Incidence of acute complications of herpes zoster among immunocompetent adults in England: a matched cohort study using routine health data

BACKGROUND

Herpes zoster can cause rare but serious complications; the frequency of these complications has not been well described.

OBJECTIVES

To quantify the risks of acute non-postherpetic neuralgia (PHN) zoster complications, to inform vaccination policy.

METHODS

We conducted a cohort study among unvaccinated immunocompetent adults with incident zoster, and age-, sex- and practice-matched control adults without zoster, using routinely collected health data from the UK Clinical Practice Research Datalink (years 2001 to 2018). Crude attributable risks of complications were estimated as the difference between Kaplan-Meier-estimated 3-month cumulative incidences in patients with zoster vs. controls. We used Cox models to obtain hazard ratios for our primary outcomes in patients with and without zoster. Primary outcomes were ocular, neurological, cutaneous, visceral and zoster-specific complications. We also assessed whether antivirals during acute zoster protected against the complications.

RESULTS

In total 178 964 incident cases of zoster and 1 799 380 controls were included. The absolute risks of zoster-specific complications within 3 months of zoster diagnosis were 0·37% [95% confidence interval (CI) 0·34-0·39] for Ramsay Hunt syndrome, 0·01% (95% CI 0·0-0·01) for disseminated zoster, 0·04% (95% CI 0·03-0·05) for zoster death and 0·97% (95% CI 0·92-1·00) for zoster hospitalization. For other complications, attributable risks were 0·48% (95% CI 0·44-0·51) for neurological complications, 1·33% (95% CI 1·28-1·39) for ocular complications, 0·29% (95% CI 0·26-0·32) for cutaneous complications and 0·78% (95% CI 0·73-0·84) for visceral complications. Attributable risks were higher among patients > 50 years old. Patients with zoster had raised risks of all primary outcomes relative to controls. Antiviral prescription was associated with reduced risk of neurological complications (hazard ratio 0·61, 95% CI 0·53-0·70).

CONCLUSIONS

Non-PHN complications of zoster were relatively common, which may affect cost-effectiveness calculations for zoster vaccination. Clinicians should be aware that zoster can lead to various complications, besides PHN.

Non-progressive periorbital necrotising fasciitis

Necrotising fasciitis is a potentially devastating soft tissue infection with a significant fatality rate. Streptococcus is commonly associated, although the cause may be polymicrobial. Early recognition is essential and aggressive surgical intervention may be required to prevent the rapid spread of infection along fascial planes. We report an unusual case of necrotising fasciitis of the eyelids with spontaneous limitation of the area of necrosis.

Sclerochoroidal calcification associated with Gitelman syndrome and calcium pyrophosphate dihydrate deposition

Sclerochoroidal calcification is an uncommon condition. Metabolic evaluation and clinical examination are important to exclude associated systemic conditions such as the Bartter and Gitelman syndromes. It has been suggested that the lesions seen in sclerochoroidal calcification are calcium pyrophosphate dihydrate crystals. This report describes the first documented case in the UK of sclerochoroidal calcification associated with Gitelman syndrome and calcium pyrophosphate dihydrate deposition.

A role for phospholipase D in GLUT4 glucose transporter translocation

Based on recent studies showing that phospholipase D (PLD)1 is associated with intracellular membranes and promotes membrane budding from the trans-Golgi, we tested its possible role in the membrane trafficking of GLUT4 glucose transporters. Using immunofluorescence confocal microscopy, expressed Myc epitope-tagged PLD1 was found to associate with intracellular vesicular structures by a mechanism that requires its N-terminal pleckstrin homology domain. Partial co-localization with expressed GLUT4 fused to green fluorescent protein in both 3T3-L1 adipocytes and Chinese hamster ovary cells was evident. Furthermore, microinjection of purified PLD into cultured adipocytes markedly potentiated the effect of a submaximal concentration of insulin to stimulate GLUT4 translocation to cell surface membranes. Insulin stimulated PLD activity in cells expressing high levels of insulin receptors but no such insulin effect was detected in 3T3-L1 adipocytes. Taken together, these results are consistent with the hypothesis that PLD1 associated with GLUT4-containing membranes acts in a constitutive manner to promote the mechanism of GLUT4 translocation by insulin.

