBMC) subsets, and serum levels of interferon-gamma and soluble interleukin-2 receptor were compared in 9 patients with FEL and 14 age-matched patients with FIU. Twenty-seven healthy infants served as controls. The treatment and outcome were also compared for patients with FEL and FIU.

RESULTS

Comparison between patients with FEL and FIU revealed significantly lower NK activity in those with FEL (p = 0.03) but failed to show any significant differences in PBMC subsets, except that the percentage of CD3+ T cells was higher in patients with FEL (p = 0.02). CD4- and CD8-dominant phenotypes were characteristic findings in both groups of patients, although increased CD19+ B cells were restricted to patients with FIU. NK activity was deficient (< 5%) in four of the seven patients with FEL tested but in only one of eight patients with FIU. By comparison to values for age-matched controls, the percentages of CD3+, CD3+DR+ and CD45RO+ PBMCs in patients with FEL were significantly high (p < 0.05) and those of CD19+ and CD45RA+ subsets were lower than normal. Among patients with FIU, PBMC subsets included significantly reduced CD3+, CD4+, CD45RA+, and CD4+CD45RA+. In this small series, the outcome of patients with FEL and FIU treated with chemotherapy was not significantly different at the time of evaluation.

CONCLUSIONS

These results indicate considerable immune heterogeneity among patients with HLH younger than 2 years. Although NK activity was useful but not diagnostic, determination of PBMC subsets and patterns of cytokine expression was not helpful in distinguishing patients with FEL from those with FIU, suggesting that the immune responses characteristic of these diseases may reflect different triggering factors, including viruses. The impact of this immune heterogeneity on patients' outcome remains to be determined.

Ocular involvement in familial erythrophagocytic lymphohistiocytosis

BACKGROUND

Familial erythrophagocytic lymphohistiocytosis (FEL), a rare, rapidly fatal childhood disorder, is characterized by intermittent fevers, hepatosplenomegaly, cytopenia, hypercytokinemia and lymphohistiocytic infiltration with erythrophagocytosis involving multiple organs. We report the clinical and histological features of two infants with FEL and emphasize the ocular findings.

METHODS

Microscopic examination of formalin-fixed, paraffin-embedded autopsy material was performed. Immunohistochemical studies were performed in case 1.

RESULTS

The first patient presented with clinical and laboratory features and a family history consistent with FEL, and a liver biopsy revealed a lymphohistiocytic infiltrate with erythrophagocytosis consistent with FEL. A deceased brother had been diagnosed with FEL. Autopsy showed widely disseminated lymphohistiocytic infiltrates affecting the liver, spleen, bone marrow, lungs, kidneys and brain. Histologic examination of both eyes disclosed a prominent lymphohistiocytic infiltrate of the optic nerve with destruction of nerve fiber bundles as well as milder infiltrates in the choroid, scleral canals, perineural areas in the orbit and the optic nerve head perivascularly. The second patient also had the typical clinical, laboratory and autopsy findings with similar involvement of most organs, including extensive infiltration of the spleen and bone marrow. Histologic examination of one eye revealed marked lymphohistiocytic infiltration of the entire choroid as well as milder infiltration in the trabecular meshwork, iris, ciliary body, optic nerve, meninges and around the central retinal vein in the optic nerve.

CONCLUSION

The findings of this study further define the ocular pathologic features of FEL, which are a part of a generalized, multiorgan disseminated disease.

Hemodynamic effects of isoprostanes (8-iso-prostaglandin F2alpha and E2) in isolated guinea pig hearts

Isoprostanes are a family of prostaglandin-related compounds formed from arachidonic acid in a cyclooxygenase-independent manner as products of free radical-initiated lipid peroxidation. To elucidate the biological activity of the F2-and E2-isoprostanes, 8-iso-prostaglandin F2alpha (8-iso-PGF2alpha) and 8-iso-prostaglandin E2 (8-iso-PGE2), we measured hemodynamic effects in isolated perfused guinea pig hearts after cumulative administration (3 x 10(-9)-10(-5) M) of these compounds into the coronary system. Coronary flow (CF), left ventricular pressure (LVP), maximal rate of pressure development (dP/dt(max)), and heart rate were determined continuously. Furthermore, net release of lactate into the coronary venous effluent and myocardial pyruvate consumption were measured. Comparative studies were performed with the known potent vasoconstrictor endothelin-1 (6 x 10(-12)-2 x 10(-9) M). Both 8-iso-PGF2alpha and 8-iso-PGE2 induced concentration-dependent decreases in CF, which declined maximally to approximately 50% of the baseline level. The potencies of the two compounds were almost identical. Alterations in CF were associated in both groups with parallel reductions of LVP and dP/dt(max); heart rate was not influenced. Furthermore, the diminished CF caused enhanced lactate release and a reduced pyruvate consumption. All isoprostane-induced hemodynamic changes were prevented by coapplication of the thromboxane A2-receptor antagonist SQ 29548 (1 microM). Endothelin-1 caused CF reductions associated with loss of myocardial contractility, just like the isoprostanes. We conclude that in isolated guinea pig hearts, 8-iso-PGF2alpha and 8-iso-PGE2 are potent vasoconstrictors. The action appears to be mediated by SQ 29548-responsive thromboxane receptors. The accompanying loss of contractility is a secondary phenomenon, elicited by infringed oxygen supply.