Chelation of iron within the erythrocytic Plasmodium falciparum parasite by iron chelators

To examine the site of action of antimalarial iron chelators, iron ligands were added to control erythrocytes and to erythrocytes parasitized with Plasmodium falciparum, and the concentration of intracellular labile iron was monitored with the fluorescent probe, calcein. The fluorescence of calcein quenches upon binding iron and increases upon releasing iron. The chelators included desferrioxamine B, 2',2'-bipyridyl, and aminophenol II, a compound that is being newly reported as having anti-plasmodial properties. Calcein-loaded parasitized cells displayed fluorescence predominantly within the cytosol of both rings and trophozoites. The addition of chelators to both control and parasitized erythrocytes led to significant increases of fluorescence (P < 0.001). Fluorescence was observed to increase within the parasite itself after addition of iron chelators, indicating that these agents bound labile iron within the plasmodium. The relative increases of fluorescence after addition of chelators were greater in control than parasitized erythrocytes (P < 0.05) as were the estimated labile iron concentrations (P < or = 0.001). These results suggest that (i) the anti-malarial action of iron chelators might result from the ability to reach the infected cell's parasite compartment and bind iron within the parasite cytosol, and (ii) the labile iron pool of the host red cell may be either utilized or stored during plasmodial growth.

BW 1023U90: a new GRP receptor antagonist for small-cell lung cancer cells

Gastrin-releasing peptide (GRP) receptor antagonists were synthesized and their ability to interact with small-cell lung cancer (SCLC) cells determined. [125I] BW1023U90, bound with high affinity (Kd = 2 nM) to a single class of sites (Bmax = 55 fmol/mg protein) using SCLC cell line NCI-H345. [125I] BW1023U90 binding was time dependent and reversible even at 37 degrees C as the ligand was minimally internalized. Specific [125I] BW1023U90 binding was inhibited with high affinity by GRP as well as bombesin (BB) but not neuromedin B (NMB). BW1023U90 inhibited the ability of BB to elevate cytosolic Ca2+ and increase the growth of SCLC cells. A BW1023U90 analogue, BW2258U89 (10 micrograms/day, SC) slowed SCLC xenograft format on in nude mice and [125I] BW 1023U90 localized to SCLC tumors 1 h after injection into nude mice. BW2258U89 (4% by weight) was placed in microspheres and slowly released over a 3-week period in nude mice bearing SCLC xenografts. The microspheres containing BW2258U89 strongly inhibited SCLC growth in vivo. A radioimmunoassay was developed for the GRP receptor antagonists and the rabbit antiserum cross-reacted totally with BW2258U89 or BW1023U90. BW2258U89 immunoreactivity (5 nM) was detected in the plasma of nude mice containing the microspheres after 1 week. These data suggest that GRP receptor antagonists bind to receptors on SCLC tumors.

GRP receptors are present in non small cell lung cancer cells

Previously, GRP receptors were characterized in small cell lung cancer cells and here non-small cell lung cancer (NSCLC) cells were investigated: (125I-Tyr4) bombesin (BN) or 125I-GRP bound with high affinity to NCI-H720 (lung carcinoid) and NCI-H1299 (large cell carcinoma) cells. Binding was specific, time dependent, and saturable. Specific (125I-Tyr4)BN binding to NCI-H1299 cells was inhibited with high affinity by GRP, BN, GRP14-27, (D-Phe6)BN6-13methyl ester, moderate affinity by NMB, and low affinity by GRP1-16. BN (10 nM) transiently elevated cytosolic calcium in a dose dependent manner. BN caused translocation of protein kinase C from the cytosol to the membrane and the translocation caused by BN was reversed by (D-Phe6)BN6-13methylester. BN stimulated arachidonic acid release and the increase caused by BN was reversed by (D-Phe6)BN6-13methylester. Using a clonogenic assay, BN stimulated the growth of NCI-H720 cells, and the number of colonies was reduced using (D-Phe6)BN6-13methylester. These data suggest that GRP receptors that are present in lung carcinoid and NSCLC cells may regulate proliferation.

A common role for target cell histocompatibility antigens in both nonspecific and specific T lymphocyte-mediated cytolysis

We have investigated the role of target cell major histocompatibility complex antigens (MHC-Ag) in nonspecific lectin-dependent lymphocyte-mediated cytolysis (LDCC). In contrast to previous reports, we provide evidence that in LDCC the lectin Concanavalin A (Con A) does not mediate lysis by simply bridging cytotoxic T lymphocytes (CTL) and targets via cell surface sugars or by activating the lytic function of CTLs attached to targets via the lectin. Lysis occurs when target cells are pretreated with lectin, but not when CTL are pretreated. Moreover, when CTL populations are used as both aggressors and targets, and only one is pretreated with lectin, lysis occurs only in the direction of the pretreated CTL target. We have observed that LDCC, as in specific CTL-mediated killing, target recognition proceeds through interaction of CTL receptors (distinct from sugar moieties) and target cell surface determinants perhaps modified by, but distinct from, the lectin itself. We present evidence that the target determinants recognized in LDCC are MHC-Ag: 1) Cells that display reduced amounts of MHC-Ag are poor targets in LDCC; 2) removal of MHC-Ag by papain renders targets refractory to LDCC, however susceptibility is regained upon regeneration of MHC-Ag; and 3) antisera to target cell MHC-Ag block LDCC. The latter finding is also observed in oxidation-dependent CTL-mediated cytotoxicity. Involvement of MHC proteins in both specific and nonspecific CTL-mediated lysis reconciles an apparent fundamental distinction between these two processes and suggests a possible role for MHC proteins in a postrecognition step(s) leading to lysis.

T lymphocyte-mediated cytolysis. II. Role of target cell histocompatibility antigens in recognition and lysis

Although compelling genetic and serologic evidence implicate target cell (TC) MHC antigens in specific cytotoxic T lymphocyte (CTL)-TC interaction leading to lysis, it is not entirely clear whether TC recognition through an MHC determinant(s) is a prerequisite for lysis to occur. In fact the finding that both specific and nonspecific TC are lysed equally well in lectin-dependent cell-mediated cytotoxicity (LDCC) challenges the necessity for TC MHC involvement in the cytolytic process beyond providing the basis for specificity in direct (nonlectin-dependent) CTL-mediated lysis. In the present paper we present evidence suggesting that even in nonspecific LDCC, as well as in nonspecific lymphocyte-mediated lysis of TC oxidized by periodate treatment or by galactose oxidase (ODCC), TC MHC components are required for lytic interactions with cytotoxic effector cells. This conclusion is based on 3 types of experimental evidence: 1) cells displaying reduced amounts of MHC proteins are poor targets in LDCC; 2) removal of H-2 by papain renders murine target cells refractory to lysis in LDCC, even though Con A binding is only slightly reduced; 3) antisera to target cell H-2-coded products block lysis in both LDCC and ODCC, whereas antisera to other cell surface antigens do not. A theory explaining nonspecific effector target interaction leading to lysis based on involvement of CTL receptor(s) and TC MHC components is presented.

T lymphocyte-mediated cytolysis. I. A common mechanism for target recognition in specific and lectin-dependent cytolysis

In this and the accompanying paper we examine the nature of the interactions between effector cells and target cells leading to lysis in T cell-mediated cytolysis reactions. In the first paper, we re-examine the role of lectin (Con A) in the process of lectin-dependent cell-mediated cytotoxicity (LDCC). Lectin has generally been thought to act simply as a bridge between the cytotoxic effector cell (EC) and the target cell (TC), thus bypassing the need for receptor-antigen interaction and accounting for the nonspecific character of this lytic reaction. A role for lectin in the activation of cytotoxic function in the EC has also been suggested. In this paper we confirm that LDCC occurs when TC alone are pretreated with lectin, but not when EC alone are pretreated with lectin, unless free lectin is also present in the assay mixture. In addition, we demonstrate that the failure of lectin-pretreated EC to bind to and lyse TC is not caused by agglutination or self-destruction of the EC. Moreover, lectin-pretreated EC are not inherently deficient in the ability to bind or lyse TC, if the latter are pretreated with lectin, or if free lectin is present in the assay. Finally, when EC are used as both effectors and targets in LDCC, lysis is observed only in the direction of the lectin-pretreated partner. From these results we conclude that in LDCC, as in specific CTL cytolysis, CTL-TC recognition proceeds through interaction of an EC surface receptor (distinct from the lectin receptor), and a TC antigen perhaps modified by, but distinct from, the lectin itself. In the accompanying paper we present evidence that this receptor-determinant interaction involves TC MHC antigen.

T lymphocyte-mediated cytolysis. I. A common mechanism for target recognition in specific and lectin-dependent cytolysis

In this and the accompanying paper we examine the nature of the interactions between effector cells and target cells leading to lysis in T cell-mediated cytolysis reactions. In the first paper, we re-examine the role of lectin (Con A) in the process of lectin-dependent cell-mediated cytotoxicity (LDCC). Lectin has generally been thought to act simply as a bridge between the cytotoxic effector cell (EC) and the target cell (TC), thus bypassing the need for receptor-antigen interaction and accounting for the nonspecific character of this lytic reaction. A role for lectin in the activation of cytotoxic function in the EC has also been suggested. In this paper we confirm that LDCC occurs when TC alone are pretreated with lectin, but not when EC alone are pretreated with lectin, unless free lectin is also present in the assay mixture. In addition, we demonstrate that the failure of lectin-pretreated EC to bind to and lyse TC is not caused by agglutination or self-destruction of the EC. Moreover, lectin-pretreated EC are not inherently deficient in the ability to bind or lyse TC, if the latter are pretreated with lectin, or if free lectin is present in the assay. Finally, when EC are used as both effectors and targets in LDCC, lysis is observed only in the direction of the lectin-pretreated partner. From these results we conclude that in LDCC, as in specific CTL cytolysis, CTL-TC recognition proceeds through interaction of an EC surface receptor (distinct from the lectin receptor), and a TC antigen perhaps modified by, but distinct from, the lectin itself. In the accompanying paper we present evidence that this receptor-determinant interaction involves TC MHC antigen.

T lymphocyte-mediated cytolysis. II. Role of target cell histocompatibility antigens in recognition and lysis

Although compelling genetic and serologic evidence implicate target cell (TC) MHC antigens in specific cytotoxic T lymphocyte (CTL)-TC interaction leading to lysis, it is not entirely clear whether TC recognition through an MHC determinant(s) is a prerequisite for lysis to occur. In fact the finding that both specific and nonspecific TC are lysed equally well in lectin-dependent cell-mediated cytotoxicity (LDCC) challenges the necessity for TC MHC involvement in the cytolytic process beyond providing the basis for specificity in direct (nonlectin-dependent) CTL-mediated lysis. In the present paper we present evidence suggesting that even in nonspecific LDCC, as well as in nonspecific lymphocyte-mediated lysis of TC oxidized by periodate treatment or by galactose oxidase (ODCC), TC MHC components are required for lytic interactions with cytotoxic effector cells. This conclusion is based on 3 types of experimental evidence: 1) cells displaying reduced amounts of MHC proteins are poor targets in LDCC; 2) removal of H-2 by papain renders murine target cells refractory to lysis in LDCC, even though Con A binding is only slightly reduced; 3) antisera to target cell H-2-coded products block lysis in both LDCC and ODCC, whereas antisera to other cell surface antigens do not. A theory explaining nonspecific effector target interaction leading to lysis based on involvement of CTL receptor(s) and TC MHC components is presented.